slaventius 2 years ago
parent 111330a105
commit 2894512538
  1. 2
      .gitignore
  2. 3
      vendor/github.com/golang/protobuf/AUTHORS
  3. 3
      vendor/github.com/golang/protobuf/CONTRIBUTORS
  4. 28
      vendor/github.com/golang/protobuf/LICENSE
  5. 524
      vendor/github.com/golang/protobuf/jsonpb/decode.go
  6. 559
      vendor/github.com/golang/protobuf/jsonpb/encode.go
  7. 69
      vendor/github.com/golang/protobuf/jsonpb/json.go
  8. 324
      vendor/github.com/golang/protobuf/proto/buffer.go
  9. 63
      vendor/github.com/golang/protobuf/proto/defaults.go
  10. 113
      vendor/github.com/golang/protobuf/proto/deprecated.go
  11. 58
      vendor/github.com/golang/protobuf/proto/discard.go
  12. 356
      vendor/github.com/golang/protobuf/proto/extensions.go
  13. 306
      vendor/github.com/golang/protobuf/proto/properties.go
  14. 167
      vendor/github.com/golang/protobuf/proto/proto.go
  15. 317
      vendor/github.com/golang/protobuf/proto/registry.go
  16. 801
      vendor/github.com/golang/protobuf/proto/text_decode.go
  17. 560
      vendor/github.com/golang/protobuf/proto/text_encode.go
  18. 78
      vendor/github.com/golang/protobuf/proto/wire.go
  19. 34
      vendor/github.com/golang/protobuf/proto/wrappers.go
  20. 179
      vendor/github.com/golang/protobuf/ptypes/any.go
  21. 62
      vendor/github.com/golang/protobuf/ptypes/any/any.pb.go
  22. 10
      vendor/github.com/golang/protobuf/ptypes/doc.go
  23. 76
      vendor/github.com/golang/protobuf/ptypes/duration.go
  24. 63
      vendor/github.com/golang/protobuf/ptypes/duration/duration.pb.go
  25. 112
      vendor/github.com/golang/protobuf/ptypes/timestamp.go
  26. 64
      vendor/github.com/golang/protobuf/ptypes/timestamp/timestamp.pb.go
  27. 13
      vendor/github.com/kelseyhightower/envconfig/.travis.yml
  28. 19
      vendor/github.com/kelseyhightower/envconfig/LICENSE
  29. 2
      vendor/github.com/kelseyhightower/envconfig/MAINTAINERS
  30. 192
      vendor/github.com/kelseyhightower/envconfig/README.md
  31. 8
      vendor/github.com/kelseyhightower/envconfig/doc.go
  32. 7
      vendor/github.com/kelseyhightower/envconfig/env_os.go
  33. 7
      vendor/github.com/kelseyhightower/envconfig/env_syscall.go
  34. 382
      vendor/github.com/kelseyhightower/envconfig/envconfig.go
  35. 164
      vendor/github.com/kelseyhightower/envconfig/usage.go
  36. 2
      vendor/github.com/klauspost/compress/.gitattributes
  37. 32
      vendor/github.com/klauspost/compress/.gitignore
  38. 141
      vendor/github.com/klauspost/compress/.goreleaser.yml
  39. 304
      vendor/github.com/klauspost/compress/LICENSE
  40. 560
      vendor/github.com/klauspost/compress/README.md
  41. 85
      vendor/github.com/klauspost/compress/compressible.go
  42. 903
      vendor/github.com/klauspost/compress/flate/deflate.go
  43. 184
      vendor/github.com/klauspost/compress/flate/dict_decoder.go
  44. 233
      vendor/github.com/klauspost/compress/flate/fast_encoder.go
  45. 1185
      vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go
  46. 412
      vendor/github.com/klauspost/compress/flate/huffman_code.go
  47. 178
      vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go
  48. 201
      vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go
  49. 793
      vendor/github.com/klauspost/compress/flate/inflate.go
  50. 1283
      vendor/github.com/klauspost/compress/flate/inflate_gen.go
  51. 240
      vendor/github.com/klauspost/compress/flate/level1.go
  52. 213
      vendor/github.com/klauspost/compress/flate/level2.go
  53. 240
      vendor/github.com/klauspost/compress/flate/level3.go
  54. 220
      vendor/github.com/klauspost/compress/flate/level4.go
  55. 302
      vendor/github.com/klauspost/compress/flate/level5.go
  56. 315
      vendor/github.com/klauspost/compress/flate/level6.go
  57. 37
      vendor/github.com/klauspost/compress/flate/regmask_amd64.go
  58. 40
      vendor/github.com/klauspost/compress/flate/regmask_other.go
  59. 305
      vendor/github.com/klauspost/compress/flate/stateless.go
  60. 379
      vendor/github.com/klauspost/compress/flate/token.go
  61. 79
      vendor/github.com/klauspost/compress/fse/README.md
  62. 122
      vendor/github.com/klauspost/compress/fse/bitreader.go
  63. 168
      vendor/github.com/klauspost/compress/fse/bitwriter.go
  64. 47
      vendor/github.com/klauspost/compress/fse/bytereader.go
  65. 683
      vendor/github.com/klauspost/compress/fse/compress.go
  66. 374
      vendor/github.com/klauspost/compress/fse/decompress.go
  67. 144
      vendor/github.com/klauspost/compress/fse/fse.go
  68. 4
      vendor/github.com/klauspost/compress/gen.sh
  69. 349
      vendor/github.com/klauspost/compress/gzip/gunzip.go
  70. 269
      vendor/github.com/klauspost/compress/gzip/gzip.go
  71. 1
      vendor/github.com/klauspost/compress/huff0/.gitignore
  72. 89
      vendor/github.com/klauspost/compress/huff0/README.md
  73. 233
      vendor/github.com/klauspost/compress/huff0/bitreader.go
  74. 95
      vendor/github.com/klauspost/compress/huff0/bitwriter.go
  75. 44
      vendor/github.com/klauspost/compress/huff0/bytereader.go
  76. 730
      vendor/github.com/klauspost/compress/huff0/compress.go
  77. 1159
      vendor/github.com/klauspost/compress/huff0/decompress.go
  78. 222
      vendor/github.com/klauspost/compress/huff0/decompress_amd64.go
  79. 847
      vendor/github.com/klauspost/compress/huff0/decompress_amd64.s
  80. 295
      vendor/github.com/klauspost/compress/huff0/decompress_generic.go
  81. 337
      vendor/github.com/klauspost/compress/huff0/huff0.go
  82. 34
      vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo.go
  83. 11
      vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo_amd64.go
  84. 36
      vendor/github.com/klauspost/compress/internal/cpuinfo/cpuinfo_amd64.s
  85. 27
      vendor/github.com/klauspost/compress/internal/snapref/LICENSE
  86. 264
      vendor/github.com/klauspost/compress/internal/snapref/decode.go
  87. 113
      vendor/github.com/klauspost/compress/internal/snapref/decode_other.go
  88. 289
      vendor/github.com/klauspost/compress/internal/snapref/encode.go
  89. 236
      vendor/github.com/klauspost/compress/internal/snapref/encode_other.go
  90. 98
      vendor/github.com/klauspost/compress/internal/snapref/snappy.go
  91. 15
      vendor/github.com/klauspost/compress/s2/.gitignore
  92. 28
      vendor/github.com/klauspost/compress/s2/LICENSE
  93. 965
      vendor/github.com/klauspost/compress/s2/README.md
  94. 1046
      vendor/github.com/klauspost/compress/s2/decode.go
  95. 568
      vendor/github.com/klauspost/compress/s2/decode_amd64.s
  96. 574
      vendor/github.com/klauspost/compress/s2/decode_arm64.s
  97. 17
      vendor/github.com/klauspost/compress/s2/decode_asm.go
  98. 267
      vendor/github.com/klauspost/compress/s2/decode_other.go
  99. 1341
      vendor/github.com/klauspost/compress/s2/encode.go
  100. 456
      vendor/github.com/klauspost/compress/s2/encode_all.go
  101. Some files were not shown because too many files have changed in this diff Show More

2
.gitignore vendored

@ -1 +1,3 @@
authDBService
vendor
_vendor

@ -1,3 +0,0 @@
# This source code refers to The Go Authors for copyright purposes.
# The master list of authors is in the main Go distribution,
# visible at http://tip.golang.org/AUTHORS.

@ -1,3 +0,0 @@
# This source code was written by the Go contributors.
# The master list of contributors is in the main Go distribution,
# visible at http://tip.golang.org/CONTRIBUTORS.

@ -1,28 +0,0 @@
Copyright 2010 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@ -1,524 +0,0 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package jsonpb
import (
"encoding/json"
"errors"
"fmt"
"io"
"math"
"reflect"
"strconv"
"strings"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/encoding/protojson"
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapJSONUnmarshalV2 = false
// UnmarshalNext unmarshals the next JSON object from d into m.
func UnmarshalNext(d *json.Decoder, m proto.Message) error {
return new(Unmarshaler).UnmarshalNext(d, m)
}
// Unmarshal unmarshals a JSON object from r into m.
func Unmarshal(r io.Reader, m proto.Message) error {
return new(Unmarshaler).Unmarshal(r, m)
}
// UnmarshalString unmarshals a JSON object from s into m.
func UnmarshalString(s string, m proto.Message) error {
return new(Unmarshaler).Unmarshal(strings.NewReader(s), m)
}
// Unmarshaler is a configurable object for converting from a JSON
// representation to a protocol buffer object.
type Unmarshaler struct {
// AllowUnknownFields specifies whether to allow messages to contain
// unknown JSON fields, as opposed to failing to unmarshal.
AllowUnknownFields bool
// AnyResolver is used to resolve the google.protobuf.Any well-known type.
// If unset, the global registry is used by default.
AnyResolver AnyResolver
}
// JSONPBUnmarshaler is implemented by protobuf messages that customize the way
// they are unmarshaled from JSON. Messages that implement this should also
// implement JSONPBMarshaler so that the custom format can be produced.
//
// The JSON unmarshaling must follow the JSON to proto specification:
// https://developers.google.com/protocol-buffers/docs/proto3#json
//
// Deprecated: Custom types should implement protobuf reflection instead.
type JSONPBUnmarshaler interface {
UnmarshalJSONPB(*Unmarshaler, []byte) error
}
// Unmarshal unmarshals a JSON object from r into m.
func (u *Unmarshaler) Unmarshal(r io.Reader, m proto.Message) error {
return u.UnmarshalNext(json.NewDecoder(r), m)
}
// UnmarshalNext unmarshals the next JSON object from d into m.
func (u *Unmarshaler) UnmarshalNext(d *json.Decoder, m proto.Message) error {
if m == nil {
return errors.New("invalid nil message")
}
// Parse the next JSON object from the stream.
raw := json.RawMessage{}
if err := d.Decode(&raw); err != nil {
return err
}
// Check for custom unmarshalers first since they may not properly
// implement protobuf reflection that the logic below relies on.
if jsu, ok := m.(JSONPBUnmarshaler); ok {
return jsu.UnmarshalJSONPB(u, raw)
}
mr := proto.MessageReflect(m)
// NOTE: For historical reasons, a top-level null is treated as a noop.
// This is incorrect, but kept for compatibility.
if string(raw) == "null" && mr.Descriptor().FullName() != "google.protobuf.Value" {
return nil
}
if wrapJSONUnmarshalV2 {
// NOTE: If input message is non-empty, we need to preserve merge semantics
// of the old jsonpb implementation. These semantics are not supported by
// the protobuf JSON specification.
isEmpty := true
mr.Range(func(protoreflect.FieldDescriptor, protoreflect.Value) bool {
isEmpty = false // at least one iteration implies non-empty
return false
})
if !isEmpty {
// Perform unmarshaling into a newly allocated, empty message.
mr = mr.New()
// Use a defer to copy all unmarshaled fields into the original message.
dst := proto.MessageReflect(m)
defer mr.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
dst.Set(fd, v)
return true
})
}
// Unmarshal using the v2 JSON unmarshaler.
opts := protojson.UnmarshalOptions{
DiscardUnknown: u.AllowUnknownFields,
}
if u.AnyResolver != nil {
opts.Resolver = anyResolver{u.AnyResolver}
}
return opts.Unmarshal(raw, mr.Interface())
} else {
if err := u.unmarshalMessage(mr, raw); err != nil {
return err
}
return protoV2.CheckInitialized(mr.Interface())
}
}
func (u *Unmarshaler) unmarshalMessage(m protoreflect.Message, in []byte) error {
md := m.Descriptor()
fds := md.Fields()
if jsu, ok := proto.MessageV1(m.Interface()).(JSONPBUnmarshaler); ok {
return jsu.UnmarshalJSONPB(u, in)
}
if string(in) == "null" && md.FullName() != "google.protobuf.Value" {
return nil
}
switch wellKnownType(md.FullName()) {
case "Any":
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return err
}
rawTypeURL, ok := jsonObject["@type"]
if !ok {
return errors.New("Any JSON doesn't have '@type'")
}
typeURL, err := unquoteString(string(rawTypeURL))
if err != nil {
return fmt.Errorf("can't unmarshal Any's '@type': %q", rawTypeURL)
}
m.Set(fds.ByNumber(1), protoreflect.ValueOfString(typeURL))
var m2 protoreflect.Message
if u.AnyResolver != nil {
mi, err := u.AnyResolver.Resolve(typeURL)
if err != nil {
return err
}
m2 = proto.MessageReflect(mi)
} else {
mt, err := protoregistry.GlobalTypes.FindMessageByURL(typeURL)
if err != nil {
if err == protoregistry.NotFound {
return fmt.Errorf("could not resolve Any message type: %v", typeURL)
}
return err
}
m2 = mt.New()
}
if wellKnownType(m2.Descriptor().FullName()) != "" {
rawValue, ok := jsonObject["value"]
if !ok {
return errors.New("Any JSON doesn't have 'value'")
}
if err := u.unmarshalMessage(m2, rawValue); err != nil {
return fmt.Errorf("can't unmarshal Any nested proto %v: %v", typeURL, err)
}
} else {
delete(jsonObject, "@type")
rawJSON, err := json.Marshal(jsonObject)
if err != nil {
return fmt.Errorf("can't generate JSON for Any's nested proto to be unmarshaled: %v", err)
}
if err = u.unmarshalMessage(m2, rawJSON); err != nil {
return fmt.Errorf("can't unmarshal Any nested proto %v: %v", typeURL, err)
}
}
rawWire, err := protoV2.Marshal(m2.Interface())
if err != nil {
return fmt.Errorf("can't marshal proto %v into Any.Value: %v", typeURL, err)
}
m.Set(fds.ByNumber(2), protoreflect.ValueOfBytes(rawWire))
return nil
case "BoolValue", "BytesValue", "StringValue",
"Int32Value", "UInt32Value", "FloatValue",
"Int64Value", "UInt64Value", "DoubleValue":
fd := fds.ByNumber(1)
v, err := u.unmarshalValue(m.NewField(fd), in, fd)
if err != nil {
return err
}
m.Set(fd, v)
return nil
case "Duration":
v, err := unquoteString(string(in))
if err != nil {
return err
}
d, err := time.ParseDuration(v)
if err != nil {
return fmt.Errorf("bad Duration: %v", err)
}
sec := d.Nanoseconds() / 1e9
nsec := d.Nanoseconds() % 1e9
m.Set(fds.ByNumber(1), protoreflect.ValueOfInt64(int64(sec)))
m.Set(fds.ByNumber(2), protoreflect.ValueOfInt32(int32(nsec)))
return nil
case "Timestamp":
v, err := unquoteString(string(in))
if err != nil {
return err
}
t, err := time.Parse(time.RFC3339Nano, v)
if err != nil {
return fmt.Errorf("bad Timestamp: %v", err)
}
sec := t.Unix()
nsec := t.Nanosecond()
m.Set(fds.ByNumber(1), protoreflect.ValueOfInt64(int64(sec)))
m.Set(fds.ByNumber(2), protoreflect.ValueOfInt32(int32(nsec)))
return nil
case "Value":
switch {
case string(in) == "null":
m.Set(fds.ByNumber(1), protoreflect.ValueOfEnum(0))
case string(in) == "true":
m.Set(fds.ByNumber(4), protoreflect.ValueOfBool(true))
case string(in) == "false":
m.Set(fds.ByNumber(4), protoreflect.ValueOfBool(false))
case hasPrefixAndSuffix('"', in, '"'):
s, err := unquoteString(string(in))
if err != nil {
return fmt.Errorf("unrecognized type for Value %q", in)
}
m.Set(fds.ByNumber(3), protoreflect.ValueOfString(s))
case hasPrefixAndSuffix('[', in, ']'):
v := m.Mutable(fds.ByNumber(6))
return u.unmarshalMessage(v.Message(), in)
case hasPrefixAndSuffix('{', in, '}'):
v := m.Mutable(fds.ByNumber(5))
return u.unmarshalMessage(v.Message(), in)
default:
f, err := strconv.ParseFloat(string(in), 0)
if err != nil {
return fmt.Errorf("unrecognized type for Value %q", in)
}
m.Set(fds.ByNumber(2), protoreflect.ValueOfFloat64(f))
}
return nil
case "ListValue":
var jsonArray []json.RawMessage
if err := json.Unmarshal(in, &jsonArray); err != nil {
return fmt.Errorf("bad ListValue: %v", err)
}
lv := m.Mutable(fds.ByNumber(1)).List()
for _, raw := range jsonArray {
ve := lv.NewElement()
if err := u.unmarshalMessage(ve.Message(), raw); err != nil {
return err
}
lv.Append(ve)
}
return nil
case "Struct":
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return fmt.Errorf("bad StructValue: %v", err)
}
mv := m.Mutable(fds.ByNumber(1)).Map()
for key, raw := range jsonObject {
kv := protoreflect.ValueOf(key).MapKey()
vv := mv.NewValue()
if err := u.unmarshalMessage(vv.Message(), raw); err != nil {
return fmt.Errorf("bad value in StructValue for key %q: %v", key, err)
}
mv.Set(kv, vv)
}
return nil
}
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return err
}
// Handle known fields.
for i := 0; i < fds.Len(); i++ {
fd := fds.Get(i)
if fd.IsWeak() && fd.Message().IsPlaceholder() {
continue // weak reference is not linked in
}
// Search for any raw JSON value associated with this field.
var raw json.RawMessage
name := string(fd.Name())
if fd.Kind() == protoreflect.GroupKind {
name = string(fd.Message().Name())
}
if v, ok := jsonObject[name]; ok {
delete(jsonObject, name)
raw = v
}
name = string(fd.JSONName())
if v, ok := jsonObject[name]; ok {
delete(jsonObject, name)
raw = v
}
field := m.NewField(fd)
// Unmarshal the field value.
if raw == nil || (string(raw) == "null" && !isSingularWellKnownValue(fd) && !isSingularJSONPBUnmarshaler(field, fd)) {
continue
}
v, err := u.unmarshalValue(field, raw, fd)
if err != nil {
return err
}
m.Set(fd, v)
}
// Handle extension fields.
for name, raw := range jsonObject {
if !strings.HasPrefix(name, "[") || !strings.HasSuffix(name, "]") {
continue
}
// Resolve the extension field by name.
xname := protoreflect.FullName(name[len("[") : len(name)-len("]")])
xt, _ := protoregistry.GlobalTypes.FindExtensionByName(xname)
if xt == nil && isMessageSet(md) {
xt, _ = protoregistry.GlobalTypes.FindExtensionByName(xname.Append("message_set_extension"))
}
if xt == nil {
continue
}
delete(jsonObject, name)
fd := xt.TypeDescriptor()
if fd.ContainingMessage().FullName() != m.Descriptor().FullName() {
return fmt.Errorf("extension field %q does not extend message %q", xname, m.Descriptor().FullName())
}
field := m.NewField(fd)
// Unmarshal the field value.
if raw == nil || (string(raw) == "null" && !isSingularWellKnownValue(fd) && !isSingularJSONPBUnmarshaler(field, fd)) {
continue
}
v, err := u.unmarshalValue(field, raw, fd)
if err != nil {
return err
}
m.Set(fd, v)
}
if !u.AllowUnknownFields && len(jsonObject) > 0 {
for name := range jsonObject {
return fmt.Errorf("unknown field %q in %v", name, md.FullName())
}
}
return nil
}
func isSingularWellKnownValue(fd protoreflect.FieldDescriptor) bool {
if md := fd.Message(); md != nil {
return md.FullName() == "google.protobuf.Value" && fd.Cardinality() != protoreflect.Repeated
}
return false
}
func isSingularJSONPBUnmarshaler(v protoreflect.Value, fd protoreflect.FieldDescriptor) bool {
if fd.Message() != nil && fd.Cardinality() != protoreflect.Repeated {
_, ok := proto.MessageV1(v.Interface()).(JSONPBUnmarshaler)
return ok
}
return false
}
func (u *Unmarshaler) unmarshalValue(v protoreflect.Value, in []byte, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
switch {
case fd.IsList():
var jsonArray []json.RawMessage
if err := json.Unmarshal(in, &jsonArray); err != nil {
return v, err
}
lv := v.List()
for _, raw := range jsonArray {
ve, err := u.unmarshalSingularValue(lv.NewElement(), raw, fd)
if err != nil {
return v, err
}
lv.Append(ve)
}
return v, nil
case fd.IsMap():
var jsonObject map[string]json.RawMessage
if err := json.Unmarshal(in, &jsonObject); err != nil {
return v, err
}
kfd := fd.MapKey()
vfd := fd.MapValue()
mv := v.Map()
for key, raw := range jsonObject {
var kv protoreflect.MapKey
if kfd.Kind() == protoreflect.StringKind {
kv = protoreflect.ValueOf(key).MapKey()
} else {
v, err := u.unmarshalSingularValue(kfd.Default(), []byte(key), kfd)
if err != nil {
return v, err
}
kv = v.MapKey()
}
vv, err := u.unmarshalSingularValue(mv.NewValue(), raw, vfd)
if err != nil {
return v, err
}
mv.Set(kv, vv)
}
return v, nil
default:
return u.unmarshalSingularValue(v, in, fd)
}
}
var nonFinite = map[string]float64{
`"NaN"`: math.NaN(),
`"Infinity"`: math.Inf(+1),
`"-Infinity"`: math.Inf(-1),
}
func (u *Unmarshaler) unmarshalSingularValue(v protoreflect.Value, in []byte, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
switch fd.Kind() {
case protoreflect.BoolKind:
return unmarshalValue(in, new(bool))
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
return unmarshalValue(trimQuote(in), new(int32))
case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return unmarshalValue(trimQuote(in), new(int64))
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
return unmarshalValue(trimQuote(in), new(uint32))
case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return unmarshalValue(trimQuote(in), new(uint64))
case protoreflect.FloatKind:
if f, ok := nonFinite[string(in)]; ok {
return protoreflect.ValueOfFloat32(float32(f)), nil
}
return unmarshalValue(trimQuote(in), new(float32))
case protoreflect.DoubleKind:
if f, ok := nonFinite[string(in)]; ok {
return protoreflect.ValueOfFloat64(float64(f)), nil
}
return unmarshalValue(trimQuote(in), new(float64))
case protoreflect.StringKind:
return unmarshalValue(in, new(string))
case protoreflect.BytesKind:
return unmarshalValue(in, new([]byte))
case protoreflect.EnumKind:
if hasPrefixAndSuffix('"', in, '"') {
vd := fd.Enum().Values().ByName(protoreflect.Name(trimQuote(in)))
if vd == nil {
return v, fmt.Errorf("unknown value %q for enum %s", in, fd.Enum().FullName())
}
return protoreflect.ValueOfEnum(vd.Number()), nil
}
return unmarshalValue(in, new(protoreflect.EnumNumber))
case protoreflect.MessageKind, protoreflect.GroupKind:
err := u.unmarshalMessage(v.Message(), in)
return v, err
default:
panic(fmt.Sprintf("invalid kind %v", fd.Kind()))
}
}
func unmarshalValue(in []byte, v interface{}) (protoreflect.Value, error) {
err := json.Unmarshal(in, v)
return protoreflect.ValueOf(reflect.ValueOf(v).Elem().Interface()), err
}
func unquoteString(in string) (out string, err error) {
err = json.Unmarshal([]byte(in), &out)
return out, err
}
func hasPrefixAndSuffix(prefix byte, in []byte, suffix byte) bool {
if len(in) >= 2 && in[0] == prefix && in[len(in)-1] == suffix {
return true
}
return false
}
// trimQuote is like unquoteString but simply strips surrounding quotes.
// This is incorrect, but is behavior done by the legacy implementation.
func trimQuote(in []byte) []byte {
if len(in) >= 2 && in[0] == '"' && in[len(in)-1] == '"' {
in = in[1 : len(in)-1]
}
return in
}

@ -1,559 +0,0 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package jsonpb
import (
"encoding/json"
"errors"
"fmt"
"io"
"math"
"reflect"
"sort"
"strconv"
"strings"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/encoding/protojson"
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapJSONMarshalV2 = false
// Marshaler is a configurable object for marshaling protocol buffer messages
// to the specified JSON representation.
type Marshaler struct {
// OrigName specifies whether to use the original protobuf name for fields.
OrigName bool
// EnumsAsInts specifies whether to render enum values as integers,
// as opposed to string values.
EnumsAsInts bool
// EmitDefaults specifies whether to render fields with zero values.
EmitDefaults bool
// Indent controls whether the output is compact or not.
// If empty, the output is compact JSON. Otherwise, every JSON object
// entry and JSON array value will be on its own line.
// Each line will be preceded by repeated copies of Indent, where the
// number of copies is the current indentation depth.
Indent string
// AnyResolver is used to resolve the google.protobuf.Any well-known type.
// If unset, the global registry is used by default.
AnyResolver AnyResolver
}
// JSONPBMarshaler is implemented by protobuf messages that customize the
// way they are marshaled to JSON. Messages that implement this should also
// implement JSONPBUnmarshaler so that the custom format can be parsed.
//
// The JSON marshaling must follow the proto to JSON specification:
// https://developers.google.com/protocol-buffers/docs/proto3#json
//
// Deprecated: Custom types should implement protobuf reflection instead.
type JSONPBMarshaler interface {
MarshalJSONPB(*Marshaler) ([]byte, error)
}
// Marshal serializes a protobuf message as JSON into w.
func (jm *Marshaler) Marshal(w io.Writer, m proto.Message) error {
b, err := jm.marshal(m)
if len(b) > 0 {
if _, err := w.Write(b); err != nil {
return err
}
}
return err
}
// MarshalToString serializes a protobuf message as JSON in string form.
func (jm *Marshaler) MarshalToString(m proto.Message) (string, error) {
b, err := jm.marshal(m)
if err != nil {
return "", err
}
return string(b), nil
}
func (jm *Marshaler) marshal(m proto.Message) ([]byte, error) {
v := reflect.ValueOf(m)
if m == nil || (v.Kind() == reflect.Ptr && v.IsNil()) {
return nil, errors.New("Marshal called with nil")
}
// Check for custom marshalers first since they may not properly
// implement protobuf reflection that the logic below relies on.
if jsm, ok := m.(JSONPBMarshaler); ok {
return jsm.MarshalJSONPB(jm)
}
if wrapJSONMarshalV2 {
opts := protojson.MarshalOptions{
UseProtoNames: jm.OrigName,
UseEnumNumbers: jm.EnumsAsInts,
EmitUnpopulated: jm.EmitDefaults,
Indent: jm.Indent,
}
if jm.AnyResolver != nil {
opts.Resolver = anyResolver{jm.AnyResolver}
}
return opts.Marshal(proto.MessageReflect(m).Interface())
} else {
// Check for unpopulated required fields first.
m2 := proto.MessageReflect(m)
if err := protoV2.CheckInitialized(m2.Interface()); err != nil {
return nil, err
}
w := jsonWriter{Marshaler: jm}
err := w.marshalMessage(m2, "", "")
return w.buf, err
}
}
type jsonWriter struct {
*Marshaler
buf []byte
}
func (w *jsonWriter) write(s string) {
w.buf = append(w.buf, s...)
}
func (w *jsonWriter) marshalMessage(m protoreflect.Message, indent, typeURL string) error {
if jsm, ok := proto.MessageV1(m.Interface()).(JSONPBMarshaler); ok {
b, err := jsm.MarshalJSONPB(w.Marshaler)
if err != nil {
return err
}
if typeURL != "" {
// we are marshaling this object to an Any type
var js map[string]*json.RawMessage
if err = json.Unmarshal(b, &js); err != nil {
return fmt.Errorf("type %T produced invalid JSON: %v", m.Interface(), err)
}
turl, err := json.Marshal(typeURL)
if err != nil {
return fmt.Errorf("failed to marshal type URL %q to JSON: %v", typeURL, err)
}
js["@type"] = (*json.RawMessage)(&turl)
if b, err = json.Marshal(js); err != nil {
return err
}
}
w.write(string(b))
return nil
}
md := m.Descriptor()
fds := md.Fields()
// Handle well-known types.
const secondInNanos = int64(time.Second / time.Nanosecond)
switch wellKnownType(md.FullName()) {
case "Any":
return w.marshalAny(m, indent)
case "BoolValue", "BytesValue", "StringValue",
"Int32Value", "UInt32Value", "FloatValue",
"Int64Value", "UInt64Value", "DoubleValue":
fd := fds.ByNumber(1)
return w.marshalValue(fd, m.Get(fd), indent)
case "Duration":
const maxSecondsInDuration = 315576000000
// "Generated output always contains 0, 3, 6, or 9 fractional digits,
// depending on required precision."
s := m.Get(fds.ByNumber(1)).Int()
ns := m.Get(fds.ByNumber(2)).Int()
if s < -maxSecondsInDuration || s > maxSecondsInDuration {
return fmt.Errorf("seconds out of range %v", s)
}
if ns <= -secondInNanos || ns >= secondInNanos {
return fmt.Errorf("ns out of range (%v, %v)", -secondInNanos, secondInNanos)
}
if (s > 0 && ns < 0) || (s < 0 && ns > 0) {
return errors.New("signs of seconds and nanos do not match")
}
var sign string
if s < 0 || ns < 0 {
sign, s, ns = "-", -1*s, -1*ns
}
x := fmt.Sprintf("%s%d.%09d", sign, s, ns)
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, ".000")
w.write(fmt.Sprintf(`"%vs"`, x))
return nil
case "Timestamp":
// "RFC 3339, where generated output will always be Z-normalized
// and uses 0, 3, 6 or 9 fractional digits."
s := m.Get(fds.ByNumber(1)).Int()
ns := m.Get(fds.ByNumber(2)).Int()
if ns < 0 || ns >= secondInNanos {
return fmt.Errorf("ns out of range [0, %v)", secondInNanos)
}
t := time.Unix(s, ns).UTC()
// time.RFC3339Nano isn't exactly right (we need to get 3/6/9 fractional digits).
x := t.Format("2006-01-02T15:04:05.000000000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, ".000")
w.write(fmt.Sprintf(`"%vZ"`, x))
return nil
case "Value":
// JSON value; which is a null, number, string, bool, object, or array.
od := md.Oneofs().Get(0)
fd := m.WhichOneof(od)
if fd == nil {
return errors.New("nil Value")
}
return w.marshalValue(fd, m.Get(fd), indent)
case "Struct", "ListValue":
// JSON object or array.
fd := fds.ByNumber(1)
return w.marshalValue(fd, m.Get(fd), indent)
}
w.write("{")
if w.Indent != "" {
w.write("\n")
}
firstField := true
if typeURL != "" {
if err := w.marshalTypeURL(indent, typeURL); err != nil {
return err
}
firstField = false
}
for i := 0; i < fds.Len(); {
fd := fds.Get(i)
if od := fd.ContainingOneof(); od != nil {
fd = m.WhichOneof(od)
i += od.Fields().Len()
if fd == nil {
continue
}
} else {
i++
}
v := m.Get(fd)
if !m.Has(fd) {
if !w.EmitDefaults || fd.ContainingOneof() != nil {
continue
}
if fd.Cardinality() != protoreflect.Repeated && (fd.Message() != nil || fd.Syntax() == protoreflect.Proto2) {
v = protoreflect.Value{} // use "null" for singular messages or proto2 scalars
}
}
if !firstField {
w.writeComma()
}
if err := w.marshalField(fd, v, indent); err != nil {
return err
}
firstField = false
}
// Handle proto2 extensions.
if md.ExtensionRanges().Len() > 0 {
// Collect a sorted list of all extension descriptor and values.
type ext struct {
desc protoreflect.FieldDescriptor
val protoreflect.Value
}
var exts []ext
m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
if fd.IsExtension() {
exts = append(exts, ext{fd, v})
}
return true
})
sort.Slice(exts, func(i, j int) bool {
return exts[i].desc.Number() < exts[j].desc.Number()
})
for _, ext := range exts {
if !firstField {
w.writeComma()
}
if err := w.marshalField(ext.desc, ext.val, indent); err != nil {
return err
}
firstField = false
}
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
}
w.write("}")
return nil
}
func (w *jsonWriter) writeComma() {
if w.Indent != "" {
w.write(",\n")
} else {
w.write(",")
}
}
func (w *jsonWriter) marshalAny(m protoreflect.Message, indent string) error {
// "If the Any contains a value that has a special JSON mapping,
// it will be converted as follows: {"@type": xxx, "value": yyy}.
// Otherwise, the value will be converted into a JSON object,
// and the "@type" field will be inserted to indicate the actual data type."
md := m.Descriptor()
typeURL := m.Get(md.Fields().ByNumber(1)).String()
rawVal := m.Get(md.Fields().ByNumber(2)).Bytes()
var m2 protoreflect.Message
if w.AnyResolver != nil {
mi, err := w.AnyResolver.Resolve(typeURL)
if err != nil {
return err
}
m2 = proto.MessageReflect(mi)
} else {
mt, err := protoregistry.GlobalTypes.FindMessageByURL(typeURL)
if err != nil {
return err
}
m2 = mt.New()
}
if err := protoV2.Unmarshal(rawVal, m2.Interface()); err != nil {
return err
}
if wellKnownType(m2.Descriptor().FullName()) == "" {
return w.marshalMessage(m2, indent, typeURL)
}
w.write("{")
if w.Indent != "" {
w.write("\n")
}
if err := w.marshalTypeURL(indent, typeURL); err != nil {
return err
}
w.writeComma()
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
w.write(`"value": `)
} else {
w.write(`"value":`)
}
if err := w.marshalMessage(m2, indent+w.Indent, ""); err != nil {
return err
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
}
w.write("}")
return nil
}
func (w *jsonWriter) marshalTypeURL(indent, typeURL string) error {
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
}
w.write(`"@type":`)
if w.Indent != "" {
w.write(" ")
}
b, err := json.Marshal(typeURL)
if err != nil {
return err
}
w.write(string(b))
return nil
}
// marshalField writes field description and value to the Writer.
func (w *jsonWriter) marshalField(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
if w.Indent != "" {
w.write(indent)
w.write(w.Indent)
}
w.write(`"`)
switch {
case fd.IsExtension():
// For message set, use the fname of the message as the extension name.
name := string(fd.FullName())
if isMessageSet(fd.ContainingMessage()) {
name = strings.TrimSuffix(name, ".message_set_extension")
}
w.write("[" + name + "]")
case w.OrigName:
name := string(fd.Name())
if fd.Kind() == protoreflect.GroupKind {
name = string(fd.Message().Name())
}
w.write(name)
default:
w.write(string(fd.JSONName()))
}
w.write(`":`)
if w.Indent != "" {
w.write(" ")
}
return w.marshalValue(fd, v, indent)
}
func (w *jsonWriter) marshalValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
switch {
case fd.IsList():
w.write("[")
comma := ""
lv := v.List()
for i := 0; i < lv.Len(); i++ {
w.write(comma)
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
w.write(w.Indent)
}
if err := w.marshalSingularValue(fd, lv.Get(i), indent+w.Indent); err != nil {
return err
}
comma = ","
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
}
w.write("]")
return nil
case fd.IsMap():
kfd := fd.MapKey()
vfd := fd.MapValue()
mv := v.Map()
// Collect a sorted list of all map keys and values.
type entry struct{ key, val protoreflect.Value }
var entries []entry
mv.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool {
entries = append(entries, entry{k.Value(), v})
return true
})
sort.Slice(entries, func(i, j int) bool {
switch kfd.Kind() {
case protoreflect.BoolKind:
return !entries[i].key.Bool() && entries[j].key.Bool()
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind, protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return entries[i].key.Int() < entries[j].key.Int()
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return entries[i].key.Uint() < entries[j].key.Uint()
case protoreflect.StringKind:
return entries[i].key.String() < entries[j].key.String()
default:
panic("invalid kind")
}
})
w.write(`{`)
comma := ""
for _, entry := range entries {
w.write(comma)
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
w.write(w.Indent)
}
s := fmt.Sprint(entry.key.Interface())
b, err := json.Marshal(s)
if err != nil {
return err
}
w.write(string(b))
w.write(`:`)
if w.Indent != "" {
w.write(` `)
}
if err := w.marshalSingularValue(vfd, entry.val, indent+w.Indent); err != nil {
return err
}
comma = ","
}
if w.Indent != "" {
w.write("\n")
w.write(indent)
w.write(w.Indent)
}
w.write(`}`)
return nil
default:
return w.marshalSingularValue(fd, v, indent)
}
}
func (w *jsonWriter) marshalSingularValue(fd protoreflect.FieldDescriptor, v protoreflect.Value, indent string) error {
switch {
case !v.IsValid():
w.write("null")
return nil
case fd.Message() != nil:
return w.marshalMessage(v.Message(), indent+w.Indent, "")
case fd.Enum() != nil:
if fd.Enum().FullName() == "google.protobuf.NullValue" {
w.write("null")
return nil
}
vd := fd.Enum().Values().ByNumber(v.Enum())
if vd == nil || w.EnumsAsInts {
w.write(strconv.Itoa(int(v.Enum())))
} else {
w.write(`"` + string(vd.Name()) + `"`)
}
return nil
default:
switch v.Interface().(type) {
case float32, float64:
switch {
case math.IsInf(v.Float(), +1):
w.write(`"Infinity"`)
return nil
case math.IsInf(v.Float(), -1):
w.write(`"-Infinity"`)
return nil
case math.IsNaN(v.Float()):
w.write(`"NaN"`)
return nil
}
case int64, uint64:
w.write(fmt.Sprintf(`"%d"`, v.Interface()))
return nil
}
b, err := json.Marshal(v.Interface())
if err != nil {
return err
}
w.write(string(b))
return nil
}
}

@ -1,69 +0,0 @@
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package jsonpb provides functionality to marshal and unmarshal between a
// protocol buffer message and JSON. It follows the specification at
// https://developers.google.com/protocol-buffers/docs/proto3#json.
//
// Do not rely on the default behavior of the standard encoding/json package
// when called on generated message types as it does not operate correctly.
//
// Deprecated: Use the "google.golang.org/protobuf/encoding/protojson"
// package instead.
package jsonpb
import (
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
"google.golang.org/protobuf/runtime/protoimpl"
)
// AnyResolver takes a type URL, present in an Any message,
// and resolves it into an instance of the associated message.
type AnyResolver interface {
Resolve(typeURL string) (proto.Message, error)
}
type anyResolver struct{ AnyResolver }
func (r anyResolver) FindMessageByName(message protoreflect.FullName) (protoreflect.MessageType, error) {
return r.FindMessageByURL(string(message))
}
func (r anyResolver) FindMessageByURL(url string) (protoreflect.MessageType, error) {
m, err := r.Resolve(url)
if err != nil {
return nil, err
}
return protoimpl.X.MessageTypeOf(m), nil
}
func (r anyResolver) FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) {
return protoregistry.GlobalTypes.FindExtensionByName(field)
}
func (r anyResolver) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) {
return protoregistry.GlobalTypes.FindExtensionByNumber(message, field)
}
func wellKnownType(s protoreflect.FullName) string {
if s.Parent() == "google.protobuf" {
switch s.Name() {
case "Empty", "Any",
"BoolValue", "BytesValue", "StringValue",
"Int32Value", "UInt32Value", "FloatValue",
"Int64Value", "UInt64Value", "DoubleValue",
"Duration", "Timestamp",
"NullValue", "Struct", "Value", "ListValue":
return string(s.Name())
}
}
return ""
}
func isMessageSet(md protoreflect.MessageDescriptor) bool {
ms, ok := md.(interface{ IsMessageSet() bool })
return ok && ms.IsMessageSet()
}

@ -1,324 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"errors"
"fmt"
"google.golang.org/protobuf/encoding/prototext"
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/runtime/protoimpl"
)
const (
WireVarint = 0
WireFixed32 = 5
WireFixed64 = 1
WireBytes = 2
WireStartGroup = 3
WireEndGroup = 4
)
// EncodeVarint returns the varint encoded bytes of v.
func EncodeVarint(v uint64) []byte {
return protowire.AppendVarint(nil, v)
}
// SizeVarint returns the length of the varint encoded bytes of v.
// This is equal to len(EncodeVarint(v)).
func SizeVarint(v uint64) int {
return protowire.SizeVarint(v)
}
// DecodeVarint parses a varint encoded integer from b,
// returning the integer value and the length of the varint.
// It returns (0, 0) if there is a parse error.
func DecodeVarint(b []byte) (uint64, int) {
v, n := protowire.ConsumeVarint(b)
if n < 0 {
return 0, 0
}
return v, n
}
// Buffer is a buffer for encoding and decoding the protobuf wire format.
// It may be reused between invocations to reduce memory usage.
type Buffer struct {
buf []byte
idx int
deterministic bool
}
// NewBuffer allocates a new Buffer initialized with buf,
// where the contents of buf are considered the unread portion of the buffer.
func NewBuffer(buf []byte) *Buffer {
return &Buffer{buf: buf}
}
// SetDeterministic specifies whether to use deterministic serialization.
//
// Deterministic serialization guarantees that for a given binary, equal
// messages will always be serialized to the same bytes. This implies:
//
// - Repeated serialization of a message will return the same bytes.
// - Different processes of the same binary (which may be executing on
// different machines) will serialize equal messages to the same bytes.
//
// Note that the deterministic serialization is NOT canonical across
// languages. It is not guaranteed to remain stable over time. It is unstable
// across different builds with schema changes due to unknown fields.
// Users who need canonical serialization (e.g., persistent storage in a
// canonical form, fingerprinting, etc.) should define their own
// canonicalization specification and implement their own serializer rather
// than relying on this API.
//
// If deterministic serialization is requested, map entries will be sorted
// by keys in lexographical order. This is an implementation detail and
// subject to change.
func (b *Buffer) SetDeterministic(deterministic bool) {
b.deterministic = deterministic
}
// SetBuf sets buf as the internal buffer,
// where the contents of buf are considered the unread portion of the buffer.
func (b *Buffer) SetBuf(buf []byte) {
b.buf = buf
b.idx = 0
}
// Reset clears the internal buffer of all written and unread data.
func (b *Buffer) Reset() {
b.buf = b.buf[:0]
b.idx = 0
}
// Bytes returns the internal buffer.
func (b *Buffer) Bytes() []byte {
return b.buf
}
// Unread returns the unread portion of the buffer.
func (b *Buffer) Unread() []byte {
return b.buf[b.idx:]
}
// Marshal appends the wire-format encoding of m to the buffer.
func (b *Buffer) Marshal(m Message) error {
var err error
b.buf, err = marshalAppend(b.buf, m, b.deterministic)
return err
}
// Unmarshal parses the wire-format message in the buffer and
// places the decoded results in m.
// It does not reset m before unmarshaling.
func (b *Buffer) Unmarshal(m Message) error {
err := UnmarshalMerge(b.Unread(), m)
b.idx = len(b.buf)
return err
}
type unknownFields struct{ XXX_unrecognized protoimpl.UnknownFields }
func (m *unknownFields) String() string { panic("not implemented") }
func (m *unknownFields) Reset() { panic("not implemented") }
func (m *unknownFields) ProtoMessage() { panic("not implemented") }
// DebugPrint dumps the encoded bytes of b with a header and footer including s
// to stdout. This is only intended for debugging.
func (*Buffer) DebugPrint(s string, b []byte) {
m := MessageReflect(new(unknownFields))
m.SetUnknown(b)
b, _ = prototext.MarshalOptions{AllowPartial: true, Indent: "\t"}.Marshal(m.Interface())
fmt.Printf("==== %s ====\n%s==== %s ====\n", s, b, s)
}
// EncodeVarint appends an unsigned varint encoding to the buffer.
func (b *Buffer) EncodeVarint(v uint64) error {
b.buf = protowire.AppendVarint(b.buf, v)
return nil
}
// EncodeZigzag32 appends a 32-bit zig-zag varint encoding to the buffer.
func (b *Buffer) EncodeZigzag32(v uint64) error {
return b.EncodeVarint(uint64((uint32(v) << 1) ^ uint32((int32(v) >> 31))))
}
// EncodeZigzag64 appends a 64-bit zig-zag varint encoding to the buffer.
func (b *Buffer) EncodeZigzag64(v uint64) error {
return b.EncodeVarint(uint64((uint64(v) << 1) ^ uint64((int64(v) >> 63))))
}
// EncodeFixed32 appends a 32-bit little-endian integer to the buffer.
func (b *Buffer) EncodeFixed32(v uint64) error {
b.buf = protowire.AppendFixed32(b.buf, uint32(v))
return nil
}
// EncodeFixed64 appends a 64-bit little-endian integer to the buffer.
func (b *Buffer) EncodeFixed64(v uint64) error {
b.buf = protowire.AppendFixed64(b.buf, uint64(v))
return nil
}
// EncodeRawBytes appends a length-prefixed raw bytes to the buffer.
func (b *Buffer) EncodeRawBytes(v []byte) error {
b.buf = protowire.AppendBytes(b.buf, v)
return nil
}
// EncodeStringBytes appends a length-prefixed raw bytes to the buffer.
// It does not validate whether v contains valid UTF-8.
func (b *Buffer) EncodeStringBytes(v string) error {
b.buf = protowire.AppendString(b.buf, v)
return nil
}
// EncodeMessage appends a length-prefixed encoded message to the buffer.
func (b *Buffer) EncodeMessage(m Message) error {
var err error
b.buf = protowire.AppendVarint(b.buf, uint64(Size(m)))
b.buf, err = marshalAppend(b.buf, m, b.deterministic)
return err
}
// DecodeVarint consumes an encoded unsigned varint from the buffer.
func (b *Buffer) DecodeVarint() (uint64, error) {
v, n := protowire.ConsumeVarint(b.buf[b.idx:])
if n < 0 {
return 0, protowire.ParseError(n)
}
b.idx += n
return uint64(v), nil
}
// DecodeZigzag32 consumes an encoded 32-bit zig-zag varint from the buffer.
func (b *Buffer) DecodeZigzag32() (uint64, error) {
v, err := b.DecodeVarint()
if err != nil {
return 0, err
}
return uint64((uint32(v) >> 1) ^ uint32((int32(v&1)<<31)>>31)), nil
}
// DecodeZigzag64 consumes an encoded 64-bit zig-zag varint from the buffer.
func (b *Buffer) DecodeZigzag64() (uint64, error) {
v, err := b.DecodeVarint()
if err != nil {
return 0, err
}
return uint64((uint64(v) >> 1) ^ uint64((int64(v&1)<<63)>>63)), nil
}
// DecodeFixed32 consumes a 32-bit little-endian integer from the buffer.
func (b *Buffer) DecodeFixed32() (uint64, error) {
v, n := protowire.ConsumeFixed32(b.buf[b.idx:])
if n < 0 {
return 0, protowire.ParseError(n)
}
b.idx += n
return uint64(v), nil
}
// DecodeFixed64 consumes a 64-bit little-endian integer from the buffer.
func (b *Buffer) DecodeFixed64() (uint64, error) {
v, n := protowire.ConsumeFixed64(b.buf[b.idx:])
if n < 0 {
return 0, protowire.ParseError(n)
}
b.idx += n
return uint64(v), nil
}
// DecodeRawBytes consumes a length-prefixed raw bytes from the buffer.
// If alloc is specified, it returns a copy the raw bytes
// rather than a sub-slice of the buffer.
func (b *Buffer) DecodeRawBytes(alloc bool) ([]byte, error) {
v, n := protowire.ConsumeBytes(b.buf[b.idx:])
if n < 0 {
return nil, protowire.ParseError(n)
}
b.idx += n
if alloc {
v = append([]byte(nil), v...)
}
return v, nil
}
// DecodeStringBytes consumes a length-prefixed raw bytes from the buffer.
// It does not validate whether the raw bytes contain valid UTF-8.
func (b *Buffer) DecodeStringBytes() (string, error) {
v, n := protowire.ConsumeString(b.buf[b.idx:])
if n < 0 {
return "", protowire.ParseError(n)
}
b.idx += n
return v, nil
}
// DecodeMessage consumes a length-prefixed message from the buffer.
// It does not reset m before unmarshaling.
func (b *Buffer) DecodeMessage(m Message) error {
v, err := b.DecodeRawBytes(false)
if err != nil {
return err
}
return UnmarshalMerge(v, m)
}
// DecodeGroup consumes a message group from the buffer.
// It assumes that the start group marker has already been consumed and
// consumes all bytes until (and including the end group marker).
// It does not reset m before unmarshaling.
func (b *Buffer) DecodeGroup(m Message) error {
v, n, err := consumeGroup(b.buf[b.idx:])
if err != nil {
return err
}
b.idx += n
return UnmarshalMerge(v, m)
}
// consumeGroup parses b until it finds an end group marker, returning
// the raw bytes of the message (excluding the end group marker) and the
// the total length of the message (including the end group marker).
func consumeGroup(b []byte) ([]byte, int, error) {
b0 := b
depth := 1 // assume this follows a start group marker
for {
_, wtyp, tagLen := protowire.ConsumeTag(b)
if tagLen < 0 {
return nil, 0, protowire.ParseError(tagLen)
}
b = b[tagLen:]
var valLen int
switch wtyp {
case protowire.VarintType:
_, valLen = protowire.ConsumeVarint(b)
case protowire.Fixed32Type:
_, valLen = protowire.ConsumeFixed32(b)
case protowire.Fixed64Type:
_, valLen = protowire.ConsumeFixed64(b)
case protowire.BytesType:
_, valLen = protowire.ConsumeBytes(b)
case protowire.StartGroupType:
depth++
case protowire.EndGroupType:
depth--
default:
return nil, 0, errors.New("proto: cannot parse reserved wire type")
}
if valLen < 0 {
return nil, 0, protowire.ParseError(valLen)
}
b = b[valLen:]
if depth == 0 {
return b0[:len(b0)-len(b)-tagLen], len(b0) - len(b), nil
}
}
}

@ -1,63 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"google.golang.org/protobuf/reflect/protoreflect"
)
// SetDefaults sets unpopulated scalar fields to their default values.
// Fields within a oneof are not set even if they have a default value.
// SetDefaults is recursively called upon any populated message fields.
func SetDefaults(m Message) {
if m != nil {
setDefaults(MessageReflect(m))
}
}
func setDefaults(m protoreflect.Message) {
fds := m.Descriptor().Fields()
for i := 0; i < fds.Len(); i++ {
fd := fds.Get(i)
if !m.Has(fd) {
if fd.HasDefault() && fd.ContainingOneof() == nil {
v := fd.Default()
if fd.Kind() == protoreflect.BytesKind {
v = protoreflect.ValueOf(append([]byte(nil), v.Bytes()...)) // copy the default bytes
}
m.Set(fd, v)
}
continue
}
}
m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
switch {
// Handle singular message.
case fd.Cardinality() != protoreflect.Repeated:
if fd.Message() != nil {
setDefaults(m.Get(fd).Message())
}
// Handle list of messages.
case fd.IsList():
if fd.Message() != nil {
ls := m.Get(fd).List()
for i := 0; i < ls.Len(); i++ {
setDefaults(ls.Get(i).Message())
}
}
// Handle map of messages.
case fd.IsMap():
if fd.MapValue().Message() != nil {
ms := m.Get(fd).Map()
ms.Range(func(_ protoreflect.MapKey, v protoreflect.Value) bool {
setDefaults(v.Message())
return true
})
}
}
return true
})
}

@ -1,113 +0,0 @@
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"encoding/json"
"errors"
"fmt"
"strconv"
protoV2 "google.golang.org/protobuf/proto"
)
var (
// Deprecated: No longer returned.
ErrNil = errors.New("proto: Marshal called with nil")
// Deprecated: No longer returned.
ErrTooLarge = errors.New("proto: message encodes to over 2 GB")
// Deprecated: No longer returned.
ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof")
)
// Deprecated: Do not use.
type Stats struct{ Emalloc, Dmalloc, Encode, Decode, Chit, Cmiss, Size uint64 }
// Deprecated: Do not use.
func GetStats() Stats { return Stats{} }
// Deprecated: Do not use.
func MarshalMessageSet(interface{}) ([]byte, error) {
return nil, errors.New("proto: not implemented")
}
// Deprecated: Do not use.
func UnmarshalMessageSet([]byte, interface{}) error {
return errors.New("proto: not implemented")
}
// Deprecated: Do not use.
func MarshalMessageSetJSON(interface{}) ([]byte, error) {
return nil, errors.New("proto: not implemented")
}
// Deprecated: Do not use.
func UnmarshalMessageSetJSON([]byte, interface{}) error {
return errors.New("proto: not implemented")
}
// Deprecated: Do not use.
func RegisterMessageSetType(Message, int32, string) {}
// Deprecated: Do not use.
func EnumName(m map[int32]string, v int32) string {
s, ok := m[v]
if ok {
return s
}
return strconv.Itoa(int(v))
}
// Deprecated: Do not use.
func UnmarshalJSONEnum(m map[string]int32, data []byte, enumName string) (int32, error) {
if data[0] == '"' {
// New style: enums are strings.
var repr string
if err := json.Unmarshal(data, &repr); err != nil {
return -1, err
}
val, ok := m[repr]
if !ok {
return 0, fmt.Errorf("unrecognized enum %s value %q", enumName, repr)
}
return val, nil
}
// Old style: enums are ints.
var val int32
if err := json.Unmarshal(data, &val); err != nil {
return 0, fmt.Errorf("cannot unmarshal %#q into enum %s", data, enumName)
}
return val, nil
}
// Deprecated: Do not use; this type existed for intenal-use only.
type InternalMessageInfo struct{}
// Deprecated: Do not use; this method existed for intenal-use only.
func (*InternalMessageInfo) DiscardUnknown(m Message) {
DiscardUnknown(m)
}
// Deprecated: Do not use; this method existed for intenal-use only.
func (*InternalMessageInfo) Marshal(b []byte, m Message, deterministic bool) ([]byte, error) {
return protoV2.MarshalOptions{Deterministic: deterministic}.MarshalAppend(b, MessageV2(m))
}
// Deprecated: Do not use; this method existed for intenal-use only.
func (*InternalMessageInfo) Merge(dst, src Message) {
protoV2.Merge(MessageV2(dst), MessageV2(src))
}
// Deprecated: Do not use; this method existed for intenal-use only.
func (*InternalMessageInfo) Size(m Message) int {
return protoV2.Size(MessageV2(m))
}
// Deprecated: Do not use; this method existed for intenal-use only.
func (*InternalMessageInfo) Unmarshal(m Message, b []byte) error {
return protoV2.UnmarshalOptions{Merge: true}.Unmarshal(b, MessageV2(m))
}

@ -1,58 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"google.golang.org/protobuf/reflect/protoreflect"
)
// DiscardUnknown recursively discards all unknown fields from this message
// and all embedded messages.
//
// When unmarshaling a message with unrecognized fields, the tags and values
// of such fields are preserved in the Message. This allows a later call to
// marshal to be able to produce a message that continues to have those
// unrecognized fields. To avoid this, DiscardUnknown is used to
// explicitly clear the unknown fields after unmarshaling.
func DiscardUnknown(m Message) {
if m != nil {
discardUnknown(MessageReflect(m))
}
}
func discardUnknown(m protoreflect.Message) {
m.Range(func(fd protoreflect.FieldDescriptor, val protoreflect.Value) bool {
switch {
// Handle singular message.
case fd.Cardinality() != protoreflect.Repeated:
if fd.Message() != nil {
discardUnknown(m.Get(fd).Message())
}
// Handle list of messages.
case fd.IsList():
if fd.Message() != nil {
ls := m.Get(fd).List()
for i := 0; i < ls.Len(); i++ {
discardUnknown(ls.Get(i).Message())
}
}
// Handle map of messages.
case fd.IsMap():
if fd.MapValue().Message() != nil {
ms := m.Get(fd).Map()
ms.Range(func(_ protoreflect.MapKey, v protoreflect.Value) bool {
discardUnknown(v.Message())
return true
})
}
}
return true
})
// Discard unknown fields.
if len(m.GetUnknown()) > 0 {
m.SetUnknown(nil)
}
}

@ -1,356 +0,0 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"errors"
"fmt"
"reflect"
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
"google.golang.org/protobuf/runtime/protoiface"
"google.golang.org/protobuf/runtime/protoimpl"
)
type (
// ExtensionDesc represents an extension descriptor and
// is used to interact with an extension field in a message.
//
// Variables of this type are generated in code by protoc-gen-go.
ExtensionDesc = protoimpl.ExtensionInfo
// ExtensionRange represents a range of message extensions.
// Used in code generated by protoc-gen-go.
ExtensionRange = protoiface.ExtensionRangeV1
// Deprecated: Do not use; this is an internal type.
Extension = protoimpl.ExtensionFieldV1
// Deprecated: Do not use; this is an internal type.
XXX_InternalExtensions = protoimpl.ExtensionFields
)
// ErrMissingExtension reports whether the extension was not present.
var ErrMissingExtension = errors.New("proto: missing extension")
var errNotExtendable = errors.New("proto: not an extendable proto.Message")
// HasExtension reports whether the extension field is present in m
// either as an explicitly populated field or as an unknown field.
func HasExtension(m Message, xt *ExtensionDesc) (has bool) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return false
}
// Check whether any populated known field matches the field number.
xtd := xt.TypeDescriptor()
if isValidExtension(mr.Descriptor(), xtd) {
has = mr.Has(xtd)
} else {
mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
has = int32(fd.Number()) == xt.Field
return !has
})
}
// Check whether any unknown field matches the field number.
for b := mr.GetUnknown(); !has && len(b) > 0; {
num, _, n := protowire.ConsumeField(b)
has = int32(num) == xt.Field
b = b[n:]
}
return has
}
// ClearExtension removes the extension field from m
// either as an explicitly populated field or as an unknown field.
func ClearExtension(m Message, xt *ExtensionDesc) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return
}
xtd := xt.TypeDescriptor()
if isValidExtension(mr.Descriptor(), xtd) {
mr.Clear(xtd)
} else {
mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
if int32(fd.Number()) == xt.Field {
mr.Clear(fd)
return false
}
return true
})
}
clearUnknown(mr, fieldNum(xt.Field))
}
// ClearAllExtensions clears all extensions from m.
// This includes populated fields and unknown fields in the extension range.
func ClearAllExtensions(m Message) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return
}
mr.Range(func(fd protoreflect.FieldDescriptor, _ protoreflect.Value) bool {
if fd.IsExtension() {
mr.Clear(fd)
}
return true
})
clearUnknown(mr, mr.Descriptor().ExtensionRanges())
}
// GetExtension retrieves a proto2 extended field from m.
//
// If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
// then GetExtension parses the encoded field and returns a Go value of the specified type.
// If the field is not present, then the default value is returned (if one is specified),
// otherwise ErrMissingExtension is reported.
//
// If the descriptor is type incomplete (i.e., ExtensionDesc.ExtensionType is nil),
// then GetExtension returns the raw encoded bytes for the extension field.
func GetExtension(m Message, xt *ExtensionDesc) (interface{}, error) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
return nil, errNotExtendable
}
// Retrieve the unknown fields for this extension field.
var bo protoreflect.RawFields
for bi := mr.GetUnknown(); len(bi) > 0; {
num, _, n := protowire.ConsumeField(bi)
if int32(num) == xt.Field {
bo = append(bo, bi[:n]...)
}
bi = bi[n:]
}
// For type incomplete descriptors, only retrieve the unknown fields.
if xt.ExtensionType == nil {
return []byte(bo), nil
}
// If the extension field only exists as unknown fields, unmarshal it.
// This is rarely done since proto.Unmarshal eagerly unmarshals extensions.
xtd := xt.TypeDescriptor()
if !isValidExtension(mr.Descriptor(), xtd) {
return nil, fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
}
if !mr.Has(xtd) && len(bo) > 0 {
m2 := mr.New()
if err := (proto.UnmarshalOptions{
Resolver: extensionResolver{xt},
}.Unmarshal(bo, m2.Interface())); err != nil {
return nil, err
}
if m2.Has(xtd) {
mr.Set(xtd, m2.Get(xtd))
clearUnknown(mr, fieldNum(xt.Field))
}
}
// Check whether the message has the extension field set or a default.
var pv protoreflect.Value
switch {
case mr.Has(xtd):
pv = mr.Get(xtd)
case xtd.HasDefault():
pv = xtd.Default()
default:
return nil, ErrMissingExtension
}
v := xt.InterfaceOf(pv)
rv := reflect.ValueOf(v)
if isScalarKind(rv.Kind()) {
rv2 := reflect.New(rv.Type())
rv2.Elem().Set(rv)
v = rv2.Interface()
}
return v, nil
}
// extensionResolver is a custom extension resolver that stores a single
// extension type that takes precedence over the global registry.
type extensionResolver struct{ xt protoreflect.ExtensionType }
func (r extensionResolver) FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) {
if xtd := r.xt.TypeDescriptor(); xtd.FullName() == field {
return r.xt, nil
}
return protoregistry.GlobalTypes.FindExtensionByName(field)
}
func (r extensionResolver) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) {
if xtd := r.xt.TypeDescriptor(); xtd.ContainingMessage().FullName() == message && xtd.Number() == field {
return r.xt, nil
}
return protoregistry.GlobalTypes.FindExtensionByNumber(message, field)
}
// GetExtensions returns a list of the extensions values present in m,
// corresponding with the provided list of extension descriptors, xts.
// If an extension is missing in m, the corresponding value is nil.
func GetExtensions(m Message, xts []*ExtensionDesc) ([]interface{}, error) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return nil, errNotExtendable
}
vs := make([]interface{}, len(xts))
for i, xt := range xts {
v, err := GetExtension(m, xt)
if err != nil {
if err == ErrMissingExtension {
continue
}
return vs, err
}
vs[i] = v
}
return vs, nil
}
// SetExtension sets an extension field in m to the provided value.
func SetExtension(m Message, xt *ExtensionDesc, v interface{}) error {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
return errNotExtendable
}
rv := reflect.ValueOf(v)
if reflect.TypeOf(v) != reflect.TypeOf(xt.ExtensionType) {
return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", v, xt.ExtensionType)
}
if rv.Kind() == reflect.Ptr {
if rv.IsNil() {
return fmt.Errorf("proto: SetExtension called with nil value of type %T", v)
}
if isScalarKind(rv.Elem().Kind()) {
v = rv.Elem().Interface()
}
}
xtd := xt.TypeDescriptor()
if !isValidExtension(mr.Descriptor(), xtd) {
return fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
}
mr.Set(xtd, xt.ValueOf(v))
clearUnknown(mr, fieldNum(xt.Field))
return nil
}
// SetRawExtension inserts b into the unknown fields of m.
//
// Deprecated: Use Message.ProtoReflect.SetUnknown instead.
func SetRawExtension(m Message, fnum int32, b []byte) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return
}
// Verify that the raw field is valid.
for b0 := b; len(b0) > 0; {
num, _, n := protowire.ConsumeField(b0)
if int32(num) != fnum {
panic(fmt.Sprintf("mismatching field number: got %d, want %d", num, fnum))
}
b0 = b0[n:]
}
ClearExtension(m, &ExtensionDesc{Field: fnum})
mr.SetUnknown(append(mr.GetUnknown(), b...))
}
// ExtensionDescs returns a list of extension descriptors found in m,
// containing descriptors for both populated extension fields in m and
// also unknown fields of m that are in the extension range.
// For the later case, an type incomplete descriptor is provided where only
// the ExtensionDesc.Field field is populated.
// The order of the extension descriptors is undefined.
func ExtensionDescs(m Message) ([]*ExtensionDesc, error) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
return nil, errNotExtendable
}
// Collect a set of known extension descriptors.
extDescs := make(map[protoreflect.FieldNumber]*ExtensionDesc)
mr.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
if fd.IsExtension() {
xt := fd.(protoreflect.ExtensionTypeDescriptor)
if xd, ok := xt.Type().(*ExtensionDesc); ok {
extDescs[fd.Number()] = xd
}
}
return true
})
// Collect a set of unknown extension descriptors.
extRanges := mr.Descriptor().ExtensionRanges()
for b := mr.GetUnknown(); len(b) > 0; {
num, _, n := protowire.ConsumeField(b)
if extRanges.Has(num) && extDescs[num] == nil {
extDescs[num] = nil
}
b = b[n:]
}
// Transpose the set of descriptors into a list.
var xts []*ExtensionDesc
for num, xt := range extDescs {
if xt == nil {
xt = &ExtensionDesc{Field: int32(num)}
}
xts = append(xts, xt)
}
return xts, nil
}
// isValidExtension reports whether xtd is a valid extension descriptor for md.
func isValidExtension(md protoreflect.MessageDescriptor, xtd protoreflect.ExtensionTypeDescriptor) bool {
return xtd.ContainingMessage() == md && md.ExtensionRanges().Has(xtd.Number())
}
// isScalarKind reports whether k is a protobuf scalar kind (except bytes).
// This function exists for historical reasons since the representation of
// scalars differs between v1 and v2, where v1 uses *T and v2 uses T.
func isScalarKind(k reflect.Kind) bool {
switch k {
case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
return true
default:
return false
}
}
// clearUnknown removes unknown fields from m where remover.Has reports true.
func clearUnknown(m protoreflect.Message, remover interface {
Has(protoreflect.FieldNumber) bool
}) {
var bo protoreflect.RawFields
for bi := m.GetUnknown(); len(bi) > 0; {
num, _, n := protowire.ConsumeField(bi)
if !remover.Has(num) {
bo = append(bo, bi[:n]...)
}
bi = bi[n:]
}
if bi := m.GetUnknown(); len(bi) != len(bo) {
m.SetUnknown(bo)
}
}
type fieldNum protoreflect.FieldNumber
func (n1 fieldNum) Has(n2 protoreflect.FieldNumber) bool {
return protoreflect.FieldNumber(n1) == n2
}

@ -1,306 +0,0 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"fmt"
"reflect"
"strconv"
"strings"
"sync"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/runtime/protoimpl"
)
// StructProperties represents protocol buffer type information for a
// generated protobuf message in the open-struct API.
//
// Deprecated: Do not use.
type StructProperties struct {
// Prop are the properties for each field.
//
// Fields belonging to a oneof are stored in OneofTypes instead, with a
// single Properties representing the parent oneof held here.
//
// The order of Prop matches the order of fields in the Go struct.
// Struct fields that are not related to protobufs have a "XXX_" prefix
// in the Properties.Name and must be ignored by the user.
Prop []*Properties
// OneofTypes contains information about the oneof fields in this message.
// It is keyed by the protobuf field name.
OneofTypes map[string]*OneofProperties
}
// Properties represents the type information for a protobuf message field.
//
// Deprecated: Do not use.
type Properties struct {
// Name is a placeholder name with little meaningful semantic value.
// If the name has an "XXX_" prefix, the entire Properties must be ignored.
Name string
// OrigName is the protobuf field name or oneof name.
OrigName string
// JSONName is the JSON name for the protobuf field.
JSONName string
// Enum is a placeholder name for enums.
// For historical reasons, this is neither the Go name for the enum,
// nor the protobuf name for the enum.
Enum string // Deprecated: Do not use.
// Weak contains the full name of the weakly referenced message.
Weak string
// Wire is a string representation of the wire type.
Wire string
// WireType is the protobuf wire type for the field.
WireType int
// Tag is the protobuf field number.
Tag int
// Required reports whether this is a required field.
Required bool
// Optional reports whether this is a optional field.
Optional bool
// Repeated reports whether this is a repeated field.
Repeated bool
// Packed reports whether this is a packed repeated field of scalars.
Packed bool
// Proto3 reports whether this field operates under the proto3 syntax.
Proto3 bool
// Oneof reports whether this field belongs within a oneof.
Oneof bool
// Default is the default value in string form.
Default string
// HasDefault reports whether the field has a default value.
HasDefault bool
// MapKeyProp is the properties for the key field for a map field.
MapKeyProp *Properties
// MapValProp is the properties for the value field for a map field.
MapValProp *Properties
}
// OneofProperties represents the type information for a protobuf oneof.
//
// Deprecated: Do not use.
type OneofProperties struct {
// Type is a pointer to the generated wrapper type for the field value.
// This is nil for messages that are not in the open-struct API.
Type reflect.Type
// Field is the index into StructProperties.Prop for the containing oneof.
Field int
// Prop is the properties for the field.
Prop *Properties
}
// String formats the properties in the protobuf struct field tag style.
func (p *Properties) String() string {
s := p.Wire
s += "," + strconv.Itoa(p.Tag)
if p.Required {
s += ",req"
}
if p.Optional {
s += ",opt"
}
if p.Repeated {
s += ",rep"
}
if p.Packed {
s += ",packed"
}
s += ",name=" + p.OrigName
if p.JSONName != "" {
s += ",json=" + p.JSONName
}
if len(p.Enum) > 0 {
s += ",enum=" + p.Enum
}
if len(p.Weak) > 0 {
s += ",weak=" + p.Weak
}
if p.Proto3 {
s += ",proto3"
}
if p.Oneof {
s += ",oneof"
}
if p.HasDefault {
s += ",def=" + p.Default
}
return s
}
// Parse populates p by parsing a string in the protobuf struct field tag style.
func (p *Properties) Parse(tag string) {
// For example: "bytes,49,opt,name=foo,def=hello!"
for len(tag) > 0 {
i := strings.IndexByte(tag, ',')
if i < 0 {
i = len(tag)
}
switch s := tag[:i]; {
case strings.HasPrefix(s, "name="):
p.OrigName = s[len("name="):]
case strings.HasPrefix(s, "json="):
p.JSONName = s[len("json="):]
case strings.HasPrefix(s, "enum="):
p.Enum = s[len("enum="):]
case strings.HasPrefix(s, "weak="):
p.Weak = s[len("weak="):]
case strings.Trim(s, "0123456789") == "":
n, _ := strconv.ParseUint(s, 10, 32)
p.Tag = int(n)
case s == "opt":
p.Optional = true
case s == "req":
p.Required = true
case s == "rep":
p.Repeated = true
case s == "varint" || s == "zigzag32" || s == "zigzag64":
p.Wire = s
p.WireType = WireVarint
case s == "fixed32":
p.Wire = s
p.WireType = WireFixed32
case s == "fixed64":
p.Wire = s
p.WireType = WireFixed64
case s == "bytes":
p.Wire = s
p.WireType = WireBytes
case s == "group":
p.Wire = s
p.WireType = WireStartGroup
case s == "packed":
p.Packed = true
case s == "proto3":
p.Proto3 = true
case s == "oneof":
p.Oneof = true
case strings.HasPrefix(s, "def="):
// The default tag is special in that everything afterwards is the
// default regardless of the presence of commas.
p.HasDefault = true
p.Default, i = tag[len("def="):], len(tag)
}
tag = strings.TrimPrefix(tag[i:], ",")
}
}
// Init populates the properties from a protocol buffer struct tag.
//
// Deprecated: Do not use.
func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
p.Name = name
p.OrigName = name
if tag == "" {
return
}
p.Parse(tag)
if typ != nil && typ.Kind() == reflect.Map {
p.MapKeyProp = new(Properties)
p.MapKeyProp.Init(nil, "Key", f.Tag.Get("protobuf_key"), nil)
p.MapValProp = new(Properties)
p.MapValProp.Init(nil, "Value", f.Tag.Get("protobuf_val"), nil)
}
}
var propertiesCache sync.Map // map[reflect.Type]*StructProperties
// GetProperties returns the list of properties for the type represented by t,
// which must be a generated protocol buffer message in the open-struct API,
// where protobuf message fields are represented by exported Go struct fields.
//
// Deprecated: Use protobuf reflection instead.
func GetProperties(t reflect.Type) *StructProperties {
if p, ok := propertiesCache.Load(t); ok {
return p.(*StructProperties)
}
p, _ := propertiesCache.LoadOrStore(t, newProperties(t))
return p.(*StructProperties)
}
func newProperties(t reflect.Type) *StructProperties {
if t.Kind() != reflect.Struct {
panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
}
var hasOneof bool
prop := new(StructProperties)
// Construct a list of properties for each field in the struct.
for i := 0; i < t.NumField(); i++ {
p := new(Properties)
f := t.Field(i)
tagField := f.Tag.Get("protobuf")
p.Init(f.Type, f.Name, tagField, &f)
tagOneof := f.Tag.Get("protobuf_oneof")
if tagOneof != "" {
hasOneof = true
p.OrigName = tagOneof
}
// Rename unrelated struct fields with the "XXX_" prefix since so much
// user code simply checks for this to exclude special fields.
if tagField == "" && tagOneof == "" && !strings.HasPrefix(p.Name, "XXX_") {
p.Name = "XXX_" + p.Name
p.OrigName = "XXX_" + p.OrigName
} else if p.Weak != "" {
p.Name = p.OrigName // avoid possible "XXX_" prefix on weak field
}
prop.Prop = append(prop.Prop, p)
}
// Construct a mapping of oneof field names to properties.
if hasOneof {
var oneofWrappers []interface{}
if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofFuncs"); ok {
oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[3].Interface().([]interface{})
}
if fn, ok := reflect.PtrTo(t).MethodByName("XXX_OneofWrappers"); ok {
oneofWrappers = fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0].Interface().([]interface{})
}
if m, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(protoreflect.ProtoMessage); ok {
if m, ok := m.ProtoReflect().(interface{ ProtoMessageInfo() *protoimpl.MessageInfo }); ok {
oneofWrappers = m.ProtoMessageInfo().OneofWrappers
}
}
prop.OneofTypes = make(map[string]*OneofProperties)
for _, wrapper := range oneofWrappers {
p := &OneofProperties{
Type: reflect.ValueOf(wrapper).Type(), // *T
Prop: new(Properties),
}
f := p.Type.Elem().Field(0)
p.Prop.Name = f.Name
p.Prop.Parse(f.Tag.Get("protobuf"))
// Determine the struct field that contains this oneof.
// Each wrapper is assignable to exactly one parent field.
var foundOneof bool
for i := 0; i < t.NumField() && !foundOneof; i++ {
if p.Type.AssignableTo(t.Field(i).Type) {
p.Field = i
foundOneof = true
}
}
if !foundOneof {
panic(fmt.Sprintf("%v is not a generated message in the open-struct API", t))
}
prop.OneofTypes[p.Prop.OrigName] = p
}
}
return prop
}
func (sp *StructProperties) Len() int { return len(sp.Prop) }
func (sp *StructProperties) Less(i, j int) bool { return false }
func (sp *StructProperties) Swap(i, j int) { return }

@ -1,167 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package proto provides functionality for handling protocol buffer messages.
// In particular, it provides marshaling and unmarshaling between a protobuf
// message and the binary wire format.
//
// See https://developers.google.com/protocol-buffers/docs/gotutorial for
// more information.
//
// Deprecated: Use the "google.golang.org/protobuf/proto" package instead.
package proto
import (
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/runtime/protoiface"
"google.golang.org/protobuf/runtime/protoimpl"
)
const (
ProtoPackageIsVersion1 = true
ProtoPackageIsVersion2 = true
ProtoPackageIsVersion3 = true
ProtoPackageIsVersion4 = true
)
// GeneratedEnum is any enum type generated by protoc-gen-go
// which is a named int32 kind.
// This type exists for documentation purposes.
type GeneratedEnum interface{}
// GeneratedMessage is any message type generated by protoc-gen-go
// which is a pointer to a named struct kind.
// This type exists for documentation purposes.
type GeneratedMessage interface{}
// Message is a protocol buffer message.
//
// This is the v1 version of the message interface and is marginally better
// than an empty interface as it lacks any method to programatically interact
// with the contents of the message.
//
// A v2 message is declared in "google.golang.org/protobuf/proto".Message and
// exposes protobuf reflection as a first-class feature of the interface.
//
// To convert a v1 message to a v2 message, use the MessageV2 function.
// To convert a v2 message to a v1 message, use the MessageV1 function.
type Message = protoiface.MessageV1
// MessageV1 converts either a v1 or v2 message to a v1 message.
// It returns nil if m is nil.
func MessageV1(m GeneratedMessage) protoiface.MessageV1 {
return protoimpl.X.ProtoMessageV1Of(m)
}
// MessageV2 converts either a v1 or v2 message to a v2 message.
// It returns nil if m is nil.
func MessageV2(m GeneratedMessage) protoV2.Message {
return protoimpl.X.ProtoMessageV2Of(m)
}
// MessageReflect returns a reflective view for a message.
// It returns nil if m is nil.
func MessageReflect(m Message) protoreflect.Message {
return protoimpl.X.MessageOf(m)
}
// Marshaler is implemented by messages that can marshal themselves.
// This interface is used by the following functions: Size, Marshal,
// Buffer.Marshal, and Buffer.EncodeMessage.
//
// Deprecated: Do not implement.
type Marshaler interface {
// Marshal formats the encoded bytes of the message.
// It should be deterministic and emit valid protobuf wire data.
// The caller takes ownership of the returned buffer.
Marshal() ([]byte, error)
}
// Unmarshaler is implemented by messages that can unmarshal themselves.
// This interface is used by the following functions: Unmarshal, UnmarshalMerge,
// Buffer.Unmarshal, Buffer.DecodeMessage, and Buffer.DecodeGroup.
//
// Deprecated: Do not implement.
type Unmarshaler interface {
// Unmarshal parses the encoded bytes of the protobuf wire input.
// The provided buffer is only valid for during method call.
// It should not reset the receiver message.
Unmarshal([]byte) error
}
// Merger is implemented by messages that can merge themselves.
// This interface is used by the following functions: Clone and Merge.
//
// Deprecated: Do not implement.
type Merger interface {
// Merge merges the contents of src into the receiver message.
// It clones all data structures in src such that it aliases no mutable
// memory referenced by src.
Merge(src Message)
}
// RequiredNotSetError is an error type returned when
// marshaling or unmarshaling a message with missing required fields.
type RequiredNotSetError struct {
err error
}
func (e *RequiredNotSetError) Error() string {
if e.err != nil {
return e.err.Error()
}
return "proto: required field not set"
}
func (e *RequiredNotSetError) RequiredNotSet() bool {
return true
}
func checkRequiredNotSet(m protoV2.Message) error {
if err := protoV2.CheckInitialized(m); err != nil {
return &RequiredNotSetError{err: err}
}
return nil
}
// Clone returns a deep copy of src.
func Clone(src Message) Message {
return MessageV1(protoV2.Clone(MessageV2(src)))
}
// Merge merges src into dst, which must be messages of the same type.
//
// Populated scalar fields in src are copied to dst, while populated
// singular messages in src are merged into dst by recursively calling Merge.
// The elements of every list field in src is appended to the corresponded
// list fields in dst. The entries of every map field in src is copied into
// the corresponding map field in dst, possibly replacing existing entries.
// The unknown fields of src are appended to the unknown fields of dst.
func Merge(dst, src Message) {
protoV2.Merge(MessageV2(dst), MessageV2(src))
}
// Equal reports whether two messages are equal.
// If two messages marshal to the same bytes under deterministic serialization,
// then Equal is guaranteed to report true.
//
// Two messages are equal if they are the same protobuf message type,
// have the same set of populated known and extension field values,
// and the same set of unknown fields values.
//
// Scalar values are compared with the equivalent of the == operator in Go,
// except bytes values which are compared using bytes.Equal and
// floating point values which specially treat NaNs as equal.
// Message values are compared by recursively calling Equal.
// Lists are equal if each element value is also equal.
// Maps are equal if they have the same set of keys, where the pair of values
// for each key is also equal.
func Equal(x, y Message) bool {
return protoV2.Equal(MessageV2(x), MessageV2(y))
}
func isMessageSet(md protoreflect.MessageDescriptor) bool {
ms, ok := md.(interface{ IsMessageSet() bool })
return ok && ms.IsMessageSet()
}

@ -1,317 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"bytes"
"compress/gzip"
"fmt"
"io/ioutil"
"reflect"
"strings"
"sync"
"google.golang.org/protobuf/reflect/protodesc"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
"google.golang.org/protobuf/runtime/protoimpl"
)
// filePath is the path to the proto source file.
type filePath = string // e.g., "google/protobuf/descriptor.proto"
// fileDescGZIP is the compressed contents of the encoded FileDescriptorProto.
type fileDescGZIP = []byte
var fileCache sync.Map // map[filePath]fileDescGZIP
// RegisterFile is called from generated code to register the compressed
// FileDescriptorProto with the file path for a proto source file.
//
// Deprecated: Use protoregistry.GlobalFiles.RegisterFile instead.
func RegisterFile(s filePath, d fileDescGZIP) {
// Decompress the descriptor.
zr, err := gzip.NewReader(bytes.NewReader(d))
if err != nil {
panic(fmt.Sprintf("proto: invalid compressed file descriptor: %v", err))
}
b, err := ioutil.ReadAll(zr)
if err != nil {
panic(fmt.Sprintf("proto: invalid compressed file descriptor: %v", err))
}
// Construct a protoreflect.FileDescriptor from the raw descriptor.
// Note that DescBuilder.Build automatically registers the constructed
// file descriptor with the v2 registry.
protoimpl.DescBuilder{RawDescriptor: b}.Build()
// Locally cache the raw descriptor form for the file.
fileCache.Store(s, d)
}
// FileDescriptor returns the compressed FileDescriptorProto given the file path
// for a proto source file. It returns nil if not found.
//
// Deprecated: Use protoregistry.GlobalFiles.FindFileByPath instead.
func FileDescriptor(s filePath) fileDescGZIP {
if v, ok := fileCache.Load(s); ok {
return v.(fileDescGZIP)
}
// Find the descriptor in the v2 registry.
var b []byte
if fd, _ := protoregistry.GlobalFiles.FindFileByPath(s); fd != nil {
b, _ = Marshal(protodesc.ToFileDescriptorProto(fd))
}
// Locally cache the raw descriptor form for the file.
if len(b) > 0 {
v, _ := fileCache.LoadOrStore(s, protoimpl.X.CompressGZIP(b))
return v.(fileDescGZIP)
}
return nil
}
// enumName is the name of an enum. For historical reasons, the enum name is
// neither the full Go name nor the full protobuf name of the enum.
// The name is the dot-separated combination of just the proto package that the
// enum is declared within followed by the Go type name of the generated enum.
type enumName = string // e.g., "my.proto.package.GoMessage_GoEnum"
// enumsByName maps enum values by name to their numeric counterpart.
type enumsByName = map[string]int32
// enumsByNumber maps enum values by number to their name counterpart.
type enumsByNumber = map[int32]string
var enumCache sync.Map // map[enumName]enumsByName
var numFilesCache sync.Map // map[protoreflect.FullName]int
// RegisterEnum is called from the generated code to register the mapping of
// enum value names to enum numbers for the enum identified by s.
//
// Deprecated: Use protoregistry.GlobalTypes.RegisterEnum instead.
func RegisterEnum(s enumName, _ enumsByNumber, m enumsByName) {
if _, ok := enumCache.Load(s); ok {
panic("proto: duplicate enum registered: " + s)
}
enumCache.Store(s, m)
// This does not forward registration to the v2 registry since this API
// lacks sufficient information to construct a complete v2 enum descriptor.
}
// EnumValueMap returns the mapping from enum value names to enum numbers for
// the enum of the given name. It returns nil if not found.
//
// Deprecated: Use protoregistry.GlobalTypes.FindEnumByName instead.
func EnumValueMap(s enumName) enumsByName {
if v, ok := enumCache.Load(s); ok {
return v.(enumsByName)
}
// Check whether the cache is stale. If the number of files in the current
// package differs, then it means that some enums may have been recently
// registered upstream that we do not know about.
var protoPkg protoreflect.FullName
if i := strings.LastIndexByte(s, '.'); i >= 0 {
protoPkg = protoreflect.FullName(s[:i])
}
v, _ := numFilesCache.Load(protoPkg)
numFiles, _ := v.(int)
if protoregistry.GlobalFiles.NumFilesByPackage(protoPkg) == numFiles {
return nil // cache is up-to-date; was not found earlier
}
// Update the enum cache for all enums declared in the given proto package.
numFiles = 0
protoregistry.GlobalFiles.RangeFilesByPackage(protoPkg, func(fd protoreflect.FileDescriptor) bool {
walkEnums(fd, func(ed protoreflect.EnumDescriptor) {
name := protoimpl.X.LegacyEnumName(ed)
if _, ok := enumCache.Load(name); !ok {
m := make(enumsByName)
evs := ed.Values()
for i := evs.Len() - 1; i >= 0; i-- {
ev := evs.Get(i)
m[string(ev.Name())] = int32(ev.Number())
}
enumCache.LoadOrStore(name, m)
}
})
numFiles++
return true
})
numFilesCache.Store(protoPkg, numFiles)
// Check cache again for enum map.
if v, ok := enumCache.Load(s); ok {
return v.(enumsByName)
}
return nil
}
// walkEnums recursively walks all enums declared in d.
func walkEnums(d interface {
Enums() protoreflect.EnumDescriptors
Messages() protoreflect.MessageDescriptors
}, f func(protoreflect.EnumDescriptor)) {
eds := d.Enums()
for i := eds.Len() - 1; i >= 0; i-- {
f(eds.Get(i))
}
mds := d.Messages()
for i := mds.Len() - 1; i >= 0; i-- {
walkEnums(mds.Get(i), f)
}
}
// messageName is the full name of protobuf message.
type messageName = string
var messageTypeCache sync.Map // map[messageName]reflect.Type
// RegisterType is called from generated code to register the message Go type
// for a message of the given name.
//
// Deprecated: Use protoregistry.GlobalTypes.RegisterMessage instead.
func RegisterType(m Message, s messageName) {
mt := protoimpl.X.LegacyMessageTypeOf(m, protoreflect.FullName(s))
if err := protoregistry.GlobalTypes.RegisterMessage(mt); err != nil {
panic(err)
}
messageTypeCache.Store(s, reflect.TypeOf(m))
}
// RegisterMapType is called from generated code to register the Go map type
// for a protobuf message representing a map entry.
//
// Deprecated: Do not use.
func RegisterMapType(m interface{}, s messageName) {
t := reflect.TypeOf(m)
if t.Kind() != reflect.Map {
panic(fmt.Sprintf("invalid map kind: %v", t))
}
if _, ok := messageTypeCache.Load(s); ok {
panic(fmt.Errorf("proto: duplicate proto message registered: %s", s))
}
messageTypeCache.Store(s, t)
}
// MessageType returns the message type for a named message.
// It returns nil if not found.
//
// Deprecated: Use protoregistry.GlobalTypes.FindMessageByName instead.
func MessageType(s messageName) reflect.Type {
if v, ok := messageTypeCache.Load(s); ok {
return v.(reflect.Type)
}
// Derive the message type from the v2 registry.
var t reflect.Type
if mt, _ := protoregistry.GlobalTypes.FindMessageByName(protoreflect.FullName(s)); mt != nil {
t = messageGoType(mt)
}
// If we could not get a concrete type, it is possible that it is a
// pseudo-message for a map entry.
if t == nil {
d, _ := protoregistry.GlobalFiles.FindDescriptorByName(protoreflect.FullName(s))
if md, _ := d.(protoreflect.MessageDescriptor); md != nil && md.IsMapEntry() {
kt := goTypeForField(md.Fields().ByNumber(1))
vt := goTypeForField(md.Fields().ByNumber(2))
t = reflect.MapOf(kt, vt)
}
}
// Locally cache the message type for the given name.
if t != nil {
v, _ := messageTypeCache.LoadOrStore(s, t)
return v.(reflect.Type)
}
return nil
}
func goTypeForField(fd protoreflect.FieldDescriptor) reflect.Type {
switch k := fd.Kind(); k {
case protoreflect.EnumKind:
if et, _ := protoregistry.GlobalTypes.FindEnumByName(fd.Enum().FullName()); et != nil {
return enumGoType(et)
}
return reflect.TypeOf(protoreflect.EnumNumber(0))
case protoreflect.MessageKind, protoreflect.GroupKind:
if mt, _ := protoregistry.GlobalTypes.FindMessageByName(fd.Message().FullName()); mt != nil {
return messageGoType(mt)
}
return reflect.TypeOf((*protoreflect.Message)(nil)).Elem()
default:
return reflect.TypeOf(fd.Default().Interface())
}
}
func enumGoType(et protoreflect.EnumType) reflect.Type {
return reflect.TypeOf(et.New(0))
}
func messageGoType(mt protoreflect.MessageType) reflect.Type {
return reflect.TypeOf(MessageV1(mt.Zero().Interface()))
}
// MessageName returns the full protobuf name for the given message type.
//
// Deprecated: Use protoreflect.MessageDescriptor.FullName instead.
func MessageName(m Message) messageName {
if m == nil {
return ""
}
if m, ok := m.(interface{ XXX_MessageName() messageName }); ok {
return m.XXX_MessageName()
}
return messageName(protoimpl.X.MessageDescriptorOf(m).FullName())
}
// RegisterExtension is called from the generated code to register
// the extension descriptor.
//
// Deprecated: Use protoregistry.GlobalTypes.RegisterExtension instead.
func RegisterExtension(d *ExtensionDesc) {
if err := protoregistry.GlobalTypes.RegisterExtension(d); err != nil {
panic(err)
}
}
type extensionsByNumber = map[int32]*ExtensionDesc
var extensionCache sync.Map // map[messageName]extensionsByNumber
// RegisteredExtensions returns a map of the registered extensions for the
// provided protobuf message, indexed by the extension field number.
//
// Deprecated: Use protoregistry.GlobalTypes.RangeExtensionsByMessage instead.
func RegisteredExtensions(m Message) extensionsByNumber {
// Check whether the cache is stale. If the number of extensions for
// the given message differs, then it means that some extensions were
// recently registered upstream that we do not know about.
s := MessageName(m)
v, _ := extensionCache.Load(s)
xs, _ := v.(extensionsByNumber)
if protoregistry.GlobalTypes.NumExtensionsByMessage(protoreflect.FullName(s)) == len(xs) {
return xs // cache is up-to-date
}
// Cache is stale, re-compute the extensions map.
xs = make(extensionsByNumber)
protoregistry.GlobalTypes.RangeExtensionsByMessage(protoreflect.FullName(s), func(xt protoreflect.ExtensionType) bool {
if xd, ok := xt.(*ExtensionDesc); ok {
xs[int32(xt.TypeDescriptor().Number())] = xd
} else {
// TODO: This implies that the protoreflect.ExtensionType is a
// custom type not generated by protoc-gen-go. We could try and
// convert the type to an ExtensionDesc.
}
return true
})
extensionCache.Store(s, xs)
return xs
}

@ -1,801 +0,0 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"encoding"
"errors"
"fmt"
"reflect"
"strconv"
"strings"
"unicode/utf8"
"google.golang.org/protobuf/encoding/prototext"
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapTextUnmarshalV2 = false
// ParseError is returned by UnmarshalText.
type ParseError struct {
Message string
// Deprecated: Do not use.
Line, Offset int
}
func (e *ParseError) Error() string {
if wrapTextUnmarshalV2 {
return e.Message
}
if e.Line == 1 {
return fmt.Sprintf("line 1.%d: %v", e.Offset, e.Message)
}
return fmt.Sprintf("line %d: %v", e.Line, e.Message)
}
// UnmarshalText parses a proto text formatted string into m.
func UnmarshalText(s string, m Message) error {
if u, ok := m.(encoding.TextUnmarshaler); ok {
return u.UnmarshalText([]byte(s))
}
m.Reset()
mi := MessageV2(m)
if wrapTextUnmarshalV2 {
err := prototext.UnmarshalOptions{
AllowPartial: true,
}.Unmarshal([]byte(s), mi)
if err != nil {
return &ParseError{Message: err.Error()}
}
return checkRequiredNotSet(mi)
} else {
if err := newTextParser(s).unmarshalMessage(mi.ProtoReflect(), ""); err != nil {
return err
}
return checkRequiredNotSet(mi)
}
}
type textParser struct {
s string // remaining input
done bool // whether the parsing is finished (success or error)
backed bool // whether back() was called
offset, line int
cur token
}
type token struct {
value string
err *ParseError
line int // line number
offset int // byte number from start of input, not start of line
unquoted string // the unquoted version of value, if it was a quoted string
}
func newTextParser(s string) *textParser {
p := new(textParser)
p.s = s
p.line = 1
p.cur.line = 1
return p
}
func (p *textParser) unmarshalMessage(m protoreflect.Message, terminator string) (err error) {
md := m.Descriptor()
fds := md.Fields()
// A struct is a sequence of "name: value", terminated by one of
// '>' or '}', or the end of the input. A name may also be
// "[extension]" or "[type/url]".
//
// The whole struct can also be an expanded Any message, like:
// [type/url] < ... struct contents ... >
seen := make(map[protoreflect.FieldNumber]bool)
for {
tok := p.next()
if tok.err != nil {
return tok.err
}
if tok.value == terminator {
break
}
if tok.value == "[" {
if err := p.unmarshalExtensionOrAny(m, seen); err != nil {
return err
}
continue
}
// This is a normal, non-extension field.
name := protoreflect.Name(tok.value)
fd := fds.ByName(name)
switch {
case fd == nil:
gd := fds.ByName(protoreflect.Name(strings.ToLower(string(name))))
if gd != nil && gd.Kind() == protoreflect.GroupKind && gd.Message().Name() == name {
fd = gd
}
case fd.Kind() == protoreflect.GroupKind && fd.Message().Name() != name:
fd = nil
case fd.IsWeak() && fd.Message().IsPlaceholder():
fd = nil
}
if fd == nil {
typeName := string(md.FullName())
if m, ok := m.Interface().(Message); ok {
t := reflect.TypeOf(m)
if t.Kind() == reflect.Ptr {
typeName = t.Elem().String()
}
}
return p.errorf("unknown field name %q in %v", name, typeName)
}
if od := fd.ContainingOneof(); od != nil && m.WhichOneof(od) != nil {
return p.errorf("field '%s' would overwrite already parsed oneof '%s'", name, od.Name())
}
if fd.Cardinality() != protoreflect.Repeated && seen[fd.Number()] {
return p.errorf("non-repeated field %q was repeated", fd.Name())
}
seen[fd.Number()] = true
// Consume any colon.
if err := p.checkForColon(fd); err != nil {
return err
}
// Parse into the field.
v := m.Get(fd)
if !m.Has(fd) && (fd.IsList() || fd.IsMap() || fd.Message() != nil) {
v = m.Mutable(fd)
}
if v, err = p.unmarshalValue(v, fd); err != nil {
return err
}
m.Set(fd, v)
if err := p.consumeOptionalSeparator(); err != nil {
return err
}
}
return nil
}
func (p *textParser) unmarshalExtensionOrAny(m protoreflect.Message, seen map[protoreflect.FieldNumber]bool) error {
name, err := p.consumeExtensionOrAnyName()
if err != nil {
return err
}
// If it contains a slash, it's an Any type URL.
if slashIdx := strings.LastIndex(name, "/"); slashIdx >= 0 {
tok := p.next()
if tok.err != nil {
return tok.err
}
// consume an optional colon
if tok.value == ":" {
tok = p.next()
if tok.err != nil {
return tok.err
}
}
var terminator string
switch tok.value {
case "<":
terminator = ">"
case "{":
terminator = "}"
default:
return p.errorf("expected '{' or '<', found %q", tok.value)
}
mt, err := protoregistry.GlobalTypes.FindMessageByURL(name)
if err != nil {
return p.errorf("unrecognized message %q in google.protobuf.Any", name[slashIdx+len("/"):])
}
m2 := mt.New()
if err := p.unmarshalMessage(m2, terminator); err != nil {
return err
}
b, err := protoV2.Marshal(m2.Interface())
if err != nil {
return p.errorf("failed to marshal message of type %q: %v", name[slashIdx+len("/"):], err)
}
urlFD := m.Descriptor().Fields().ByName("type_url")
valFD := m.Descriptor().Fields().ByName("value")
if seen[urlFD.Number()] {
return p.errorf("Any message unpacked multiple times, or %q already set", urlFD.Name())
}
if seen[valFD.Number()] {
return p.errorf("Any message unpacked multiple times, or %q already set", valFD.Name())
}
m.Set(urlFD, protoreflect.ValueOfString(name))
m.Set(valFD, protoreflect.ValueOfBytes(b))
seen[urlFD.Number()] = true
seen[valFD.Number()] = true
return nil
}
xname := protoreflect.FullName(name)
xt, _ := protoregistry.GlobalTypes.FindExtensionByName(xname)
if xt == nil && isMessageSet(m.Descriptor()) {
xt, _ = protoregistry.GlobalTypes.FindExtensionByName(xname.Append("message_set_extension"))
}
if xt == nil {
return p.errorf("unrecognized extension %q", name)
}
fd := xt.TypeDescriptor()
if fd.ContainingMessage().FullName() != m.Descriptor().FullName() {
return p.errorf("extension field %q does not extend message %q", name, m.Descriptor().FullName())
}
if err := p.checkForColon(fd); err != nil {
return err
}
v := m.Get(fd)
if !m.Has(fd) && (fd.IsList() || fd.IsMap() || fd.Message() != nil) {
v = m.Mutable(fd)
}
v, err = p.unmarshalValue(v, fd)
if err != nil {
return err
}
m.Set(fd, v)
return p.consumeOptionalSeparator()
}
func (p *textParser) unmarshalValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
tok := p.next()
if tok.err != nil {
return v, tok.err
}
if tok.value == "" {
return v, p.errorf("unexpected EOF")
}
switch {
case fd.IsList():
lv := v.List()
var err error
if tok.value == "[" {
// Repeated field with list notation, like [1,2,3].
for {
vv := lv.NewElement()
vv, err = p.unmarshalSingularValue(vv, fd)
if err != nil {
return v, err
}
lv.Append(vv)
tok := p.next()
if tok.err != nil {
return v, tok.err
}
if tok.value == "]" {
break
}
if tok.value != "," {
return v, p.errorf("Expected ']' or ',' found %q", tok.value)
}
}
return v, nil
}
// One value of the repeated field.
p.back()
vv := lv.NewElement()
vv, err = p.unmarshalSingularValue(vv, fd)
if err != nil {
return v, err
}
lv.Append(vv)
return v, nil
case fd.IsMap():
// The map entry should be this sequence of tokens:
// < key : KEY value : VALUE >
// However, implementations may omit key or value, and technically
// we should support them in any order.
var terminator string
switch tok.value {
case "<":
terminator = ">"
case "{":
terminator = "}"
default:
return v, p.errorf("expected '{' or '<', found %q", tok.value)
}
keyFD := fd.MapKey()
valFD := fd.MapValue()
mv := v.Map()
kv := keyFD.Default()
vv := mv.NewValue()
for {
tok := p.next()
if tok.err != nil {
return v, tok.err
}
if tok.value == terminator {
break
}
var err error
switch tok.value {
case "key":
if err := p.consumeToken(":"); err != nil {
return v, err
}
if kv, err = p.unmarshalSingularValue(kv, keyFD); err != nil {
return v, err
}
if err := p.consumeOptionalSeparator(); err != nil {
return v, err
}
case "value":
if err := p.checkForColon(valFD); err != nil {
return v, err
}
if vv, err = p.unmarshalSingularValue(vv, valFD); err != nil {
return v, err
}
if err := p.consumeOptionalSeparator(); err != nil {
return v, err
}
default:
p.back()
return v, p.errorf(`expected "key", "value", or %q, found %q`, terminator, tok.value)
}
}
mv.Set(kv.MapKey(), vv)
return v, nil
default:
p.back()
return p.unmarshalSingularValue(v, fd)
}
}
func (p *textParser) unmarshalSingularValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) (protoreflect.Value, error) {
tok := p.next()
if tok.err != nil {
return v, tok.err
}
if tok.value == "" {
return v, p.errorf("unexpected EOF")
}
switch fd.Kind() {
case protoreflect.BoolKind:
switch tok.value {
case "true", "1", "t", "True":
return protoreflect.ValueOfBool(true), nil
case "false", "0", "f", "False":
return protoreflect.ValueOfBool(false), nil
}
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
return protoreflect.ValueOfInt32(int32(x)), nil
}
// The C++ parser accepts large positive hex numbers that uses
// two's complement arithmetic to represent negative numbers.
// This feature is here for backwards compatibility with C++.
if strings.HasPrefix(tok.value, "0x") {
if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
return protoreflect.ValueOfInt32(int32(-(int64(^x) + 1))), nil
}
}
case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
if x, err := strconv.ParseInt(tok.value, 0, 64); err == nil {
return protoreflect.ValueOfInt64(int64(x)), nil
}
// The C++ parser accepts large positive hex numbers that uses
// two's complement arithmetic to represent negative numbers.
// This feature is here for backwards compatibility with C++.
if strings.HasPrefix(tok.value, "0x") {
if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
return protoreflect.ValueOfInt64(int64(-(int64(^x) + 1))), nil
}
}
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
return protoreflect.ValueOfUint32(uint32(x)), nil
}
case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
return protoreflect.ValueOfUint64(uint64(x)), nil
}
case protoreflect.FloatKind:
// Ignore 'f' for compatibility with output generated by C++,
// but don't remove 'f' when the value is "-inf" or "inf".
v := tok.value
if strings.HasSuffix(v, "f") && v != "-inf" && v != "inf" {
v = v[:len(v)-len("f")]
}
if x, err := strconv.ParseFloat(v, 32); err == nil {
return protoreflect.ValueOfFloat32(float32(x)), nil
}
case protoreflect.DoubleKind:
// Ignore 'f' for compatibility with output generated by C++,
// but don't remove 'f' when the value is "-inf" or "inf".
v := tok.value
if strings.HasSuffix(v, "f") && v != "-inf" && v != "inf" {
v = v[:len(v)-len("f")]
}
if x, err := strconv.ParseFloat(v, 64); err == nil {
return protoreflect.ValueOfFloat64(float64(x)), nil
}
case protoreflect.StringKind:
if isQuote(tok.value[0]) {
return protoreflect.ValueOfString(tok.unquoted), nil
}
case protoreflect.BytesKind:
if isQuote(tok.value[0]) {
return protoreflect.ValueOfBytes([]byte(tok.unquoted)), nil
}
case protoreflect.EnumKind:
if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
return protoreflect.ValueOfEnum(protoreflect.EnumNumber(x)), nil
}
vd := fd.Enum().Values().ByName(protoreflect.Name(tok.value))
if vd != nil {
return protoreflect.ValueOfEnum(vd.Number()), nil
}
case protoreflect.MessageKind, protoreflect.GroupKind:
var terminator string
switch tok.value {
case "{":
terminator = "}"
case "<":
terminator = ">"
default:
return v, p.errorf("expected '{' or '<', found %q", tok.value)
}
err := p.unmarshalMessage(v.Message(), terminator)
return v, err
default:
panic(fmt.Sprintf("invalid kind %v", fd.Kind()))
}
return v, p.errorf("invalid %v: %v", fd.Kind(), tok.value)
}
// Consume a ':' from the input stream (if the next token is a colon),
// returning an error if a colon is needed but not present.
func (p *textParser) checkForColon(fd protoreflect.FieldDescriptor) *ParseError {
tok := p.next()
if tok.err != nil {
return tok.err
}
if tok.value != ":" {
if fd.Message() == nil {
return p.errorf("expected ':', found %q", tok.value)
}
p.back()
}
return nil
}
// consumeExtensionOrAnyName consumes an extension name or an Any type URL and
// the following ']'. It returns the name or URL consumed.
func (p *textParser) consumeExtensionOrAnyName() (string, error) {
tok := p.next()
if tok.err != nil {
return "", tok.err
}
// If extension name or type url is quoted, it's a single token.
if len(tok.value) > 2 && isQuote(tok.value[0]) && tok.value[len(tok.value)-1] == tok.value[0] {
name, err := unquoteC(tok.value[1:len(tok.value)-1], rune(tok.value[0]))
if err != nil {
return "", err
}
return name, p.consumeToken("]")
}
// Consume everything up to "]"
var parts []string
for tok.value != "]" {
parts = append(parts, tok.value)
tok = p.next()
if tok.err != nil {
return "", p.errorf("unrecognized type_url or extension name: %s", tok.err)
}
if p.done && tok.value != "]" {
return "", p.errorf("unclosed type_url or extension name")
}
}
return strings.Join(parts, ""), nil
}
// consumeOptionalSeparator consumes an optional semicolon or comma.
// It is used in unmarshalMessage to provide backward compatibility.
func (p *textParser) consumeOptionalSeparator() error {
tok := p.next()
if tok.err != nil {
return tok.err
}
if tok.value != ";" && tok.value != "," {
p.back()
}
return nil
}
func (p *textParser) errorf(format string, a ...interface{}) *ParseError {
pe := &ParseError{fmt.Sprintf(format, a...), p.cur.line, p.cur.offset}
p.cur.err = pe
p.done = true
return pe
}
func (p *textParser) skipWhitespace() {
i := 0
for i < len(p.s) && (isWhitespace(p.s[i]) || p.s[i] == '#') {
if p.s[i] == '#' {
// comment; skip to end of line or input
for i < len(p.s) && p.s[i] != '\n' {
i++
}
if i == len(p.s) {
break
}
}
if p.s[i] == '\n' {
p.line++
}
i++
}
p.offset += i
p.s = p.s[i:len(p.s)]
if len(p.s) == 0 {
p.done = true
}
}
func (p *textParser) advance() {
// Skip whitespace
p.skipWhitespace()
if p.done {
return
}
// Start of non-whitespace
p.cur.err = nil
p.cur.offset, p.cur.line = p.offset, p.line
p.cur.unquoted = ""
switch p.s[0] {
case '<', '>', '{', '}', ':', '[', ']', ';', ',', '/':
// Single symbol
p.cur.value, p.s = p.s[0:1], p.s[1:len(p.s)]
case '"', '\'':
// Quoted string
i := 1
for i < len(p.s) && p.s[i] != p.s[0] && p.s[i] != '\n' {
if p.s[i] == '\\' && i+1 < len(p.s) {
// skip escaped char
i++
}
i++
}
if i >= len(p.s) || p.s[i] != p.s[0] {
p.errorf("unmatched quote")
return
}
unq, err := unquoteC(p.s[1:i], rune(p.s[0]))
if err != nil {
p.errorf("invalid quoted string %s: %v", p.s[0:i+1], err)
return
}
p.cur.value, p.s = p.s[0:i+1], p.s[i+1:len(p.s)]
p.cur.unquoted = unq
default:
i := 0
for i < len(p.s) && isIdentOrNumberChar(p.s[i]) {
i++
}
if i == 0 {
p.errorf("unexpected byte %#x", p.s[0])
return
}
p.cur.value, p.s = p.s[0:i], p.s[i:len(p.s)]
}
p.offset += len(p.cur.value)
}
// Back off the parser by one token. Can only be done between calls to next().
// It makes the next advance() a no-op.
func (p *textParser) back() { p.backed = true }
// Advances the parser and returns the new current token.
func (p *textParser) next() *token {
if p.backed || p.done {
p.backed = false
return &p.cur
}
p.advance()
if p.done {
p.cur.value = ""
} else if len(p.cur.value) > 0 && isQuote(p.cur.value[0]) {
// Look for multiple quoted strings separated by whitespace,
// and concatenate them.
cat := p.cur
for {
p.skipWhitespace()
if p.done || !isQuote(p.s[0]) {
break
}
p.advance()
if p.cur.err != nil {
return &p.cur
}
cat.value += " " + p.cur.value
cat.unquoted += p.cur.unquoted
}
p.done = false // parser may have seen EOF, but we want to return cat
p.cur = cat
}
return &p.cur
}
func (p *textParser) consumeToken(s string) error {
tok := p.next()
if tok.err != nil {
return tok.err
}
if tok.value != s {
p.back()
return p.errorf("expected %q, found %q", s, tok.value)
}
return nil
}
var errBadUTF8 = errors.New("proto: bad UTF-8")
func unquoteC(s string, quote rune) (string, error) {
// This is based on C++'s tokenizer.cc.
// Despite its name, this is *not* parsing C syntax.
// For instance, "\0" is an invalid quoted string.
// Avoid allocation in trivial cases.
simple := true
for _, r := range s {
if r == '\\' || r == quote {
simple = false
break
}
}
if simple {
return s, nil
}
buf := make([]byte, 0, 3*len(s)/2)
for len(s) > 0 {
r, n := utf8.DecodeRuneInString(s)
if r == utf8.RuneError && n == 1 {
return "", errBadUTF8
}
s = s[n:]
if r != '\\' {
if r < utf8.RuneSelf {
buf = append(buf, byte(r))
} else {
buf = append(buf, string(r)...)
}
continue
}
ch, tail, err := unescape(s)
if err != nil {
return "", err
}
buf = append(buf, ch...)
s = tail
}
return string(buf), nil
}
func unescape(s string) (ch string, tail string, err error) {
r, n := utf8.DecodeRuneInString(s)
if r == utf8.RuneError && n == 1 {
return "", "", errBadUTF8
}
s = s[n:]
switch r {
case 'a':
return "\a", s, nil
case 'b':
return "\b", s, nil
case 'f':
return "\f", s, nil
case 'n':
return "\n", s, nil
case 'r':
return "\r", s, nil
case 't':
return "\t", s, nil
case 'v':
return "\v", s, nil
case '?':
return "?", s, nil // trigraph workaround
case '\'', '"', '\\':
return string(r), s, nil
case '0', '1', '2', '3', '4', '5', '6', '7':
if len(s) < 2 {
return "", "", fmt.Errorf(`\%c requires 2 following digits`, r)
}
ss := string(r) + s[:2]
s = s[2:]
i, err := strconv.ParseUint(ss, 8, 8)
if err != nil {
return "", "", fmt.Errorf(`\%s contains non-octal digits`, ss)
}
return string([]byte{byte(i)}), s, nil
case 'x', 'X', 'u', 'U':
var n int
switch r {
case 'x', 'X':
n = 2
case 'u':
n = 4
case 'U':
n = 8
}
if len(s) < n {
return "", "", fmt.Errorf(`\%c requires %d following digits`, r, n)
}
ss := s[:n]
s = s[n:]
i, err := strconv.ParseUint(ss, 16, 64)
if err != nil {
return "", "", fmt.Errorf(`\%c%s contains non-hexadecimal digits`, r, ss)
}
if r == 'x' || r == 'X' {
return string([]byte{byte(i)}), s, nil
}
if i > utf8.MaxRune {
return "", "", fmt.Errorf(`\%c%s is not a valid Unicode code point`, r, ss)
}
return string(rune(i)), s, nil
}
return "", "", fmt.Errorf(`unknown escape \%c`, r)
}
func isIdentOrNumberChar(c byte) bool {
switch {
case 'A' <= c && c <= 'Z', 'a' <= c && c <= 'z':
return true
case '0' <= c && c <= '9':
return true
}
switch c {
case '-', '+', '.', '_':
return true
}
return false
}
func isWhitespace(c byte) bool {
switch c {
case ' ', '\t', '\n', '\r':
return true
}
return false
}
func isQuote(c byte) bool {
switch c {
case '"', '\'':
return true
}
return false
}

@ -1,560 +0,0 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
"bytes"
"encoding"
"fmt"
"io"
"math"
"sort"
"strings"
"google.golang.org/protobuf/encoding/prototext"
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
)
const wrapTextMarshalV2 = false
// TextMarshaler is a configurable text format marshaler.
type TextMarshaler struct {
Compact bool // use compact text format (one line)
ExpandAny bool // expand google.protobuf.Any messages of known types
}
// Marshal writes the proto text format of m to w.
func (tm *TextMarshaler) Marshal(w io.Writer, m Message) error {
b, err := tm.marshal(m)
if len(b) > 0 {
if _, err := w.Write(b); err != nil {
return err
}
}
return err
}
// Text returns a proto text formatted string of m.
func (tm *TextMarshaler) Text(m Message) string {
b, _ := tm.marshal(m)
return string(b)
}
func (tm *TextMarshaler) marshal(m Message) ([]byte, error) {
mr := MessageReflect(m)
if mr == nil || !mr.IsValid() {
return []byte("<nil>"), nil
}
if wrapTextMarshalV2 {
if m, ok := m.(encoding.TextMarshaler); ok {
return m.MarshalText()
}
opts := prototext.MarshalOptions{
AllowPartial: true,
EmitUnknown: true,
}
if !tm.Compact {
opts.Indent = " "
}
if !tm.ExpandAny {
opts.Resolver = (*protoregistry.Types)(nil)
}
return opts.Marshal(mr.Interface())
} else {
w := &textWriter{
compact: tm.Compact,
expandAny: tm.ExpandAny,
complete: true,
}
if m, ok := m.(encoding.TextMarshaler); ok {
b, err := m.MarshalText()
if err != nil {
return nil, err
}
w.Write(b)
return w.buf, nil
}
err := w.writeMessage(mr)
return w.buf, err
}
}
var (
defaultTextMarshaler = TextMarshaler{}
compactTextMarshaler = TextMarshaler{Compact: true}
)
// MarshalText writes the proto text format of m to w.
func MarshalText(w io.Writer, m Message) error { return defaultTextMarshaler.Marshal(w, m) }
// MarshalTextString returns a proto text formatted string of m.
func MarshalTextString(m Message) string { return defaultTextMarshaler.Text(m) }
// CompactText writes the compact proto text format of m to w.
func CompactText(w io.Writer, m Message) error { return compactTextMarshaler.Marshal(w, m) }
// CompactTextString returns a compact proto text formatted string of m.
func CompactTextString(m Message) string { return compactTextMarshaler.Text(m) }
var (
newline = []byte("\n")
endBraceNewline = []byte("}\n")
posInf = []byte("inf")
negInf = []byte("-inf")
nan = []byte("nan")
)
// textWriter is an io.Writer that tracks its indentation level.
type textWriter struct {
compact bool // same as TextMarshaler.Compact
expandAny bool // same as TextMarshaler.ExpandAny
complete bool // whether the current position is a complete line
indent int // indentation level; never negative
buf []byte
}
func (w *textWriter) Write(p []byte) (n int, _ error) {
newlines := bytes.Count(p, newline)
if newlines == 0 {
if !w.compact && w.complete {
w.writeIndent()
}
w.buf = append(w.buf, p...)
w.complete = false
return len(p), nil
}
frags := bytes.SplitN(p, newline, newlines+1)
if w.compact {
for i, frag := range frags {
if i > 0 {
w.buf = append(w.buf, ' ')
n++
}
w.buf = append(w.buf, frag...)
n += len(frag)
}
return n, nil
}
for i, frag := range frags {
if w.complete {
w.writeIndent()
}
w.buf = append(w.buf, frag...)
n += len(frag)
if i+1 < len(frags) {
w.buf = append(w.buf, '\n')
n++
}
}
w.complete = len(frags[len(frags)-1]) == 0
return n, nil
}
func (w *textWriter) WriteByte(c byte) error {
if w.compact && c == '\n' {
c = ' '
}
if !w.compact && w.complete {
w.writeIndent()
}
w.buf = append(w.buf, c)
w.complete = c == '\n'
return nil
}
func (w *textWriter) writeName(fd protoreflect.FieldDescriptor) {
if !w.compact && w.complete {
w.writeIndent()
}
w.complete = false
if fd.Kind() != protoreflect.GroupKind {
w.buf = append(w.buf, fd.Name()...)
w.WriteByte(':')
} else {
// Use message type name for group field name.
w.buf = append(w.buf, fd.Message().Name()...)
}
if !w.compact {
w.WriteByte(' ')
}
}
func requiresQuotes(u string) bool {
// When type URL contains any characters except [0-9A-Za-z./\-]*, it must be quoted.
for _, ch := range u {
switch {
case ch == '.' || ch == '/' || ch == '_':
continue
case '0' <= ch && ch <= '9':
continue
case 'A' <= ch && ch <= 'Z':
continue
case 'a' <= ch && ch <= 'z':
continue
default:
return true
}
}
return false
}
// writeProto3Any writes an expanded google.protobuf.Any message.
//
// It returns (false, nil) if sv value can't be unmarshaled (e.g. because
// required messages are not linked in).
//
// It returns (true, error) when sv was written in expanded format or an error
// was encountered.
func (w *textWriter) writeProto3Any(m protoreflect.Message) (bool, error) {
md := m.Descriptor()
fdURL := md.Fields().ByName("type_url")
fdVal := md.Fields().ByName("value")
url := m.Get(fdURL).String()
mt, err := protoregistry.GlobalTypes.FindMessageByURL(url)
if err != nil {
return false, nil
}
b := m.Get(fdVal).Bytes()
m2 := mt.New()
if err := proto.Unmarshal(b, m2.Interface()); err != nil {
return false, nil
}
w.Write([]byte("["))
if requiresQuotes(url) {
w.writeQuotedString(url)
} else {
w.Write([]byte(url))
}
if w.compact {
w.Write([]byte("]:<"))
} else {
w.Write([]byte("]: <\n"))
w.indent++
}
if err := w.writeMessage(m2); err != nil {
return true, err
}
if w.compact {
w.Write([]byte("> "))
} else {
w.indent--
w.Write([]byte(">\n"))
}
return true, nil
}
func (w *textWriter) writeMessage(m protoreflect.Message) error {
md := m.Descriptor()
if w.expandAny && md.FullName() == "google.protobuf.Any" {
if canExpand, err := w.writeProto3Any(m); canExpand {
return err
}
}
fds := md.Fields()
for i := 0; i < fds.Len(); {
fd := fds.Get(i)
if od := fd.ContainingOneof(); od != nil {
fd = m.WhichOneof(od)
i += od.Fields().Len()
} else {
i++
}
if fd == nil || !m.Has(fd) {
continue
}
switch {
case fd.IsList():
lv := m.Get(fd).List()
for j := 0; j < lv.Len(); j++ {
w.writeName(fd)
v := lv.Get(j)
if err := w.writeSingularValue(v, fd); err != nil {
return err
}
w.WriteByte('\n')
}
case fd.IsMap():
kfd := fd.MapKey()
vfd := fd.MapValue()
mv := m.Get(fd).Map()
type entry struct{ key, val protoreflect.Value }
var entries []entry
mv.Range(func(k protoreflect.MapKey, v protoreflect.Value) bool {
entries = append(entries, entry{k.Value(), v})
return true
})
sort.Slice(entries, func(i, j int) bool {
switch kfd.Kind() {
case protoreflect.BoolKind:
return !entries[i].key.Bool() && entries[j].key.Bool()
case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind, protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
return entries[i].key.Int() < entries[j].key.Int()
case protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
return entries[i].key.Uint() < entries[j].key.Uint()
case protoreflect.StringKind:
return entries[i].key.String() < entries[j].key.String()
default:
panic("invalid kind")
}
})
for _, entry := range entries {
w.writeName(fd)
w.WriteByte('<')
if !w.compact {
w.WriteByte('\n')
}
w.indent++
w.writeName(kfd)
if err := w.writeSingularValue(entry.key, kfd); err != nil {
return err
}
w.WriteByte('\n')
w.writeName(vfd)
if err := w.writeSingularValue(entry.val, vfd); err != nil {
return err
}
w.WriteByte('\n')
w.indent--
w.WriteByte('>')
w.WriteByte('\n')
}
default:
w.writeName(fd)
if err := w.writeSingularValue(m.Get(fd), fd); err != nil {
return err
}
w.WriteByte('\n')
}
}
if b := m.GetUnknown(); len(b) > 0 {
w.writeUnknownFields(b)
}
return w.writeExtensions(m)
}
func (w *textWriter) writeSingularValue(v protoreflect.Value, fd protoreflect.FieldDescriptor) error {
switch fd.Kind() {
case protoreflect.FloatKind, protoreflect.DoubleKind:
switch vf := v.Float(); {
case math.IsInf(vf, +1):
w.Write(posInf)
case math.IsInf(vf, -1):
w.Write(negInf)
case math.IsNaN(vf):
w.Write(nan)
default:
fmt.Fprint(w, v.Interface())
}
case protoreflect.StringKind:
// NOTE: This does not validate UTF-8 for historical reasons.
w.writeQuotedString(string(v.String()))
case protoreflect.BytesKind:
w.writeQuotedString(string(v.Bytes()))
case protoreflect.MessageKind, protoreflect.GroupKind:
var bra, ket byte = '<', '>'
if fd.Kind() == protoreflect.GroupKind {
bra, ket = '{', '}'
}
w.WriteByte(bra)
if !w.compact {
w.WriteByte('\n')
}
w.indent++
m := v.Message()
if m2, ok := m.Interface().(encoding.TextMarshaler); ok {
b, err := m2.MarshalText()
if err != nil {
return err
}
w.Write(b)
} else {
w.writeMessage(m)
}
w.indent--
w.WriteByte(ket)
case protoreflect.EnumKind:
if ev := fd.Enum().Values().ByNumber(v.Enum()); ev != nil {
fmt.Fprint(w, ev.Name())
} else {
fmt.Fprint(w, v.Enum())
}
default:
fmt.Fprint(w, v.Interface())
}
return nil
}
// writeQuotedString writes a quoted string in the protocol buffer text format.
func (w *textWriter) writeQuotedString(s string) {
w.WriteByte('"')
for i := 0; i < len(s); i++ {
switch c := s[i]; c {
case '\n':
w.buf = append(w.buf, `\n`...)
case '\r':
w.buf = append(w.buf, `\r`...)
case '\t':
w.buf = append(w.buf, `\t`...)
case '"':
w.buf = append(w.buf, `\"`...)
case '\\':
w.buf = append(w.buf, `\\`...)
default:
if isPrint := c >= 0x20 && c < 0x7f; isPrint {
w.buf = append(w.buf, c)
} else {
w.buf = append(w.buf, fmt.Sprintf(`\%03o`, c)...)
}
}
}
w.WriteByte('"')
}
func (w *textWriter) writeUnknownFields(b []byte) {
if !w.compact {
fmt.Fprintf(w, "/* %d unknown bytes */\n", len(b))
}
for len(b) > 0 {
num, wtyp, n := protowire.ConsumeTag(b)
if n < 0 {
return
}
b = b[n:]
if wtyp == protowire.EndGroupType {
w.indent--
w.Write(endBraceNewline)
continue
}
fmt.Fprint(w, num)
if wtyp != protowire.StartGroupType {
w.WriteByte(':')
}
if !w.compact || wtyp == protowire.StartGroupType {
w.WriteByte(' ')
}
switch wtyp {
case protowire.VarintType:
v, n := protowire.ConsumeVarint(b)
if n < 0 {
return
}
b = b[n:]
fmt.Fprint(w, v)
case protowire.Fixed32Type:
v, n := protowire.ConsumeFixed32(b)
if n < 0 {
return
}
b = b[n:]
fmt.Fprint(w, v)
case protowire.Fixed64Type:
v, n := protowire.ConsumeFixed64(b)
if n < 0 {
return
}
b = b[n:]
fmt.Fprint(w, v)
case protowire.BytesType:
v, n := protowire.ConsumeBytes(b)
if n < 0 {
return
}
b = b[n:]
fmt.Fprintf(w, "%q", v)
case protowire.StartGroupType:
w.WriteByte('{')
w.indent++
default:
fmt.Fprintf(w, "/* unknown wire type %d */", wtyp)
}
w.WriteByte('\n')
}
}
// writeExtensions writes all the extensions in m.
func (w *textWriter) writeExtensions(m protoreflect.Message) error {
md := m.Descriptor()
if md.ExtensionRanges().Len() == 0 {
return nil
}
type ext struct {
desc protoreflect.FieldDescriptor
val protoreflect.Value
}
var exts []ext
m.Range(func(fd protoreflect.FieldDescriptor, v protoreflect.Value) bool {
if fd.IsExtension() {
exts = append(exts, ext{fd, v})
}
return true
})
sort.Slice(exts, func(i, j int) bool {
return exts[i].desc.Number() < exts[j].desc.Number()
})
for _, ext := range exts {
// For message set, use the name of the message as the extension name.
name := string(ext.desc.FullName())
if isMessageSet(ext.desc.ContainingMessage()) {
name = strings.TrimSuffix(name, ".message_set_extension")
}
if !ext.desc.IsList() {
if err := w.writeSingularExtension(name, ext.val, ext.desc); err != nil {
return err
}
} else {
lv := ext.val.List()
for i := 0; i < lv.Len(); i++ {
if err := w.writeSingularExtension(name, lv.Get(i), ext.desc); err != nil {
return err
}
}
}
}
return nil
}
func (w *textWriter) writeSingularExtension(name string, v protoreflect.Value, fd protoreflect.FieldDescriptor) error {
fmt.Fprintf(w, "[%s]:", name)
if !w.compact {
w.WriteByte(' ')
}
if err := w.writeSingularValue(v, fd); err != nil {
return err
}
w.WriteByte('\n')
return nil
}
func (w *textWriter) writeIndent() {
if !w.complete {
return
}
for i := 0; i < w.indent*2; i++ {
w.buf = append(w.buf, ' ')
}
w.complete = false
}

@ -1,78 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
import (
protoV2 "google.golang.org/protobuf/proto"
"google.golang.org/protobuf/runtime/protoiface"
)
// Size returns the size in bytes of the wire-format encoding of m.
func Size(m Message) int {
if m == nil {
return 0
}
mi := MessageV2(m)
return protoV2.Size(mi)
}
// Marshal returns the wire-format encoding of m.
func Marshal(m Message) ([]byte, error) {
b, err := marshalAppend(nil, m, false)
if b == nil {
b = zeroBytes
}
return b, err
}
var zeroBytes = make([]byte, 0, 0)
func marshalAppend(buf []byte, m Message, deterministic bool) ([]byte, error) {
if m == nil {
return nil, ErrNil
}
mi := MessageV2(m)
nbuf, err := protoV2.MarshalOptions{
Deterministic: deterministic,
AllowPartial: true,
}.MarshalAppend(buf, mi)
if err != nil {
return buf, err
}
if len(buf) == len(nbuf) {
if !mi.ProtoReflect().IsValid() {
return buf, ErrNil
}
}
return nbuf, checkRequiredNotSet(mi)
}
// Unmarshal parses a wire-format message in b and places the decoded results in m.
//
// Unmarshal resets m before starting to unmarshal, so any existing data in m is always
// removed. Use UnmarshalMerge to preserve and append to existing data.
func Unmarshal(b []byte, m Message) error {
m.Reset()
return UnmarshalMerge(b, m)
}
// UnmarshalMerge parses a wire-format message in b and places the decoded results in m.
func UnmarshalMerge(b []byte, m Message) error {
mi := MessageV2(m)
out, err := protoV2.UnmarshalOptions{
AllowPartial: true,
Merge: true,
}.UnmarshalState(protoiface.UnmarshalInput{
Buf: b,
Message: mi.ProtoReflect(),
})
if err != nil {
return err
}
if out.Flags&protoiface.UnmarshalInitialized > 0 {
return nil
}
return checkRequiredNotSet(mi)
}

@ -1,34 +0,0 @@
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proto
// Bool stores v in a new bool value and returns a pointer to it.
func Bool(v bool) *bool { return &v }
// Int stores v in a new int32 value and returns a pointer to it.
//
// Deprecated: Use Int32 instead.
func Int(v int) *int32 { return Int32(int32(v)) }
// Int32 stores v in a new int32 value and returns a pointer to it.
func Int32(v int32) *int32 { return &v }
// Int64 stores v in a new int64 value and returns a pointer to it.
func Int64(v int64) *int64 { return &v }
// Uint32 stores v in a new uint32 value and returns a pointer to it.
func Uint32(v uint32) *uint32 { return &v }
// Uint64 stores v in a new uint64 value and returns a pointer to it.
func Uint64(v uint64) *uint64 { return &v }
// Float32 stores v in a new float32 value and returns a pointer to it.
func Float32(v float32) *float32 { return &v }
// Float64 stores v in a new float64 value and returns a pointer to it.
func Float64(v float64) *float64 { return &v }
// String stores v in a new string value and returns a pointer to it.
func String(v string) *string { return &v }

@ -1,179 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ptypes
import (
"fmt"
"strings"
"github.com/golang/protobuf/proto"
"google.golang.org/protobuf/reflect/protoreflect"
"google.golang.org/protobuf/reflect/protoregistry"
anypb "github.com/golang/protobuf/ptypes/any"
)
const urlPrefix = "type.googleapis.com/"
// AnyMessageName returns the message name contained in an anypb.Any message.
// Most type assertions should use the Is function instead.
//
// Deprecated: Call the any.MessageName method instead.
func AnyMessageName(any *anypb.Any) (string, error) {
name, err := anyMessageName(any)
return string(name), err
}
func anyMessageName(any *anypb.Any) (protoreflect.FullName, error) {
if any == nil {
return "", fmt.Errorf("message is nil")
}
name := protoreflect.FullName(any.TypeUrl)
if i := strings.LastIndex(any.TypeUrl, "/"); i >= 0 {
name = name[i+len("/"):]
}
if !name.IsValid() {
return "", fmt.Errorf("message type url %q is invalid", any.TypeUrl)
}
return name, nil
}
// MarshalAny marshals the given message m into an anypb.Any message.
//
// Deprecated: Call the anypb.New function instead.
func MarshalAny(m proto.Message) (*anypb.Any, error) {
switch dm := m.(type) {
case DynamicAny:
m = dm.Message
case *DynamicAny:
if dm == nil {
return nil, proto.ErrNil
}
m = dm.Message
}
b, err := proto.Marshal(m)
if err != nil {
return nil, err
}
return &anypb.Any{TypeUrl: urlPrefix + proto.MessageName(m), Value: b}, nil
}
// Empty returns a new message of the type specified in an anypb.Any message.
// It returns protoregistry.NotFound if the corresponding message type could not
// be resolved in the global registry.
//
// Deprecated: Use protoregistry.GlobalTypes.FindMessageByName instead
// to resolve the message name and create a new instance of it.
func Empty(any *anypb.Any) (proto.Message, error) {
name, err := anyMessageName(any)
if err != nil {
return nil, err
}
mt, err := protoregistry.GlobalTypes.FindMessageByName(name)
if err != nil {
return nil, err
}
return proto.MessageV1(mt.New().Interface()), nil
}
// UnmarshalAny unmarshals the encoded value contained in the anypb.Any message
// into the provided message m. It returns an error if the target message
// does not match the type in the Any message or if an unmarshal error occurs.
//
// The target message m may be a *DynamicAny message. If the underlying message
// type could not be resolved, then this returns protoregistry.NotFound.
//
// Deprecated: Call the any.UnmarshalTo method instead.
func UnmarshalAny(any *anypb.Any, m proto.Message) error {
if dm, ok := m.(*DynamicAny); ok {
if dm.Message == nil {
var err error
dm.Message, err = Empty(any)
if err != nil {
return err
}
}
m = dm.Message
}
anyName, err := AnyMessageName(any)
if err != nil {
return err
}
msgName := proto.MessageName(m)
if anyName != msgName {
return fmt.Errorf("mismatched message type: got %q want %q", anyName, msgName)
}
return proto.Unmarshal(any.Value, m)
}
// Is reports whether the Any message contains a message of the specified type.
//
// Deprecated: Call the any.MessageIs method instead.
func Is(any *anypb.Any, m proto.Message) bool {
if any == nil || m == nil {
return false
}
name := proto.MessageName(m)
if !strings.HasSuffix(any.TypeUrl, name) {
return false
}
return len(any.TypeUrl) == len(name) || any.TypeUrl[len(any.TypeUrl)-len(name)-1] == '/'
}
// DynamicAny is a value that can be passed to UnmarshalAny to automatically
// allocate a proto.Message for the type specified in an anypb.Any message.
// The allocated message is stored in the embedded proto.Message.
//
// Example:
// var x ptypes.DynamicAny
// if err := ptypes.UnmarshalAny(a, &x); err != nil { ... }
// fmt.Printf("unmarshaled message: %v", x.Message)
//
// Deprecated: Use the any.UnmarshalNew method instead to unmarshal
// the any message contents into a new instance of the underlying message.
type DynamicAny struct{ proto.Message }
func (m DynamicAny) String() string {
if m.Message == nil {
return "<nil>"
}
return m.Message.String()
}
func (m DynamicAny) Reset() {
if m.Message == nil {
return
}
m.Message.Reset()
}
func (m DynamicAny) ProtoMessage() {
return
}
func (m DynamicAny) ProtoReflect() protoreflect.Message {
if m.Message == nil {
return nil
}
return dynamicAny{proto.MessageReflect(m.Message)}
}
type dynamicAny struct{ protoreflect.Message }
func (m dynamicAny) Type() protoreflect.MessageType {
return dynamicAnyType{m.Message.Type()}
}
func (m dynamicAny) New() protoreflect.Message {
return dynamicAnyType{m.Message.Type()}.New()
}
func (m dynamicAny) Interface() protoreflect.ProtoMessage {
return DynamicAny{proto.MessageV1(m.Message.Interface())}
}
type dynamicAnyType struct{ protoreflect.MessageType }
func (t dynamicAnyType) New() protoreflect.Message {
return dynamicAny{t.MessageType.New()}
}
func (t dynamicAnyType) Zero() protoreflect.Message {
return dynamicAny{t.MessageType.Zero()}
}

@ -1,62 +0,0 @@
// Code generated by protoc-gen-go. DO NOT EDIT.
// source: github.com/golang/protobuf/ptypes/any/any.proto
package any
import (
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
anypb "google.golang.org/protobuf/types/known/anypb"
reflect "reflect"
)
// Symbols defined in public import of google/protobuf/any.proto.
type Any = anypb.Any
var File_github_com_golang_protobuf_ptypes_any_any_proto protoreflect.FileDescriptor
var file_github_com_golang_protobuf_ptypes_any_any_proto_rawDesc = []byte{
0x0a, 0x2f, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c,
0x61, 0x6e, 0x67, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79,
0x70, 0x65, 0x73, 0x2f, 0x61, 0x6e, 0x79, 0x2f, 0x61, 0x6e, 0x79, 0x2e, 0x70, 0x72, 0x6f, 0x74,
0x6f, 0x1a, 0x19, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62,
0x75, 0x66, 0x2f, 0x61, 0x6e, 0x79, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x42, 0x2b, 0x5a, 0x29,
0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c, 0x61, 0x6e,
0x67, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79, 0x70, 0x65,
0x73, 0x2f, 0x61, 0x6e, 0x79, 0x3b, 0x61, 0x6e, 0x79, 0x50, 0x00, 0x62, 0x06, 0x70, 0x72, 0x6f,
0x74, 0x6f, 0x33,
}
var file_github_com_golang_protobuf_ptypes_any_any_proto_goTypes = []interface{}{}
var file_github_com_golang_protobuf_ptypes_any_any_proto_depIdxs = []int32{
0, // [0:0] is the sub-list for method output_type
0, // [0:0] is the sub-list for method input_type
0, // [0:0] is the sub-list for extension type_name
0, // [0:0] is the sub-list for extension extendee
0, // [0:0] is the sub-list for field type_name
}
func init() { file_github_com_golang_protobuf_ptypes_any_any_proto_init() }
func file_github_com_golang_protobuf_ptypes_any_any_proto_init() {
if File_github_com_golang_protobuf_ptypes_any_any_proto != nil {
return
}
type x struct{}
out := protoimpl.TypeBuilder{
File: protoimpl.DescBuilder{
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
RawDescriptor: file_github_com_golang_protobuf_ptypes_any_any_proto_rawDesc,
NumEnums: 0,
NumMessages: 0,
NumExtensions: 0,
NumServices: 0,
},
GoTypes: file_github_com_golang_protobuf_ptypes_any_any_proto_goTypes,
DependencyIndexes: file_github_com_golang_protobuf_ptypes_any_any_proto_depIdxs,
}.Build()
File_github_com_golang_protobuf_ptypes_any_any_proto = out.File
file_github_com_golang_protobuf_ptypes_any_any_proto_rawDesc = nil
file_github_com_golang_protobuf_ptypes_any_any_proto_goTypes = nil
file_github_com_golang_protobuf_ptypes_any_any_proto_depIdxs = nil
}

@ -1,10 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package ptypes provides functionality for interacting with well-known types.
//
// Deprecated: Well-known types have specialized functionality directly
// injected into the generated packages for each message type.
// See the deprecation notice for each function for the suggested alternative.
package ptypes

@ -1,76 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ptypes
import (
"errors"
"fmt"
"time"
durationpb "github.com/golang/protobuf/ptypes/duration"
)
// Range of google.protobuf.Duration as specified in duration.proto.
// This is about 10,000 years in seconds.
const (
maxSeconds = int64(10000 * 365.25 * 24 * 60 * 60)
minSeconds = -maxSeconds
)
// Duration converts a durationpb.Duration to a time.Duration.
// Duration returns an error if dur is invalid or overflows a time.Duration.
//
// Deprecated: Call the dur.AsDuration and dur.CheckValid methods instead.
func Duration(dur *durationpb.Duration) (time.Duration, error) {
if err := validateDuration(dur); err != nil {
return 0, err
}
d := time.Duration(dur.Seconds) * time.Second
if int64(d/time.Second) != dur.Seconds {
return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
}
if dur.Nanos != 0 {
d += time.Duration(dur.Nanos) * time.Nanosecond
if (d < 0) != (dur.Nanos < 0) {
return 0, fmt.Errorf("duration: %v is out of range for time.Duration", dur)
}
}
return d, nil
}
// DurationProto converts a time.Duration to a durationpb.Duration.
//
// Deprecated: Call the durationpb.New function instead.
func DurationProto(d time.Duration) *durationpb.Duration {
nanos := d.Nanoseconds()
secs := nanos / 1e9
nanos -= secs * 1e9
return &durationpb.Duration{
Seconds: int64(secs),
Nanos: int32(nanos),
}
}
// validateDuration determines whether the durationpb.Duration is valid
// according to the definition in google/protobuf/duration.proto.
// A valid durpb.Duration may still be too large to fit into a time.Duration
// Note that the range of durationpb.Duration is about 10,000 years,
// while the range of time.Duration is about 290 years.
func validateDuration(dur *durationpb.Duration) error {
if dur == nil {
return errors.New("duration: nil Duration")
}
if dur.Seconds < minSeconds || dur.Seconds > maxSeconds {
return fmt.Errorf("duration: %v: seconds out of range", dur)
}
if dur.Nanos <= -1e9 || dur.Nanos >= 1e9 {
return fmt.Errorf("duration: %v: nanos out of range", dur)
}
// Seconds and Nanos must have the same sign, unless d.Nanos is zero.
if (dur.Seconds < 0 && dur.Nanos > 0) || (dur.Seconds > 0 && dur.Nanos < 0) {
return fmt.Errorf("duration: %v: seconds and nanos have different signs", dur)
}
return nil
}

@ -1,63 +0,0 @@
// Code generated by protoc-gen-go. DO NOT EDIT.
// source: github.com/golang/protobuf/ptypes/duration/duration.proto
package duration
import (
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
durationpb "google.golang.org/protobuf/types/known/durationpb"
reflect "reflect"
)
// Symbols defined in public import of google/protobuf/duration.proto.
type Duration = durationpb.Duration
var File_github_com_golang_protobuf_ptypes_duration_duration_proto protoreflect.FileDescriptor
var file_github_com_golang_protobuf_ptypes_duration_duration_proto_rawDesc = []byte{
0x0a, 0x39, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c,
0x61, 0x6e, 0x67, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79,
0x70, 0x65, 0x73, 0x2f, 0x64, 0x75, 0x72, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x2f, 0x64, 0x75, 0x72,
0x61, 0x74, 0x69, 0x6f, 0x6e, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x1a, 0x1e, 0x67, 0x6f, 0x6f,
0x67, 0x6c, 0x65, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x64, 0x75, 0x72,
0x61, 0x74, 0x69, 0x6f, 0x6e, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x42, 0x35, 0x5a, 0x33, 0x67,
0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c, 0x61, 0x6e, 0x67,
0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79, 0x70, 0x65, 0x73,
0x2f, 0x64, 0x75, 0x72, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x3b, 0x64, 0x75, 0x72, 0x61, 0x74, 0x69,
0x6f, 0x6e, 0x50, 0x00, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
}
var file_github_com_golang_protobuf_ptypes_duration_duration_proto_goTypes = []interface{}{}
var file_github_com_golang_protobuf_ptypes_duration_duration_proto_depIdxs = []int32{
0, // [0:0] is the sub-list for method output_type
0, // [0:0] is the sub-list for method input_type
0, // [0:0] is the sub-list for extension type_name
0, // [0:0] is the sub-list for extension extendee
0, // [0:0] is the sub-list for field type_name
}
func init() { file_github_com_golang_protobuf_ptypes_duration_duration_proto_init() }
func file_github_com_golang_protobuf_ptypes_duration_duration_proto_init() {
if File_github_com_golang_protobuf_ptypes_duration_duration_proto != nil {
return
}
type x struct{}
out := protoimpl.TypeBuilder{
File: protoimpl.DescBuilder{
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
RawDescriptor: file_github_com_golang_protobuf_ptypes_duration_duration_proto_rawDesc,
NumEnums: 0,
NumMessages: 0,
NumExtensions: 0,
NumServices: 0,
},
GoTypes: file_github_com_golang_protobuf_ptypes_duration_duration_proto_goTypes,
DependencyIndexes: file_github_com_golang_protobuf_ptypes_duration_duration_proto_depIdxs,
}.Build()
File_github_com_golang_protobuf_ptypes_duration_duration_proto = out.File
file_github_com_golang_protobuf_ptypes_duration_duration_proto_rawDesc = nil
file_github_com_golang_protobuf_ptypes_duration_duration_proto_goTypes = nil
file_github_com_golang_protobuf_ptypes_duration_duration_proto_depIdxs = nil
}

@ -1,112 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ptypes
import (
"errors"
"fmt"
"time"
timestamppb "github.com/golang/protobuf/ptypes/timestamp"
)
// Range of google.protobuf.Duration as specified in timestamp.proto.
const (
// Seconds field of the earliest valid Timestamp.
// This is time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
minValidSeconds = -62135596800
// Seconds field just after the latest valid Timestamp.
// This is time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC).Unix().
maxValidSeconds = 253402300800
)
// Timestamp converts a timestamppb.Timestamp to a time.Time.
// It returns an error if the argument is invalid.
//
// Unlike most Go functions, if Timestamp returns an error, the first return
// value is not the zero time.Time. Instead, it is the value obtained from the
// time.Unix function when passed the contents of the Timestamp, in the UTC
// locale. This may or may not be a meaningful time; many invalid Timestamps
// do map to valid time.Times.
//
// A nil Timestamp returns an error. The first return value in that case is
// undefined.
//
// Deprecated: Call the ts.AsTime and ts.CheckValid methods instead.
func Timestamp(ts *timestamppb.Timestamp) (time.Time, error) {
// Don't return the zero value on error, because corresponds to a valid
// timestamp. Instead return whatever time.Unix gives us.
var t time.Time
if ts == nil {
t = time.Unix(0, 0).UTC() // treat nil like the empty Timestamp
} else {
t = time.Unix(ts.Seconds, int64(ts.Nanos)).UTC()
}
return t, validateTimestamp(ts)
}
// TimestampNow returns a google.protobuf.Timestamp for the current time.
//
// Deprecated: Call the timestamppb.Now function instead.
func TimestampNow() *timestamppb.Timestamp {
ts, err := TimestampProto(time.Now())
if err != nil {
panic("ptypes: time.Now() out of Timestamp range")
}
return ts
}
// TimestampProto converts the time.Time to a google.protobuf.Timestamp proto.
// It returns an error if the resulting Timestamp is invalid.
//
// Deprecated: Call the timestamppb.New function instead.
func TimestampProto(t time.Time) (*timestamppb.Timestamp, error) {
ts := &timestamppb.Timestamp{
Seconds: t.Unix(),
Nanos: int32(t.Nanosecond()),
}
if err := validateTimestamp(ts); err != nil {
return nil, err
}
return ts, nil
}
// TimestampString returns the RFC 3339 string for valid Timestamps.
// For invalid Timestamps, it returns an error message in parentheses.
//
// Deprecated: Call the ts.AsTime method instead,
// followed by a call to the Format method on the time.Time value.
func TimestampString(ts *timestamppb.Timestamp) string {
t, err := Timestamp(ts)
if err != nil {
return fmt.Sprintf("(%v)", err)
}
return t.Format(time.RFC3339Nano)
}
// validateTimestamp determines whether a Timestamp is valid.
// A valid timestamp represents a time in the range [0001-01-01, 10000-01-01)
// and has a Nanos field in the range [0, 1e9).
//
// If the Timestamp is valid, validateTimestamp returns nil.
// Otherwise, it returns an error that describes the problem.
//
// Every valid Timestamp can be represented by a time.Time,
// but the converse is not true.
func validateTimestamp(ts *timestamppb.Timestamp) error {
if ts == nil {
return errors.New("timestamp: nil Timestamp")
}
if ts.Seconds < minValidSeconds {
return fmt.Errorf("timestamp: %v before 0001-01-01", ts)
}
if ts.Seconds >= maxValidSeconds {
return fmt.Errorf("timestamp: %v after 10000-01-01", ts)
}
if ts.Nanos < 0 || ts.Nanos >= 1e9 {
return fmt.Errorf("timestamp: %v: nanos not in range [0, 1e9)", ts)
}
return nil
}

@ -1,64 +0,0 @@
// Code generated by protoc-gen-go. DO NOT EDIT.
// source: github.com/golang/protobuf/ptypes/timestamp/timestamp.proto
package timestamp
import (
protoreflect "google.golang.org/protobuf/reflect/protoreflect"
protoimpl "google.golang.org/protobuf/runtime/protoimpl"
timestamppb "google.golang.org/protobuf/types/known/timestamppb"
reflect "reflect"
)
// Symbols defined in public import of google/protobuf/timestamp.proto.
type Timestamp = timestamppb.Timestamp
var File_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto protoreflect.FileDescriptor
var file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_rawDesc = []byte{
0x0a, 0x3b, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c,
0x61, 0x6e, 0x67, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79,
0x70, 0x65, 0x73, 0x2f, 0x74, 0x69, 0x6d, 0x65, 0x73, 0x74, 0x61, 0x6d, 0x70, 0x2f, 0x74, 0x69,
0x6d, 0x65, 0x73, 0x74, 0x61, 0x6d, 0x70, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x1a, 0x1f, 0x67,
0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x74,
0x69, 0x6d, 0x65, 0x73, 0x74, 0x61, 0x6d, 0x70, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x42, 0x37,
0x5a, 0x35, 0x67, 0x69, 0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x67, 0x6f, 0x6c,
0x61, 0x6e, 0x67, 0x2f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x62, 0x75, 0x66, 0x2f, 0x70, 0x74, 0x79,
0x70, 0x65, 0x73, 0x2f, 0x74, 0x69, 0x6d, 0x65, 0x73, 0x74, 0x61, 0x6d, 0x70, 0x3b, 0x74, 0x69,
0x6d, 0x65, 0x73, 0x74, 0x61, 0x6d, 0x70, 0x50, 0x00, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f,
0x33,
}
var file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_goTypes = []interface{}{}
var file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_depIdxs = []int32{
0, // [0:0] is the sub-list for method output_type
0, // [0:0] is the sub-list for method input_type
0, // [0:0] is the sub-list for extension type_name
0, // [0:0] is the sub-list for extension extendee
0, // [0:0] is the sub-list for field type_name
}
func init() { file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_init() }
func file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_init() {
if File_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto != nil {
return
}
type x struct{}
out := protoimpl.TypeBuilder{
File: protoimpl.DescBuilder{
GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
RawDescriptor: file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_rawDesc,
NumEnums: 0,
NumMessages: 0,
NumExtensions: 0,
NumServices: 0,
},
GoTypes: file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_goTypes,
DependencyIndexes: file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_depIdxs,
}.Build()
File_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto = out.File
file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_rawDesc = nil
file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_goTypes = nil
file_github_com_golang_protobuf_ptypes_timestamp_timestamp_proto_depIdxs = nil
}

@ -1,13 +0,0 @@
language: go
go:
- 1.4.x
- 1.5.x
- 1.6.x
- 1.7.x
- 1.8.x
- 1.9.x
- 1.10.x
- 1.11.x
- 1.12.x
- tip

@ -1,19 +0,0 @@
Copyright (c) 2013 Kelsey Hightower
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

@ -1,2 +0,0 @@
Kelsey Hightower kelsey.hightower@gmail.com github.com/kelseyhightower
Travis Parker travis.parker@gmail.com github.com/teepark

@ -1,192 +0,0 @@
# envconfig
[![Build Status](https://travis-ci.org/kelseyhightower/envconfig.svg)](https://travis-ci.org/kelseyhightower/envconfig)
```Go
import "github.com/kelseyhightower/envconfig"
```
## Documentation
See [godoc](http://godoc.org/github.com/kelseyhightower/envconfig)
## Usage
Set some environment variables:
```Bash
export MYAPP_DEBUG=false
export MYAPP_PORT=8080
export MYAPP_USER=Kelsey
export MYAPP_RATE="0.5"
export MYAPP_TIMEOUT="3m"
export MYAPP_USERS="rob,ken,robert"
export MYAPP_COLORCODES="red:1,green:2,blue:3"
```
Write some code:
```Go
package main
import (
"fmt"
"log"
"time"
"github.com/kelseyhightower/envconfig"
)
type Specification struct {
Debug bool
Port int
User string
Users []string
Rate float32
Timeout time.Duration
ColorCodes map[string]int
}
func main() {
var s Specification
err := envconfig.Process("myapp", &s)
if err != nil {
log.Fatal(err.Error())
}
format := "Debug: %v\nPort: %d\nUser: %s\nRate: %f\nTimeout: %s\n"
_, err = fmt.Printf(format, s.Debug, s.Port, s.User, s.Rate, s.Timeout)
if err != nil {
log.Fatal(err.Error())
}
fmt.Println("Users:")
for _, u := range s.Users {
fmt.Printf(" %s\n", u)
}
fmt.Println("Color codes:")
for k, v := range s.ColorCodes {
fmt.Printf(" %s: %d\n", k, v)
}
}
```
Results:
```Bash
Debug: false
Port: 8080
User: Kelsey
Rate: 0.500000
Timeout: 3m0s
Users:
rob
ken
robert
Color codes:
red: 1
green: 2
blue: 3
```
## Struct Tag Support
Envconfig supports the use of struct tags to specify alternate, default, and required
environment variables.
For example, consider the following struct:
```Go
type Specification struct {
ManualOverride1 string `envconfig:"manual_override_1"`
DefaultVar string `default:"foobar"`
RequiredVar string `required:"true"`
IgnoredVar string `ignored:"true"`
AutoSplitVar string `split_words:"true"`
RequiredAndAutoSplitVar string `required:"true" split_words:"true"`
}
```
Envconfig has automatic support for CamelCased struct elements when the
`split_words:"true"` tag is supplied. Without this tag, `AutoSplitVar` above
would look for an environment variable called `MYAPP_AUTOSPLITVAR`. With the
setting applied it will look for `MYAPP_AUTO_SPLIT_VAR`. Note that numbers
will get globbed into the previous word. If the setting does not do the
right thing, you may use a manual override.
Envconfig will process value for `ManualOverride1` by populating it with the
value for `MYAPP_MANUAL_OVERRIDE_1`. Without this struct tag, it would have
instead looked up `MYAPP_MANUALOVERRIDE1`. With the `split_words:"true"` tag
it would have looked up `MYAPP_MANUAL_OVERRIDE1`.
```Bash
export MYAPP_MANUAL_OVERRIDE_1="this will be the value"
# export MYAPP_MANUALOVERRIDE1="and this will not"
```
If envconfig can't find an environment variable value for `MYAPP_DEFAULTVAR`,
it will populate it with "foobar" as a default value.
If envconfig can't find an environment variable value for `MYAPP_REQUIREDVAR`,
it will return an error when asked to process the struct. If
`MYAPP_REQUIREDVAR` is present but empty, envconfig will not return an error.
If envconfig can't find an environment variable in the form `PREFIX_MYVAR`, and there
is a struct tag defined, it will try to populate your variable with an environment
variable that directly matches the envconfig tag in your struct definition:
```shell
export SERVICE_HOST=127.0.0.1
export MYAPP_DEBUG=true
```
```Go
type Specification struct {
ServiceHost string `envconfig:"SERVICE_HOST"`
Debug bool
}
```
Envconfig won't process a field with the "ignored" tag set to "true", even if a corresponding
environment variable is set.
## Supported Struct Field Types
envconfig supports these struct field types:
* string
* int8, int16, int32, int64
* bool
* float32, float64
* slices of any supported type
* maps (keys and values of any supported type)
* [encoding.TextUnmarshaler](https://golang.org/pkg/encoding/#TextUnmarshaler)
* [encoding.BinaryUnmarshaler](https://golang.org/pkg/encoding/#BinaryUnmarshaler)
* [time.Duration](https://golang.org/pkg/time/#Duration)
Embedded structs using these fields are also supported.
## Custom Decoders
Any field whose type (or pointer-to-type) implements `envconfig.Decoder` can
control its own deserialization:
```Bash
export DNS_SERVER=8.8.8.8
```
```Go
type IPDecoder net.IP
func (ipd *IPDecoder) Decode(value string) error {
*ipd = IPDecoder(net.ParseIP(value))
return nil
}
type DNSConfig struct {
Address IPDecoder `envconfig:"DNS_SERVER"`
}
```
Also, envconfig will use a `Set(string) error` method like from the
[flag.Value](https://godoc.org/flag#Value) interface if implemented.

@ -1,8 +0,0 @@
// Copyright (c) 2013 Kelsey Hightower. All rights reserved.
// Use of this source code is governed by the MIT License that can be found in
// the LICENSE file.
// Package envconfig implements decoding of environment variables based on a user
// defined specification. A typical use is using environment variables for
// configuration settings.
package envconfig

@ -1,7 +0,0 @@
// +build appengine go1.5
package envconfig
import "os"
var lookupEnv = os.LookupEnv

@ -1,7 +0,0 @@
// +build !appengine,!go1.5
package envconfig
import "syscall"
var lookupEnv = syscall.Getenv

@ -1,382 +0,0 @@
// Copyright (c) 2013 Kelsey Hightower. All rights reserved.
// Use of this source code is governed by the MIT License that can be found in
// the LICENSE file.
package envconfig
import (
"encoding"
"errors"
"fmt"
"os"
"reflect"
"regexp"
"strconv"
"strings"
"time"
)
// ErrInvalidSpecification indicates that a specification is of the wrong type.
var ErrInvalidSpecification = errors.New("specification must be a struct pointer")
var gatherRegexp = regexp.MustCompile("([^A-Z]+|[A-Z]+[^A-Z]+|[A-Z]+)")
var acronymRegexp = regexp.MustCompile("([A-Z]+)([A-Z][^A-Z]+)")
// A ParseError occurs when an environment variable cannot be converted to
// the type required by a struct field during assignment.
type ParseError struct {
KeyName string
FieldName string
TypeName string
Value string
Err error
}
// Decoder has the same semantics as Setter, but takes higher precedence.
// It is provided for historical compatibility.
type Decoder interface {
Decode(value string) error
}
// Setter is implemented by types can self-deserialize values.
// Any type that implements flag.Value also implements Setter.
type Setter interface {
Set(value string) error
}
func (e *ParseError) Error() string {
return fmt.Sprintf("envconfig.Process: assigning %[1]s to %[2]s: converting '%[3]s' to type %[4]s. details: %[5]s", e.KeyName, e.FieldName, e.Value, e.TypeName, e.Err)
}
// varInfo maintains information about the configuration variable
type varInfo struct {
Name string
Alt string
Key string
Field reflect.Value
Tags reflect.StructTag
}
// GatherInfo gathers information about the specified struct
func gatherInfo(prefix string, spec interface{}) ([]varInfo, error) {
s := reflect.ValueOf(spec)
if s.Kind() != reflect.Ptr {
return nil, ErrInvalidSpecification
}
s = s.Elem()
if s.Kind() != reflect.Struct {
return nil, ErrInvalidSpecification
}
typeOfSpec := s.Type()
// over allocate an info array, we will extend if needed later
infos := make([]varInfo, 0, s.NumField())
for i := 0; i < s.NumField(); i++ {
f := s.Field(i)
ftype := typeOfSpec.Field(i)
if !f.CanSet() || isTrue(ftype.Tag.Get("ignored")) {
continue
}
for f.Kind() == reflect.Ptr {
if f.IsNil() {
if f.Type().Elem().Kind() != reflect.Struct {
// nil pointer to a non-struct: leave it alone
break
}
// nil pointer to struct: create a zero instance
f.Set(reflect.New(f.Type().Elem()))
}
f = f.Elem()
}
// Capture information about the config variable
info := varInfo{
Name: ftype.Name,
Field: f,
Tags: ftype.Tag,
Alt: strings.ToUpper(ftype.Tag.Get("envconfig")),
}
// Default to the field name as the env var name (will be upcased)
info.Key = info.Name
// Best effort to un-pick camel casing as separate words
if isTrue(ftype.Tag.Get("split_words")) {
words := gatherRegexp.FindAllStringSubmatch(ftype.Name, -1)
if len(words) > 0 {
var name []string
for _, words := range words {
if m := acronymRegexp.FindStringSubmatch(words[0]); len(m) == 3 {
name = append(name, m[1], m[2])
} else {
name = append(name, words[0])
}
}
info.Key = strings.Join(name, "_")
}
}
if info.Alt != "" {
info.Key = info.Alt
}
if prefix != "" {
info.Key = fmt.Sprintf("%s_%s", prefix, info.Key)
}
info.Key = strings.ToUpper(info.Key)
infos = append(infos, info)
if f.Kind() == reflect.Struct {
// honor Decode if present
if decoderFrom(f) == nil && setterFrom(f) == nil && textUnmarshaler(f) == nil && binaryUnmarshaler(f) == nil {
innerPrefix := prefix
if !ftype.Anonymous {
innerPrefix = info.Key
}
embeddedPtr := f.Addr().Interface()
embeddedInfos, err := gatherInfo(innerPrefix, embeddedPtr)
if err != nil {
return nil, err
}
infos = append(infos[:len(infos)-1], embeddedInfos...)
continue
}
}
}
return infos, nil
}
// CheckDisallowed checks that no environment variables with the prefix are set
// that we don't know how or want to parse. This is likely only meaningful with
// a non-empty prefix.
func CheckDisallowed(prefix string, spec interface{}) error {
infos, err := gatherInfo(prefix, spec)
if err != nil {
return err
}
vars := make(map[string]struct{})
for _, info := range infos {
vars[info.Key] = struct{}{}
}
if prefix != "" {
prefix = strings.ToUpper(prefix) + "_"
}
for _, env := range os.Environ() {
if !strings.HasPrefix(env, prefix) {
continue
}
v := strings.SplitN(env, "=", 2)[0]
if _, found := vars[v]; !found {
return fmt.Errorf("unknown environment variable %s", v)
}
}
return nil
}
// Process populates the specified struct based on environment variables
func Process(prefix string, spec interface{}) error {
infos, err := gatherInfo(prefix, spec)
for _, info := range infos {
// `os.Getenv` cannot differentiate between an explicitly set empty value
// and an unset value. `os.LookupEnv` is preferred to `syscall.Getenv`,
// but it is only available in go1.5 or newer. We're using Go build tags
// here to use os.LookupEnv for >=go1.5
value, ok := lookupEnv(info.Key)
if !ok && info.Alt != "" {
value, ok = lookupEnv(info.Alt)
}
def := info.Tags.Get("default")
if def != "" && !ok {
value = def
}
req := info.Tags.Get("required")
if !ok && def == "" {
if isTrue(req) {
key := info.Key
if info.Alt != "" {
key = info.Alt
}
return fmt.Errorf("required key %s missing value", key)
}
continue
}
err = processField(value, info.Field)
if err != nil {
return &ParseError{
KeyName: info.Key,
FieldName: info.Name,
TypeName: info.Field.Type().String(),
Value: value,
Err: err,
}
}
}
return err
}
// MustProcess is the same as Process but panics if an error occurs
func MustProcess(prefix string, spec interface{}) {
if err := Process(prefix, spec); err != nil {
panic(err)
}
}
func processField(value string, field reflect.Value) error {
typ := field.Type()
decoder := decoderFrom(field)
if decoder != nil {
return decoder.Decode(value)
}
// look for Set method if Decode not defined
setter := setterFrom(field)
if setter != nil {
return setter.Set(value)
}
if t := textUnmarshaler(field); t != nil {
return t.UnmarshalText([]byte(value))
}
if b := binaryUnmarshaler(field); b != nil {
return b.UnmarshalBinary([]byte(value))
}
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
if field.IsNil() {
field.Set(reflect.New(typ))
}
field = field.Elem()
}
switch typ.Kind() {
case reflect.String:
field.SetString(value)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
var (
val int64
err error
)
if field.Kind() == reflect.Int64 && typ.PkgPath() == "time" && typ.Name() == "Duration" {
var d time.Duration
d, err = time.ParseDuration(value)
val = int64(d)
} else {
val, err = strconv.ParseInt(value, 0, typ.Bits())
}
if err != nil {
return err
}
field.SetInt(val)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
val, err := strconv.ParseUint(value, 0, typ.Bits())
if err != nil {
return err
}
field.SetUint(val)
case reflect.Bool:
val, err := strconv.ParseBool(value)
if err != nil {
return err
}
field.SetBool(val)
case reflect.Float32, reflect.Float64:
val, err := strconv.ParseFloat(value, typ.Bits())
if err != nil {
return err
}
field.SetFloat(val)
case reflect.Slice:
sl := reflect.MakeSlice(typ, 0, 0)
if typ.Elem().Kind() == reflect.Uint8 {
sl = reflect.ValueOf([]byte(value))
} else if len(strings.TrimSpace(value)) != 0 {
vals := strings.Split(value, ",")
sl = reflect.MakeSlice(typ, len(vals), len(vals))
for i, val := range vals {
err := processField(val, sl.Index(i))
if err != nil {
return err
}
}
}
field.Set(sl)
case reflect.Map:
mp := reflect.MakeMap(typ)
if len(strings.TrimSpace(value)) != 0 {
pairs := strings.Split(value, ",")
for _, pair := range pairs {
kvpair := strings.Split(pair, ":")
if len(kvpair) != 2 {
return fmt.Errorf("invalid map item: %q", pair)
}
k := reflect.New(typ.Key()).Elem()
err := processField(kvpair[0], k)
if err != nil {
return err
}
v := reflect.New(typ.Elem()).Elem()
err = processField(kvpair[1], v)
if err != nil {
return err
}
mp.SetMapIndex(k, v)
}
}
field.Set(mp)
}
return nil
}
func interfaceFrom(field reflect.Value, fn func(interface{}, *bool)) {
// it may be impossible for a struct field to fail this check
if !field.CanInterface() {
return
}
var ok bool
fn(field.Interface(), &ok)
if !ok && field.CanAddr() {
fn(field.Addr().Interface(), &ok)
}
}
func decoderFrom(field reflect.Value) (d Decoder) {
interfaceFrom(field, func(v interface{}, ok *bool) { d, *ok = v.(Decoder) })
return d
}
func setterFrom(field reflect.Value) (s Setter) {
interfaceFrom(field, func(v interface{}, ok *bool) { s, *ok = v.(Setter) })
return s
}
func textUnmarshaler(field reflect.Value) (t encoding.TextUnmarshaler) {
interfaceFrom(field, func(v interface{}, ok *bool) { t, *ok = v.(encoding.TextUnmarshaler) })
return t
}
func binaryUnmarshaler(field reflect.Value) (b encoding.BinaryUnmarshaler) {
interfaceFrom(field, func(v interface{}, ok *bool) { b, *ok = v.(encoding.BinaryUnmarshaler) })
return b
}
func isTrue(s string) bool {
b, _ := strconv.ParseBool(s)
return b
}

@ -1,164 +0,0 @@
// Copyright (c) 2016 Kelsey Hightower and others. All rights reserved.
// Use of this source code is governed by the MIT License that can be found in
// the LICENSE file.
package envconfig
import (
"encoding"
"fmt"
"io"
"os"
"reflect"
"strconv"
"strings"
"text/tabwriter"
"text/template"
)
const (
// DefaultListFormat constant to use to display usage in a list format
DefaultListFormat = `This application is configured via the environment. The following environment
variables can be used:
{{range .}}
{{usage_key .}}
[description] {{usage_description .}}
[type] {{usage_type .}}
[default] {{usage_default .}}
[required] {{usage_required .}}{{end}}
`
// DefaultTableFormat constant to use to display usage in a tabular format
DefaultTableFormat = `This application is configured via the environment. The following environment
variables can be used:
KEY TYPE DEFAULT REQUIRED DESCRIPTION
{{range .}}{{usage_key .}} {{usage_type .}} {{usage_default .}} {{usage_required .}} {{usage_description .}}
{{end}}`
)
var (
decoderType = reflect.TypeOf((*Decoder)(nil)).Elem()
setterType = reflect.TypeOf((*Setter)(nil)).Elem()
textUnmarshalerType = reflect.TypeOf((*encoding.TextUnmarshaler)(nil)).Elem()
binaryUnmarshalerType = reflect.TypeOf((*encoding.BinaryUnmarshaler)(nil)).Elem()
)
func implementsInterface(t reflect.Type) bool {
return t.Implements(decoderType) ||
reflect.PtrTo(t).Implements(decoderType) ||
t.Implements(setterType) ||
reflect.PtrTo(t).Implements(setterType) ||
t.Implements(textUnmarshalerType) ||
reflect.PtrTo(t).Implements(textUnmarshalerType) ||
t.Implements(binaryUnmarshalerType) ||
reflect.PtrTo(t).Implements(binaryUnmarshalerType)
}
// toTypeDescription converts Go types into a human readable description
func toTypeDescription(t reflect.Type) string {
switch t.Kind() {
case reflect.Array, reflect.Slice:
if t.Elem().Kind() == reflect.Uint8 {
return "String"
}
return fmt.Sprintf("Comma-separated list of %s", toTypeDescription(t.Elem()))
case reflect.Map:
return fmt.Sprintf(
"Comma-separated list of %s:%s pairs",
toTypeDescription(t.Key()),
toTypeDescription(t.Elem()),
)
case reflect.Ptr:
return toTypeDescription(t.Elem())
case reflect.Struct:
if implementsInterface(t) && t.Name() != "" {
return t.Name()
}
return ""
case reflect.String:
name := t.Name()
if name != "" && name != "string" {
return name
}
return "String"
case reflect.Bool:
name := t.Name()
if name != "" && name != "bool" {
return name
}
return "True or False"
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
name := t.Name()
if name != "" && !strings.HasPrefix(name, "int") {
return name
}
return "Integer"
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
name := t.Name()
if name != "" && !strings.HasPrefix(name, "uint") {
return name
}
return "Unsigned Integer"
case reflect.Float32, reflect.Float64:
name := t.Name()
if name != "" && !strings.HasPrefix(name, "float") {
return name
}
return "Float"
}
return fmt.Sprintf("%+v", t)
}
// Usage writes usage information to stdout using the default header and table format
func Usage(prefix string, spec interface{}) error {
// The default is to output the usage information as a table
// Create tabwriter instance to support table output
tabs := tabwriter.NewWriter(os.Stdout, 1, 0, 4, ' ', 0)
err := Usagef(prefix, spec, tabs, DefaultTableFormat)
tabs.Flush()
return err
}
// Usagef writes usage information to the specified io.Writer using the specifed template specification
func Usagef(prefix string, spec interface{}, out io.Writer, format string) error {
// Specify the default usage template functions
functions := template.FuncMap{
"usage_key": func(v varInfo) string { return v.Key },
"usage_description": func(v varInfo) string { return v.Tags.Get("desc") },
"usage_type": func(v varInfo) string { return toTypeDescription(v.Field.Type()) },
"usage_default": func(v varInfo) string { return v.Tags.Get("default") },
"usage_required": func(v varInfo) (string, error) {
req := v.Tags.Get("required")
if req != "" {
reqB, err := strconv.ParseBool(req)
if err != nil {
return "", err
}
if reqB {
req = "true"
}
}
return req, nil
},
}
tmpl, err := template.New("envconfig").Funcs(functions).Parse(format)
if err != nil {
return err
}
return Usaget(prefix, spec, out, tmpl)
}
// Usaget writes usage information to the specified io.Writer using the specified template
func Usaget(prefix string, spec interface{}, out io.Writer, tmpl *template.Template) error {
// gather first
infos, err := gatherInfo(prefix, spec)
if err != nil {
return err
}
return tmpl.Execute(out, infos)
}

@ -1,2 +0,0 @@
* -text
*.bin -text -diff

@ -1,32 +0,0 @@
# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe
*.test
*.prof
/s2/cmd/_s2sx/sfx-exe
# Linux perf files
perf.data
perf.data.old
# gdb history
.gdb_history

@ -1,141 +0,0 @@
# This is an example goreleaser.yaml file with some sane defaults.
# Make sure to check the documentation at http://goreleaser.com
before:
hooks:
- ./gen.sh
- go install mvdan.cc/garble@latest
builds:
-
id: "s2c"
binary: s2c
main: ./s2/cmd/s2c/main.go
flags:
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
gobinary: garble
-
id: "s2d"
binary: s2d
main: ./s2/cmd/s2d/main.go
flags:
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
gobinary: garble
-
id: "s2sx"
binary: s2sx
main: ./s2/cmd/_s2sx/main.go
flags:
- -modfile=s2sx.mod
- -trimpath
env:
- CGO_ENABLED=0
goos:
- aix
- linux
- freebsd
- netbsd
- windows
- darwin
goarch:
- 386
- amd64
- arm
- arm64
- ppc64
- ppc64le
- mips64
- mips64le
goarm:
- 7
gobinary: garble
archives:
-
id: s2-binaries
name_template: "s2-{{ .Os }}_{{ .Arch }}_{{ .Version }}"
replacements:
aix: AIX
darwin: OSX
linux: Linux
windows: Windows
386: i386
amd64: x86_64
freebsd: FreeBSD
netbsd: NetBSD
format_overrides:
- goos: windows
format: zip
files:
- unpack/*
- s2/LICENSE
- s2/README.md
checksum:
name_template: 'checksums.txt'
snapshot:
name_template: "{{ .Tag }}-next"
changelog:
sort: asc
filters:
exclude:
- '^doc:'
- '^docs:'
- '^test:'
- '^tests:'
- '^Update\sREADME.md'
nfpms:
-
file_name_template: "s2_package_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
vendor: Klaus Post
homepage: https://github.com/klauspost/compress
maintainer: Klaus Post <klauspost@gmail.com>
description: S2 Compression Tool
license: BSD 3-Clause
formats:
- deb
- rpm
replacements:
darwin: Darwin
linux: Linux
freebsd: FreeBSD
amd64: x86_64

@ -1,304 +0,0 @@
Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
------------------
Files: gzhttp/*
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright 2016-2017 The New York Times Company
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
------------------
Files: s2/cmd/internal/readahead/*
The MIT License (MIT)
Copyright (c) 2015 Klaus Post
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
---------------------
Files: snappy/*
Files: internal/snapref/*
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-----------------
Files: s2/cmd/internal/filepathx/*
Copyright 2016 The filepathx Authors
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

@ -1,560 +0,0 @@
# compress
This package provides various compression algorithms.
* [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and decompression in pure Go.
* [S2](https://github.com/klauspost/compress/tree/master/s2#s2-compression) is a high performance replacement for Snappy.
* Optimized [deflate](https://godoc.org/github.com/klauspost/compress/flate) packages which can be used as a dropin replacement for [gzip](https://godoc.org/github.com/klauspost/compress/gzip), [zip](https://godoc.org/github.com/klauspost/compress/zip) and [zlib](https://godoc.org/github.com/klauspost/compress/zlib).
* [snappy](https://github.com/klauspost/compress/tree/master/snappy) is a drop-in replacement for `github.com/golang/snappy` offering better compression and concurrent streams.
* [huff0](https://github.com/klauspost/compress/tree/master/huff0) and [FSE](https://github.com/klauspost/compress/tree/master/fse) implementations for raw entropy encoding.
* [gzhttp](https://github.com/klauspost/compress/tree/master/gzhttp) Provides client and server wrappers for handling gzipped requests efficiently.
* [pgzip](https://github.com/klauspost/pgzip) is a separate package that provides a very fast parallel gzip implementation.
* [fuzz package](https://github.com/klauspost/compress-fuzz) for fuzz testing all compressors/decompressors here.
[![Go Reference](https://pkg.go.dev/badge/klauspost/compress.svg)](https://pkg.go.dev/github.com/klauspost/compress?tab=subdirectories)
[![Go](https://github.com/klauspost/compress/actions/workflows/go.yml/badge.svg)](https://github.com/klauspost/compress/actions/workflows/go.yml)
[![Sourcegraph Badge](https://sourcegraph.com/github.com/klauspost/compress/-/badge.svg)](https://sourcegraph.com/github.com/klauspost/compress?badge)
# changelog
* July 13, 2022 (v1.15.8)
* gzip: fix stack exhaustion bug in Reader.Read https://github.com/klauspost/compress/pull/641
* s2: Add Index header trim/restore https://github.com/klauspost/compress/pull/638
* zstd: Optimize seqdeq amd64 asm by @greatroar in https://github.com/klauspost/compress/pull/636
* zstd: Improve decoder memcopy https://github.com/klauspost/compress/pull/637
* huff0: Pass a single bitReader pointer to asm by @greatroar in https://github.com/klauspost/compress/pull/634
* zstd: Branchless getBits for amd64 w/o BMI2 by @greatroar in https://github.com/klauspost/compress/pull/640
* gzhttp: Remove header before writing https://github.com/klauspost/compress/pull/639
* June 29, 2022 (v1.15.7)
* s2: Fix absolute forward seeks https://github.com/klauspost/compress/pull/633
* zip: Merge upstream https://github.com/klauspost/compress/pull/631
* zip: Re-add zip64 fix https://github.com/klauspost/compress/pull/624
* zstd: translate fseDecoder.buildDtable into asm by @WojciechMula in https://github.com/klauspost/compress/pull/598
* flate: Faster histograms https://github.com/klauspost/compress/pull/620
* deflate: Use compound hcode https://github.com/klauspost/compress/pull/622
* June 3, 2022 (v1.15.6)
* s2: Improve coding for long, close matches https://github.com/klauspost/compress/pull/613
* s2c: Add Snappy/S2 stream recompression https://github.com/klauspost/compress/pull/611
* zstd: Always use configured block size https://github.com/klauspost/compress/pull/605
* zstd: Fix incorrect hash table placement for dict encoding in default https://github.com/klauspost/compress/pull/606
* zstd: Apply default config to ZipDecompressor without options https://github.com/klauspost/compress/pull/608
* gzhttp: Exclude more common archive formats https://github.com/klauspost/compress/pull/612
* s2: Add ReaderIgnoreCRC https://github.com/klauspost/compress/pull/609
* s2: Remove sanity load on index creation https://github.com/klauspost/compress/pull/607
* snappy: Use dedicated function for scoring https://github.com/klauspost/compress/pull/614
* s2c+s2d: Use official snappy framed extension https://github.com/klauspost/compress/pull/610
* May 25, 2022 (v1.15.5)
* s2: Add concurrent stream decompression https://github.com/klauspost/compress/pull/602
* s2: Fix final emit oob read crash on amd64 https://github.com/klauspost/compress/pull/601
* huff0: asm implementation of Decompress1X by @WojciechMula https://github.com/klauspost/compress/pull/596
* zstd: Use 1 less goroutine for stream decoding https://github.com/klauspost/compress/pull/588
* zstd: Copy literal in 16 byte blocks when possible https://github.com/klauspost/compress/pull/592
* zstd: Speed up when WithDecoderLowmem(false) https://github.com/klauspost/compress/pull/599
* zstd: faster next state update in BMI2 version of decode by @WojciechMula in https://github.com/klauspost/compress/pull/593
* huff0: Do not check max size when reading table. https://github.com/klauspost/compress/pull/586
* flate: Inplace hashing for level 7-9 by @klauspost in https://github.com/klauspost/compress/pull/590
* May 11, 2022 (v1.15.4)
* huff0: decompress directly into output by @WojciechMula in [#577](https://github.com/klauspost/compress/pull/577)
* inflate: Keep dict on stack [#581](https://github.com/klauspost/compress/pull/581)
* zstd: Faster decoding memcopy in asm [#583](https://github.com/klauspost/compress/pull/583)
* zstd: Fix ignored crc [#580](https://github.com/klauspost/compress/pull/580)
* May 5, 2022 (v1.15.3)
* zstd: Allow to ignore checksum checking by @WojciechMula [#572](https://github.com/klauspost/compress/pull/572)
* s2: Fix incorrect seek for io.SeekEnd in [#575](https://github.com/klauspost/compress/pull/575)
* Apr 26, 2022 (v1.15.2)
* zstd: Add x86-64 assembly for decompression on streams and blocks. Contributed by [@WojciechMula](https://github.com/WojciechMula). Typically 2x faster. [#528](https://github.com/klauspost/compress/pull/528) [#531](https://github.com/klauspost/compress/pull/531) [#545](https://github.com/klauspost/compress/pull/545) [#537](https://github.com/klauspost/compress/pull/537)
* zstd: Add options to ZipDecompressor and fixes [#539](https://github.com/klauspost/compress/pull/539)
* s2: Use sorted search for index [#555](https://github.com/klauspost/compress/pull/555)
* Minimum version is Go 1.16, added CI test on 1.18.
* Mar 11, 2022 (v1.15.1)
* huff0: Add x86 assembly of Decode4X by @WojciechMula in [#512](https://github.com/klauspost/compress/pull/512)
* zstd: Reuse zip decoders in [#514](https://github.com/klauspost/compress/pull/514)
* zstd: Detect extra block data and report as corrupted in [#520](https://github.com/klauspost/compress/pull/520)
* zstd: Handle zero sized frame content size stricter in [#521](https://github.com/klauspost/compress/pull/521)
* zstd: Add stricter block size checks in [#523](https://github.com/klauspost/compress/pull/523)
* Mar 3, 2022 (v1.15.0)
* zstd: Refactor decoder by @klauspost in [#498](https://github.com/klauspost/compress/pull/498)
* zstd: Add stream encoding without goroutines by @klauspost in [#505](https://github.com/klauspost/compress/pull/505)
* huff0: Prevent single blocks exceeding 16 bits by @klauspost in[#507](https://github.com/klauspost/compress/pull/507)
* flate: Inline literal emission by @klauspost in [#509](https://github.com/klauspost/compress/pull/509)
* gzhttp: Add zstd to transport by @klauspost in [#400](https://github.com/klauspost/compress/pull/400)
* gzhttp: Make content-type optional by @klauspost in [#510](https://github.com/klauspost/compress/pull/510)
<details>
<summary>See Details</summary>
Both compression and decompression now supports "synchronous" stream operations. This means that whenever "concurrency" is set to 1, they will operate without spawning goroutines.
Stream decompression is now faster on asynchronous, since the goroutine allocation much more effectively splits the workload. On typical streams this will typically use 2 cores fully for decompression. When a stream has finished decoding no goroutines will be left over, so decoders can now safely be pooled and still be garbage collected.
While the release has been extensively tested, it is recommended to testing when upgrading.
</details>
* Feb 22, 2022 (v1.14.4)
* flate: Fix rare huffman only (-2) corruption. [#503](https://github.com/klauspost/compress/pull/503)
* zip: Update deprecated CreateHeaderRaw to correctly call CreateRaw by @saracen in [#502](https://github.com/klauspost/compress/pull/502)
* zip: don't read data descriptor early by @saracen in [#501](https://github.com/klauspost/compress/pull/501) #501
* huff0: Use static decompression buffer up to 30% faster by @klauspost in [#499](https://github.com/klauspost/compress/pull/499) [#500](https://github.com/klauspost/compress/pull/500)
* Feb 17, 2022 (v1.14.3)
* flate: Improve fastest levels compression speed ~10% more throughput. [#482](https://github.com/klauspost/compress/pull/482) [#489](https://github.com/klauspost/compress/pull/489) [#490](https://github.com/klauspost/compress/pull/490) [#491](https://github.com/klauspost/compress/pull/491) [#494](https://github.com/klauspost/compress/pull/494) [#478](https://github.com/klauspost/compress/pull/478)
* flate: Faster decompression speed, ~5-10%. [#483](https://github.com/klauspost/compress/pull/483)
* s2: Faster compression with Go v1.18 and amd64 microarch level 3+. [#484](https://github.com/klauspost/compress/pull/484) [#486](https://github.com/klauspost/compress/pull/486)
* Jan 25, 2022 (v1.14.2)
* zstd: improve header decoder by @dsnet [#476](https://github.com/klauspost/compress/pull/476)
* zstd: Add bigger default blocks [#469](https://github.com/klauspost/compress/pull/469)
* zstd: Remove unused decompression buffer [#470](https://github.com/klauspost/compress/pull/470)
* zstd: Fix logically dead code by @ningmingxiao [#472](https://github.com/klauspost/compress/pull/472)
* flate: Improve level 7-9 [#471](https://github.com/klauspost/compress/pull/471) [#473](https://github.com/klauspost/compress/pull/473)
* zstd: Add noasm tag for xxhash [#475](https://github.com/klauspost/compress/pull/475)
* Jan 11, 2022 (v1.14.1)
* s2: Add stream index in [#462](https://github.com/klauspost/compress/pull/462)
* flate: Speed and efficiency improvements in [#439](https://github.com/klauspost/compress/pull/439) [#461](https://github.com/klauspost/compress/pull/461) [#455](https://github.com/klauspost/compress/pull/455) [#452](https://github.com/klauspost/compress/pull/452) [#458](https://github.com/klauspost/compress/pull/458)
* zstd: Performance improvement in [#420]( https://github.com/klauspost/compress/pull/420) [#456](https://github.com/klauspost/compress/pull/456) [#437](https://github.com/klauspost/compress/pull/437) [#467](https://github.com/klauspost/compress/pull/467) [#468](https://github.com/klauspost/compress/pull/468)
* zstd: add arm64 xxhash assembly in [#464](https://github.com/klauspost/compress/pull/464)
* Add garbled for binaries for s2 in [#445](https://github.com/klauspost/compress/pull/445)
<details>
<summary>See changes to v1.13.x</summary>
* Aug 30, 2021 (v1.13.5)
* gz/zlib/flate: Alias stdlib errors [#425](https://github.com/klauspost/compress/pull/425)
* s2: Add block support to commandline tools [#413](https://github.com/klauspost/compress/pull/413)
* zstd: pooledZipWriter should return Writers to the same pool [#426](https://github.com/klauspost/compress/pull/426)
* Removed golang/snappy as external dependency for tests [#421](https://github.com/klauspost/compress/pull/421)
* Aug 12, 2021 (v1.13.4)
* Add [snappy replacement package](https://github.com/klauspost/compress/tree/master/snappy).
* zstd: Fix incorrect encoding in "best" mode [#415](https://github.com/klauspost/compress/pull/415)
* Aug 3, 2021 (v1.13.3)
* zstd: Improve Best compression [#404](https://github.com/klauspost/compress/pull/404)
* zstd: Fix WriteTo error forwarding [#411](https://github.com/klauspost/compress/pull/411)
* gzhttp: Return http.HandlerFunc instead of http.Handler. Unlikely breaking change. [#406](https://github.com/klauspost/compress/pull/406)
* s2sx: Fix max size error [#399](https://github.com/klauspost/compress/pull/399)
* zstd: Add optional stream content size on reset [#401](https://github.com/klauspost/compress/pull/401)
* zstd: use SpeedBestCompression for level >= 10 [#410](https://github.com/klauspost/compress/pull/410)
* Jun 14, 2021 (v1.13.1)
* s2: Add full Snappy output support [#396](https://github.com/klauspost/compress/pull/396)
* zstd: Add configurable [Decoder window](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithDecoderMaxWindow) size [#394](https://github.com/klauspost/compress/pull/394)
* gzhttp: Add header to skip compression [#389](https://github.com/klauspost/compress/pull/389)
* s2: Improve speed with bigger output margin [#395](https://github.com/klauspost/compress/pull/395)
* Jun 3, 2021 (v1.13.0)
* Added [gzhttp](https://github.com/klauspost/compress/tree/master/gzhttp#gzip-handler) which allows wrapping HTTP servers and clients with GZIP compressors.
* zstd: Detect short invalid signatures [#382](https://github.com/klauspost/compress/pull/382)
* zstd: Spawn decoder goroutine only if needed. [#380](https://github.com/klauspost/compress/pull/380)
</details>
<details>
<summary>See changes to v1.12.x</summary>
* May 25, 2021 (v1.12.3)
* deflate: Better/faster Huffman encoding [#374](https://github.com/klauspost/compress/pull/374)
* deflate: Allocate less for history. [#375](https://github.com/klauspost/compress/pull/375)
* zstd: Forward read errors [#373](https://github.com/klauspost/compress/pull/373)
* Apr 27, 2021 (v1.12.2)
* zstd: Improve better/best compression [#360](https://github.com/klauspost/compress/pull/360) [#364](https://github.com/klauspost/compress/pull/364) [#365](https://github.com/klauspost/compress/pull/365)
* zstd: Add helpers to compress/decompress zstd inside zip files [#363](https://github.com/klauspost/compress/pull/363)
* deflate: Improve level 5+6 compression [#367](https://github.com/klauspost/compress/pull/367)
* s2: Improve better/best compression [#358](https://github.com/klauspost/compress/pull/358) [#359](https://github.com/klauspost/compress/pull/358)
* s2: Load after checking src limit on amd64. [#362](https://github.com/klauspost/compress/pull/362)
* s2sx: Limit max executable size [#368](https://github.com/klauspost/compress/pull/368)
* Apr 14, 2021 (v1.12.1)
* snappy package removed. Upstream added as dependency.
* s2: Better compression in "best" mode [#353](https://github.com/klauspost/compress/pull/353)
* s2sx: Add stdin input and detect pre-compressed from signature [#352](https://github.com/klauspost/compress/pull/352)
* s2c/s2d: Add http as possible input [#348](https://github.com/klauspost/compress/pull/348)
* s2c/s2d/s2sx: Always truncate when writing files [#352](https://github.com/klauspost/compress/pull/352)
* zstd: Reduce memory usage further when using [WithLowerEncoderMem](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithLowerEncoderMem) [#346](https://github.com/klauspost/compress/pull/346)
* s2: Fix potential problem with amd64 assembly and profilers [#349](https://github.com/klauspost/compress/pull/349)
</details>
<details>
<summary>See changes to v1.11.x</summary>
* Mar 26, 2021 (v1.11.13)
* zstd: Big speedup on small dictionary encodes [#344](https://github.com/klauspost/compress/pull/344) [#345](https://github.com/klauspost/compress/pull/345)
* zstd: Add [WithLowerEncoderMem](https://pkg.go.dev/github.com/klauspost/compress/zstd#WithLowerEncoderMem) encoder option [#336](https://github.com/klauspost/compress/pull/336)
* deflate: Improve entropy compression [#338](https://github.com/klauspost/compress/pull/338)
* s2: Clean up and minor performance improvement in best [#341](https://github.com/klauspost/compress/pull/341)
* Mar 5, 2021 (v1.11.12)
* s2: Add `s2sx` binary that creates [self extracting archives](https://github.com/klauspost/compress/tree/master/s2#s2sx-self-extracting-archives).
* s2: Speed up decompression on non-assembly platforms [#328](https://github.com/klauspost/compress/pull/328)
* Mar 1, 2021 (v1.11.9)
* s2: Add ARM64 decompression assembly. Around 2x output speed. [#324](https://github.com/klauspost/compress/pull/324)
* s2: Improve "better" speed and efficiency. [#325](https://github.com/klauspost/compress/pull/325)
* s2: Fix binaries.
* Feb 25, 2021 (v1.11.8)
* s2: Fixed occational out-of-bounds write on amd64. Upgrade recommended.
* s2: Add AMD64 assembly for better mode. 25-50% faster. [#315](https://github.com/klauspost/compress/pull/315)
* s2: Less upfront decoder allocation. [#322](https://github.com/klauspost/compress/pull/322)
* zstd: Faster "compression" of incompressible data. [#314](https://github.com/klauspost/compress/pull/314)
* zip: Fix zip64 headers. [#313](https://github.com/klauspost/compress/pull/313)
* Jan 14, 2021 (v1.11.7)
* Use Bytes() interface to get bytes across packages. [#309](https://github.com/klauspost/compress/pull/309)
* s2: Add 'best' compression option. [#310](https://github.com/klauspost/compress/pull/310)
* s2: Add ReaderMaxBlockSize, changes `s2.NewReader` signature to include varargs. [#311](https://github.com/klauspost/compress/pull/311)
* s2: Fix crash on small better buffers. [#308](https://github.com/klauspost/compress/pull/308)
* s2: Clean up decoder. [#312](https://github.com/klauspost/compress/pull/312)
* Jan 7, 2021 (v1.11.6)
* zstd: Make decoder allocations smaller [#306](https://github.com/klauspost/compress/pull/306)
* zstd: Free Decoder resources when Reset is called with a nil io.Reader [#305](https://github.com/klauspost/compress/pull/305)
* Dec 20, 2020 (v1.11.4)
* zstd: Add Best compression mode [#304](https://github.com/klauspost/compress/pull/304)
* Add header decoder [#299](https://github.com/klauspost/compress/pull/299)
* s2: Add uncompressed stream option [#297](https://github.com/klauspost/compress/pull/297)
* Simplify/speed up small blocks with known max size. [#300](https://github.com/klauspost/compress/pull/300)
* zstd: Always reset literal dict encoder [#303](https://github.com/klauspost/compress/pull/303)
* Nov 15, 2020 (v1.11.3)
* inflate: 10-15% faster decompression [#293](https://github.com/klauspost/compress/pull/293)
* zstd: Tweak DecodeAll default allocation [#295](https://github.com/klauspost/compress/pull/295)
* Oct 11, 2020 (v1.11.2)
* s2: Fix out of bounds read in "better" block compression [#291](https://github.com/klauspost/compress/pull/291)
* Oct 1, 2020 (v1.11.1)
* zstd: Set allLitEntropy true in default configuration [#286](https://github.com/klauspost/compress/pull/286)
* Sept 8, 2020 (v1.11.0)
* zstd: Add experimental compression [dictionaries](https://github.com/klauspost/compress/tree/master/zstd#dictionaries) [#281](https://github.com/klauspost/compress/pull/281)
* zstd: Fix mixed Write and ReadFrom calls [#282](https://github.com/klauspost/compress/pull/282)
* inflate/gz: Limit variable shifts, ~5% faster decompression [#274](https://github.com/klauspost/compress/pull/274)
</details>
<details>
<summary>See changes to v1.10.x</summary>
* July 8, 2020 (v1.10.11)
* zstd: Fix extra block when compressing with ReadFrom. [#278](https://github.com/klauspost/compress/pull/278)
* huff0: Also populate compression table when reading decoding table. [#275](https://github.com/klauspost/compress/pull/275)
* June 23, 2020 (v1.10.10)
* zstd: Skip entropy compression in fastest mode when no matches. [#270](https://github.com/klauspost/compress/pull/270)
* June 16, 2020 (v1.10.9):
* zstd: API change for specifying dictionaries. See [#268](https://github.com/klauspost/compress/pull/268)
* zip: update CreateHeaderRaw to handle zip64 fields. [#266](https://github.com/klauspost/compress/pull/266)
* Fuzzit tests removed. The service has been purchased and is no longer available.
* June 5, 2020 (v1.10.8):
* 1.15x faster zstd block decompression. [#265](https://github.com/klauspost/compress/pull/265)
* June 1, 2020 (v1.10.7):
* Added zstd decompression [dictionary support](https://github.com/klauspost/compress/tree/master/zstd#dictionaries)
* Increase zstd decompression speed up to 1.19x. [#259](https://github.com/klauspost/compress/pull/259)
* Remove internal reset call in zstd compression and reduce allocations. [#263](https://github.com/klauspost/compress/pull/263)
* May 21, 2020: (v1.10.6)
* zstd: Reduce allocations while decoding. [#258](https://github.com/klauspost/compress/pull/258), [#252](https://github.com/klauspost/compress/pull/252)
* zstd: Stricter decompression checks.
* April 12, 2020: (v1.10.5)
* s2-commands: Flush output when receiving SIGINT. [#239](https://github.com/klauspost/compress/pull/239)
* Apr 8, 2020: (v1.10.4)
* zstd: Minor/special case optimizations. [#251](https://github.com/klauspost/compress/pull/251), [#250](https://github.com/klauspost/compress/pull/250), [#249](https://github.com/klauspost/compress/pull/249), [#247](https://github.com/klauspost/compress/pull/247)
* Mar 11, 2020: (v1.10.3)
* s2: Use S2 encoder in pure Go mode for Snappy output as well. [#245](https://github.com/klauspost/compress/pull/245)
* s2: Fix pure Go block encoder. [#244](https://github.com/klauspost/compress/pull/244)
* zstd: Added "better compression" mode. [#240](https://github.com/klauspost/compress/pull/240)
* zstd: Improve speed of fastest compression mode by 5-10% [#241](https://github.com/klauspost/compress/pull/241)
* zstd: Skip creating encoders when not needed. [#238](https://github.com/klauspost/compress/pull/238)
* Feb 27, 2020: (v1.10.2)
* Close to 50% speedup in inflate (gzip/zip decompression). [#236](https://github.com/klauspost/compress/pull/236) [#234](https://github.com/klauspost/compress/pull/234) [#232](https://github.com/klauspost/compress/pull/232)
* Reduce deflate level 1-6 memory usage up to 59%. [#227](https://github.com/klauspost/compress/pull/227)
* Feb 18, 2020: (v1.10.1)
* Fix zstd crash when resetting multiple times without sending data. [#226](https://github.com/klauspost/compress/pull/226)
* deflate: Fix dictionary use on level 1-6. [#224](https://github.com/klauspost/compress/pull/224)
* Remove deflate writer reference when closing. [#224](https://github.com/klauspost/compress/pull/224)
* Feb 4, 2020: (v1.10.0)
* Add optional dictionary to [stateless deflate](https://pkg.go.dev/github.com/klauspost/compress/flate?tab=doc#StatelessDeflate). Breaking change, send `nil` for previous behaviour. [#216](https://github.com/klauspost/compress/pull/216)
* Fix buffer overflow on repeated small block deflate. [#218](https://github.com/klauspost/compress/pull/218)
* Allow copying content from an existing ZIP file without decompressing+compressing. [#214](https://github.com/klauspost/compress/pull/214)
* Added [S2](https://github.com/klauspost/compress/tree/master/s2#s2-compression) AMD64 assembler and various optimizations. Stream speed >10GB/s. [#186](https://github.com/klauspost/compress/pull/186)
</details>
<details>
<summary>See changes prior to v1.10.0</summary>
* Jan 20,2020 (v1.9.8) Optimize gzip/deflate with better size estimates and faster table generation. [#207](https://github.com/klauspost/compress/pull/207) by [luyu6056](https://github.com/luyu6056), [#206](https://github.com/klauspost/compress/pull/206).
* Jan 11, 2020: S2 Encode/Decode will use provided buffer if capacity is big enough. [#204](https://github.com/klauspost/compress/pull/204)
* Jan 5, 2020: (v1.9.7) Fix another zstd regression in v1.9.5 - v1.9.6 removed.
* Jan 4, 2020: (v1.9.6) Regression in v1.9.5 fixed causing corrupt zstd encodes in rare cases.
* Jan 4, 2020: Faster IO in [s2c + s2d commandline tools](https://github.com/klauspost/compress/tree/master/s2#commandline-tools) compression/decompression. [#192](https://github.com/klauspost/compress/pull/192)
* Dec 29, 2019: Removed v1.9.5 since fuzz tests showed a compatibility problem with the reference zstandard decoder.
* Dec 29, 2019: (v1.9.5) zstd: 10-20% faster block compression. [#199](https://github.com/klauspost/compress/pull/199)
* Dec 29, 2019: [zip](https://godoc.org/github.com/klauspost/compress/zip) package updated with latest Go features
* Dec 29, 2019: zstd: Single segment flag condintions tweaked. [#197](https://github.com/klauspost/compress/pull/197)
* Dec 18, 2019: s2: Faster compression when ReadFrom is used. [#198](https://github.com/klauspost/compress/pull/198)
* Dec 10, 2019: s2: Fix repeat length output when just above at 16MB limit.
* Dec 10, 2019: zstd: Add function to get decoder as io.ReadCloser. [#191](https://github.com/klauspost/compress/pull/191)
* Dec 3, 2019: (v1.9.4) S2: limit max repeat length. [#188](https://github.com/klauspost/compress/pull/188)
* Dec 3, 2019: Add [WithNoEntropyCompression](https://godoc.org/github.com/klauspost/compress/zstd#WithNoEntropyCompression) to zstd [#187](https://github.com/klauspost/compress/pull/187)
* Dec 3, 2019: Reduce memory use for tests. Check for leaked goroutines.
* Nov 28, 2019 (v1.9.3) Less allocations in stateless deflate.
* Nov 28, 2019: 5-20% Faster huff0 decode. Impacts zstd as well. [#184](https://github.com/klauspost/compress/pull/184)
* Nov 12, 2019 (v1.9.2) Added [Stateless Compression](#stateless-compression) for gzip/deflate.
* Nov 12, 2019: Fixed zstd decompression of large single blocks. [#180](https://github.com/klauspost/compress/pull/180)
* Nov 11, 2019: Set default [s2c](https://github.com/klauspost/compress/tree/master/s2#commandline-tools) block size to 4MB.
* Nov 11, 2019: Reduce inflate memory use by 1KB.
* Nov 10, 2019: Less allocations in deflate bit writer.
* Nov 10, 2019: Fix inconsistent error returned by zstd decoder.
* Oct 28, 2019 (v1.9.1) ztsd: Fix crash when compressing blocks. [#174](https://github.com/klauspost/compress/pull/174)
* Oct 24, 2019 (v1.9.0) zstd: Fix rare data corruption [#173](https://github.com/klauspost/compress/pull/173)
* Oct 24, 2019 zstd: Fix huff0 out of buffer write [#171](https://github.com/klauspost/compress/pull/171) and always return errors [#172](https://github.com/klauspost/compress/pull/172)
* Oct 10, 2019: Big deflate rewrite, 30-40% faster with better compression [#105](https://github.com/klauspost/compress/pull/105)
</details>
<details>
<summary>See changes prior to v1.9.0</summary>
* Oct 10, 2019: (v1.8.6) zstd: Allow partial reads to get flushed data. [#169](https://github.com/klauspost/compress/pull/169)
* Oct 3, 2019: Fix inconsistent results on broken zstd streams.
* Sep 25, 2019: Added `-rm` (remove source files) and `-q` (no output except errors) to `s2c` and `s2d` [commands](https://github.com/klauspost/compress/tree/master/s2#commandline-tools)
* Sep 16, 2019: (v1.8.4) Add `s2c` and `s2d` [commandline tools](https://github.com/klauspost/compress/tree/master/s2#commandline-tools).
* Sep 10, 2019: (v1.8.3) Fix s2 decoder [Skip](https://godoc.org/github.com/klauspost/compress/s2#Reader.Skip).
* Sep 7, 2019: zstd: Added [WithWindowSize](https://godoc.org/github.com/klauspost/compress/zstd#WithWindowSize), contributed by [ianwilkes](https://github.com/ianwilkes).
* Sep 5, 2019: (v1.8.2) Add [WithZeroFrames](https://godoc.org/github.com/klauspost/compress/zstd#WithZeroFrames) which adds full zero payload block encoding option.
* Sep 5, 2019: Lazy initialization of zstandard predefined en/decoder tables.
* Aug 26, 2019: (v1.8.1) S2: 1-2% compression increase in "better" compression mode.
* Aug 26, 2019: zstd: Check maximum size of Huffman 1X compressed literals while decoding.
* Aug 24, 2019: (v1.8.0) Added [S2 compression](https://github.com/klauspost/compress/tree/master/s2#s2-compression), a high performance replacement for Snappy.
* Aug 21, 2019: (v1.7.6) Fixed minor issues found by fuzzer. One could lead to zstd not decompressing.
* Aug 18, 2019: Add [fuzzit](https://fuzzit.dev/) continuous fuzzing.
* Aug 14, 2019: zstd: Skip incompressible data 2x faster. [#147](https://github.com/klauspost/compress/pull/147)
* Aug 4, 2019 (v1.7.5): Better literal compression. [#146](https://github.com/klauspost/compress/pull/146)
* Aug 4, 2019: Faster zstd compression. [#143](https://github.com/klauspost/compress/pull/143) [#144](https://github.com/klauspost/compress/pull/144)
* Aug 4, 2019: Faster zstd decompression. [#145](https://github.com/klauspost/compress/pull/145) [#143](https://github.com/klauspost/compress/pull/143) [#142](https://github.com/klauspost/compress/pull/142)
* July 15, 2019 (v1.7.4): Fix double EOF block in rare cases on zstd encoder.
* July 15, 2019 (v1.7.3): Minor speedup/compression increase in default zstd encoder.
* July 14, 2019: zstd decoder: Fix decompression error on multiple uses with mixed content.
* July 7, 2019 (v1.7.2): Snappy update, zstd decoder potential race fix.
* June 17, 2019: zstd decompression bugfix.
* June 17, 2019: fix 32 bit builds.
* June 17, 2019: Easier use in modules (less dependencies).
* June 9, 2019: New stronger "default" [zstd](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression mode. Matches zstd default compression ratio.
* June 5, 2019: 20-40% throughput in [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and better compression.
* June 5, 2019: deflate/gzip compression: Reduce memory usage of lower compression levels.
* June 2, 2019: Added [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression!
* May 25, 2019: deflate/gzip: 10% faster bit writer, mostly visible in lower levels.
* Apr 22, 2019: [zstd](https://github.com/klauspost/compress/tree/master/zstd#zstd) decompression added.
* Aug 1, 2018: Added [huff0 README](https://github.com/klauspost/compress/tree/master/huff0#huff0-entropy-compression).
* Jul 8, 2018: Added [Performance Update 2018](#performance-update-2018) below.
* Jun 23, 2018: Merged [Go 1.11 inflate optimizations](https://go-review.googlesource.com/c/go/+/102235). Go 1.9 is now required. Backwards compatible version tagged with [v1.3.0](https://github.com/klauspost/compress/releases/tag/v1.3.0).
* Apr 2, 2018: Added [huff0](https://godoc.org/github.com/klauspost/compress/huff0) en/decoder. Experimental for now, API may change.
* Mar 4, 2018: Added [FSE Entropy](https://godoc.org/github.com/klauspost/compress/fse) en/decoder. Experimental for now, API may change.
* Nov 3, 2017: Add compression [Estimate](https://godoc.org/github.com/klauspost/compress#Estimate) function.
* May 28, 2017: Reduce allocations when resetting decoder.
* Apr 02, 2017: Change back to official crc32, since changes were merged in Go 1.7.
* Jan 14, 2017: Reduce stack pressure due to array copies. See [Issue #18625](https://github.com/golang/go/issues/18625).
* Oct 25, 2016: Level 2-4 have been rewritten and now offers significantly better performance than before.
* Oct 20, 2016: Port zlib changes from Go 1.7 to fix zlib writer issue. Please update.
* Oct 16, 2016: Go 1.7 changes merged. Apples to apples this package is a few percent faster, but has a significantly better balance between speed and compression per level.
* Mar 24, 2016: Always attempt Huffman encoding on level 4-7. This improves base 64 encoded data compression.
* Mar 24, 2016: Small speedup for level 1-3.
* Feb 19, 2016: Faster bit writer, level -2 is 15% faster, level 1 is 4% faster.
* Feb 19, 2016: Handle small payloads faster in level 1-3.
* Feb 19, 2016: Added faster level 2 + 3 compression modes.
* Feb 19, 2016: [Rebalanced compression levels](https://blog.klauspost.com/rebalancing-deflate-compression-levels/), so there is a more even progresssion in terms of compression. New default level is 5.
* Feb 14, 2016: Snappy: Merge upstream changes.
* Feb 14, 2016: Snappy: Fix aggressive skipping.
* Feb 14, 2016: Snappy: Update benchmark.
* Feb 13, 2016: Deflate: Fixed assembler problem that could lead to sub-optimal compression.
* Feb 12, 2016: Snappy: Added AMD64 SSE 4.2 optimizations to matching, which makes easy to compress material run faster. Typical speedup is around 25%.
* Feb 9, 2016: Added Snappy package fork. This version is 5-7% faster, much more on hard to compress content.
* Jan 30, 2016: Optimize level 1 to 3 by not considering static dictionary or storing uncompressed. ~4-5% speedup.
* Jan 16, 2016: Optimization on deflate level 1,2,3 compression.
* Jan 8 2016: Merge [CL 18317](https://go-review.googlesource.com/#/c/18317): fix reading, writing of zip64 archives.
* Dec 8 2015: Make level 1 and -2 deterministic even if write size differs.
* Dec 8 2015: Split encoding functions, so hashing and matching can potentially be inlined. 1-3% faster on AMD64. 5% faster on other platforms.
* Dec 8 2015: Fixed rare [one byte out-of bounds read](https://github.com/klauspost/compress/issues/20). Please update!
* Nov 23 2015: Optimization on token writer. ~2-4% faster. Contributed by [@dsnet](https://github.com/dsnet).
* Nov 20 2015: Small optimization to bit writer on 64 bit systems.
* Nov 17 2015: Fixed out-of-bound errors if the underlying Writer returned an error. See [#15](https://github.com/klauspost/compress/issues/15).
* Nov 12 2015: Added [io.WriterTo](https://golang.org/pkg/io/#WriterTo) support to gzip/inflate.
* Nov 11 2015: Merged [CL 16669](https://go-review.googlesource.com/#/c/16669/4): archive/zip: enable overriding (de)compressors per file
* Oct 15 2015: Added skipping on uncompressible data. Random data speed up >5x.
</details>
# deflate usage
The packages are drop-in replacements for standard libraries. Simply replace the import path to use them:
| old import | new import | Documentation
|--------------------|-----------------------------------------|--------------------|
| `compress/gzip` | `github.com/klauspost/compress/gzip` | [gzip](https://pkg.go.dev/github.com/klauspost/compress/gzip?tab=doc)
| `compress/zlib` | `github.com/klauspost/compress/zlib` | [zlib](https://pkg.go.dev/github.com/klauspost/compress/zlib?tab=doc)
| `archive/zip` | `github.com/klauspost/compress/zip` | [zip](https://pkg.go.dev/github.com/klauspost/compress/zip?tab=doc)
| `compress/flate` | `github.com/klauspost/compress/flate` | [flate](https://pkg.go.dev/github.com/klauspost/compress/flate?tab=doc)
* Optimized [deflate](https://godoc.org/github.com/klauspost/compress/flate) packages which can be used as a dropin replacement for [gzip](https://godoc.org/github.com/klauspost/compress/gzip), [zip](https://godoc.org/github.com/klauspost/compress/zip) and [zlib](https://godoc.org/github.com/klauspost/compress/zlib).
You may also be interested in [pgzip](https://github.com/klauspost/pgzip), which is a drop in replacement for gzip, which support multithreaded compression on big files and the optimized [crc32](https://github.com/klauspost/crc32) package used by these packages.
The packages contains the same as the standard library, so you can use the godoc for that: [gzip](http://golang.org/pkg/compress/gzip/), [zip](http://golang.org/pkg/archive/zip/), [zlib](http://golang.org/pkg/compress/zlib/), [flate](http://golang.org/pkg/compress/flate/).
Currently there is only minor speedup on decompression (mostly CRC32 calculation).
Memory usage is typically 1MB for a Writer. stdlib is in the same range.
If you expect to have a lot of concurrently allocated Writers consider using
the stateless compress described below.
For compression performance, see: [this spreadsheet](https://docs.google.com/spreadsheets/d/1nuNE2nPfuINCZJRMt6wFWhKpToF95I47XjSsc-1rbPQ/edit?usp=sharing).
# Stateless compression
This package offers stateless compression as a special option for gzip/deflate.
It will do compression but without maintaining any state between Write calls.
This means there will be no memory kept between Write calls, but compression and speed will be suboptimal.
This is only relevant in cases where you expect to run many thousands of compressors concurrently,
but with very little activity. This is *not* intended for regular web servers serving individual requests.
Because of this, the size of actual Write calls will affect output size.
In gzip, specify level `-3` / `gzip.StatelessCompression` to enable.
For direct deflate use, NewStatelessWriter and StatelessDeflate are available. See [documentation](https://godoc.org/github.com/klauspost/compress/flate#NewStatelessWriter)
A `bufio.Writer` can of course be used to control write sizes. For example, to use a 4KB buffer:
```
// replace 'ioutil.Discard' with your output.
gzw, err := gzip.NewWriterLevel(ioutil.Discard, gzip.StatelessCompression)
if err != nil {
return err
}
defer gzw.Close()
w := bufio.NewWriterSize(gzw, 4096)
defer w.Flush()
// Write to 'w'
```
This will only use up to 4KB in memory when the writer is idle.
Compression is almost always worse than the fastest compression level
and each write will allocate (a little) memory.
# Performance Update 2018
It has been a while since we have been looking at the speed of this package compared to the standard library, so I thought I would re-do my tests and give some overall recommendations based on the current state. All benchmarks have been performed with Go 1.10 on my Desktop Intel(R) Core(TM) i7-2600 CPU @3.40GHz. Since I last ran the tests, I have gotten more RAM, which means tests with big files are no longer limited by my SSD.
The raw results are in my [updated spreadsheet](https://docs.google.com/spreadsheets/d/1nuNE2nPfuINCZJRMt6wFWhKpToF95I47XjSsc-1rbPQ/edit?usp=sharing). Due to cgo changes and upstream updates i could not get the cgo version of gzip to compile. Instead I included the [zstd](https://github.com/datadog/zstd) cgo implementation. If I get cgo gzip to work again, I might replace the results in the sheet.
The columns to take note of are: *MB/s* - the throughput. *Reduction* - the data size reduction in percent of the original. *Rel Speed* relative speed compared to the standard library at the same level. *Smaller* - how many percent smaller is the compressed output compared to stdlib. Negative means the output was bigger. *Loss* means the loss (or gain) in compression as a percentage difference of the input.
The `gzstd` (standard library gzip) and `gzkp` (this package gzip) only uses one CPU core. [`pgzip`](https://github.com/klauspost/pgzip), [`bgzf`](https://github.com/biogo/hts/tree/master/bgzf) uses all 4 cores. [`zstd`](https://github.com/DataDog/zstd) uses one core, and is a beast (but not Go, yet).
## Overall differences.
There appears to be a roughly 5-10% speed advantage over the standard library when comparing at similar compression levels.
The biggest difference you will see is the result of [re-balancing](https://blog.klauspost.com/rebalancing-deflate-compression-levels/) the compression levels. I wanted by library to give a smoother transition between the compression levels than the standard library.
This package attempts to provide a more smooth transition, where "1" is taking a lot of shortcuts, "5" is the reasonable trade-off and "9" is the "give me the best compression", and the values in between gives something reasonable in between. The standard library has big differences in levels 1-4, but levels 5-9 having no significant gains - often spending a lot more time than can be justified by the achieved compression.
There are links to all the test data in the [spreadsheet](https://docs.google.com/spreadsheets/d/1nuNE2nPfuINCZJRMt6wFWhKpToF95I47XjSsc-1rbPQ/edit?usp=sharing) in the top left field on each tab.
## Web Content
This test set aims to emulate typical use in a web server. The test-set is 4GB data in 53k files, and is a mixture of (mostly) HTML, JS, CSS.
Since level 1 and 9 are close to being the same code, they are quite close. But looking at the levels in-between the differences are quite big.
Looking at level 6, this package is 88% faster, but will output about 6% more data. For a web server, this means you can serve 88% more data, but have to pay for 6% more bandwidth. You can draw your own conclusions on what would be the most expensive for your case.
## Object files
This test is for typical data files stored on a server. In this case it is a collection of Go precompiled objects. They are very compressible.
The picture is similar to the web content, but with small differences since this is very compressible. Levels 2-3 offer good speed, but is sacrificing quite a bit of compression.
The standard library seems suboptimal on level 3 and 4 - offering both worse compression and speed than level 6 & 7 of this package respectively.
## Highly Compressible File
This is a JSON file with very high redundancy. The reduction starts at 95% on level 1, so in real life terms we are dealing with something like a highly redundant stream of data, etc.
It is definitely visible that we are dealing with specialized content here, so the results are very scattered. This package does not do very well at levels 1-4, but picks up significantly at level 5 and levels 7 and 8 offering great speed for the achieved compression.
So if you know you content is extremely compressible you might want to go slightly higher than the defaults. The standard library has a huge gap between levels 3 and 4 in terms of speed (2.75x slowdown), so it offers little "middle ground".
## Medium-High Compressible
This is a pretty common test corpus: [enwik9](http://mattmahoney.net/dc/textdata.html). It contains the first 10^9 bytes of the English Wikipedia dump on Mar. 3, 2006. This is a very good test of typical text based compression and more data heavy streams.
We see a similar picture here as in "Web Content". On equal levels some compression is sacrificed for more speed. Level 5 seems to be the best trade-off between speed and size, beating stdlib level 3 in both.
## Medium Compressible
I will combine two test sets, one [10GB file set](http://mattmahoney.net/dc/10gb.html) and a VM disk image (~8GB). Both contain different data types and represent a typical backup scenario.
The most notable thing is how quickly the standard library drops to very low compression speeds around level 5-6 without any big gains in compression. Since this type of data is fairly common, this does not seem like good behavior.
## Un-compressible Content
This is mainly a test of how good the algorithms are at detecting un-compressible input. The standard library only offers this feature with very conservative settings at level 1. Obviously there is no reason for the algorithms to try to compress input that cannot be compressed. The only downside is that it might skip some compressible data on false detections.
## Huffman only compression
This compression library adds a special compression level, named `HuffmanOnly`, which allows near linear time compression. This is done by completely disabling matching of previous data, and only reduce the number of bits to represent each character.
This means that often used characters, like 'e' and ' ' (space) in text use the fewest bits to represent, and rare characters like '¤' takes more bits to represent. For more information see [wikipedia](https://en.wikipedia.org/wiki/Huffman_coding) or this nice [video](https://youtu.be/ZdooBTdW5bM).
Since this type of compression has much less variance, the compression speed is mostly unaffected by the input data, and is usually more than *180MB/s* for a single core.
The downside is that the compression ratio is usually considerably worse than even the fastest conventional compression. The compression ratio can never be better than 8:1 (12.5%).
The linear time compression can be used as a "better than nothing" mode, where you cannot risk the encoder to slow down on some content. For comparison, the size of the "Twain" text is *233460 bytes* (+29% vs. level 1) and encode speed is 144MB/s (4.5x level 1). So in this case you trade a 30% size increase for a 4 times speedup.
For more information see my blog post on [Fast Linear Time Compression](http://blog.klauspost.com/constant-time-gzipzip-compression/).
This is implemented on Go 1.7 as "Huffman Only" mode, though not exposed for gzip.
# Other packages
Here are other packages of good quality and pure Go (no cgo wrappers or autoconverted code):
* [github.com/pierrec/lz4](https://github.com/pierrec/lz4) - strong multithreaded LZ4 compression.
* [github.com/cosnicolaou/pbzip2](https://github.com/cosnicolaou/pbzip2) - multithreaded bzip2 decompression.
* [github.com/dsnet/compress](https://github.com/dsnet/compress) - brotli decompression, bzip2 writer.
# license
This code is licensed under the same conditions as the original Go code. See LICENSE file.

@ -1,85 +0,0 @@
package compress
import "math"
// Estimate returns a normalized compressibility estimate of block b.
// Values close to zero are likely uncompressible.
// Values above 0.1 are likely to be compressible.
// Values above 0.5 are very compressible.
// Very small lengths will return 0.
func Estimate(b []byte) float64 {
if len(b) < 16 {
return 0
}
// Correctly predicted order 1
hits := 0
lastMatch := false
var o1 [256]byte
var hist [256]int
c1 := byte(0)
for _, c := range b {
if c == o1[c1] {
// We only count a hit if there was two correct predictions in a row.
if lastMatch {
hits++
}
lastMatch = true
} else {
lastMatch = false
}
o1[c1] = c
c1 = c
hist[c]++
}
// Use x^0.6 to give better spread
prediction := math.Pow(float64(hits)/float64(len(b)), 0.6)
// Calculate histogram distribution
variance := float64(0)
avg := float64(len(b)) / 256
for _, v := range hist {
Δ := float64(v) - avg
variance += Δ * Δ
}
stddev := math.Sqrt(float64(variance)) / float64(len(b))
exp := math.Sqrt(1 / float64(len(b)))
// Subtract expected stddev
stddev -= exp
if stddev < 0 {
stddev = 0
}
stddev *= 1 + exp
// Use x^0.4 to give better spread
entropy := math.Pow(stddev, 0.4)
// 50/50 weight between prediction and histogram distribution
return math.Pow((prediction+entropy)/2, 0.9)
}
// ShannonEntropyBits returns the number of bits minimum required to represent
// an entropy encoding of the input bytes.
// https://en.wiktionary.org/wiki/Shannon_entropy
func ShannonEntropyBits(b []byte) int {
if len(b) == 0 {
return 0
}
var hist [256]int
for _, c := range b {
hist[c]++
}
shannon := float64(0)
invTotal := 1.0 / float64(len(b))
for _, v := range hist[:] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
}
}
return int(math.Ceil(shannon))
}

@ -1,903 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Copyright (c) 2015 Klaus Post
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"encoding/binary"
"fmt"
"io"
"math"
)
const (
NoCompression = 0
BestSpeed = 1
BestCompression = 9
DefaultCompression = -1
// HuffmanOnly disables Lempel-Ziv match searching and only performs Huffman
// entropy encoding. This mode is useful in compressing data that has
// already been compressed with an LZ style algorithm (e.g. Snappy or LZ4)
// that lacks an entropy encoder. Compression gains are achieved when
// certain bytes in the input stream occur more frequently than others.
//
// Note that HuffmanOnly produces a compressed output that is
// RFC 1951 compliant. That is, any valid DEFLATE decompressor will
// continue to be able to decompress this output.
HuffmanOnly = -2
ConstantCompression = HuffmanOnly // compatibility alias.
logWindowSize = 15
windowSize = 1 << logWindowSize
windowMask = windowSize - 1
logMaxOffsetSize = 15 // Standard DEFLATE
minMatchLength = 4 // The smallest match that the compressor looks for
maxMatchLength = 258 // The longest match for the compressor
minOffsetSize = 1 // The shortest offset that makes any sense
// The maximum number of tokens we will encode at the time.
// Smaller sizes usually creates less optimal blocks.
// Bigger can make context switching slow.
// We use this for levels 7-9, so we make it big.
maxFlateBlockTokens = 1 << 15
maxStoreBlockSize = 65535
hashBits = 17 // After 17 performance degrades
hashSize = 1 << hashBits
hashMask = (1 << hashBits) - 1
hashShift = (hashBits + minMatchLength - 1) / minMatchLength
maxHashOffset = 1 << 28
skipNever = math.MaxInt32
debugDeflate = false
)
type compressionLevel struct {
good, lazy, nice, chain, fastSkipHashing, level int
}
// Compression levels have been rebalanced from zlib deflate defaults
// to give a bigger spread in speed and compression.
// See https://blog.klauspost.com/rebalancing-deflate-compression-levels/
var levels = []compressionLevel{
{}, // 0
// Level 1-6 uses specialized algorithm - values not used
{0, 0, 0, 0, 0, 1},
{0, 0, 0, 0, 0, 2},
{0, 0, 0, 0, 0, 3},
{0, 0, 0, 0, 0, 4},
{0, 0, 0, 0, 0, 5},
{0, 0, 0, 0, 0, 6},
// Levels 7-9 use increasingly more lazy matching
// and increasingly stringent conditions for "good enough".
{8, 12, 16, 24, skipNever, 7},
{16, 30, 40, 64, skipNever, 8},
{32, 258, 258, 1024, skipNever, 9},
}
// advancedState contains state for the advanced levels, with bigger hash tables, etc.
type advancedState struct {
// deflate state
length int
offset int
maxInsertIndex int
chainHead int
hashOffset int
ii uint16 // position of last match, intended to overflow to reset.
// input window: unprocessed data is window[index:windowEnd]
index int
estBitsPerByte int
hashMatch [maxMatchLength + minMatchLength]uint32
// Input hash chains
// hashHead[hashValue] contains the largest inputIndex with the specified hash value
// If hashHead[hashValue] is within the current window, then
// hashPrev[hashHead[hashValue] & windowMask] contains the previous index
// with the same hash value.
hashHead [hashSize]uint32
hashPrev [windowSize]uint32
}
type compressor struct {
compressionLevel
h *huffmanEncoder
w *huffmanBitWriter
// compression algorithm
fill func(*compressor, []byte) int // copy data to window
step func(*compressor) // process window
window []byte
windowEnd int
blockStart int // window index where current tokens start
err error
// queued output tokens
tokens tokens
fast fastEnc
state *advancedState
sync bool // requesting flush
byteAvailable bool // if true, still need to process window[index-1].
}
func (d *compressor) fillDeflate(b []byte) int {
s := d.state
if s.index >= 2*windowSize-(minMatchLength+maxMatchLength) {
// shift the window by windowSize
copy(d.window[:], d.window[windowSize:2*windowSize])
s.index -= windowSize
d.windowEnd -= windowSize
if d.blockStart >= windowSize {
d.blockStart -= windowSize
} else {
d.blockStart = math.MaxInt32
}
s.hashOffset += windowSize
if s.hashOffset > maxHashOffset {
delta := s.hashOffset - 1
s.hashOffset -= delta
s.chainHead -= delta
// Iterate over slices instead of arrays to avoid copying
// the entire table onto the stack (Issue #18625).
for i, v := range s.hashPrev[:] {
if int(v) > delta {
s.hashPrev[i] = uint32(int(v) - delta)
} else {
s.hashPrev[i] = 0
}
}
for i, v := range s.hashHead[:] {
if int(v) > delta {
s.hashHead[i] = uint32(int(v) - delta)
} else {
s.hashHead[i] = 0
}
}
}
}
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
func (d *compressor) writeBlock(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
var window []byte
if d.blockStart <= index {
window = d.window[d.blockStart:index]
}
d.blockStart = index
//d.w.writeBlock(tok, eof, window)
d.w.writeBlockDynamic(tok, eof, window, d.sync)
return d.w.err
}
return nil
}
// writeBlockSkip writes the current block and uses the number of tokens
// to determine if the block should be stored on no matches, or
// only huffman encoded.
func (d *compressor) writeBlockSkip(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
if d.blockStart <= index {
window := d.window[d.blockStart:index]
// If we removed less than a 64th of all literals
// we huffman compress the block.
if int(tok.n) > len(window)-int(tok.n>>6) {
d.w.writeBlockHuff(eof, window, d.sync)
} else {
// Write a dynamic huffman block.
d.w.writeBlockDynamic(tok, eof, window, d.sync)
}
} else {
d.w.writeBlock(tok, eof, nil)
}
d.blockStart = index
return d.w.err
}
return nil
}
// fillWindow will fill the current window with the supplied
// dictionary and calculate all hashes.
// This is much faster than doing a full encode.
// Should only be used after a start/reset.
func (d *compressor) fillWindow(b []byte) {
// Do not fill window if we are in store-only or huffman mode.
if d.level <= 0 {
return
}
if d.fast != nil {
// encode the last data, but discard the result
if len(b) > maxMatchOffset {
b = b[len(b)-maxMatchOffset:]
}
d.fast.Encode(&d.tokens, b)
d.tokens.Reset()
return
}
s := d.state
// If we are given too much, cut it.
if len(b) > windowSize {
b = b[len(b)-windowSize:]
}
// Add all to window.
n := copy(d.window[d.windowEnd:], b)
// Calculate 256 hashes at the time (more L1 cache hits)
loops := (n + 256 - minMatchLength) / 256
for j := 0; j < loops; j++ {
startindex := j * 256
end := startindex + 256 + minMatchLength - 1
if end > n {
end = n
}
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize <= 0 {
continue
}
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
// Update window information.
d.windowEnd += n
s.index = n
}
// Try to find a match starting at index whose length is greater than prevSize.
// We only look at chainCount possibilities before giving up.
// pos = s.index, prevHead = s.chainHead-s.hashOffset, prevLength=minMatchLength-1, lookahead
func (d *compressor) findMatch(pos int, prevHead int, lookahead int) (length, offset int, ok bool) {
minMatchLook := maxMatchLength
if lookahead < minMatchLook {
minMatchLook = lookahead
}
win := d.window[0 : pos+minMatchLook]
// We quit when we get a match that's at least nice long
nice := len(win) - pos
if d.nice < nice {
nice = d.nice
}
// If we've got a match that's good enough, only look in 1/4 the chain.
tries := d.chain
length = minMatchLength - 1
wEnd := win[pos+length]
wPos := win[pos:]
minIndex := pos - windowSize
if minIndex < 0 {
minIndex = 0
}
offset = 0
cGain := 0
if d.chain < 100 {
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
length = n
offset = pos - i
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
// Some like it higher (CSV), some like it lower (JSON)
const baseCost = 6
// Base is 4 bytes at with an additional cost.
// Matches must be better than this.
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
// Calculate gain. Estimate
newGain := d.h.bitLengthRaw(wPos[:n]) - int(offsetExtraBits[offsetCode(uint32(pos-i))]) - baseCost - int(lengthExtraBits[lengthCodes[(n-3)&255]])
//fmt.Println(n, "gain:", newGain, "prev:", cGain, "raw:", d.h.bitLengthRaw(wPos[:n]))
if newGain > cGain {
length = n
offset = pos - i
cGain = newGain
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
func (d *compressor) writeStoredBlock(buf []byte) error {
if d.w.writeStoredHeader(len(buf), false); d.w.err != nil {
return d.w.err
}
d.w.writeBytes(buf)
return d.w.err
}
// hash4 returns a hash representation of the first 4 bytes
// of the supplied slice.
// The caller must ensure that len(b) >= 4.
func hash4(b []byte) uint32 {
return hash4u(binary.LittleEndian.Uint32(b), hashBits)
}
// bulkHash4 will compute hashes using the same
// algorithm as hash4
func bulkHash4(b []byte, dst []uint32) {
if len(b) < 4 {
return
}
hb := binary.LittleEndian.Uint32(b)
dst[0] = hash4u(hb, hashBits)
end := len(b) - 4 + 1
for i := 1; i < end; i++ {
hb = (hb >> 8) | uint32(b[i+3])<<24
dst[i] = hash4u(hb, hashBits)
}
}
func (d *compressor) initDeflate() {
d.window = make([]byte, 2*windowSize)
d.byteAvailable = false
d.err = nil
if d.state == nil {
return
}
s := d.state
s.index = 0
s.hashOffset = 1
s.length = minMatchLength - 1
s.offset = 0
s.chainHead = -1
}
// deflateLazy is the same as deflate, but with d.fastSkipHashing == skipNever,
// meaning it always has lazy matching on.
func (d *compressor) deflateLazy() {
s := d.state
// Sanity enables additional runtime tests.
// It's intended to be used during development
// to supplement the currently ad-hoc unit tests.
const sanity = debugDeflate
if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync {
return
}
if d.windowEnd != s.index && d.chain > 100 {
// Get literal huffman coder.
if d.h == nil {
d.h = newHuffmanEncoder(maxFlateBlockTokens)
}
var tmp [256]uint16
for _, v := range d.window[s.index:d.windowEnd] {
tmp[v]++
}
d.h.generate(tmp[:], 15)
}
s.maxInsertIndex = d.windowEnd - (minMatchLength - 1)
for {
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
lookahead := d.windowEnd - s.index
if lookahead < minMatchLength+maxMatchLength {
if !d.sync {
return
}
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
if lookahead == 0 {
// Flush current output block if any.
if d.byteAvailable {
// There is still one pending token that needs to be flushed
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
}
if d.tokens.n > 0 {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
return
}
}
if s.index < s.maxInsertIndex {
// Update the hash
hash := hash4(d.window[s.index:])
ch := s.hashHead[hash]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[hash] = uint32(s.index + s.hashOffset)
}
prevLength := s.length
prevOffset := s.offset
s.length = minMatchLength - 1
s.offset = 0
minIndex := s.index - windowSize
if minIndex < 0 {
minIndex = 0
}
if s.chainHead-s.hashOffset >= minIndex && lookahead > prevLength && prevLength < d.lazy {
if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead); ok {
s.length = newLength
s.offset = newOffset
}
}
if prevLength >= minMatchLength && s.length <= prevLength {
// Check for better match at end...
//
// checkOff must be >=2 since we otherwise risk checking s.index
// Offset of 2 seems to yield best results.
const checkOff = 2
prevIndex := s.index - 1
if prevIndex+prevLength+checkOff < s.maxInsertIndex {
end := lookahead
if lookahead > maxMatchLength {
end = maxMatchLength
}
end += prevIndex
idx := prevIndex + prevLength - (4 - checkOff)
h := hash4(d.window[idx:])
ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength + (4 - checkOff)
if ch2 > minIndex {
length := matchLen(d.window[prevIndex:end], d.window[ch2:])
// It seems like a pure length metric is best.
if length > prevLength {
prevLength = length
prevOffset = prevIndex - ch2
}
}
}
// There was a match at the previous step, and the current match is
// not better. Output the previous match.
d.tokens.AddMatch(uint32(prevLength-3), uint32(prevOffset-minOffsetSize))
// Insert in the hash table all strings up to the end of the match.
// index and index-1 are already inserted. If there is not enough
// lookahead, the last two strings are not inserted into the hash
// table.
newIndex := s.index + prevLength - 1
// Calculate missing hashes
end := newIndex
if end > s.maxInsertIndex {
end = s.maxInsertIndex
}
end += minMatchLength - 1
startindex := s.index + 1
if startindex > s.maxInsertIndex {
startindex = s.maxInsertIndex
}
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize > 0 {
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
s.index = newIndex
d.byteAvailable = false
s.length = minMatchLength - 1
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.ii = 0
} else {
// Reset, if we got a match this run.
if s.length >= minMatchLength {
s.ii = 0
}
// We have a byte waiting. Emit it.
if d.byteAvailable {
s.ii++
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
// If we have a long run of no matches, skip additional bytes
// Resets when s.ii overflows after 64KB.
if n := int(s.ii) - d.chain; n > 0 {
n = 1 + int(n>>6)
for j := 0; j < n; j++ {
if s.index >= d.windowEnd-1 {
break
}
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
// Index...
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
s.index++
}
// Flush last byte
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
// s.length = minMatchLength - 1 // not needed, since s.ii is reset above, so it should never be > minMatchLength
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
}
} else {
s.index++
d.byteAvailable = true
}
}
}
}
func (d *compressor) store() {
if d.windowEnd > 0 && (d.windowEnd == maxStoreBlockSize || d.sync) {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
d.windowEnd = 0
}
}
// fillWindow will fill the buffer with data for huffman-only compression.
// The number of bytes copied is returned.
func (d *compressor) fillBlock(b []byte) int {
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
// storeHuff will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeHuff() {
if d.windowEnd < len(d.window) && !d.sync || d.windowEnd == 0 {
return
}
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
d.windowEnd = 0
}
// storeFast will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeFast() {
// We only compress if we have maxStoreBlockSize.
if d.windowEnd < len(d.window) {
if !d.sync {
return
}
// Handle extremely small sizes.
if d.windowEnd < 128 {
if d.windowEnd == 0 {
return
}
if d.windowEnd <= 32 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
} else {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], true)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
d.fast.Reset()
return
}
}
d.fast.Encode(&d.tokens, d.window[:d.windowEnd])
// If we made zero matches, store the block as is.
if d.tokens.n == 0 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
// If we removed less than 1/16th, huffman compress the block.
} else if int(d.tokens.n) > d.windowEnd-(d.windowEnd>>4) {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
} else {
d.w.writeBlockDynamic(&d.tokens, false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
}
// write will add input byte to the stream.
// Unless an error occurs all bytes will be consumed.
func (d *compressor) write(b []byte) (n int, err error) {
if d.err != nil {
return 0, d.err
}
n = len(b)
for len(b) > 0 {
if d.windowEnd == len(d.window) || d.sync {
d.step(d)
}
b = b[d.fill(d, b):]
if d.err != nil {
return 0, d.err
}
}
return n, d.err
}
func (d *compressor) syncFlush() error {
d.sync = true
if d.err != nil {
return d.err
}
d.step(d)
if d.err == nil {
d.w.writeStoredHeader(0, false)
d.w.flush()
d.err = d.w.err
}
d.sync = false
return d.err
}
func (d *compressor) init(w io.Writer, level int) (err error) {
d.w = newHuffmanBitWriter(w)
switch {
case level == NoCompression:
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).store
case level == ConstantCompression:
d.w.logNewTablePenalty = 10
d.window = make([]byte, 32<<10)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeHuff
case level == DefaultCompression:
level = 5
fallthrough
case level >= 1 && level <= 6:
d.w.logNewTablePenalty = 7
d.fast = newFastEnc(level)
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeFast
case 7 <= level && level <= 9:
d.w.logNewTablePenalty = 8
d.state = &advancedState{}
d.compressionLevel = levels[level]
d.initDeflate()
d.fill = (*compressor).fillDeflate
d.step = (*compressor).deflateLazy
default:
return fmt.Errorf("flate: invalid compression level %d: want value in range [-2, 9]", level)
}
d.level = level
return nil
}
// reset the state of the compressor.
func (d *compressor) reset(w io.Writer) {
d.w.reset(w)
d.sync = false
d.err = nil
// We only need to reset a few things for Snappy.
if d.fast != nil {
d.fast.Reset()
d.windowEnd = 0
d.tokens.Reset()
return
}
switch d.compressionLevel.chain {
case 0:
// level was NoCompression or ConstantCompresssion.
d.windowEnd = 0
default:
s := d.state
s.chainHead = -1
for i := range s.hashHead {
s.hashHead[i] = 0
}
for i := range s.hashPrev {
s.hashPrev[i] = 0
}
s.hashOffset = 1
s.index, d.windowEnd = 0, 0
d.blockStart, d.byteAvailable = 0, false
d.tokens.Reset()
s.length = minMatchLength - 1
s.offset = 0
s.ii = 0
s.maxInsertIndex = 0
}
}
func (d *compressor) close() error {
if d.err != nil {
return d.err
}
d.sync = true
d.step(d)
if d.err != nil {
return d.err
}
if d.w.writeStoredHeader(0, true); d.w.err != nil {
return d.w.err
}
d.w.flush()
d.w.reset(nil)
return d.w.err
}
// NewWriter returns a new Writer compressing data at the given level.
// Following zlib, levels range from 1 (BestSpeed) to 9 (BestCompression);
// higher levels typically run slower but compress more.
// Level 0 (NoCompression) does not attempt any compression; it only adds the
// necessary DEFLATE framing.
// Level -1 (DefaultCompression) uses the default compression level.
// Level -2 (ConstantCompression) will use Huffman compression only, giving
// a very fast compression for all types of input, but sacrificing considerable
// compression efficiency.
//
// If level is in the range [-2, 9] then the error returned will be nil.
// Otherwise the error returned will be non-nil.
func NewWriter(w io.Writer, level int) (*Writer, error) {
var dw Writer
if err := dw.d.init(w, level); err != nil {
return nil, err
}
return &dw, nil
}
// NewWriterDict is like NewWriter but initializes the new
// Writer with a preset dictionary. The returned Writer behaves
// as if the dictionary had been written to it without producing
// any compressed output. The compressed data written to w
// can only be decompressed by a Reader initialized with the
// same dictionary.
func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) {
zw, err := NewWriter(w, level)
if err != nil {
return nil, err
}
zw.d.fillWindow(dict)
zw.dict = append(zw.dict, dict...) // duplicate dictionary for Reset method.
return zw, err
}
// A Writer takes data written to it and writes the compressed
// form of that data to an underlying writer (see NewWriter).
type Writer struct {
d compressor
dict []byte
}
// Write writes data to w, which will eventually write the
// compressed form of data to its underlying writer.
func (w *Writer) Write(data []byte) (n int, err error) {
return w.d.write(data)
}
// Flush flushes any pending data to the underlying writer.
// It is useful mainly in compressed network protocols, to ensure that
// a remote reader has enough data to reconstruct a packet.
// Flush does not return until the data has been written.
// Calling Flush when there is no pending data still causes the Writer
// to emit a sync marker of at least 4 bytes.
// If the underlying writer returns an error, Flush returns that error.
//
// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
func (w *Writer) Flush() error {
// For more about flushing:
// http://www.bolet.org/~pornin/deflate-flush.html
return w.d.syncFlush()
}
// Close flushes and closes the writer.
func (w *Writer) Close() error {
return w.d.close()
}
// Reset discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level and dictionary.
func (w *Writer) Reset(dst io.Writer) {
if len(w.dict) > 0 {
// w was created with NewWriterDict
w.d.reset(dst)
if dst != nil {
w.d.fillWindow(w.dict)
}
} else {
// w was created with NewWriter
w.d.reset(dst)
}
}
// ResetDict discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level, but sets a specific dictionary.
func (w *Writer) ResetDict(dst io.Writer, dict []byte) {
w.dict = dict
w.d.reset(dst)
w.d.fillWindow(w.dict)
}

@ -1,184 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// dictDecoder implements the LZ77 sliding dictionary as used in decompression.
// LZ77 decompresses data through sequences of two forms of commands:
//
// * Literal insertions: Runs of one or more symbols are inserted into the data
// stream as is. This is accomplished through the writeByte method for a
// single symbol, or combinations of writeSlice/writeMark for multiple symbols.
// Any valid stream must start with a literal insertion if no preset dictionary
// is used.
//
// * Backward copies: Runs of one or more symbols are copied from previously
// emitted data. Backward copies come as the tuple (dist, length) where dist
// determines how far back in the stream to copy from and length determines how
// many bytes to copy. Note that it is valid for the length to be greater than
// the distance. Since LZ77 uses forward copies, that situation is used to
// perform a form of run-length encoding on repeated runs of symbols.
// The writeCopy and tryWriteCopy are used to implement this command.
//
// For performance reasons, this implementation performs little to no sanity
// checks about the arguments. As such, the invariants documented for each
// method call must be respected.
type dictDecoder struct {
hist []byte // Sliding window history
// Invariant: 0 <= rdPos <= wrPos <= len(hist)
wrPos int // Current output position in buffer
rdPos int // Have emitted hist[:rdPos] already
full bool // Has a full window length been written yet?
}
// init initializes dictDecoder to have a sliding window dictionary of the given
// size. If a preset dict is provided, it will initialize the dictionary with
// the contents of dict.
func (dd *dictDecoder) init(size int, dict []byte) {
*dd = dictDecoder{hist: dd.hist}
if cap(dd.hist) < size {
dd.hist = make([]byte, size)
}
dd.hist = dd.hist[:size]
if len(dict) > len(dd.hist) {
dict = dict[len(dict)-len(dd.hist):]
}
dd.wrPos = copy(dd.hist, dict)
if dd.wrPos == len(dd.hist) {
dd.wrPos = 0
dd.full = true
}
dd.rdPos = dd.wrPos
}
// histSize reports the total amount of historical data in the dictionary.
func (dd *dictDecoder) histSize() int {
if dd.full {
return len(dd.hist)
}
return dd.wrPos
}
// availRead reports the number of bytes that can be flushed by readFlush.
func (dd *dictDecoder) availRead() int {
return dd.wrPos - dd.rdPos
}
// availWrite reports the available amount of output buffer space.
func (dd *dictDecoder) availWrite() int {
return len(dd.hist) - dd.wrPos
}
// writeSlice returns a slice of the available buffer to write data to.
//
// This invariant will be kept: len(s) <= availWrite()
func (dd *dictDecoder) writeSlice() []byte {
return dd.hist[dd.wrPos:]
}
// writeMark advances the writer pointer by cnt.
//
// This invariant must be kept: 0 <= cnt <= availWrite()
func (dd *dictDecoder) writeMark(cnt int) {
dd.wrPos += cnt
}
// writeByte writes a single byte to the dictionary.
//
// This invariant must be kept: 0 < availWrite()
func (dd *dictDecoder) writeByte(c byte) {
dd.hist[dd.wrPos] = c
dd.wrPos++
}
// writeCopy copies a string at a given (dist, length) to the output.
// This returns the number of bytes copied and may be less than the requested
// length if the available space in the output buffer is too small.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) writeCopy(dist, length int) int {
dstBase := dd.wrPos
dstPos := dstBase
srcPos := dstPos - dist
endPos := dstPos + length
if endPos > len(dd.hist) {
endPos = len(dd.hist)
}
// Copy non-overlapping section after destination position.
//
// This section is non-overlapping in that the copy length for this section
// is always less than or equal to the backwards distance. This can occur
// if a distance refers to data that wraps-around in the buffer.
// Thus, a backwards copy is performed here; that is, the exact bytes in
// the source prior to the copy is placed in the destination.
if srcPos < 0 {
srcPos += len(dd.hist)
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:])
srcPos = 0
}
// Copy possibly overlapping section before destination position.
//
// This section can overlap if the copy length for this section is larger
// than the backwards distance. This is allowed by LZ77 so that repeated
// strings can be succinctly represented using (dist, length) pairs.
// Thus, a forwards copy is performed here; that is, the bytes copied is
// possibly dependent on the resulting bytes in the destination as the copy
// progresses along. This is functionally equivalent to the following:
//
// for i := 0; i < endPos-dstPos; i++ {
// dd.hist[dstPos+i] = dd.hist[srcPos+i]
// }
// dstPos = endPos
//
for dstPos < endPos {
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// tryWriteCopy tries to copy a string at a given (distance, length) to the
// output. This specialized version is optimized for short distances.
//
// This method is designed to be inlined for performance reasons.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) tryWriteCopy(dist, length int) int {
dstPos := dd.wrPos
endPos := dstPos + length
if dstPos < dist || endPos > len(dd.hist) {
return 0
}
dstBase := dstPos
srcPos := dstPos - dist
// Copy possibly overlapping section before destination position.
loop:
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
if dstPos < endPos {
goto loop // Avoid for-loop so that this function can be inlined
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// readFlush returns a slice of the historical buffer that is ready to be
// emitted to the user. The data returned by readFlush must be fully consumed
// before calling any other dictDecoder methods.
func (dd *dictDecoder) readFlush() []byte {
toRead := dd.hist[dd.rdPos:dd.wrPos]
dd.rdPos = dd.wrPos
if dd.wrPos == len(dd.hist) {
dd.wrPos, dd.rdPos = 0, 0
dd.full = true
}
return toRead
}

@ -1,233 +0,0 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Modified for deflate by Klaus Post (c) 2015.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"encoding/binary"
"fmt"
"math/bits"
)
type fastEnc interface {
Encode(dst *tokens, src []byte)
Reset()
}
func newFastEnc(level int) fastEnc {
switch level {
case 1:
return &fastEncL1{fastGen: fastGen{cur: maxStoreBlockSize}}
case 2:
return &fastEncL2{fastGen: fastGen{cur: maxStoreBlockSize}}
case 3:
return &fastEncL3{fastGen: fastGen{cur: maxStoreBlockSize}}
case 4:
return &fastEncL4{fastGen: fastGen{cur: maxStoreBlockSize}}
case 5:
return &fastEncL5{fastGen: fastGen{cur: maxStoreBlockSize}}
case 6:
return &fastEncL6{fastGen: fastGen{cur: maxStoreBlockSize}}
default:
panic("invalid level specified")
}
}
const (
tableBits = 15 // Bits used in the table
tableSize = 1 << tableBits // Size of the table
tableShift = 32 - tableBits // Right-shift to get the tableBits most significant bits of a uint32.
baseMatchOffset = 1 // The smallest match offset
baseMatchLength = 3 // The smallest match length per the RFC section 3.2.5
maxMatchOffset = 1 << 15 // The largest match offset
bTableBits = 17 // Bits used in the big tables
bTableSize = 1 << bTableBits // Size of the table
allocHistory = maxStoreBlockSize * 5 // Size to preallocate for history.
bufferReset = (1 << 31) - allocHistory - maxStoreBlockSize - 1 // Reset the buffer offset when reaching this.
)
const (
prime3bytes = 506832829
prime4bytes = 2654435761
prime5bytes = 889523592379
prime6bytes = 227718039650203
prime7bytes = 58295818150454627
prime8bytes = 0xcf1bbcdcb7a56463
)
func load32(b []byte, i int) uint32 {
// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
b = b[i:]
b = b[:4]
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
func load64(b []byte, i int) uint64 {
return binary.LittleEndian.Uint64(b[i:])
}
func load3232(b []byte, i int32) uint32 {
return binary.LittleEndian.Uint32(b[i:])
}
func load6432(b []byte, i int32) uint64 {
return binary.LittleEndian.Uint64(b[i:])
}
func hash(u uint32) uint32 {
return (u * 0x1e35a7bd) >> tableShift
}
type tableEntry struct {
offset int32
}
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastGen struct {
hist []byte
cur int32
}
func (e *fastGen) addBlock(src []byte) int32 {
// check if we have space already
if len(e.hist)+len(src) > cap(e.hist) {
if cap(e.hist) == 0 {
e.hist = make([]byte, 0, allocHistory)
} else {
if cap(e.hist) < maxMatchOffset*2 {
panic("unexpected buffer size")
}
// Move down
offset := int32(len(e.hist)) - maxMatchOffset
copy(e.hist[0:maxMatchOffset], e.hist[offset:])
e.cur += offset
e.hist = e.hist[:maxMatchOffset]
}
}
s := int32(len(e.hist))
e.hist = append(e.hist, src...)
return s
}
// hash4 returns the hash of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <32.
func hash4u(u uint32, h uint8) uint32 {
return (u * prime4bytes) >> (32 - h)
}
type tableEntryPrev struct {
Cur tableEntry
Prev tableEntry
}
// hash4x64 returns the hash of the lowest 4 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <32.
func hash4x64(u uint64, h uint8) uint32 {
return (uint32(u) * prime4bytes) >> ((32 - h) & reg8SizeMask32)
}
// hash7 returns the hash of the lowest 7 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash7(u uint64, h uint8) uint32 {
return uint32(((u << (64 - 56)) * prime7bytes) >> ((64 - h) & reg8SizeMask64))
}
// hash8 returns the hash of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash8(u uint64, h uint8) uint32 {
return uint32((u * prime8bytes) >> ((64 - h) & reg8SizeMask64))
}
// hash6 returns the hash of the lowest 6 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash6(u uint64, h uint8) uint32 {
return uint32(((u << (64 - 48)) * prime6bytes) >> ((64 - h) & reg8SizeMask64))
}
// matchlen will return the match length between offsets and t in src.
// The maximum length returned is maxMatchLength - 4.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlen(s, t int32, src []byte) int32 {
if debugDecode {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
s1 := int(s) + maxMatchLength - 4
if s1 > len(src) {
s1 = len(src)
}
// Extend the match to be as long as possible.
return int32(matchLen(src[s:s1], src[t:]))
}
// matchlenLong will return the match length between offsets and t in src.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlenLong(s, t int32, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
// Extend the match to be as long as possible.
return int32(matchLen(src[s:], src[t:]))
}
// Reset the encoding table.
func (e *fastGen) Reset() {
if cap(e.hist) < allocHistory {
e.hist = make([]byte, 0, allocHistory)
}
// We offset current position so everything will be out of reach.
// If we are above the buffer reset it will be cleared anyway since len(hist) == 0.
if e.cur <= bufferReset {
e.cur += maxMatchOffset + int32(len(e.hist))
}
e.hist = e.hist[:0]
}
// matchLen returns the maximum length.
// 'a' must be the shortest of the two.
func matchLen(a, b []byte) int {
var checked int
for len(a) >= 8 {
if diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b); diff != 0 {
return checked + (bits.TrailingZeros64(diff) >> 3)
}
checked += 8
a = a[8:]
b = b[8:]
}
b = b[:len(a)]
for i := range a {
if a[i] != b[i] {
return i + checked
}
}
return len(a) + checked
}

File diff suppressed because it is too large Load Diff

@ -1,412 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"math"
"math/bits"
)
const (
maxBitsLimit = 16
// number of valid literals
literalCount = 286
)
// hcode is a huffman code with a bit code and bit length.
type hcode uint32
func (h hcode) len() uint8 {
return uint8(h)
}
func (h hcode) code64() uint64 {
return uint64(h >> 8)
}
func (h hcode) zero() bool {
return h == 0
}
type huffmanEncoder struct {
codes []hcode
bitCount [17]int32
// Allocate a reusable buffer with the longest possible frequency table.
// Possible lengths are codegenCodeCount, offsetCodeCount and literalCount.
// The largest of these is literalCount, so we allocate for that case.
freqcache [literalCount + 1]literalNode
}
type literalNode struct {
literal uint16
freq uint16
}
// A levelInfo describes the state of the constructed tree for a given depth.
type levelInfo struct {
// Our level. for better printing
level int32
// The frequency of the last node at this level
lastFreq int32
// The frequency of the next character to add to this level
nextCharFreq int32
// The frequency of the next pair (from level below) to add to this level.
// Only valid if the "needed" value of the next lower level is 0.
nextPairFreq int32
// The number of chains remaining to generate for this level before moving
// up to the next level
needed int32
}
// set sets the code and length of an hcode.
func (h *hcode) set(code uint16, length uint8) {
*h = hcode(length) | (hcode(code) << 8)
}
func newhcode(code uint16, length uint8) hcode {
return hcode(length) | (hcode(code) << 8)
}
func reverseBits(number uint16, bitLength byte) uint16 {
return bits.Reverse16(number << ((16 - bitLength) & 15))
}
func maxNode() literalNode { return literalNode{math.MaxUint16, math.MaxUint16} }
func newHuffmanEncoder(size int) *huffmanEncoder {
// Make capacity to next power of two.
c := uint(bits.Len32(uint32(size - 1)))
return &huffmanEncoder{codes: make([]hcode, size, 1<<c)}
}
// Generates a HuffmanCode corresponding to the fixed literal table
func generateFixedLiteralEncoding() *huffmanEncoder {
h := newHuffmanEncoder(literalCount)
codes := h.codes
var ch uint16
for ch = 0; ch < literalCount; ch++ {
var bits uint16
var size uint8
switch {
case ch < 144:
// size 8, 000110000 .. 10111111
bits = ch + 48
size = 8
case ch < 256:
// size 9, 110010000 .. 111111111
bits = ch + 400 - 144
size = 9
case ch < 280:
// size 7, 0000000 .. 0010111
bits = ch - 256
size = 7
default:
// size 8, 11000000 .. 11000111
bits = ch + 192 - 280
size = 8
}
codes[ch] = newhcode(reverseBits(bits, size), size)
}
return h
}
func generateFixedOffsetEncoding() *huffmanEncoder {
h := newHuffmanEncoder(30)
codes := h.codes
for ch := range codes {
codes[ch] = newhcode(reverseBits(uint16(ch), 5), 5)
}
return h
}
var fixedLiteralEncoding = generateFixedLiteralEncoding()
var fixedOffsetEncoding = generateFixedOffsetEncoding()
func (h *huffmanEncoder) bitLength(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
total += int(f) * int(h.codes[i].len())
}
}
return total
}
func (h *huffmanEncoder) bitLengthRaw(b []byte) int {
var total int
for _, f := range b {
total += int(h.codes[f].len())
}
return total
}
// canReuseBits returns the number of bits or math.MaxInt32 if the encoder cannot be reused.
func (h *huffmanEncoder) canReuseBits(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
code := h.codes[i]
if code.zero() {
return math.MaxInt32
}
total += int(f) * int(code.len())
}
}
return total
}
// Return the number of literals assigned to each bit size in the Huffman encoding
//
// This method is only called when list.length >= 3
// The cases of 0, 1, and 2 literals are handled by special case code.
//
// list An array of the literals with non-zero frequencies
// and their associated frequencies. The array is in order of increasing
// frequency, and has as its last element a special element with frequency
// MaxInt32
// maxBits The maximum number of bits that should be used to encode any literal.
// Must be less than 16.
// return An integer array in which array[i] indicates the number of literals
// that should be encoded in i bits.
func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
if maxBits >= maxBitsLimit {
panic("flate: maxBits too large")
}
n := int32(len(list))
list = list[0 : n+1]
list[n] = maxNode()
// The tree can't have greater depth than n - 1, no matter what. This
// saves a little bit of work in some small cases
if maxBits > n-1 {
maxBits = n - 1
}
// Create information about each of the levels.
// A bogus "Level 0" whose sole purpose is so that
// level1.prev.needed==0. This makes level1.nextPairFreq
// be a legitimate value that never gets chosen.
var levels [maxBitsLimit]levelInfo
// leafCounts[i] counts the number of literals at the left
// of ancestors of the rightmost node at level i.
// leafCounts[i][j] is the number of literals at the left
// of the level j ancestor.
var leafCounts [maxBitsLimit][maxBitsLimit]int32
// Descending to only have 1 bounds check.
l2f := int32(list[2].freq)
l1f := int32(list[1].freq)
l0f := int32(list[0].freq) + int32(list[1].freq)
for level := int32(1); level <= maxBits; level++ {
// For every level, the first two items are the first two characters.
// We initialize the levels as if we had already figured this out.
levels[level] = levelInfo{
level: level,
lastFreq: l1f,
nextCharFreq: l2f,
nextPairFreq: l0f,
}
leafCounts[level][level] = 2
if level == 1 {
levels[level].nextPairFreq = math.MaxInt32
}
}
// We need a total of 2*n - 2 items at top level and have already generated 2.
levels[maxBits].needed = 2*n - 4
level := uint32(maxBits)
for level < 16 {
l := &levels[level]
if l.nextPairFreq == math.MaxInt32 && l.nextCharFreq == math.MaxInt32 {
// We've run out of both leafs and pairs.
// End all calculations for this level.
// To make sure we never come back to this level or any lower level,
// set nextPairFreq impossibly large.
l.needed = 0
levels[level+1].nextPairFreq = math.MaxInt32
level++
continue
}
prevFreq := l.lastFreq
if l.nextCharFreq < l.nextPairFreq {
// The next item on this row is a leaf node.
n := leafCounts[level][level] + 1
l.lastFreq = l.nextCharFreq
// Lower leafCounts are the same of the previous node.
leafCounts[level][level] = n
e := list[n]
if e.literal < math.MaxUint16 {
l.nextCharFreq = int32(e.freq)
} else {
l.nextCharFreq = math.MaxInt32
}
} else {
// The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two
// more values in the level below
l.lastFreq = l.nextPairFreq
// Take leaf counts from the lower level, except counts[level] remains the same.
if true {
save := leafCounts[level][level]
leafCounts[level] = leafCounts[level-1]
leafCounts[level][level] = save
} else {
copy(leafCounts[level][:level], leafCounts[level-1][:level])
}
levels[l.level-1].needed = 2
}
if l.needed--; l.needed == 0 {
// We've done everything we need to do for this level.
// Continue calculating one level up. Fill in nextPairFreq
// of that level with the sum of the two nodes we've just calculated on
// this level.
if l.level == maxBits {
// All done!
break
}
levels[l.level+1].nextPairFreq = prevFreq + l.lastFreq
level++
} else {
// If we stole from below, move down temporarily to replenish it.
for levels[level-1].needed > 0 {
level--
}
}
}
// Somethings is wrong if at the end, the top level is null or hasn't used
// all of the leaves.
if leafCounts[maxBits][maxBits] != n {
panic("leafCounts[maxBits][maxBits] != n")
}
bitCount := h.bitCount[:maxBits+1]
bits := 1
counts := &leafCounts[maxBits]
for level := maxBits; level > 0; level-- {
// chain.leafCount gives the number of literals requiring at least "bits"
// bits to encode.
bitCount[bits] = counts[level] - counts[level-1]
bits++
}
return bitCount
}
// Look at the leaves and assign them a bit count and an encoding as specified
// in RFC 1951 3.2.2
func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalNode) {
code := uint16(0)
for n, bits := range bitCount {
code <<= 1
if n == 0 || bits == 0 {
continue
}
// The literals list[len(list)-bits] .. list[len(list)-bits]
// are encoded using "bits" bits, and get the values
// code, code + 1, .... The code values are
// assigned in literal order (not frequency order).
chunk := list[len(list)-int(bits):]
sortByLiteral(chunk)
for _, node := range chunk {
h.codes[node.literal] = newhcode(reverseBits(code, uint8(n)), uint8(n))
code++
}
list = list[0 : len(list)-int(bits)]
}
}
// Update this Huffman Code object to be the minimum code for the specified frequency count.
//
// freq An array of frequencies, in which frequency[i] gives the frequency of literal i.
// maxBits The maximum number of bits to use for any literal.
func (h *huffmanEncoder) generate(freq []uint16, maxBits int32) {
list := h.freqcache[:len(freq)+1]
codes := h.codes[:len(freq)]
// Number of non-zero literals
count := 0
// Set list to be the set of all non-zero literals and their frequencies
for i, f := range freq {
if f != 0 {
list[count] = literalNode{uint16(i), f}
count++
} else {
codes[i] = 0
}
}
list[count] = literalNode{}
list = list[:count]
if count <= 2 {
// Handle the small cases here, because they are awkward for the general case code. With
// two or fewer literals, everything has bit length 1.
for i, node := range list {
// "list" is in order of increasing literal value.
h.codes[node.literal].set(uint16(i), 1)
}
return
}
sortByFreq(list)
// Get the number of literals for each bit count
bitCount := h.bitCounts(list, maxBits)
// And do the assignment
h.assignEncodingAndSize(bitCount, list)
}
// atLeastOne clamps the result between 1 and 15.
func atLeastOne(v float32) float32 {
if v < 1 {
return 1
}
if v > 15 {
return 15
}
return v
}
func histogram(b []byte, h []uint16) {
if true && len(b) >= 8<<10 {
// Split for bigger inputs
histogramSplit(b, h)
} else {
h = h[:256]
for _, t := range b {
h[t]++
}
}
}
func histogramSplit(b []byte, h []uint16) {
// Tested, and slightly faster than 2-way.
// Writing to separate arrays and combining is also slightly slower.
h = h[:256]
for len(b)&3 != 0 {
h[b[0]]++
b = b[1:]
}
n := len(b) / 4
x, y, z, w := b[:n], b[n:], b[n+n:], b[n+n+n:]
y, z, w = y[:len(x)], z[:len(x)], w[:len(x)]
for i, t := range x {
v0 := &h[t]
v1 := &h[y[i]]
v3 := &h[w[i]]
v2 := &h[z[i]]
*v0++
*v1++
*v2++
*v3++
}
}

@ -1,178 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByFreq(data []literalNode) {
n := len(data)
quickSortByFreq(data, 0, n, maxDepth(n))
}
func quickSortByFreq(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivotByFreq(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSortByFreq(data, a, mlo, maxDepth)
a = mhi // i.e., quickSortByFreq(data, mhi, b)
} else {
quickSortByFreq(data, mhi, b, maxDepth)
b = mlo // i.e., quickSortByFreq(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].freq == data[i-6].freq && data[i].literal < data[i-6].literal || data[i].freq < data[i-6].freq {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSortByFreq(data, a, b)
}
}
// siftDownByFreq implements the heap property on data[lo, hi).
// first is an offset into the array where the root of the heap lies.
func siftDownByFreq(data []literalNode, lo, hi, first int) {
root := lo
for {
child := 2*root + 1
if child >= hi {
break
}
if child+1 < hi && (data[first+child].freq == data[first+child+1].freq && data[first+child].literal < data[first+child+1].literal || data[first+child].freq < data[first+child+1].freq) {
child++
}
if data[first+root].freq == data[first+child].freq && data[first+root].literal > data[first+child].literal || data[first+root].freq > data[first+child].freq {
return
}
data[first+root], data[first+child] = data[first+child], data[first+root]
root = child
}
}
func doPivotByFreq(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThreeSortByFreq(data, lo, lo+s, lo+2*s)
medianOfThreeSortByFreq(data, m, m-s, m+s)
medianOfThreeSortByFreq(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThreeSortByFreq(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ {
}
b := a
for {
for ; b < c && (data[pivot].freq == data[b].freq && data[pivot].literal > data[b].literal || data[pivot].freq > data[b].freq); b++ { // data[b] <= pivot
}
for ; b < c && (data[pivot].freq == data[c-1].freq && data[pivot].literal < data[c-1].literal || data[pivot].freq < data[c-1].freq); c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].freq == data[hi-1].freq && data[pivot].literal > data[hi-1].literal || data[pivot].freq > data[hi-1].freq { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].freq == data[pivot].freq && data[m].literal > data[pivot].literal || data[m].freq > data[pivot].freq { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && (data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq); b-- { // data[b] == pivot
}
for ; a < b && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSortByFreq(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && (data[j].freq == data[j-1].freq && data[j].literal < data[j-1].literal || data[j].freq < data[j-1].freq); j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// quickSortByFreq, loosely following Bentley and McIlroy,
// ``Engineering a Sort Function,'' SP&E November 1993.
// medianOfThreeSortByFreq moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThreeSortByFreq(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].freq == data[m1].freq && data[m2].literal < data[m1].literal || data[m2].freq < data[m1].freq {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}

@ -1,201 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByLiteral(data []literalNode) {
n := len(data)
quickSort(data, 0, n, maxDepth(n))
}
func quickSort(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivot(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSort(data, a, mlo, maxDepth)
a = mhi // i.e., quickSort(data, mhi, b)
} else {
quickSort(data, mhi, b, maxDepth)
b = mlo // i.e., quickSort(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].literal < data[i-6].literal {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSort(data, a, b)
}
}
func heapSort(data []literalNode, a, b int) {
first := a
lo := 0
hi := b - a
// Build heap with greatest element at top.
for i := (hi - 1) / 2; i >= 0; i-- {
siftDown(data, i, hi, first)
}
// Pop elements, largest first, into end of data.
for i := hi - 1; i >= 0; i-- {
data[first], data[first+i] = data[first+i], data[first]
siftDown(data, lo, i, first)
}
}
// siftDown implements the heap property on data[lo, hi).
// first is an offset into the array where the root of the heap lies.
func siftDown(data []literalNode, lo, hi, first int) {
root := lo
for {
child := 2*root + 1
if child >= hi {
break
}
if child+1 < hi && data[first+child].literal < data[first+child+1].literal {
child++
}
if data[first+root].literal > data[first+child].literal {
return
}
data[first+root], data[first+child] = data[first+child], data[first+root]
root = child
}
}
func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThree(data, lo, lo+s, lo+2*s)
medianOfThree(data, m, m-s, m+s)
medianOfThree(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThree(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && data[a].literal < data[pivot].literal; a++ {
}
b := a
for {
for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot
}
for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].literal > data[pivot].literal { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot
}
for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSort(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && data[j].literal < data[j-1].literal; j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// maxDepth returns a threshold at which quicksort should switch
// to heapsort. It returns 2*ceil(lg(n+1)).
func maxDepth(n int) int {
var depth int
for i := n; i > 0; i >>= 1 {
depth++
}
return depth * 2
}
// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThree(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].literal < data[m1].literal {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}

@ -1,793 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package flate implements the DEFLATE compressed data format, described in
// RFC 1951. The gzip and zlib packages implement access to DEFLATE-based file
// formats.
package flate
import (
"bufio"
"compress/flate"
"fmt"
"io"
"math/bits"
"sync"
)
const (
maxCodeLen = 16 // max length of Huffman code
maxCodeLenMask = 15 // mask for max length of Huffman code
// The next three numbers come from the RFC section 3.2.7, with the
// additional proviso in section 3.2.5 which implies that distance codes
// 30 and 31 should never occur in compressed data.
maxNumLit = 286
maxNumDist = 30
numCodes = 19 // number of codes in Huffman meta-code
debugDecode = false
)
// Value of length - 3 and extra bits.
type lengthExtra struct {
length, extra uint8
}
var decCodeToLen = [32]lengthExtra{{length: 0x0, extra: 0x0}, {length: 0x1, extra: 0x0}, {length: 0x2, extra: 0x0}, {length: 0x3, extra: 0x0}, {length: 0x4, extra: 0x0}, {length: 0x5, extra: 0x0}, {length: 0x6, extra: 0x0}, {length: 0x7, extra: 0x0}, {length: 0x8, extra: 0x1}, {length: 0xa, extra: 0x1}, {length: 0xc, extra: 0x1}, {length: 0xe, extra: 0x1}, {length: 0x10, extra: 0x2}, {length: 0x14, extra: 0x2}, {length: 0x18, extra: 0x2}, {length: 0x1c, extra: 0x2}, {length: 0x20, extra: 0x3}, {length: 0x28, extra: 0x3}, {length: 0x30, extra: 0x3}, {length: 0x38, extra: 0x3}, {length: 0x40, extra: 0x4}, {length: 0x50, extra: 0x4}, {length: 0x60, extra: 0x4}, {length: 0x70, extra: 0x4}, {length: 0x80, extra: 0x5}, {length: 0xa0, extra: 0x5}, {length: 0xc0, extra: 0x5}, {length: 0xe0, extra: 0x5}, {length: 0xff, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}}
var bitMask32 = [32]uint32{
0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF,
0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF,
0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF,
} // up to 32 bits
// Initialize the fixedHuffmanDecoder only once upon first use.
var fixedOnce sync.Once
var fixedHuffmanDecoder huffmanDecoder
// A CorruptInputError reports the presence of corrupt input at a given offset.
type CorruptInputError = flate.CorruptInputError
// An InternalError reports an error in the flate code itself.
type InternalError string
func (e InternalError) Error() string { return "flate: internal error: " + string(e) }
// A ReadError reports an error encountered while reading input.
//
// Deprecated: No longer returned.
type ReadError = flate.ReadError
// A WriteError reports an error encountered while writing output.
//
// Deprecated: No longer returned.
type WriteError = flate.WriteError
// Resetter resets a ReadCloser returned by NewReader or NewReaderDict to
// to switch to a new underlying Reader. This permits reusing a ReadCloser
// instead of allocating a new one.
type Resetter interface {
// Reset discards any buffered data and resets the Resetter as if it was
// newly initialized with the given reader.
Reset(r io.Reader, dict []byte) error
}
// The data structure for decoding Huffman tables is based on that of
// zlib. There is a lookup table of a fixed bit width (huffmanChunkBits),
// For codes smaller than the table width, there are multiple entries
// (each combination of trailing bits has the same value). For codes
// larger than the table width, the table contains a link to an overflow
// table. The width of each entry in the link table is the maximum code
// size minus the chunk width.
//
// Note that you can do a lookup in the table even without all bits
// filled. Since the extra bits are zero, and the DEFLATE Huffman codes
// have the property that shorter codes come before longer ones, the
// bit length estimate in the result is a lower bound on the actual
// number of bits.
//
// See the following:
// http://www.gzip.org/algorithm.txt
// chunk & 15 is number of bits
// chunk >> 4 is value, including table link
const (
huffmanChunkBits = 9
huffmanNumChunks = 1 << huffmanChunkBits
huffmanCountMask = 15
huffmanValueShift = 4
)
type huffmanDecoder struct {
maxRead int // the maximum number of bits we can read and not overread
chunks *[huffmanNumChunks]uint16 // chunks as described above
links [][]uint16 // overflow links
linkMask uint32 // mask the width of the link table
}
// Initialize Huffman decoding tables from array of code lengths.
// Following this function, h is guaranteed to be initialized into a complete
// tree (i.e., neither over-subscribed nor under-subscribed). The exception is a
// degenerate case where the tree has only a single symbol with length 1. Empty
// trees are permitted.
func (h *huffmanDecoder) init(lengths []int) bool {
// Sanity enables additional runtime tests during Huffman
// table construction. It's intended to be used during
// development to supplement the currently ad-hoc unit tests.
const sanity = false
if h.chunks == nil {
h.chunks = &[huffmanNumChunks]uint16{}
}
if h.maxRead != 0 {
*h = huffmanDecoder{chunks: h.chunks, links: h.links}
}
// Count number of codes of each length,
// compute maxRead and max length.
var count [maxCodeLen]int
var min, max int
for _, n := range lengths {
if n == 0 {
continue
}
if min == 0 || n < min {
min = n
}
if n > max {
max = n
}
count[n&maxCodeLenMask]++
}
// Empty tree. The decompressor.huffSym function will fail later if the tree
// is used. Technically, an empty tree is only valid for the HDIST tree and
// not the HCLEN and HLIT tree. However, a stream with an empty HCLEN tree
// is guaranteed to fail since it will attempt to use the tree to decode the
// codes for the HLIT and HDIST trees. Similarly, an empty HLIT tree is
// guaranteed to fail later since the compressed data section must be
// composed of at least one symbol (the end-of-block marker).
if max == 0 {
return true
}
code := 0
var nextcode [maxCodeLen]int
for i := min; i <= max; i++ {
code <<= 1
nextcode[i&maxCodeLenMask] = code
code += count[i&maxCodeLenMask]
}
// Check that the coding is complete (i.e., that we've
// assigned all 2-to-the-max possible bit sequences).
// Exception: To be compatible with zlib, we also need to
// accept degenerate single-code codings. See also
// TestDegenerateHuffmanCoding.
if code != 1<<uint(max) && !(code == 1 && max == 1) {
if debugDecode {
fmt.Println("coding failed, code, max:", code, max, code == 1<<uint(max), code == 1 && max == 1, "(one should be true)")
}
return false
}
h.maxRead = min
chunks := h.chunks[:]
for i := range chunks {
chunks[i] = 0
}
if max > huffmanChunkBits {
numLinks := 1 << (uint(max) - huffmanChunkBits)
h.linkMask = uint32(numLinks - 1)
// create link tables
link := nextcode[huffmanChunkBits+1] >> 1
if cap(h.links) < huffmanNumChunks-link {
h.links = make([][]uint16, huffmanNumChunks-link)
} else {
h.links = h.links[:huffmanNumChunks-link]
}
for j := uint(link); j < huffmanNumChunks; j++ {
reverse := int(bits.Reverse16(uint16(j)))
reverse >>= uint(16 - huffmanChunkBits)
off := j - uint(link)
if sanity && h.chunks[reverse] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[reverse] = uint16(off<<huffmanValueShift | (huffmanChunkBits + 1))
if cap(h.links[off]) < numLinks {
h.links[off] = make([]uint16, numLinks)
} else {
links := h.links[off][:0]
h.links[off] = links[:numLinks]
}
}
} else {
h.links = h.links[:0]
}
for i, n := range lengths {
if n == 0 {
continue
}
code := nextcode[n]
nextcode[n]++
chunk := uint16(i<<huffmanValueShift | n)
reverse := int(bits.Reverse16(uint16(code)))
reverse >>= uint(16 - n)
if n <= huffmanChunkBits {
for off := reverse; off < len(h.chunks); off += 1 << uint(n) {
// We should never need to overwrite
// an existing chunk. Also, 0 is
// never a valid chunk, because the
// lower 4 "count" bits should be
// between 1 and 15.
if sanity && h.chunks[off] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[off] = chunk
}
} else {
j := reverse & (huffmanNumChunks - 1)
if sanity && h.chunks[j]&huffmanCountMask != huffmanChunkBits+1 {
// Longer codes should have been
// associated with a link table above.
panic("impossible: not an indirect chunk")
}
value := h.chunks[j] >> huffmanValueShift
linktab := h.links[value]
reverse >>= huffmanChunkBits
for off := reverse; off < len(linktab); off += 1 << uint(n-huffmanChunkBits) {
if sanity && linktab[off] != 0 {
panic("impossible: overwriting existing chunk")
}
linktab[off] = chunk
}
}
}
if sanity {
// Above we've sanity checked that we never overwrote
// an existing entry. Here we additionally check that
// we filled the tables completely.
for i, chunk := range h.chunks {
if chunk == 0 {
// As an exception, in the degenerate
// single-code case, we allow odd
// chunks to be missing.
if code == 1 && i%2 == 1 {
continue
}
panic("impossible: missing chunk")
}
}
for _, linktab := range h.links {
for _, chunk := range linktab {
if chunk == 0 {
panic("impossible: missing chunk")
}
}
}
}
return true
}
// The actual read interface needed by NewReader.
// If the passed in io.Reader does not also have ReadByte,
// the NewReader will introduce its own buffering.
type Reader interface {
io.Reader
io.ByteReader
}
// Decompress state.
type decompressor struct {
// Input source.
r Reader
roffset int64
// Huffman decoders for literal/length, distance.
h1, h2 huffmanDecoder
// Length arrays used to define Huffman codes.
bits *[maxNumLit + maxNumDist]int
codebits *[numCodes]int
// Output history, buffer.
dict dictDecoder
// Next step in the decompression,
// and decompression state.
step func(*decompressor)
stepState int
err error
toRead []byte
hl, hd *huffmanDecoder
copyLen int
copyDist int
// Temporary buffer (avoids repeated allocation).
buf [4]byte
// Input bits, in top of b.
b uint32
nb uint
final bool
}
func (f *decompressor) nextBlock() {
for f.nb < 1+2 {
if f.err = f.moreBits(); f.err != nil {
return
}
}
f.final = f.b&1 == 1
f.b >>= 1
typ := f.b & 3
f.b >>= 2
f.nb -= 1 + 2
switch typ {
case 0:
f.dataBlock()
if debugDecode {
fmt.Println("stored block")
}
case 1:
// compressed, fixed Huffman tables
f.hl = &fixedHuffmanDecoder
f.hd = nil
f.huffmanBlockDecoder()()
if debugDecode {
fmt.Println("predefinied huffman block")
}
case 2:
// compressed, dynamic Huffman tables
if f.err = f.readHuffman(); f.err != nil {
break
}
f.hl = &f.h1
f.hd = &f.h2
f.huffmanBlockDecoder()()
if debugDecode {
fmt.Println("dynamic huffman block")
}
default:
// 3 is reserved.
if debugDecode {
fmt.Println("reserved data block encountered")
}
f.err = CorruptInputError(f.roffset)
}
}
func (f *decompressor) Read(b []byte) (int, error) {
for {
if len(f.toRead) > 0 {
n := copy(b, f.toRead)
f.toRead = f.toRead[n:]
if len(f.toRead) == 0 {
return n, f.err
}
return n, nil
}
if f.err != nil {
return 0, f.err
}
f.step(f)
if f.err != nil && len(f.toRead) == 0 {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
}
}
}
// Support the io.WriteTo interface for io.Copy and friends.
func (f *decompressor) WriteTo(w io.Writer) (int64, error) {
total := int64(0)
flushed := false
for {
if len(f.toRead) > 0 {
n, err := w.Write(f.toRead)
total += int64(n)
if err != nil {
f.err = err
return total, err
}
if n != len(f.toRead) {
return total, io.ErrShortWrite
}
f.toRead = f.toRead[:0]
}
if f.err != nil && flushed {
if f.err == io.EOF {
return total, nil
}
return total, f.err
}
if f.err == nil {
f.step(f)
}
if len(f.toRead) == 0 && f.err != nil && !flushed {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
flushed = true
}
}
}
func (f *decompressor) Close() error {
if f.err == io.EOF {
return nil
}
return f.err
}
// RFC 1951 section 3.2.7.
// Compression with dynamic Huffman codes
var codeOrder = [...]int{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}
func (f *decompressor) readHuffman() error {
// HLIT[5], HDIST[5], HCLEN[4].
for f.nb < 5+5+4 {
if err := f.moreBits(); err != nil {
return err
}
}
nlit := int(f.b&0x1F) + 257
if nlit > maxNumLit {
if debugDecode {
fmt.Println("nlit > maxNumLit", nlit)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
ndist := int(f.b&0x1F) + 1
if ndist > maxNumDist {
if debugDecode {
fmt.Println("ndist > maxNumDist", ndist)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
nclen := int(f.b&0xF) + 4
// numCodes is 19, so nclen is always valid.
f.b >>= 4
f.nb -= 5 + 5 + 4
// (HCLEN+4)*3 bits: code lengths in the magic codeOrder order.
for i := 0; i < nclen; i++ {
for f.nb < 3 {
if err := f.moreBits(); err != nil {
return err
}
}
f.codebits[codeOrder[i]] = int(f.b & 0x7)
f.b >>= 3
f.nb -= 3
}
for i := nclen; i < len(codeOrder); i++ {
f.codebits[codeOrder[i]] = 0
}
if !f.h1.init(f.codebits[0:]) {
if debugDecode {
fmt.Println("init codebits failed")
}
return CorruptInputError(f.roffset)
}
// HLIT + 257 code lengths, HDIST + 1 code lengths,
// using the code length Huffman code.
for i, n := 0, nlit+ndist; i < n; {
x, err := f.huffSym(&f.h1)
if err != nil {
return err
}
if x < 16 {
// Actual length.
f.bits[i] = x
i++
continue
}
// Repeat previous length or zero.
var rep int
var nb uint
var b int
switch x {
default:
return InternalError("unexpected length code")
case 16:
rep = 3
nb = 2
if i == 0 {
if debugDecode {
fmt.Println("i==0")
}
return CorruptInputError(f.roffset)
}
b = f.bits[i-1]
case 17:
rep = 3
nb = 3
b = 0
case 18:
rep = 11
nb = 7
b = 0
}
for f.nb < nb {
if err := f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits:", err)
}
return err
}
}
rep += int(f.b & uint32(1<<(nb&regSizeMaskUint32)-1))
f.b >>= nb & regSizeMaskUint32
f.nb -= nb
if i+rep > n {
if debugDecode {
fmt.Println("i+rep > n", i, rep, n)
}
return CorruptInputError(f.roffset)
}
for j := 0; j < rep; j++ {
f.bits[i] = b
i++
}
}
if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) {
if debugDecode {
fmt.Println("init2 failed")
}
return CorruptInputError(f.roffset)
}
// As an optimization, we can initialize the maxRead bits to read at a time
// for the HLIT tree to the length of the EOB marker since we know that
// every block must terminate with one. This preserves the property that
// we never read any extra bytes after the end of the DEFLATE stream.
if f.h1.maxRead < f.bits[endBlockMarker] {
f.h1.maxRead = f.bits[endBlockMarker]
}
if !f.final {
// If not the final block, the smallest block possible is
// a predefined table, BTYPE=01, with a single EOB marker.
// This will take up 3 + 7 bits.
f.h1.maxRead += 10
}
return nil
}
// Copy a single uncompressed data block from input to output.
func (f *decompressor) dataBlock() {
// Uncompressed.
// Discard current half-byte.
left := (f.nb) & 7
f.nb -= left
f.b >>= left
offBytes := f.nb >> 3
// Unfilled values will be overwritten.
f.buf[0] = uint8(f.b)
f.buf[1] = uint8(f.b >> 8)
f.buf[2] = uint8(f.b >> 16)
f.buf[3] = uint8(f.b >> 24)
f.roffset += int64(offBytes)
f.nb, f.b = 0, 0
// Length then ones-complement of length.
nr, err := io.ReadFull(f.r, f.buf[offBytes:4])
f.roffset += int64(nr)
if err != nil {
f.err = noEOF(err)
return
}
n := uint16(f.buf[0]) | uint16(f.buf[1])<<8
nn := uint16(f.buf[2]) | uint16(f.buf[3])<<8
if nn != ^n {
if debugDecode {
ncomp := ^n
fmt.Println("uint16(nn) != uint16(^n)", nn, ncomp)
}
f.err = CorruptInputError(f.roffset)
return
}
if n == 0 {
f.toRead = f.dict.readFlush()
f.finishBlock()
return
}
f.copyLen = int(n)
f.copyData()
}
// copyData copies f.copyLen bytes from the underlying reader into f.hist.
// It pauses for reads when f.hist is full.
func (f *decompressor) copyData() {
buf := f.dict.writeSlice()
if len(buf) > f.copyLen {
buf = buf[:f.copyLen]
}
cnt, err := io.ReadFull(f.r, buf)
f.roffset += int64(cnt)
f.copyLen -= cnt
f.dict.writeMark(cnt)
if err != nil {
f.err = noEOF(err)
return
}
if f.dict.availWrite() == 0 || f.copyLen > 0 {
f.toRead = f.dict.readFlush()
f.step = (*decompressor).copyData
return
}
f.finishBlock()
}
func (f *decompressor) finishBlock() {
if f.final {
if f.dict.availRead() > 0 {
f.toRead = f.dict.readFlush()
}
f.err = io.EOF
}
f.step = (*decompressor).nextBlock
}
// noEOF returns err, unless err == io.EOF, in which case it returns io.ErrUnexpectedEOF.
func noEOF(e error) error {
if e == io.EOF {
return io.ErrUnexpectedEOF
}
return e
}
func (f *decompressor) moreBits() error {
c, err := f.r.ReadByte()
if err != nil {
return noEOF(err)
}
f.roffset++
f.b |= uint32(c) << (f.nb & regSizeMaskUint32)
f.nb += 8
return nil
}
// Read the next Huffman-encoded symbol from f according to h.
func (f *decompressor) huffSym(h *huffmanDecoder) (int, error) {
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
// with single element, huffSym must error on these two edge cases. In both
// cases, the chunks slice will be 0 for the invalid sequence, leading it
// satisfy the n == 0 check below.
n := uint(h.maxRead)
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
// but is smart enough to keep local variables in registers, so use nb and b,
// inline call to moreBits and reassign b,nb back to f on return.
nb, b := f.nb, f.b
for {
for nb < n {
c, err := f.r.ReadByte()
if err != nil {
f.b = b
f.nb = nb
return 0, noEOF(err)
}
f.roffset++
b |= uint32(c) << (nb & regSizeMaskUint32)
nb += 8
}
chunk := h.chunks[b&(huffmanNumChunks-1)]
n = uint(chunk & huffmanCountMask)
if n > huffmanChunkBits {
chunk = h.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&h.linkMask]
n = uint(chunk & huffmanCountMask)
}
if n <= nb {
if n == 0 {
f.b = b
f.nb = nb
if debugDecode {
fmt.Println("huffsym: n==0")
}
f.err = CorruptInputError(f.roffset)
return 0, f.err
}
f.b = b >> (n & regSizeMaskUint32)
f.nb = nb - n
return int(chunk >> huffmanValueShift), nil
}
}
}
func makeReader(r io.Reader) Reader {
if rr, ok := r.(Reader); ok {
return rr
}
return bufio.NewReader(r)
}
func fixedHuffmanDecoderInit() {
fixedOnce.Do(func() {
// These come from the RFC section 3.2.6.
var bits [288]int
for i := 0; i < 144; i++ {
bits[i] = 8
}
for i := 144; i < 256; i++ {
bits[i] = 9
}
for i := 256; i < 280; i++ {
bits[i] = 7
}
for i := 280; i < 288; i++ {
bits[i] = 8
}
fixedHuffmanDecoder.init(bits[:])
})
}
func (f *decompressor) Reset(r io.Reader, dict []byte) error {
*f = decompressor{
r: makeReader(r),
bits: f.bits,
codebits: f.codebits,
h1: f.h1,
h2: f.h2,
dict: f.dict,
step: (*decompressor).nextBlock,
}
f.dict.init(maxMatchOffset, dict)
return nil
}
// NewReader returns a new ReadCloser that can be used
// to read the uncompressed version of r.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
// It is the caller's responsibility to call Close on the ReadCloser
// when finished reading.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReader(r io.Reader) io.ReadCloser {
fixedHuffmanDecoderInit()
var f decompressor
f.r = makeReader(r)
f.bits = new([maxNumLit + maxNumDist]int)
f.codebits = new([numCodes]int)
f.step = (*decompressor).nextBlock
f.dict.init(maxMatchOffset, nil)
return &f
}
// NewReaderDict is like NewReader but initializes the reader
// with a preset dictionary. The returned Reader behaves as if
// the uncompressed data stream started with the given dictionary,
// which has already been read. NewReaderDict is typically used
// to read data compressed by NewWriterDict.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser {
fixedHuffmanDecoderInit()
var f decompressor
f.r = makeReader(r)
f.bits = new([maxNumLit + maxNumDist]int)
f.codebits = new([numCodes]int)
f.step = (*decompressor).nextBlock
f.dict.init(maxMatchOffset, dict)
return &f
}

File diff suppressed because it is too large Load Diff

@ -1,240 +0,0 @@
package flate
import (
"encoding/binary"
"fmt"
"math/bits"
)
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL1 struct {
fastGen
table [tableSize]tableEntry
}
// EncodeL1 uses a similar algorithm to level 1
func (e *fastEncL1) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3232(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hash(cv)
candidate = e.table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hash(uint32(now))
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == load3232(src, candidate.offset-e.cur) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = uint32(now)
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == load3232(src, candidate.offset-e.cur) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
cv = uint32(now)
s = nextS
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset - e.cur
var l = int32(4)
if false {
l = e.matchlenLong(s+4, t+4, src) + 4
} else {
// inlined:
a := src[s+4:]
b := src[t+4:]
for len(a) >= 8 {
if diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b); diff != 0 {
l += int32(bits.TrailingZeros64(diff) >> 3)
break
}
l += 8
a = a[8:]
b = b[8:]
}
if len(a) < 8 {
b = b[:len(a)]
for i := range a {
if a[i] != b[i] {
break
}
l++
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
if false {
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
} else {
// Inlined...
xoffset := uint32(s - t - baseMatchOffset)
xlength := l
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
dst.extraHist[lengthCodes1[uint8(xl)]]++
dst.offHist[oc]++
dst.tokens[dst.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
dst.n++
}
}
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+4) < len(src) {
cv := load3232(src, s)
e.table[hash(cv)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hash(uint32(x))
e.table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hash(uint32(x))
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x) != load3232(src, candidate.offset-e.cur) {
cv = uint32(x >> 8)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,213 +0,0 @@
package flate
import "fmt"
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL2 struct {
fastGen
table [bTableSize]tableEntry
}
// EncodeL2 uses a similar algorithm to level 1, but is capable
// of matching across blocks giving better compression at a small slowdown.
func (e *fastEncL2) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3232(src, s)
for {
// When should we start skipping if we haven't found matches in a long while.
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hash4u(cv, bTableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidate = e.table[nextHash]
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hash4u(uint32(now), bTableBits)
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == load3232(src, candidate.offset-e.cur) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = uint32(now)
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == load3232(src, candidate.offset-e.cur) {
break
}
cv = uint32(now)
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset - e.cur
l := e.matchlenLong(s+4, t+4, src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+4) < len(src) {
cv := load3232(src, s)
e.table[hash4u(cv, bTableBits)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every second hash in-between, but offset by 1.
for i := s - l + 2; i < s-5; i += 7 {
x := load6432(src, i)
nextHash := hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i}
// Skip one
x >>= 16
nextHash = hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i + 2}
// Skip one
x >>= 16
nextHash = hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i + 4}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hash4u(uint32(x), bTableBits)
prevHash2 := hash4u(uint32(x>>8), bTableBits)
e.table[prevHash] = tableEntry{offset: o}
e.table[prevHash2] = tableEntry{offset: o + 1}
currHash := hash4u(uint32(x>>16), bTableBits)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x>>16) != load3232(src, candidate.offset-e.cur) {
cv = uint32(x >> 24)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,240 +0,0 @@
package flate
import "fmt"
// fastEncL3
type fastEncL3 struct {
fastGen
table [1 << 16]tableEntryPrev
}
// Encode uses a similar algorithm to level 2, will check up to two candidates.
func (e *fastEncL3) Encode(dst *tokens, src []byte) {
const (
inputMargin = 8 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
tableBits = 16
tableSize = 1 << tableBits
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
}
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
e.table[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// Skip if too small.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3232(src, s)
for {
const skipLog = 6
nextS := s
var candidate tableEntry
for {
nextHash := hash4u(cv, tableBits)
s = nextS
nextS = s + 1 + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash]
now := load3232(src, nextS)
// Safe offset distance until s + 4...
minOffset := e.cur + s - (maxMatchOffset - 4)
e.table[nextHash] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur}}
// Check both candidates
candidate = candidates.Cur
if candidate.offset < minOffset {
cv = now
// Previous will also be invalid, we have nothing.
continue
}
if cv == load3232(src, candidate.offset-e.cur) {
if candidates.Prev.offset < minOffset || cv != load3232(src, candidates.Prev.offset-e.cur) {
break
}
// Both match and are valid, pick longest.
offset := s - (candidate.offset - e.cur)
o2 := s - (candidates.Prev.offset - e.cur)
l1, l2 := matchLen(src[s+4:], src[s-offset+4:]), matchLen(src[s+4:], src[s-o2+4:])
if l2 > l1 {
candidate = candidates.Prev
}
break
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if candidate.offset > minOffset && cv == load3232(src, candidate.offset-e.cur) {
break
}
}
cv = now
}
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
//
t := candidate.offset - e.cur
l := e.matchlenLong(s+4, t+4, src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
t += l
// Index first pair after match end.
if int(t+4) < len(src) && t > 0 {
cv := load3232(src, t)
nextHash := hash4u(cv, tableBits)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + t},
}
}
goto emitRemainder
}
// Store every 5th hash in-between.
for i := s - l + 2; i < s-5; i += 5 {
nextHash := hash4u(load3232(src, i), tableBits)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + i}}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to s.
x := load6432(src, s-2)
prevHash := hash4u(uint32(x), tableBits)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 2},
}
x >>= 8
prevHash = hash4u(uint32(x), tableBits)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 1},
}
x >>= 8
currHash := hash4u(uint32(x), tableBits)
candidates := e.table[currHash]
cv = uint32(x)
e.table[currHash] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur},
}
// Check both candidates
candidate = candidates.Cur
minOffset := e.cur + s - (maxMatchOffset - 4)
if candidate.offset > minOffset {
if cv == load3232(src, candidate.offset-e.cur) {
// Found a match...
continue
}
candidate = candidates.Prev
if candidate.offset > minOffset && cv == load3232(src, candidate.offset-e.cur) {
// Match at prev...
continue
}
}
cv = uint32(x >> 8)
s++
break
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,220 +0,0 @@
package flate
import "fmt"
type fastEncL4 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntry
}
func (e *fastEncL4) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.bTable[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var t int32
for {
nextHashS := hash4x64(cv, tableBits)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
e.bTable[nextHashL] = entry
t = lCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.offset-e.cur) {
// We got a long match. Use that.
break
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
// Found a 4 match...
lCandidate = e.bTable[hash7(next, tableBits)]
// If the next long is a candidate, check if we should use that instead...
lOff := nextS - (lCandidate.offset - e.cur)
if lOff < maxMatchOffset && load3232(src, lCandidate.offset-e.cur) == uint32(next) {
l1, l2 := matchLen(src[s+4:], src[t+4:]), matchLen(src[nextS+4:], src[nextS-lOff+4:])
if l2 > l1 {
s = nextS
t = lCandidate.offset - e.cur
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Extend the 4-byte match as long as possible.
l := e.matchlenLong(s+4, t+4, src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic("s-t")
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+8) < len(src) {
cv := load6432(src, s)
e.table[hash4x64(cv, tableBits)] = tableEntry{offset: s + e.cur}
e.bTable[hash7(cv, tableBits)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every 3rd hash in-between
if true {
i := nextS
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hash4u(uint32(cv>>8), tableBits)] = t2
i += 3
for ; i < s-1; i += 3 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hash4u(uint32(cv>>8), tableBits)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hash4x64(x, tableBits)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
e.bTable[prevHashL] = tableEntry{offset: o}
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,302 +0,0 @@
package flate
import "fmt"
type fastEncL5 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL5) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hash4x64(cv, tableBits)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
nextHashS = hash4x64(next, tableBits)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
if l == 0 {
// Extend the 4-byte match as long as possible.
l = e.matchlenLong(s+4, t+4, src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(s+l, t+l, src)
}
// Try to locate a better match by checking the end of best match...
if sAt := s + l; l < 30 && sAt < sLimit {
eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset
// Test current
t2 := eLong - e.cur - l
off := s - t2
if t2 >= 0 && off < maxMatchOffset && off > 0 {
if l2 := e.matchlenLong(s, t2, src); l2 > l {
t = t2
l = l2
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// Store every 3rd hash in-between.
if true {
const hashEvery = 3
i := s - l + 1
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
e.table[hash4x64(cv, tableBits)] = t
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// Do an long at i+1
cv >>= 8
t = tableEntry{offset: t.offset + 1}
eLong = &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// We only have enough bits for a short entry at i+2
cv >>= 8
t = tableEntry{offset: t.offset + 1}
e.table[hash4x64(cv, tableBits)] = t
// Skip one - otherwise we risk hitting 's'
i += 4
for ; i < s-1; i += hashEvery {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hash4u(uint32(cv>>8), tableBits)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hash4x64(x, tableBits)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,315 +0,0 @@
package flate
import "fmt"
type fastEncL6 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL6) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
// Repeat MUST be > 1 and within range
repeat := int32(1)
for {
const skipLog = 7
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hash4x64(cv, tableBits)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
// Calculate hashes of 'next'
nextHashS = hash4x64(next, tableBits)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) {
// Long candidate matches at least 4 bytes.
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check the previous long candidate as well.
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
// Current value did not match, but check if previous long value does.
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
// Look up next long candidate (at nextS)
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check repeat at s + repOff
const repOff = 1
t2 := s - repeat + repOff
if load3232(src, t2) == uint32(cv>>(8*repOff)) {
ml := e.matchlen(s+4+repOff, t2+4, src) + 4
if ml > l {
t = t2
l = ml
s += repOff
// Not worth checking more.
break
}
}
// If the next long is a candidate, use that...
t2 = lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
// This is ok, but check previous as well.
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
// Extend the 4-byte match as long as possible.
if l == 0 {
l = e.matchlenLong(s+4, t+4, src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(s+l, t+l, src)
}
// Try to locate a better match by checking the end-of-match...
if sAt := s + l; sAt < sLimit {
eLong := &e.bTable[hash7(load6432(src, sAt), tableBits)]
// Test current
t2 := eLong.Cur.offset - e.cur - l
off := s - t2
if off < maxMatchOffset {
if off > 0 && t2 >= 0 {
if l2 := e.matchlenLong(s, t2, src); l2 > l {
t = t2
l = l2
}
}
// Test next:
t2 = eLong.Prev.offset - e.cur - l
off := s - t2
if off > 0 && off < maxMatchOffset && t2 >= 0 {
if l2 := e.matchlenLong(s, t2, src); l2 > l {
t = t2
l = l2
}
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if false {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
repeat = s - t
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index after match end.
for i := nextS + 1; i < int32(len(src))-8; i += 2 {
cv := load6432(src, i)
e.table[hash4x64(cv, tableBits)] = tableEntry{offset: i + e.cur}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur}, eLong.Cur
}
goto emitRemainder
}
// Store every long hash in-between and every second short.
if true {
for i := nextS + 1; i < s-1; i += 2 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong2 := &e.bTable[hash7(cv>>8, tableBits)]
e.table[hash4x64(cv, tableBits)] = t
eLong.Cur, eLong.Prev = t, eLong.Cur
eLong2.Cur, eLong2.Prev = t2, eLong2.Cur
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
cv = load6432(src, s)
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,37 +0,0 @@
package flate
const (
// Masks for shifts with register sizes of the shift value.
// This can be used to work around the x86 design of shifting by mod register size.
// It can be used when a variable shift is always smaller than the register size.
// reg8SizeMaskX - shift value is 8 bits, shifted is X
reg8SizeMask8 = 7
reg8SizeMask16 = 15
reg8SizeMask32 = 31
reg8SizeMask64 = 63
// reg16SizeMaskX - shift value is 16 bits, shifted is X
reg16SizeMask8 = reg8SizeMask8
reg16SizeMask16 = reg8SizeMask16
reg16SizeMask32 = reg8SizeMask32
reg16SizeMask64 = reg8SizeMask64
// reg32SizeMaskX - shift value is 32 bits, shifted is X
reg32SizeMask8 = reg8SizeMask8
reg32SizeMask16 = reg8SizeMask16
reg32SizeMask32 = reg8SizeMask32
reg32SizeMask64 = reg8SizeMask64
// reg64SizeMaskX - shift value is 64 bits, shifted is X
reg64SizeMask8 = reg8SizeMask8
reg64SizeMask16 = reg8SizeMask16
reg64SizeMask32 = reg8SizeMask32
reg64SizeMask64 = reg8SizeMask64
// regSizeMaskUintX - shift value is uint, shifted is X
regSizeMaskUint8 = reg8SizeMask8
regSizeMaskUint16 = reg8SizeMask16
regSizeMaskUint32 = reg8SizeMask32
regSizeMaskUint64 = reg8SizeMask64
)

@ -1,40 +0,0 @@
//go:build !amd64
// +build !amd64
package flate
const (
// Masks for shifts with register sizes of the shift value.
// This can be used to work around the x86 design of shifting by mod register size.
// It can be used when a variable shift is always smaller than the register size.
// reg8SizeMaskX - shift value is 8 bits, shifted is X
reg8SizeMask8 = 0xff
reg8SizeMask16 = 0xff
reg8SizeMask32 = 0xff
reg8SizeMask64 = 0xff
// reg16SizeMaskX - shift value is 16 bits, shifted is X
reg16SizeMask8 = 0xffff
reg16SizeMask16 = 0xffff
reg16SizeMask32 = 0xffff
reg16SizeMask64 = 0xffff
// reg32SizeMaskX - shift value is 32 bits, shifted is X
reg32SizeMask8 = 0xffffffff
reg32SizeMask16 = 0xffffffff
reg32SizeMask32 = 0xffffffff
reg32SizeMask64 = 0xffffffff
// reg64SizeMaskX - shift value is 64 bits, shifted is X
reg64SizeMask8 = 0xffffffffffffffff
reg64SizeMask16 = 0xffffffffffffffff
reg64SizeMask32 = 0xffffffffffffffff
reg64SizeMask64 = 0xffffffffffffffff
// regSizeMaskUintX - shift value is uint, shifted is X
regSizeMaskUint8 = ^uint(0)
regSizeMaskUint16 = ^uint(0)
regSizeMaskUint32 = ^uint(0)
regSizeMaskUint64 = ^uint(0)
)

@ -1,305 +0,0 @@
package flate
import (
"io"
"math"
"sync"
)
const (
maxStatelessBlock = math.MaxInt16
// dictionary will be taken from maxStatelessBlock, so limit it.
maxStatelessDict = 8 << 10
slTableBits = 13
slTableSize = 1 << slTableBits
slTableShift = 32 - slTableBits
)
type statelessWriter struct {
dst io.Writer
closed bool
}
func (s *statelessWriter) Close() error {
if s.closed {
return nil
}
s.closed = true
// Emit EOF block
return StatelessDeflate(s.dst, nil, true, nil)
}
func (s *statelessWriter) Write(p []byte) (n int, err error) {
err = StatelessDeflate(s.dst, p, false, nil)
if err != nil {
return 0, err
}
return len(p), nil
}
func (s *statelessWriter) Reset(w io.Writer) {
s.dst = w
s.closed = false
}
// NewStatelessWriter will do compression but without maintaining any state
// between Write calls.
// There will be no memory kept between Write calls,
// but compression and speed will be suboptimal.
// Because of this, the size of actual Write calls will affect output size.
func NewStatelessWriter(dst io.Writer) io.WriteCloser {
return &statelessWriter{dst: dst}
}
// bitWriterPool contains bit writers that can be reused.
var bitWriterPool = sync.Pool{
New: func() interface{} {
return newHuffmanBitWriter(nil)
},
}
// StatelessDeflate allows compressing directly to a Writer without retaining state.
// When returning everything will be flushed.
// Up to 8KB of an optional dictionary can be given which is presumed to precede the block.
// Longer dictionaries will be truncated and will still produce valid output.
// Sending nil dictionary is perfectly fine.
func StatelessDeflate(out io.Writer, in []byte, eof bool, dict []byte) error {
var dst tokens
bw := bitWriterPool.Get().(*huffmanBitWriter)
bw.reset(out)
defer func() {
// don't keep a reference to our output
bw.reset(nil)
bitWriterPool.Put(bw)
}()
if eof && len(in) == 0 {
// Just write an EOF block.
// Could be faster...
bw.writeStoredHeader(0, true)
bw.flush()
return bw.err
}
// Truncate dict
if len(dict) > maxStatelessDict {
dict = dict[len(dict)-maxStatelessDict:]
}
for len(in) > 0 {
todo := in
if len(todo) > maxStatelessBlock-len(dict) {
todo = todo[:maxStatelessBlock-len(dict)]
}
in = in[len(todo):]
uncompressed := todo
if len(dict) > 0 {
// combine dict and source
bufLen := len(todo) + len(dict)
combined := make([]byte, bufLen)
copy(combined, dict)
copy(combined[len(dict):], todo)
todo = combined
}
// Compress
statelessEnc(&dst, todo, int16(len(dict)))
isEof := eof && len(in) == 0
if dst.n == 0 {
bw.writeStoredHeader(len(uncompressed), isEof)
if bw.err != nil {
return bw.err
}
bw.writeBytes(uncompressed)
} else if int(dst.n) > len(uncompressed)-len(uncompressed)>>4 {
// If we removed less than 1/16th, huffman compress the block.
bw.writeBlockHuff(isEof, uncompressed, len(in) == 0)
} else {
bw.writeBlockDynamic(&dst, isEof, uncompressed, len(in) == 0)
}
if len(in) > 0 {
// Retain a dict if we have more
dict = todo[len(todo)-maxStatelessDict:]
dst.Reset()
}
if bw.err != nil {
return bw.err
}
}
if !eof {
// Align, only a stored block can do that.
bw.writeStoredHeader(0, false)
}
bw.flush()
return bw.err
}
func hashSL(u uint32) uint32 {
return (u * 0x1e35a7bd) >> slTableShift
}
func load3216(b []byte, i int16) uint32 {
// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
b = b[i:]
b = b[:4]
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
func load6416(b []byte, i int16) uint64 {
// Help the compiler eliminate bounds checks on the read so it can be done in a single read.
b = b[i:]
b = b[:8]
return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
}
func statelessEnc(dst *tokens, src []byte, startAt int16) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
type tableEntry struct {
offset int16
}
var table [slTableSize]tableEntry
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src)-int(startAt) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = 0
return
}
// Index until startAt
if startAt > 0 {
cv := load3232(src, 0)
for i := int16(0); i < startAt; i++ {
table[hashSL(cv)] = tableEntry{offset: i}
cv = (cv >> 8) | (uint32(src[i+4]) << 24)
}
}
s := startAt + 1
nextEmit := startAt
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := int16(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3216(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hashSL(cv)
candidate = table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit || nextS <= 0 {
goto emitRemainder
}
now := load6416(src, nextS)
table[nextHash] = tableEntry{offset: s}
nextHash = hashSL(uint32(now))
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
// Do one right away...
cv = uint32(now)
s = nextS
nextS++
candidate = table[nextHash]
now >>= 8
table[nextHash] = tableEntry{offset: s}
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
cv = uint32(now)
s = nextS
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset
l := int16(matchLen(src[s+4:], src[t+4:]) + 4)
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
dst.AddMatchLong(int32(l), uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load6416(src, s-2)
o := s - 2
prevHash := hashSL(uint32(x))
table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hashSL(uint32(x))
candidate = table[currHash]
table[currHash] = tableEntry{offset: o + 2}
if uint32(x) != load3216(src, candidate.offset) {
cv = uint32(x >> 8)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}

@ -1,379 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
)
const (
// bits 0-16 xoffset = offset - MIN_OFFSET_SIZE, or literal - 16 bits
// bits 16-22 offsetcode - 5 bits
// bits 22-30 xlength = length - MIN_MATCH_LENGTH - 8 bits
// bits 30-32 type 0 = literal 1=EOF 2=Match 3=Unused - 2 bits
lengthShift = 22
offsetMask = 1<<lengthShift - 1
typeMask = 3 << 30
literalType = 0 << 30
matchType = 1 << 30
matchOffsetOnlyMask = 0xffff
)
// The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH)
// is lengthCodes[length - MIN_MATCH_LENGTH]
var lengthCodes = [256]uint8{
0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15,
15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18,
18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 28,
}
// lengthCodes1 is length codes, but starting at 1.
var lengthCodes1 = [256]uint8{
1, 2, 3, 4, 5, 6, 7, 8, 9, 9,
10, 10, 11, 11, 12, 12, 13, 13, 13, 13,
14, 14, 14, 14, 15, 15, 15, 15, 16, 16,
16, 16, 17, 17, 17, 17, 17, 17, 17, 17,
18, 18, 18, 18, 18, 18, 18, 18, 19, 19,
19, 19, 19, 19, 19, 19, 20, 20, 20, 20,
20, 20, 20, 20, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 29,
}
var offsetCodes = [256]uint32{
0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
}
// offsetCodes14 are offsetCodes, but with 14 added.
var offsetCodes14 = [256]uint32{
14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
}
type token uint32
type tokens struct {
extraHist [32]uint16 // codes 256->maxnumlit
offHist [32]uint16 // offset codes
litHist [256]uint16 // codes 0->255
nFilled int
n uint16 // Must be able to contain maxStoreBlockSize
tokens [maxStoreBlockSize + 1]token
}
func (t *tokens) Reset() {
if t.n == 0 {
return
}
t.n = 0
t.nFilled = 0
for i := range t.litHist[:] {
t.litHist[i] = 0
}
for i := range t.extraHist[:] {
t.extraHist[i] = 0
}
for i := range t.offHist[:] {
t.offHist[i] = 0
}
}
func (t *tokens) Fill() {
if t.n == 0 {
return
}
for i, v := range t.litHist[:] {
if v == 0 {
t.litHist[i] = 1
t.nFilled++
}
}
for i, v := range t.extraHist[:literalCount-256] {
if v == 0 {
t.nFilled++
t.extraHist[i] = 1
}
}
for i, v := range t.offHist[:offsetCodeCount] {
if v == 0 {
t.offHist[i] = 1
}
}
}
func indexTokens(in []token) tokens {
var t tokens
t.indexTokens(in)
return t
}
func (t *tokens) indexTokens(in []token) {
t.Reset()
for _, tok := range in {
if tok < matchType {
t.AddLiteral(tok.literal())
continue
}
t.AddMatch(uint32(tok.length()), tok.offset()&matchOffsetOnlyMask)
}
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
func emitLiteral(dst *tokens, lit []byte) {
for _, v := range lit {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
func (t *tokens) AddLiteral(lit byte) {
t.tokens[t.n] = token(lit)
t.litHist[lit]++
t.n++
}
// from https://stackoverflow.com/a/28730362
func mFastLog2(val float32) float32 {
ux := int32(math.Float32bits(val))
log2 := (float32)(((ux >> 23) & 255) - 128)
ux &= -0x7f800001
ux += 127 << 23
uval := math.Float32frombits(uint32(ux))
log2 += ((-0.34484843)*uval+2.02466578)*uval - 0.67487759
return log2
}
// EstimatedBits will return an minimum size estimated by an *optimal*
// compression of the block.
// The size of the block
func (t *tokens) EstimatedBits() int {
shannon := float32(0)
bits := int(0)
nMatches := 0
total := int(t.n) + t.nFilled
if total > 0 {
invTotal := 1.0 / float32(total)
for _, v := range t.litHist[:] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
}
}
// Just add 15 for EOB
shannon += 15
for i, v := range t.extraHist[1 : literalCount-256] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(lengthExtraBits[i&31]) * int(v)
nMatches += int(v)
}
}
}
if nMatches > 0 {
invTotal := 1.0 / float32(nMatches)
for i, v := range t.offHist[:offsetCodeCount] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(offsetExtraBits[i&31]) * int(v)
}
}
}
return int(shannon) + bits
}
// AddMatch adds a match to the tokens.
// This function is very sensitive to inlining and right on the border.
func (t *tokens) AddMatch(xlength uint32, xoffset uint32) {
if debugDeflate {
if xlength >= maxMatchLength+baseMatchLength {
panic(fmt.Errorf("invalid length: %v", xlength))
}
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oCode := offsetCode(xoffset)
xoffset |= oCode << 16
t.extraHist[lengthCodes1[uint8(xlength)]]++
t.offHist[oCode&31]++
t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset)
t.n++
}
// AddMatchLong adds a match to the tokens, potentially longer than max match length.
// Length should NOT have the base subtracted, only offset should.
func (t *tokens) AddMatchLong(xlength int32, xoffset uint32) {
if debugDeflate {
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
// We need to have at least baseMatchLength left over for next loop.
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
t.extraHist[lengthCodes1[uint8(xl)]]++
t.offHist[oc&31]++
t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
t.n++
}
}
func (t *tokens) AddEOB() {
t.tokens[t.n] = token(endBlockMarker)
t.extraHist[0]++
t.n++
}
func (t *tokens) Slice() []token {
return t.tokens[:t.n]
}
// VarInt returns the tokens as varint encoded bytes.
func (t *tokens) VarInt() []byte {
var b = make([]byte, binary.MaxVarintLen32*int(t.n))
var off int
for _, v := range t.tokens[:t.n] {
off += binary.PutUvarint(b[off:], uint64(v))
}
return b[:off]
}
// FromVarInt restores t to the varint encoded tokens provided.
// Any data in t is removed.
func (t *tokens) FromVarInt(b []byte) error {
var buf = bytes.NewReader(b)
var toks []token
for {
r, err := binary.ReadUvarint(buf)
if err == io.EOF {
break
}
if err != nil {
return err
}
toks = append(toks, token(r))
}
t.indexTokens(toks)
return nil
}
// Returns the type of a token
func (t token) typ() uint32 { return uint32(t) & typeMask }
// Returns the literal of a literal token
func (t token) literal() uint8 { return uint8(t) }
// Returns the extra offset of a match token
func (t token) offset() uint32 { return uint32(t) & offsetMask }
func (t token) length() uint8 { return uint8(t >> lengthShift) }
// Convert length to code.
func lengthCode(len uint8) uint8 { return lengthCodes[len] }
// Returns the offset code corresponding to a specific offset
func offsetCode(off uint32) uint32 {
if false {
if off < uint32(len(offsetCodes)) {
return offsetCodes[off&255]
} else if off>>7 < uint32(len(offsetCodes)) {
return offsetCodes[(off>>7)&255] + 14
} else {
return offsetCodes[(off>>14)&255] + 28
}
}
if off < uint32(len(offsetCodes)) {
return offsetCodes[uint8(off)]
}
return offsetCodes14[uint8(off>>7)]
}

@ -1,79 +0,0 @@
# Finite State Entropy
This package provides Finite State Entropy encoding and decoding.
Finite State Entropy (also referenced as [tANS](https://en.wikipedia.org/wiki/Asymmetric_numeral_systems#tANS))
encoding provides a fast near-optimal symbol encoding/decoding
for byte blocks as implemented in [zstandard](https://github.com/facebook/zstd).
This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/fse)
## News
* Feb 2018: First implementation released. Consider this beta software for now.
# Usage
This package provides a low level interface that allows to compress single independent blocks.
Each block is separate, and there is no built in integrity checks.
This means that the caller should keep track of block sizes and also do checksums if needed.
Compressing a block is done via the [`Compress`](https://godoc.org/github.com/klauspost/compress/fse#Compress) function.
You must provide input and will receive the output and maybe an error.
These error values can be returned:
| Error | Description |
|---------------------|-----------------------------------------------------------------------------|
| `<nil>` | Everything ok, output is returned |
| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
| `(error)` | An internal error occurred. |
As can be seen above there are errors that will be returned even under normal operation so it is important to handle these.
To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/fse#Scratch) object
that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
object can be used for both.
Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
Decompressing is done by calling the [`Decompress`](https://godoc.org/github.com/klauspost/compress/fse#Decompress) function.
You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
your input was likely corrupted.
It is important to note that a successful decoding does *not* mean your output matches your original input.
There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
For more detailed usage, see examples in the [godoc documentation](https://godoc.org/github.com/klauspost/compress/fse#pkg-examples).
# Performance
A lot of factors are affecting speed. Block sizes and compressibility of the material are primary factors.
All compression functions are currently only running on the calling goroutine so only one core will be used per block.
The compressor is significantly faster if symbols are kept as small as possible. The highest byte value of the input
is used to reduce some of the processing, so if all your input is above byte value 64 for instance, it may be
beneficial to transpose all your input values down by 64.
With moderate block sizes around 64k speed are typically 200MB/s per core for compression and
around 300MB/s decompression speed.
The same hardware typically does Huffman (deflate) encoding at 125MB/s and decompression at 100MB/s.
# Plans
At one point, more internals will be exposed to facilitate more "expert" usage of the components.
A streaming interface is also likely to be implemented. Likely compatible with [FSE stream format](https://github.com/Cyan4973/FiniteStateEntropy/blob/dev/programs/fileio.c#L261).
# Contributing
Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
changes will likely not be accepted. If in doubt open an issue before writing the PR.

@ -1,122 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import (
"encoding/binary"
"errors"
"io"
)
// bitReader reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReader struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReader) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.bitsRead += 8 - uint8(highBits(uint32(v)))
return nil
}
// getBits will return n bits. n can be 0.
func (b *bitReader) getBits(n uint8) uint16 {
if n == 0 || b.bitsRead >= 64 {
return 0
}
return b.getBitsFast(n)
}
// getBitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReader) getBitsFast(n uint8) uint16 {
const regMask = 64 - 1
v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask))
b.bitsRead += n
return v
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReader) fillFast() {
if b.bitsRead < 32 {
return
}
// 2 bounds checks.
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value = (b.value << 32) | uint64(low)
b.bitsRead -= 32
b.off -= 4
}
// fill() will make sure at least 32 bits are available.
func (b *bitReader) fill() {
if b.bitsRead < 32 {
return
}
if b.off > 4 {
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value = (b.value << 32) | uint64(low)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value = (b.value << 8) | uint64(b.in[b.off-1])
b.bitsRead -= 8
b.off--
}
}
// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
func (b *bitReader) fillFastStart() {
// Do single re-slice to avoid bounds checks.
b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
b.bitsRead = 0
b.off -= 8
}
// finished returns true if all bits have been read from the bit stream.
func (b *bitReader) finished() bool {
return b.bitsRead >= 64 && b.off == 0
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReader) close() error {
// Release reference.
b.in = nil
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}

@ -1,168 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import "fmt"
// bitWriter will write bits.
// First bit will be LSB of the first byte of output.
type bitWriter struct {
bitContainer uint64
nBits uint8
out []byte
}
// bitMask16 is bitmasks. Has extra to avoid bounds check.
var bitMask16 = [32]uint16{
0, 1, 3, 7, 0xF, 0x1F,
0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF} /* up to 16 bits */
// addBits16NC will add up to 16 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16NC(value uint16, bits uint8) {
b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63)
b.nBits += bits
}
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// addBits16ZeroNC will add up to 16 bits.
// It will not check if there is space for them,
// so the caller must ensure that it has flushed recently.
// This is fastest if bits can be zero.
func (b *bitWriter) addBits16ZeroNC(value uint16, bits uint8) {
if bits == 0 {
return
}
value <<= (16 - bits) & 15
value >>= (16 - bits) & 15
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// flush will flush all pending full bytes.
// There will be at least 56 bits available for writing when this has been called.
// Using flush32 is faster, but leaves less space for writing.
func (b *bitWriter) flush() {
v := b.nBits >> 3
switch v {
case 0:
case 1:
b.out = append(b.out,
byte(b.bitContainer),
)
case 2:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
)
case 3:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
)
case 4:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
)
case 5:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
)
case 6:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
)
case 7:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
byte(b.bitContainer>>48),
)
case 8:
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24),
byte(b.bitContainer>>32),
byte(b.bitContainer>>40),
byte(b.bitContainer>>48),
byte(b.bitContainer>>56),
)
default:
panic(fmt.Errorf("bits (%d) > 64", b.nBits))
}
b.bitContainer >>= v << 3
b.nBits &= 7
}
// flush32 will flush out, so there are at least 32 bits available for writing.
func (b *bitWriter) flush32() {
if b.nBits < 32 {
return
}
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24))
b.nBits -= 32
b.bitContainer >>= 32
}
// flushAlign will flush remaining full bytes and align to next byte boundary.
func (b *bitWriter) flushAlign() {
nbBytes := (b.nBits + 7) >> 3
for i := uint8(0); i < nbBytes; i++ {
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
}
b.nBits = 0
b.bitContainer = 0
}
// close will write the alignment bit and write the final byte(s)
// to the output.
func (b *bitWriter) close() error {
// End mark
b.addBits16Clean(1, 1)
// flush until next byte.
b.flushAlign()
return nil
}
// reset and continue writing by appending to out.
func (b *bitWriter) reset(out []byte) {
b.bitContainer = 0
b.nBits = 0
b.out = out
}

@ -1,47 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
// byteReader provides a byte reader that reads
// little endian values from a byte stream.
// The input stream is manually advanced.
// The reader performs no bounds checks.
type byteReader struct {
b []byte
off int
}
// init will initialize the reader and set the input.
func (b *byteReader) init(in []byte) {
b.b = in
b.off = 0
}
// advance the stream b n bytes.
func (b *byteReader) advance(n uint) {
b.off += int(n)
}
// Uint32 returns a little endian uint32 starting at current offset.
func (b byteReader) Uint32() uint32 {
b2 := b.b[b.off:]
b2 = b2[:4]
v3 := uint32(b2[3])
v2 := uint32(b2[2])
v1 := uint32(b2[1])
v0 := uint32(b2[0])
return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
}
// unread returns the unread portion of the input.
func (b byteReader) unread() []byte {
return b.b[b.off:]
}
// remain will return the number of bytes remaining.
func (b byteReader) remain() int {
return len(b.b) - b.off
}

@ -1,683 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package fse
import (
"errors"
"fmt"
)
// Compress the input bytes. Input must be < 2GB.
// Provide a Scratch buffer to avoid memory allocations.
// Note that the output is also kept in the scratch buffer.
// If input is too hard to compress, ErrIncompressible is returned.
// If input is a single byte value repeated ErrUseRLE is returned.
func Compress(in []byte, s *Scratch) ([]byte, error) {
if len(in) <= 1 {
return nil, ErrIncompressible
}
if len(in) > (2<<30)-1 {
return nil, errors.New("input too big, must be < 2GB")
}
s, err := s.prepare(in)
if err != nil {
return nil, err
}
// Create histogram, if none was provided.
maxCount := s.maxCount
if maxCount == 0 {
maxCount = s.countSimple(in)
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount == len(in) {
// One symbol, use RLE
return nil, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return nil, ErrIncompressible
}
s.optimalTableLog()
err = s.normalizeCount()
if err != nil {
return nil, err
}
err = s.writeCount()
if err != nil {
return nil, err
}
if false {
err = s.validateNorm()
if err != nil {
return nil, err
}
}
err = s.buildCTable()
if err != nil {
return nil, err
}
err = s.compress(in)
if err != nil {
return nil, err
}
s.Out = s.bw.out
// Check if we compressed.
if len(s.Out) >= len(in) {
return nil, ErrIncompressible
}
return s.Out, nil
}
// cState contains the compression state of a stream.
type cState struct {
bw *bitWriter
stateTable []uint16
state uint16
}
// init will initialize the compression state to the first symbol of the stream.
func (c *cState) init(bw *bitWriter, ct *cTable, tableLog uint8, first symbolTransform) {
c.bw = bw
c.stateTable = ct.stateTable
nbBitsOut := (first.deltaNbBits + (1 << 15)) >> 16
im := int32((nbBitsOut << 16) - first.deltaNbBits)
lu := (im >> nbBitsOut) + first.deltaFindState
c.state = c.stateTable[lu]
}
// encode the output symbol provided and write it to the bitstream.
func (c *cState) encode(symbolTT symbolTransform) {
nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16
dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState
c.bw.addBits16NC(c.state, uint8(nbBitsOut))
c.state = c.stateTable[dstState]
}
// encode the output symbol provided and write it to the bitstream.
func (c *cState) encodeZero(symbolTT symbolTransform) {
nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16
dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState
c.bw.addBits16ZeroNC(c.state, uint8(nbBitsOut))
c.state = c.stateTable[dstState]
}
// flush will write the tablelog to the output and flush the remaining full bytes.
func (c *cState) flush(tableLog uint8) {
c.bw.flush32()
c.bw.addBits16NC(c.state, tableLog)
c.bw.flush()
}
// compress is the main compression loop that will encode the input from the last byte to the first.
func (s *Scratch) compress(src []byte) error {
if len(src) <= 2 {
return errors.New("compress: src too small")
}
tt := s.ct.symbolTT[:256]
s.bw.reset(s.Out)
// Our two states each encodes every second byte.
// Last byte encoded (first byte decoded) will always be encoded by c1.
var c1, c2 cState
// Encode so remaining size is divisible by 4.
ip := len(src)
if ip&1 == 1 {
c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]])
c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]])
c1.encodeZero(tt[src[ip-3]])
ip -= 3
} else {
c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]])
c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]])
ip -= 2
}
if ip&2 != 0 {
c2.encodeZero(tt[src[ip-1]])
c1.encodeZero(tt[src[ip-2]])
ip -= 2
}
// Main compression loop.
switch {
case !s.zeroBits && s.actualTableLog <= 8:
// We can encode 4 symbols without requiring a flush.
// We do not need to check if any output is 0 bits.
for ip >= 4 {
s.bw.flush32()
v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1]
c2.encode(tt[v0])
c1.encode(tt[v1])
c2.encode(tt[v2])
c1.encode(tt[v3])
ip -= 4
}
case !s.zeroBits:
// We do not need to check if any output is 0 bits.
for ip >= 4 {
s.bw.flush32()
v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1]
c2.encode(tt[v0])
c1.encode(tt[v1])
s.bw.flush32()
c2.encode(tt[v2])
c1.encode(tt[v3])
ip -= 4
}
case s.actualTableLog <= 8:
// We can encode 4 symbols without requiring a flush
for ip >= 4 {
s.bw.flush32()
v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1]
c2.encodeZero(tt[v0])
c1.encodeZero(tt[v1])
c2.encodeZero(tt[v2])
c1.encodeZero(tt[v3])
ip -= 4
}
default:
for ip >= 4 {
s.bw.flush32()
v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1]
c2.encodeZero(tt[v0])
c1.encodeZero(tt[v1])
s.bw.flush32()
c2.encodeZero(tt[v2])
c1.encodeZero(tt[v3])
ip -= 4
}
}
// Flush final state.
// Used to initialize state when decoding.
c2.flush(s.actualTableLog)
c1.flush(s.actualTableLog)
return s.bw.close()
}
// writeCount will write the normalized histogram count to header.
// This is read back by readNCount.
func (s *Scratch) writeCount() error {
var (
tableLog = s.actualTableLog
tableSize = 1 << tableLog
previous0 bool
charnum uint16
maxHeaderSize = ((int(s.symbolLen) * int(tableLog)) >> 3) + 3
// Write Table Size
bitStream = uint32(tableLog - minTablelog)
bitCount = uint(4)
remaining = int16(tableSize + 1) /* +1 for extra accuracy */
threshold = int16(tableSize)
nbBits = uint(tableLog + 1)
)
if cap(s.Out) < maxHeaderSize {
s.Out = make([]byte, 0, s.br.remain()+maxHeaderSize)
}
outP := uint(0)
out := s.Out[:maxHeaderSize]
// stops at 1
for remaining > 1 {
if previous0 {
start := charnum
for s.norm[charnum] == 0 {
charnum++
}
for charnum >= start+24 {
start += 24
bitStream += uint32(0xFFFF) << bitCount
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
}
for charnum >= start+3 {
start += 3
bitStream += 3 << bitCount
bitCount += 2
}
bitStream += uint32(charnum-start) << bitCount
bitCount += 2
if bitCount > 16 {
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
bitCount -= 16
}
}
count := s.norm[charnum]
charnum++
max := (2*threshold - 1) - remaining
if count < 0 {
remaining += count
} else {
remaining -= count
}
count++ // +1 for extra accuracy
if count >= threshold {
count += max // [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[
}
bitStream += uint32(count) << bitCount
bitCount += nbBits
if count < max {
bitCount--
}
previous0 = count == 1
if remaining < 1 {
return errors.New("internal error: remaining<1")
}
for remaining < threshold {
nbBits--
threshold >>= 1
}
if bitCount > 16 {
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += 2
bitStream >>= 16
bitCount -= 16
}
}
out[outP] = byte(bitStream)
out[outP+1] = byte(bitStream >> 8)
outP += (bitCount + 7) / 8
if charnum > s.symbolLen {
return errors.New("internal error: charnum > s.symbolLen")
}
s.Out = out[:outP]
return nil
}
// symbolTransform contains the state transform for a symbol.
type symbolTransform struct {
deltaFindState int32
deltaNbBits uint32
}
// String prints values as a human readable string.
func (s symbolTransform) String() string {
return fmt.Sprintf("dnbits: %08x, fs:%d", s.deltaNbBits, s.deltaFindState)
}
// cTable contains tables used for compression.
type cTable struct {
tableSymbol []byte
stateTable []uint16
symbolTT []symbolTransform
}
// allocCtable will allocate tables needed for compression.
// If existing tables a re big enough, they are simply re-used.
func (s *Scratch) allocCtable() {
tableSize := 1 << s.actualTableLog
// get tableSymbol that is big enough.
if cap(s.ct.tableSymbol) < tableSize {
s.ct.tableSymbol = make([]byte, tableSize)
}
s.ct.tableSymbol = s.ct.tableSymbol[:tableSize]
ctSize := tableSize
if cap(s.ct.stateTable) < ctSize {
s.ct.stateTable = make([]uint16, ctSize)
}
s.ct.stateTable = s.ct.stateTable[:ctSize]
if cap(s.ct.symbolTT) < 256 {
s.ct.symbolTT = make([]symbolTransform, 256)
}
s.ct.symbolTT = s.ct.symbolTT[:256]
}
// buildCTable will populate the compression table so it is ready to be used.
func (s *Scratch) buildCTable() error {
tableSize := uint32(1 << s.actualTableLog)
highThreshold := tableSize - 1
var cumul [maxSymbolValue + 2]int16
s.allocCtable()
tableSymbol := s.ct.tableSymbol[:tableSize]
// symbol start positions
{
cumul[0] = 0
for ui, v := range s.norm[:s.symbolLen-1] {
u := byte(ui) // one less than reference
if v == -1 {
// Low proba symbol
cumul[u+1] = cumul[u] + 1
tableSymbol[highThreshold] = u
highThreshold--
} else {
cumul[u+1] = cumul[u] + v
}
}
// Encode last symbol separately to avoid overflowing u
u := int(s.symbolLen - 1)
v := s.norm[s.symbolLen-1]
if v == -1 {
// Low proba symbol
cumul[u+1] = cumul[u] + 1
tableSymbol[highThreshold] = byte(u)
highThreshold--
} else {
cumul[u+1] = cumul[u] + v
}
if uint32(cumul[s.symbolLen]) != tableSize {
return fmt.Errorf("internal error: expected cumul[s.symbolLen] (%d) == tableSize (%d)", cumul[s.symbolLen], tableSize)
}
cumul[s.symbolLen] = int16(tableSize) + 1
}
// Spread symbols
s.zeroBits = false
{
step := tableStep(tableSize)
tableMask := tableSize - 1
var position uint32
// if any symbol > largeLimit, we may have 0 bits output.
largeLimit := int16(1 << (s.actualTableLog - 1))
for ui, v := range s.norm[:s.symbolLen] {
symbol := byte(ui)
if v > largeLimit {
s.zeroBits = true
}
for nbOccurrences := int16(0); nbOccurrences < v; nbOccurrences++ {
tableSymbol[position] = symbol
position = (position + step) & tableMask
for position > highThreshold {
position = (position + step) & tableMask
} /* Low proba area */
}
}
// Check if we have gone through all positions
if position != 0 {
return errors.New("position!=0")
}
}
// Build table
table := s.ct.stateTable
{
tsi := int(tableSize)
for u, v := range tableSymbol {
// TableU16 : sorted by symbol order; gives next state value
table[cumul[v]] = uint16(tsi + u)
cumul[v]++
}
}
// Build Symbol Transformation Table
{
total := int16(0)
symbolTT := s.ct.symbolTT[:s.symbolLen]
tableLog := s.actualTableLog
tl := (uint32(tableLog) << 16) - (1 << tableLog)
for i, v := range s.norm[:s.symbolLen] {
switch v {
case 0:
case -1, 1:
symbolTT[i].deltaNbBits = tl
symbolTT[i].deltaFindState = int32(total - 1)
total++
default:
maxBitsOut := uint32(tableLog) - highBits(uint32(v-1))
minStatePlus := uint32(v) << maxBitsOut
symbolTT[i].deltaNbBits = (maxBitsOut << 16) - minStatePlus
symbolTT[i].deltaFindState = int32(total - v)
total += v
}
}
if total != int16(tableSize) {
return fmt.Errorf("total mismatch %d (got) != %d (want)", total, tableSize)
}
}
return nil
}
// countSimple will create a simple histogram in s.count.
// Returns the biggest count.
// Does not update s.clearCount.
func (s *Scratch) countSimple(in []byte) (max int) {
for _, v := range in {
s.count[v]++
}
m := uint32(0)
for i, v := range s.count[:] {
if v > m {
m = v
}
if v > 0 {
s.symbolLen = uint16(i) + 1
}
}
return int(m)
}
// minTableLog provides the minimum logSize to safely represent a distribution.
func (s *Scratch) minTableLog() uint8 {
minBitsSrc := highBits(uint32(s.br.remain()-1)) + 1
minBitsSymbols := highBits(uint32(s.symbolLen-1)) + 2
if minBitsSrc < minBitsSymbols {
return uint8(minBitsSrc)
}
return uint8(minBitsSymbols)
}
// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog
func (s *Scratch) optimalTableLog() {
tableLog := s.TableLog
minBits := s.minTableLog()
maxBitsSrc := uint8(highBits(uint32(s.br.remain()-1))) - 2
if maxBitsSrc < tableLog {
// Accuracy can be reduced
tableLog = maxBitsSrc
}
if minBits > tableLog {
tableLog = minBits
}
// Need a minimum to safely represent all symbol values
if tableLog < minTablelog {
tableLog = minTablelog
}
if tableLog > maxTableLog {
tableLog = maxTableLog
}
s.actualTableLog = tableLog
}
var rtbTable = [...]uint32{0, 473195, 504333, 520860, 550000, 700000, 750000, 830000}
// normalizeCount will normalize the count of the symbols so
// the total is equal to the table size.
func (s *Scratch) normalizeCount() error {
var (
tableLog = s.actualTableLog
scale = 62 - uint64(tableLog)
step = (1 << 62) / uint64(s.br.remain())
vStep = uint64(1) << (scale - 20)
stillToDistribute = int16(1 << tableLog)
largest int
largestP int16
lowThreshold = (uint32)(s.br.remain() >> tableLog)
)
for i, cnt := range s.count[:s.symbolLen] {
// already handled
// if (count[s] == s.length) return 0; /* rle special case */
if cnt == 0 {
s.norm[i] = 0
continue
}
if cnt <= lowThreshold {
s.norm[i] = -1
stillToDistribute--
} else {
proba := (int16)((uint64(cnt) * step) >> scale)
if proba < 8 {
restToBeat := vStep * uint64(rtbTable[proba])
v := uint64(cnt)*step - (uint64(proba) << scale)
if v > restToBeat {
proba++
}
}
if proba > largestP {
largestP = proba
largest = i
}
s.norm[i] = proba
stillToDistribute -= proba
}
}
if -stillToDistribute >= (s.norm[largest] >> 1) {
// corner case, need another normalization method
return s.normalizeCount2()
}
s.norm[largest] += stillToDistribute
return nil
}
// Secondary normalization method.
// To be used when primary method fails.
func (s *Scratch) normalizeCount2() error {
const notYetAssigned = -2
var (
distributed uint32
total = uint32(s.br.remain())
tableLog = s.actualTableLog
lowThreshold = total >> tableLog
lowOne = (total * 3) >> (tableLog + 1)
)
for i, cnt := range s.count[:s.symbolLen] {
if cnt == 0 {
s.norm[i] = 0
continue
}
if cnt <= lowThreshold {
s.norm[i] = -1
distributed++
total -= cnt
continue
}
if cnt <= lowOne {
s.norm[i] = 1
distributed++
total -= cnt
continue
}
s.norm[i] = notYetAssigned
}
toDistribute := (1 << tableLog) - distributed
if (total / toDistribute) > lowOne {
// risk of rounding to zero
lowOne = (total * 3) / (toDistribute * 2)
for i, cnt := range s.count[:s.symbolLen] {
if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) {
s.norm[i] = 1
distributed++
total -= cnt
continue
}
}
toDistribute = (1 << tableLog) - distributed
}
if distributed == uint32(s.symbolLen)+1 {
// all values are pretty poor;
// probably incompressible data (should have already been detected);
// find max, then give all remaining points to max
var maxV int
var maxC uint32
for i, cnt := range s.count[:s.symbolLen] {
if cnt > maxC {
maxV = i
maxC = cnt
}
}
s.norm[maxV] += int16(toDistribute)
return nil
}
if total == 0 {
// all of the symbols were low enough for the lowOne or lowThreshold
for i := uint32(0); toDistribute > 0; i = (i + 1) % (uint32(s.symbolLen)) {
if s.norm[i] > 0 {
toDistribute--
s.norm[i]++
}
}
return nil
}
var (
vStepLog = 62 - uint64(tableLog)
mid = uint64((1 << (vStepLog - 1)) - 1)
rStep = (((1 << vStepLog) * uint64(toDistribute)) + mid) / uint64(total) // scale on remaining
tmpTotal = mid
)
for i, cnt := range s.count[:s.symbolLen] {
if s.norm[i] == notYetAssigned {
var (
end = tmpTotal + uint64(cnt)*rStep
sStart = uint32(tmpTotal >> vStepLog)
sEnd = uint32(end >> vStepLog)
weight = sEnd - sStart
)
if weight < 1 {
return errors.New("weight < 1")
}
s.norm[i] = int16(weight)
tmpTotal = end
}
}
return nil
}
// validateNorm validates the normalized histogram table.
func (s *Scratch) validateNorm() (err error) {
var total int
for _, v := range s.norm[:s.symbolLen] {
if v >= 0 {
total += int(v)
} else {
total -= int(v)
}
}
defer func() {
if err == nil {
return
}
fmt.Printf("selected TableLog: %d, Symbol length: %d\n", s.actualTableLog, s.symbolLen)
for i, v := range s.norm[:s.symbolLen] {
fmt.Printf("%3d: %5d -> %4d \n", i, s.count[i], v)
}
}()
if total != (1 << s.actualTableLog) {
return fmt.Errorf("warning: Total == %d != %d", total, 1<<s.actualTableLog)
}
for i, v := range s.count[s.symbolLen:] {
if v != 0 {
return fmt.Errorf("warning: Found symbol out of range, %d after cut", i)
}
}
return nil
}

@ -1,374 +0,0 @@
package fse
import (
"errors"
"fmt"
)
const (
tablelogAbsoluteMax = 15
)
// Decompress a block of data.
// You can provide a scratch buffer to avoid allocations.
// If nil is provided a temporary one will be allocated.
// It is possible, but by no way guaranteed that corrupt data will
// return an error.
// It is up to the caller to verify integrity of the returned data.
// Use a predefined Scrach to set maximum acceptable output size.
func Decompress(b []byte, s *Scratch) ([]byte, error) {
s, err := s.prepare(b)
if err != nil {
return nil, err
}
s.Out = s.Out[:0]
err = s.readNCount()
if err != nil {
return nil, err
}
err = s.buildDtable()
if err != nil {
return nil, err
}
err = s.decompress()
if err != nil {
return nil, err
}
return s.Out, nil
}
// readNCount will read the symbol distribution so decoding tables can be constructed.
func (s *Scratch) readNCount() error {
var (
charnum uint16
previous0 bool
b = &s.br
)
iend := b.remain()
if iend < 4 {
return errors.New("input too small")
}
bitStream := b.Uint32()
nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog
if nbBits > tablelogAbsoluteMax {
return errors.New("tableLog too large")
}
bitStream >>= 4
bitCount := uint(4)
s.actualTableLog = uint8(nbBits)
remaining := int32((1 << nbBits) + 1)
threshold := int32(1 << nbBits)
gotTotal := int32(0)
nbBits++
for remaining > 1 {
if previous0 {
n0 := charnum
for (bitStream & 0xFFFF) == 0xFFFF {
n0 += 24
if b.off < iend-5 {
b.advance(2)
bitStream = b.Uint32() >> bitCount
} else {
bitStream >>= 16
bitCount += 16
}
}
for (bitStream & 3) == 3 {
n0 += 3
bitStream >>= 2
bitCount += 2
}
n0 += uint16(bitStream & 3)
bitCount += 2
if n0 > maxSymbolValue {
return errors.New("maxSymbolValue too small")
}
for charnum < n0 {
s.norm[charnum&0xff] = 0
charnum++
}
if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 {
b.advance(bitCount >> 3)
bitCount &= 7
bitStream = b.Uint32() >> bitCount
} else {
bitStream >>= 2
}
}
max := (2*(threshold) - 1) - (remaining)
var count int32
if (int32(bitStream) & (threshold - 1)) < max {
count = int32(bitStream) & (threshold - 1)
bitCount += nbBits - 1
} else {
count = int32(bitStream) & (2*threshold - 1)
if count >= threshold {
count -= max
}
bitCount += nbBits
}
count-- // extra accuracy
if count < 0 {
// -1 means +1
remaining += count
gotTotal -= count
} else {
remaining -= count
gotTotal += count
}
s.norm[charnum&0xff] = int16(count)
charnum++
previous0 = count == 0
for remaining < threshold {
nbBits--
threshold >>= 1
}
if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 {
b.advance(bitCount >> 3)
bitCount &= 7
} else {
bitCount -= (uint)(8 * (len(b.b) - 4 - b.off))
b.off = len(b.b) - 4
}
bitStream = b.Uint32() >> (bitCount & 31)
}
s.symbolLen = charnum
if s.symbolLen <= 1 {
return fmt.Errorf("symbolLen (%d) too small", s.symbolLen)
}
if s.symbolLen > maxSymbolValue+1 {
return fmt.Errorf("symbolLen (%d) too big", s.symbolLen)
}
if remaining != 1 {
return fmt.Errorf("corruption detected (remaining %d != 1)", remaining)
}
if bitCount > 32 {
return fmt.Errorf("corruption detected (bitCount %d > 32)", bitCount)
}
if gotTotal != 1<<s.actualTableLog {
return fmt.Errorf("corruption detected (total %d != %d)", gotTotal, 1<<s.actualTableLog)
}
b.advance((bitCount + 7) >> 3)
return nil
}
// decSymbol contains information about a state entry,
// Including the state offset base, the output symbol and
// the number of bits to read for the low part of the destination state.
type decSymbol struct {
newState uint16
symbol uint8
nbBits uint8
}
// allocDtable will allocate decoding tables if they are not big enough.
func (s *Scratch) allocDtable() {
tableSize := 1 << s.actualTableLog
if cap(s.decTable) < tableSize {
s.decTable = make([]decSymbol, tableSize)
}
s.decTable = s.decTable[:tableSize]
if cap(s.ct.tableSymbol) < 256 {
s.ct.tableSymbol = make([]byte, 256)
}
s.ct.tableSymbol = s.ct.tableSymbol[:256]
if cap(s.ct.stateTable) < 256 {
s.ct.stateTable = make([]uint16, 256)
}
s.ct.stateTable = s.ct.stateTable[:256]
}
// buildDtable will build the decoding table.
func (s *Scratch) buildDtable() error {
tableSize := uint32(1 << s.actualTableLog)
highThreshold := tableSize - 1
s.allocDtable()
symbolNext := s.ct.stateTable[:256]
// Init, lay down lowprob symbols
s.zeroBits = false
{
largeLimit := int16(1 << (s.actualTableLog - 1))
for i, v := range s.norm[:s.symbolLen] {
if v == -1 {
s.decTable[highThreshold].symbol = uint8(i)
highThreshold--
symbolNext[i] = 1
} else {
if v >= largeLimit {
s.zeroBits = true
}
symbolNext[i] = uint16(v)
}
}
}
// Spread symbols
{
tableMask := tableSize - 1
step := tableStep(tableSize)
position := uint32(0)
for ss, v := range s.norm[:s.symbolLen] {
for i := 0; i < int(v); i++ {
s.decTable[position].symbol = uint8(ss)
position = (position + step) & tableMask
for position > highThreshold {
// lowprob area
position = (position + step) & tableMask
}
}
}
if position != 0 {
// position must reach all cells once, otherwise normalizedCounter is incorrect
return errors.New("corrupted input (position != 0)")
}
}
// Build Decoding table
{
tableSize := uint16(1 << s.actualTableLog)
for u, v := range s.decTable {
symbol := v.symbol
nextState := symbolNext[symbol]
symbolNext[symbol] = nextState + 1
nBits := s.actualTableLog - byte(highBits(uint32(nextState)))
s.decTable[u].nbBits = nBits
newState := (nextState << nBits) - tableSize
if newState >= tableSize {
return fmt.Errorf("newState (%d) outside table size (%d)", newState, tableSize)
}
if newState == uint16(u) && nBits == 0 {
// Seems weird that this is possible with nbits > 0.
return fmt.Errorf("newState (%d) == oldState (%d) and no bits", newState, u)
}
s.decTable[u].newState = newState
}
}
return nil
}
// decompress will decompress the bitstream.
// If the buffer is over-read an error is returned.
func (s *Scratch) decompress() error {
br := &s.bits
br.init(s.br.unread())
var s1, s2 decoder
// Initialize and decode first state and symbol.
s1.init(br, s.decTable, s.actualTableLog)
s2.init(br, s.decTable, s.actualTableLog)
// Use temp table to avoid bound checks/append penalty.
var tmp = s.ct.tableSymbol[:256]
var off uint8
// Main part
if !s.zeroBits {
for br.off >= 8 {
br.fillFast()
tmp[off+0] = s1.nextFast()
tmp[off+1] = s2.nextFast()
br.fillFast()
tmp[off+2] = s1.nextFast()
tmp[off+3] = s2.nextFast()
off += 4
// When off is 0, we have overflowed and should write.
if off == 0 {
s.Out = append(s.Out, tmp...)
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
}
} else {
for br.off >= 8 {
br.fillFast()
tmp[off+0] = s1.next()
tmp[off+1] = s2.next()
br.fillFast()
tmp[off+2] = s1.next()
tmp[off+3] = s2.next()
off += 4
if off == 0 {
s.Out = append(s.Out, tmp...)
// When off is 0, we have overflowed and should write.
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
}
}
s.Out = append(s.Out, tmp[:off]...)
// Final bits, a bit more expensive check
for {
if s1.finished() {
s.Out = append(s.Out, s1.final(), s2.final())
break
}
br.fill()
s.Out = append(s.Out, s1.next())
if s2.finished() {
s.Out = append(s.Out, s2.final(), s1.final())
break
}
s.Out = append(s.Out, s2.next())
if len(s.Out) >= s.DecompressLimit {
return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit)
}
}
return br.close()
}
// decoder keeps track of the current state and updates it from the bitstream.
type decoder struct {
state uint16
br *bitReader
dt []decSymbol
}
// init will initialize the decoder and read the first state from the stream.
func (d *decoder) init(in *bitReader, dt []decSymbol, tableLog uint8) {
d.dt = dt
d.br = in
d.state = in.getBits(tableLog)
}
// next returns the next symbol and sets the next state.
// At least tablelog bits must be available in the bit reader.
func (d *decoder) next() uint8 {
n := &d.dt[d.state]
lowBits := d.br.getBits(n.nbBits)
d.state = n.newState + lowBits
return n.symbol
}
// finished returns true if all bits have been read from the bitstream
// and the next state would require reading bits from the input.
func (d *decoder) finished() bool {
return d.br.finished() && d.dt[d.state].nbBits > 0
}
// final returns the current state symbol without decoding the next.
func (d *decoder) final() uint8 {
return d.dt[d.state].symbol
}
// nextFast returns the next symbol and sets the next state.
// This can only be used if no symbols are 0 bits.
// At least tablelog bits must be available in the bit reader.
func (d *decoder) nextFast() uint8 {
n := d.dt[d.state]
lowBits := d.br.getBitsFast(n.nbBits)
d.state = n.newState + lowBits
return n.symbol
}

@ -1,144 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
// Package fse provides Finite State Entropy encoding and decoding.
//
// Finite State Entropy encoding provides a fast near-optimal symbol encoding/decoding
// for byte blocks as implemented in zstd.
//
// See https://github.com/klauspost/compress/tree/master/fse for more information.
package fse
import (
"errors"
"fmt"
"math/bits"
)
const (
/*!MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
* Increasing memory usage improves compression ratio
* Reduced memory usage can improve speed, due to cache effect
* Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
maxMemoryUsage = 14
defaultMemoryUsage = 13
maxTableLog = maxMemoryUsage - 2
maxTablesize = 1 << maxTableLog
defaultTablelog = defaultMemoryUsage - 2
minTablelog = 5
maxSymbolValue = 255
)
var (
// ErrIncompressible is returned when input is judged to be too hard to compress.
ErrIncompressible = errors.New("input is not compressible")
// ErrUseRLE is returned from the compressor when the input is a single byte value repeated.
ErrUseRLE = errors.New("input is single value repeated")
)
// Scratch provides temporary storage for compression and decompression.
type Scratch struct {
// Private
count [maxSymbolValue + 1]uint32
norm [maxSymbolValue + 1]int16
br byteReader
bits bitReader
bw bitWriter
ct cTable // Compression tables.
decTable []decSymbol // Decompression table.
maxCount int // count of the most probable symbol
// Per block parameters.
// These can be used to override compression parameters of the block.
// Do not touch, unless you know what you are doing.
// Out is output buffer.
// If the scratch is re-used before the caller is done processing the output,
// set this field to nil.
// Otherwise the output buffer will be re-used for next Compression/Decompression step
// and allocation will be avoided.
Out []byte
// DecompressLimit limits the maximum decoded size acceptable.
// If > 0 decompression will stop when approximately this many bytes
// has been decoded.
// If 0, maximum size will be 2GB.
DecompressLimit int
symbolLen uint16 // Length of active part of the symbol table.
actualTableLog uint8 // Selected tablelog.
zeroBits bool // no bits has prob > 50%.
clearCount bool // clear count
// MaxSymbolValue will override the maximum symbol value of the next block.
MaxSymbolValue uint8
// TableLog will attempt to override the tablelog for the next block.
TableLog uint8
}
// Histogram allows to populate the histogram and skip that step in the compression,
// It otherwise allows to inspect the histogram when compression is done.
// To indicate that you have populated the histogram call HistogramFinished
// with the value of the highest populated symbol, as well as the number of entries
// in the most populated entry. These are accepted at face value.
// The returned slice will always be length 256.
func (s *Scratch) Histogram() []uint32 {
return s.count[:]
}
// HistogramFinished can be called to indicate that the histogram has been populated.
// maxSymbol is the index of the highest set symbol of the next data segment.
// maxCount is the number of entries in the most populated entry.
// These are accepted at face value.
func (s *Scratch) HistogramFinished(maxSymbol uint8, maxCount int) {
s.maxCount = maxCount
s.symbolLen = uint16(maxSymbol) + 1
s.clearCount = maxCount != 0
}
// prepare will prepare and allocate scratch tables used for both compression and decompression.
func (s *Scratch) prepare(in []byte) (*Scratch, error) {
if s == nil {
s = &Scratch{}
}
if s.MaxSymbolValue == 0 {
s.MaxSymbolValue = 255
}
if s.TableLog == 0 {
s.TableLog = defaultTablelog
}
if s.TableLog > maxTableLog {
return nil, fmt.Errorf("tableLog (%d) > maxTableLog (%d)", s.TableLog, maxTableLog)
}
if cap(s.Out) == 0 {
s.Out = make([]byte, 0, len(in))
}
if s.clearCount && s.maxCount == 0 {
for i := range s.count {
s.count[i] = 0
}
s.clearCount = false
}
s.br.init(in)
if s.DecompressLimit == 0 {
// Max size 2GB.
s.DecompressLimit = (2 << 30) - 1
}
return s, nil
}
// tableStep returns the next table index.
func tableStep(tableSize uint32) uint32 {
return (tableSize >> 1) + (tableSize >> 3) + 3
}
func highBits(val uint32) (n uint32) {
return uint32(bits.Len32(val) - 1)
}

@ -1,4 +0,0 @@
#!/bin/sh
cd s2/cmd/_s2sx/ || exit 1
go generate .

@ -1,349 +0,0 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package gzip implements reading and writing of gzip format compressed files,
// as specified in RFC 1952.
package gzip
import (
"bufio"
"compress/gzip"
"encoding/binary"
"hash/crc32"
"io"
"time"
"github.com/klauspost/compress/flate"
)
const (
gzipID1 = 0x1f
gzipID2 = 0x8b
gzipDeflate = 8
flagText = 1 << 0
flagHdrCrc = 1 << 1
flagExtra = 1 << 2
flagName = 1 << 3
flagComment = 1 << 4
)
var (
// ErrChecksum is returned when reading GZIP data that has an invalid checksum.
ErrChecksum = gzip.ErrChecksum
// ErrHeader is returned when reading GZIP data that has an invalid header.
ErrHeader = gzip.ErrHeader
)
var le = binary.LittleEndian
// noEOF converts io.EOF to io.ErrUnexpectedEOF.
func noEOF(err error) error {
if err == io.EOF {
return io.ErrUnexpectedEOF
}
return err
}
// The gzip file stores a header giving metadata about the compressed file.
// That header is exposed as the fields of the Writer and Reader structs.
//
// Strings must be UTF-8 encoded and may only contain Unicode code points
// U+0001 through U+00FF, due to limitations of the GZIP file format.
type Header struct {
Comment string // comment
Extra []byte // "extra data"
ModTime time.Time // modification time
Name string // file name
OS byte // operating system type
}
// A Reader is an io.Reader that can be read to retrieve
// uncompressed data from a gzip-format compressed file.
//
// In general, a gzip file can be a concatenation of gzip files,
// each with its own header. Reads from the Reader
// return the concatenation of the uncompressed data of each.
// Only the first header is recorded in the Reader fields.
//
// Gzip files store a length and checksum of the uncompressed data.
// The Reader will return a ErrChecksum when Read
// reaches the end of the uncompressed data if it does not
// have the expected length or checksum. Clients should treat data
// returned by Read as tentative until they receive the io.EOF
// marking the end of the data.
type Reader struct {
Header // valid after NewReader or Reader.Reset
r flate.Reader
br *bufio.Reader
decompressor io.ReadCloser
digest uint32 // CRC-32, IEEE polynomial (section 8)
size uint32 // Uncompressed size (section 2.3.1)
buf [512]byte
err error
multistream bool
}
// NewReader creates a new Reader reading the given reader.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
//
// It is the caller's responsibility to call Close on the Reader when done.
//
// The Reader.Header fields will be valid in the Reader returned.
func NewReader(r io.Reader) (*Reader, error) {
z := new(Reader)
if err := z.Reset(r); err != nil {
return nil, err
}
return z, nil
}
// Reset discards the Reader z's state and makes it equivalent to the
// result of its original state from NewReader, but reading from r instead.
// This permits reusing a Reader rather than allocating a new one.
func (z *Reader) Reset(r io.Reader) error {
*z = Reader{
decompressor: z.decompressor,
multistream: true,
}
if rr, ok := r.(flate.Reader); ok {
z.r = rr
} else {
// Reuse if we can.
if z.br != nil {
z.br.Reset(r)
} else {
z.br = bufio.NewReader(r)
}
z.r = z.br
}
z.Header, z.err = z.readHeader()
return z.err
}
// Multistream controls whether the reader supports multistream files.
//
// If enabled (the default), the Reader expects the input to be a sequence
// of individually gzipped data streams, each with its own header and
// trailer, ending at EOF. The effect is that the concatenation of a sequence
// of gzipped files is treated as equivalent to the gzip of the concatenation
// of the sequence. This is standard behavior for gzip readers.
//
// Calling Multistream(false) disables this behavior; disabling the behavior
// can be useful when reading file formats that distinguish individual gzip
// data streams or mix gzip data streams with other data streams.
// In this mode, when the Reader reaches the end of the data stream,
// Read returns io.EOF. If the underlying reader implements io.ByteReader,
// it will be left positioned just after the gzip stream.
// To start the next stream, call z.Reset(r) followed by z.Multistream(false).
// If there is no next stream, z.Reset(r) will return io.EOF.
func (z *Reader) Multistream(ok bool) {
z.multistream = ok
}
// readString reads a NUL-terminated string from z.r.
// It treats the bytes read as being encoded as ISO 8859-1 (Latin-1) and
// will output a string encoded using UTF-8.
// This method always updates z.digest with the data read.
func (z *Reader) readString() (string, error) {
var err error
needConv := false
for i := 0; ; i++ {
if i >= len(z.buf) {
return "", ErrHeader
}
z.buf[i], err = z.r.ReadByte()
if err != nil {
return "", err
}
if z.buf[i] > 0x7f {
needConv = true
}
if z.buf[i] == 0 {
// Digest covers the NUL terminator.
z.digest = crc32.Update(z.digest, crc32.IEEETable, z.buf[:i+1])
// Strings are ISO 8859-1, Latin-1 (RFC 1952, section 2.3.1).
if needConv {
s := make([]rune, 0, i)
for _, v := range z.buf[:i] {
s = append(s, rune(v))
}
return string(s), nil
}
return string(z.buf[:i]), nil
}
}
}
// readHeader reads the GZIP header according to section 2.3.1.
// This method does not set z.err.
func (z *Reader) readHeader() (hdr Header, err error) {
if _, err = io.ReadFull(z.r, z.buf[:10]); err != nil {
// RFC 1952, section 2.2, says the following:
// A gzip file consists of a series of "members" (compressed data sets).
//
// Other than this, the specification does not clarify whether a
// "series" is defined as "one or more" or "zero or more". To err on the
// side of caution, Go interprets this to mean "zero or more".
// Thus, it is okay to return io.EOF here.
return hdr, err
}
if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate {
return hdr, ErrHeader
}
flg := z.buf[3]
hdr.ModTime = time.Unix(int64(le.Uint32(z.buf[4:8])), 0)
// z.buf[8] is XFL and is currently ignored.
hdr.OS = z.buf[9]
z.digest = crc32.ChecksumIEEE(z.buf[:10])
if flg&flagExtra != 0 {
if _, err = io.ReadFull(z.r, z.buf[:2]); err != nil {
return hdr, noEOF(err)
}
z.digest = crc32.Update(z.digest, crc32.IEEETable, z.buf[:2])
data := make([]byte, le.Uint16(z.buf[:2]))
if _, err = io.ReadFull(z.r, data); err != nil {
return hdr, noEOF(err)
}
z.digest = crc32.Update(z.digest, crc32.IEEETable, data)
hdr.Extra = data
}
var s string
if flg&flagName != 0 {
if s, err = z.readString(); err != nil {
return hdr, err
}
hdr.Name = s
}
if flg&flagComment != 0 {
if s, err = z.readString(); err != nil {
return hdr, err
}
hdr.Comment = s
}
if flg&flagHdrCrc != 0 {
if _, err = io.ReadFull(z.r, z.buf[:2]); err != nil {
return hdr, noEOF(err)
}
digest := le.Uint16(z.buf[:2])
if digest != uint16(z.digest) {
return hdr, ErrHeader
}
}
z.digest = 0
if z.decompressor == nil {
z.decompressor = flate.NewReader(z.r)
} else {
z.decompressor.(flate.Resetter).Reset(z.r, nil)
}
return hdr, nil
}
// Read implements io.Reader, reading uncompressed bytes from its underlying Reader.
func (z *Reader) Read(p []byte) (n int, err error) {
if z.err != nil {
return 0, z.err
}
for n == 0 {
n, z.err = z.decompressor.Read(p)
z.digest = crc32.Update(z.digest, crc32.IEEETable, p[:n])
z.size += uint32(n)
if z.err != io.EOF {
// In the normal case we return here.
return n, z.err
}
// Finished file; check checksum and size.
if _, err := io.ReadFull(z.r, z.buf[:8]); err != nil {
z.err = noEOF(err)
return n, z.err
}
digest := le.Uint32(z.buf[:4])
size := le.Uint32(z.buf[4:8])
if digest != z.digest || size != z.size {
z.err = ErrChecksum
return n, z.err
}
z.digest, z.size = 0, 0
// File is ok; check if there is another.
if !z.multistream {
return n, io.EOF
}
z.err = nil // Remove io.EOF
if _, z.err = z.readHeader(); z.err != nil {
return n, z.err
}
}
return n, nil
}
// Support the io.WriteTo interface for io.Copy and friends.
func (z *Reader) WriteTo(w io.Writer) (int64, error) {
total := int64(0)
crcWriter := crc32.NewIEEE()
for {
if z.err != nil {
if z.err == io.EOF {
return total, nil
}
return total, z.err
}
// We write both to output and digest.
mw := io.MultiWriter(w, crcWriter)
n, err := z.decompressor.(io.WriterTo).WriteTo(mw)
total += n
z.size += uint32(n)
if err != nil {
z.err = err
return total, z.err
}
// Finished file; check checksum + size.
if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
z.err = err
return total, err
}
z.digest = crcWriter.Sum32()
digest := le.Uint32(z.buf[:4])
size := le.Uint32(z.buf[4:8])
if digest != z.digest || size != z.size {
z.err = ErrChecksum
return total, z.err
}
z.digest, z.size = 0, 0
// File is ok; check if there is another.
if !z.multistream {
return total, nil
}
crcWriter.Reset()
z.err = nil // Remove io.EOF
if _, z.err = z.readHeader(); z.err != nil {
if z.err == io.EOF {
return total, nil
}
return total, z.err
}
}
}
// Close closes the Reader. It does not close the underlying io.Reader.
// In order for the GZIP checksum to be verified, the reader must be
// fully consumed until the io.EOF.
func (z *Reader) Close() error { return z.decompressor.Close() }

@ -1,269 +0,0 @@
// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package gzip
import (
"errors"
"fmt"
"hash/crc32"
"io"
"github.com/klauspost/compress/flate"
)
// These constants are copied from the flate package, so that code that imports
// "compress/gzip" does not also have to import "compress/flate".
const (
NoCompression = flate.NoCompression
BestSpeed = flate.BestSpeed
BestCompression = flate.BestCompression
DefaultCompression = flate.DefaultCompression
ConstantCompression = flate.ConstantCompression
HuffmanOnly = flate.HuffmanOnly
// StatelessCompression will do compression but without maintaining any state
// between Write calls.
// There will be no memory kept between Write calls,
// but compression and speed will be suboptimal.
// Because of this, the size of actual Write calls will affect output size.
StatelessCompression = -3
)
// A Writer is an io.WriteCloser.
// Writes to a Writer are compressed and written to w.
type Writer struct {
Header // written at first call to Write, Flush, or Close
w io.Writer
level int
err error
compressor *flate.Writer
digest uint32 // CRC-32, IEEE polynomial (section 8)
size uint32 // Uncompressed size (section 2.3.1)
wroteHeader bool
closed bool
buf [10]byte
}
// NewWriter returns a new Writer.
// Writes to the returned writer are compressed and written to w.
//
// It is the caller's responsibility to call Close on the WriteCloser when done.
// Writes may be buffered and not flushed until Close.
//
// Callers that wish to set the fields in Writer.Header must do so before
// the first call to Write, Flush, or Close.
func NewWriter(w io.Writer) *Writer {
z, _ := NewWriterLevel(w, DefaultCompression)
return z
}
// NewWriterLevel is like NewWriter but specifies the compression level instead
// of assuming DefaultCompression.
//
// The compression level can be DefaultCompression, NoCompression, or any
// integer value between BestSpeed and BestCompression inclusive. The error
// returned will be nil if the level is valid.
func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
if level < StatelessCompression || level > BestCompression {
return nil, fmt.Errorf("gzip: invalid compression level: %d", level)
}
z := new(Writer)
z.init(w, level)
return z, nil
}
func (z *Writer) init(w io.Writer, level int) {
compressor := z.compressor
if level != StatelessCompression {
if compressor != nil {
compressor.Reset(w)
}
}
*z = Writer{
Header: Header{
OS: 255, // unknown
},
w: w,
level: level,
compressor: compressor,
}
}
// Reset discards the Writer z's state and makes it equivalent to the
// result of its original state from NewWriter or NewWriterLevel, but
// writing to w instead. This permits reusing a Writer rather than
// allocating a new one.
func (z *Writer) Reset(w io.Writer) {
z.init(w, z.level)
}
// writeBytes writes a length-prefixed byte slice to z.w.
func (z *Writer) writeBytes(b []byte) error {
if len(b) > 0xffff {
return errors.New("gzip.Write: Extra data is too large")
}
le.PutUint16(z.buf[:2], uint16(len(b)))
_, err := z.w.Write(z.buf[:2])
if err != nil {
return err
}
_, err = z.w.Write(b)
return err
}
// writeString writes a UTF-8 string s in GZIP's format to z.w.
// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
func (z *Writer) writeString(s string) (err error) {
// GZIP stores Latin-1 strings; error if non-Latin-1; convert if non-ASCII.
needconv := false
for _, v := range s {
if v == 0 || v > 0xff {
return errors.New("gzip.Write: non-Latin-1 header string")
}
if v > 0x7f {
needconv = true
}
}
if needconv {
b := make([]byte, 0, len(s))
for _, v := range s {
b = append(b, byte(v))
}
_, err = z.w.Write(b)
} else {
_, err = io.WriteString(z.w, s)
}
if err != nil {
return err
}
// GZIP strings are NUL-terminated.
z.buf[0] = 0
_, err = z.w.Write(z.buf[:1])
return err
}
// Write writes a compressed form of p to the underlying io.Writer. The
// compressed bytes are not necessarily flushed until the Writer is closed.
func (z *Writer) Write(p []byte) (int, error) {
if z.err != nil {
return 0, z.err
}
var n int
// Write the GZIP header lazily.
if !z.wroteHeader {
z.wroteHeader = true
z.buf[0] = gzipID1
z.buf[1] = gzipID2
z.buf[2] = gzipDeflate
z.buf[3] = 0
if z.Extra != nil {
z.buf[3] |= 0x04
}
if z.Name != "" {
z.buf[3] |= 0x08
}
if z.Comment != "" {
z.buf[3] |= 0x10
}
le.PutUint32(z.buf[4:8], uint32(z.ModTime.Unix()))
if z.level == BestCompression {
z.buf[8] = 2
} else if z.level == BestSpeed {
z.buf[8] = 4
} else {
z.buf[8] = 0
}
z.buf[9] = z.OS
n, z.err = z.w.Write(z.buf[:10])
if z.err != nil {
return n, z.err
}
if z.Extra != nil {
z.err = z.writeBytes(z.Extra)
if z.err != nil {
return n, z.err
}
}
if z.Name != "" {
z.err = z.writeString(z.Name)
if z.err != nil {
return n, z.err
}
}
if z.Comment != "" {
z.err = z.writeString(z.Comment)
if z.err != nil {
return n, z.err
}
}
if z.compressor == nil && z.level != StatelessCompression {
z.compressor, _ = flate.NewWriter(z.w, z.level)
}
}
z.size += uint32(len(p))
z.digest = crc32.Update(z.digest, crc32.IEEETable, p)
if z.level == StatelessCompression {
return len(p), flate.StatelessDeflate(z.w, p, false, nil)
}
n, z.err = z.compressor.Write(p)
return n, z.err
}
// Flush flushes any pending compressed data to the underlying writer.
//
// It is useful mainly in compressed network protocols, to ensure that
// a remote reader has enough data to reconstruct a packet. Flush does
// not return until the data has been written. If the underlying
// writer returns an error, Flush returns that error.
//
// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
func (z *Writer) Flush() error {
if z.err != nil {
return z.err
}
if z.closed || z.level == StatelessCompression {
return nil
}
if !z.wroteHeader {
z.Write(nil)
if z.err != nil {
return z.err
}
}
z.err = z.compressor.Flush()
return z.err
}
// Close closes the Writer, flushing any unwritten data to the underlying
// io.Writer, but does not close the underlying io.Writer.
func (z *Writer) Close() error {
if z.err != nil {
return z.err
}
if z.closed {
return nil
}
z.closed = true
if !z.wroteHeader {
z.Write(nil)
if z.err != nil {
return z.err
}
}
if z.level == StatelessCompression {
z.err = flate.StatelessDeflate(z.w, nil, true, nil)
} else {
z.err = z.compressor.Close()
}
if z.err != nil {
return z.err
}
le.PutUint32(z.buf[:4], z.digest)
le.PutUint32(z.buf[4:8], z.size)
_, z.err = z.w.Write(z.buf[:8])
return z.err
}

@ -1 +0,0 @@
/huff0-fuzz.zip

@ -1,89 +0,0 @@
# Huff0 entropy compression
This package provides Huff0 encoding and decoding as used in zstd.
[Huff0](https://github.com/Cyan4973/FiniteStateEntropy#new-generation-entropy-coders),
a Huffman codec designed for modern CPU, featuring OoO (Out of Order) operations on multiple ALU
(Arithmetic Logic Unit), achieving extremely fast compression and decompression speeds.
This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/huff0)
## News
This is used as part of the [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd) compression and decompression package.
This ensures that most functionality is well tested.
# Usage
This package provides a low level interface that allows to compress single independent blocks.
Each block is separate, and there is no built in integrity checks.
This means that the caller should keep track of block sizes and also do checksums if needed.
Compressing a block is done via the [`Compress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress1X) and
[`Compress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress4X) functions.
You must provide input and will receive the output and maybe an error.
These error values can be returned:
| Error | Description |
|---------------------|-----------------------------------------------------------------------------|
| `<nil>` | Everything ok, output is returned |
| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
| `ErrTooBig` | Returned if the input block exceeds the maximum allowed size (128 Kib) |
| `(error)` | An internal error occurred. |
As can be seen above some of there are errors that will be returned even under normal operation so it is important to handle these.
To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object
that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
object can be used for both.
Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
The `Scratch` object will retain state that allows to re-use previous tables for encoding and decoding.
## Tables and re-use
Huff0 allows for reusing tables from the previous block to save space if that is expected to give better/faster results.
The Scratch object allows you to set a [`ReusePolicy`](https://godoc.org/github.com/klauspost/compress/huff0#ReusePolicy)
that controls this behaviour. See the documentation for details. This can be altered between each block.
Do however note that this information is *not* stored in the output block and it is up to the users of the package to
record whether [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable) should be called,
based on the boolean reported back from the CompressXX call.
If you want to store the table separate from the data, you can access them as `OutData` and `OutTable` on the
[`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object.
## Decompressing
The first part of decoding is to initialize the decoding table through [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable).
This will initialize the decoding tables.
You can supply the complete block to `ReadTable` and it will return the data part of the block
which can be given to the decompressor.
Decompressing is done by calling the [`Decompress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress1X)
or [`Decompress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress4X) function.
For concurrently decompressing content with a fixed table a stateless [`Decoder`](https://godoc.org/github.com/klauspost/compress/huff0#Decoder) can be requested which will remain correct as long as the scratch is unchanged. The capacity of the provided slice indicates the expected output size.
You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
your input was likely corrupted.
It is important to note that a successful decoding does *not* mean your output matches your original input.
There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
# Contributing
Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
changes will likely not be accepted. If in doubt open an issue before writing the PR.

@ -1,233 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package huff0
import (
"encoding/binary"
"errors"
"fmt"
"io"
)
// bitReader reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReaderBytes struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReaderBytes) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.advance(8 - uint8(highBit32(uint32(v))))
return nil
}
// peekBitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReaderBytes) peekByteFast() uint8 {
got := uint8(b.value >> 56)
return got
}
func (b *bitReaderBytes) advance(n uint8) {
b.bitsRead += n
b.value <<= n & 63
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReaderBytes) fillFast() {
if b.bitsRead < 32 {
return
}
// 2 bounds checks.
v := b.in[b.off-4 : b.off]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value |= uint64(low) << (b.bitsRead - 32)
b.bitsRead -= 32
b.off -= 4
}
// fillFastStart() assumes the bitReaderBytes is empty and there is at least 8 bytes to read.
func (b *bitReaderBytes) fillFastStart() {
// Do single re-slice to avoid bounds checks.
b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
b.bitsRead = 0
b.off -= 8
}
// fill() will make sure at least 32 bits are available.
func (b *bitReaderBytes) fill() {
if b.bitsRead < 32 {
return
}
if b.off > 4 {
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value |= uint64(low) << (b.bitsRead - 32)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value |= uint64(b.in[b.off-1]) << (b.bitsRead - 8)
b.bitsRead -= 8
b.off--
}
}
// finished returns true if all bits have been read from the bit stream.
func (b *bitReaderBytes) finished() bool {
return b.off == 0 && b.bitsRead >= 64
}
func (b *bitReaderBytes) remaining() uint {
return b.off*8 + uint(64-b.bitsRead)
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReaderBytes) close() error {
// Release reference.
b.in = nil
if b.remaining() > 0 {
return fmt.Errorf("corrupt input: %d bits remain on stream", b.remaining())
}
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}
// bitReaderShifted reads a bitstream in reverse.
// The last set bit indicates the start of the stream and is used
// for aligning the input.
type bitReaderShifted struct {
in []byte
off uint // next byte to read is at in[off - 1]
value uint64
bitsRead uint8
}
// init initializes and resets the bit reader.
func (b *bitReaderShifted) init(in []byte) error {
if len(in) < 1 {
return errors.New("corrupt stream: too short")
}
b.in = in
b.off = uint(len(in))
// The highest bit of the last byte indicates where to start
v := in[len(in)-1]
if v == 0 {
return errors.New("corrupt stream, did not find end of stream")
}
b.bitsRead = 64
b.value = 0
if len(in) >= 8 {
b.fillFastStart()
} else {
b.fill()
b.fill()
}
b.advance(8 - uint8(highBit32(uint32(v))))
return nil
}
// peekBitsFast requires that at least one bit is requested every time.
// There are no checks if the buffer is filled.
func (b *bitReaderShifted) peekBitsFast(n uint8) uint16 {
return uint16(b.value >> ((64 - n) & 63))
}
func (b *bitReaderShifted) advance(n uint8) {
b.bitsRead += n
b.value <<= n & 63
}
// fillFast() will make sure at least 32 bits are available.
// There must be at least 4 bytes available.
func (b *bitReaderShifted) fillFast() {
if b.bitsRead < 32 {
return
}
// 2 bounds checks.
v := b.in[b.off-4 : b.off]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
b.bitsRead -= 32
b.off -= 4
}
// fillFastStart() assumes the bitReaderShifted is empty and there is at least 8 bytes to read.
func (b *bitReaderShifted) fillFastStart() {
// Do single re-slice to avoid bounds checks.
b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
b.bitsRead = 0
b.off -= 8
}
// fill() will make sure at least 32 bits are available.
func (b *bitReaderShifted) fill() {
if b.bitsRead < 32 {
return
}
if b.off > 4 {
v := b.in[b.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
b.value |= uint64(low) << ((b.bitsRead - 32) & 63)
b.bitsRead -= 32
b.off -= 4
return
}
for b.off > 0 {
b.value |= uint64(b.in[b.off-1]) << ((b.bitsRead - 8) & 63)
b.bitsRead -= 8
b.off--
}
}
func (b *bitReaderShifted) remaining() uint {
return b.off*8 + uint(64-b.bitsRead)
}
// close the bitstream and returns an error if out-of-buffer reads occurred.
func (b *bitReaderShifted) close() error {
// Release reference.
b.in = nil
if b.remaining() > 0 {
return fmt.Errorf("corrupt input: %d bits remain on stream", b.remaining())
}
if b.bitsRead > 64 {
return io.ErrUnexpectedEOF
}
return nil
}

@ -1,95 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package huff0
// bitWriter will write bits.
// First bit will be LSB of the first byte of output.
type bitWriter struct {
bitContainer uint64
nBits uint8
out []byte
}
// bitMask16 is bitmasks. Has extra to avoid bounds check.
var bitMask16 = [32]uint16{
0, 1, 3, 7, 0xF, 0x1F,
0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
0xFFFF, 0xFFFF} /* up to 16 bits */
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
b.bitContainer |= uint64(value) << (b.nBits & 63)
b.nBits += bits
}
// encSymbol will add up to 16 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) encSymbol(ct cTable, symbol byte) {
enc := ct[symbol]
b.bitContainer |= uint64(enc.val) << (b.nBits & 63)
if false {
if enc.nBits == 0 {
panic("nbits 0")
}
}
b.nBits += enc.nBits
}
// encTwoSymbols will add up to 32 bits. value may not contain more set bits than indicated.
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
func (b *bitWriter) encTwoSymbols(ct cTable, av, bv byte) {
encA := ct[av]
encB := ct[bv]
sh := b.nBits & 63
combined := uint64(encA.val) | (uint64(encB.val) << (encA.nBits & 63))
b.bitContainer |= combined << sh
if false {
if encA.nBits == 0 {
panic("nbitsA 0")
}
if encB.nBits == 0 {
panic("nbitsB 0")
}
}
b.nBits += encA.nBits + encB.nBits
}
// flush32 will flush out, so there are at least 32 bits available for writing.
func (b *bitWriter) flush32() {
if b.nBits < 32 {
return
}
b.out = append(b.out,
byte(b.bitContainer),
byte(b.bitContainer>>8),
byte(b.bitContainer>>16),
byte(b.bitContainer>>24))
b.nBits -= 32
b.bitContainer >>= 32
}
// flushAlign will flush remaining full bytes and align to next byte boundary.
func (b *bitWriter) flushAlign() {
nbBytes := (b.nBits + 7) >> 3
for i := uint8(0); i < nbBytes; i++ {
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
}
b.nBits = 0
b.bitContainer = 0
}
// close will write the alignment bit and write the final byte(s)
// to the output.
func (b *bitWriter) close() error {
// End mark
b.addBits16Clean(1, 1)
// flush until next byte.
b.flushAlign()
return nil
}

@ -1,44 +0,0 @@
// Copyright 2018 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
package huff0
// byteReader provides a byte reader that reads
// little endian values from a byte stream.
// The input stream is manually advanced.
// The reader performs no bounds checks.
type byteReader struct {
b []byte
off int
}
// init will initialize the reader and set the input.
func (b *byteReader) init(in []byte) {
b.b = in
b.off = 0
}
// Int32 returns a little endian int32 starting at current offset.
func (b byteReader) Int32() int32 {
v3 := int32(b.b[b.off+3])
v2 := int32(b.b[b.off+2])
v1 := int32(b.b[b.off+1])
v0 := int32(b.b[b.off])
return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0
}
// Uint32 returns a little endian uint32 starting at current offset.
func (b byteReader) Uint32() uint32 {
v3 := uint32(b.b[b.off+3])
v2 := uint32(b.b[b.off+2])
v1 := uint32(b.b[b.off+1])
v0 := uint32(b.b[b.off])
return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0
}
// remain will return the number of bytes remaining.
func (b byteReader) remain() int {
return len(b.b) - b.off
}

@ -1,730 +0,0 @@
package huff0
import (
"fmt"
"math"
"runtime"
"sync"
)
// Compress1X will compress the input.
// The output can be decoded using Decompress1X.
// Supply a Scratch object. The scratch object contains state about re-use,
// So when sharing across independent encodes, be sure to set the re-use policy.
func Compress1X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) {
s, err = s.prepare(in)
if err != nil {
return nil, false, err
}
return compress(in, s, s.compress1X)
}
// Compress4X will compress the input. The input is split into 4 independent blocks
// and compressed similar to Compress1X.
// The output can be decoded using Decompress4X.
// Supply a Scratch object. The scratch object contains state about re-use,
// So when sharing across independent encodes, be sure to set the re-use policy.
func Compress4X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) {
s, err = s.prepare(in)
if err != nil {
return nil, false, err
}
if false {
// TODO: compress4Xp only slightly faster.
const parallelThreshold = 8 << 10
if len(in) < parallelThreshold || runtime.GOMAXPROCS(0) == 1 {
return compress(in, s, s.compress4X)
}
return compress(in, s, s.compress4Xp)
}
return compress(in, s, s.compress4X)
}
func compress(in []byte, s *Scratch, compressor func(src []byte) ([]byte, error)) (out []byte, reUsed bool, err error) {
// Nuke previous table if we cannot reuse anyway.
if s.Reuse == ReusePolicyNone {
s.prevTable = s.prevTable[:0]
}
// Create histogram, if none was provided.
maxCount := s.maxCount
var canReuse = false
if maxCount == 0 {
maxCount, canReuse = s.countSimple(in)
} else {
canReuse = s.canUseTable(s.prevTable)
}
// We want the output size to be less than this:
wantSize := len(in)
if s.WantLogLess > 0 {
wantSize -= wantSize >> s.WantLogLess
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount >= len(in) {
if maxCount > len(in) {
return nil, false, fmt.Errorf("maxCount (%d) > length (%d)", maxCount, len(in))
}
if len(in) == 1 {
return nil, false, ErrIncompressible
}
// One symbol, use RLE
return nil, false, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return nil, false, ErrIncompressible
}
if s.Reuse == ReusePolicyMust && !canReuse {
// We must reuse, but we can't.
return nil, false, ErrIncompressible
}
if (s.Reuse == ReusePolicyPrefer || s.Reuse == ReusePolicyMust) && canReuse {
keepTable := s.cTable
keepTL := s.actualTableLog
s.cTable = s.prevTable
s.actualTableLog = s.prevTableLog
s.Out, err = compressor(in)
s.cTable = keepTable
s.actualTableLog = keepTL
if err == nil && len(s.Out) < wantSize {
s.OutData = s.Out
return s.Out, true, nil
}
if s.Reuse == ReusePolicyMust {
return nil, false, ErrIncompressible
}
// Do not attempt to re-use later.
s.prevTable = s.prevTable[:0]
}
// Calculate new table.
err = s.buildCTable()
if err != nil {
return nil, false, err
}
if false && !s.canUseTable(s.cTable) {
panic("invalid table generated")
}
if s.Reuse == ReusePolicyAllow && canReuse {
hSize := len(s.Out)
oldSize := s.prevTable.estimateSize(s.count[:s.symbolLen])
newSize := s.cTable.estimateSize(s.count[:s.symbolLen])
if oldSize <= hSize+newSize || hSize+12 >= wantSize {
// Retain cTable even if we re-use.
keepTable := s.cTable
keepTL := s.actualTableLog
s.cTable = s.prevTable
s.actualTableLog = s.prevTableLog
s.Out, err = compressor(in)
// Restore ctable.
s.cTable = keepTable
s.actualTableLog = keepTL
if err != nil {
return nil, false, err
}
if len(s.Out) >= wantSize {
return nil, false, ErrIncompressible
}
s.OutData = s.Out
return s.Out, true, nil
}
}
// Use new table
err = s.cTable.write(s)
if err != nil {
s.OutTable = nil
return nil, false, err
}
s.OutTable = s.Out
// Compress using new table
s.Out, err = compressor(in)
if err != nil {
s.OutTable = nil
return nil, false, err
}
if len(s.Out) >= wantSize {
s.OutTable = nil
return nil, false, ErrIncompressible
}
// Move current table into previous.
s.prevTable, s.prevTableLog, s.cTable = s.cTable, s.actualTableLog, s.prevTable[:0]
s.OutData = s.Out[len(s.OutTable):]
return s.Out, false, nil
}
// EstimateSizes will estimate the data sizes
func EstimateSizes(in []byte, s *Scratch) (tableSz, dataSz, reuseSz int, err error) {
s, err = s.prepare(in)
if err != nil {
return 0, 0, 0, err
}
// Create histogram, if none was provided.
tableSz, dataSz, reuseSz = -1, -1, -1
maxCount := s.maxCount
var canReuse = false
if maxCount == 0 {
maxCount, canReuse = s.countSimple(in)
} else {
canReuse = s.canUseTable(s.prevTable)
}
// We want the output size to be less than this:
wantSize := len(in)
if s.WantLogLess > 0 {
wantSize -= wantSize >> s.WantLogLess
}
// Reset for next run.
s.clearCount = true
s.maxCount = 0
if maxCount >= len(in) {
if maxCount > len(in) {
return 0, 0, 0, fmt.Errorf("maxCount (%d) > length (%d)", maxCount, len(in))
}
if len(in) == 1 {
return 0, 0, 0, ErrIncompressible
}
// One symbol, use RLE
return 0, 0, 0, ErrUseRLE
}
if maxCount == 1 || maxCount < (len(in)>>7) {
// Each symbol present maximum once or too well distributed.
return 0, 0, 0, ErrIncompressible
}
// Calculate new table.
err = s.buildCTable()
if err != nil {
return 0, 0, 0, err
}
if false && !s.canUseTable(s.cTable) {
panic("invalid table generated")
}
tableSz, err = s.cTable.estTableSize(s)
if err != nil {
return 0, 0, 0, err
}
if canReuse {
reuseSz = s.prevTable.estimateSize(s.count[:s.symbolLen])
}
dataSz = s.cTable.estimateSize(s.count[:s.symbolLen])
// Restore
return tableSz, dataSz, reuseSz, nil
}
func (s *Scratch) compress1X(src []byte) ([]byte, error) {
return s.compress1xDo(s.Out, src)
}
func (s *Scratch) compress1xDo(dst, src []byte) ([]byte, error) {
var bw = bitWriter{out: dst}
// N is length divisible by 4.
n := len(src)
n -= n & 3
cTable := s.cTable[:256]
// Encode last bytes.
for i := len(src) & 3; i > 0; i-- {
bw.encSymbol(cTable, src[n+i-1])
}
n -= 4
if s.actualTableLog <= 8 {
for ; n >= 0; n -= 4 {
tmp := src[n : n+4]
// tmp should be len 4
bw.flush32()
bw.encTwoSymbols(cTable, tmp[3], tmp[2])
bw.encTwoSymbols(cTable, tmp[1], tmp[0])
}
} else {
for ; n >= 0; n -= 4 {
tmp := src[n : n+4]
// tmp should be len 4
bw.flush32()
bw.encTwoSymbols(cTable, tmp[3], tmp[2])
bw.flush32()
bw.encTwoSymbols(cTable, tmp[1], tmp[0])
}
}
err := bw.close()
return bw.out, err
}
var sixZeros [6]byte
func (s *Scratch) compress4X(src []byte) ([]byte, error) {
if len(src) < 12 {
return nil, ErrIncompressible
}
segmentSize := (len(src) + 3) / 4
// Add placeholder for output length
offsetIdx := len(s.Out)
s.Out = append(s.Out, sixZeros[:]...)
for i := 0; i < 4; i++ {
toDo := src
if len(toDo) > segmentSize {
toDo = toDo[:segmentSize]
}
src = src[len(toDo):]
var err error
idx := len(s.Out)
s.Out, err = s.compress1xDo(s.Out, toDo)
if err != nil {
return nil, err
}
if len(s.Out)-idx > math.MaxUint16 {
// We cannot store the size in the jump table
return nil, ErrIncompressible
}
// Write compressed length as little endian before block.
if i < 3 {
// Last length is not written.
length := len(s.Out) - idx
s.Out[i*2+offsetIdx] = byte(length)
s.Out[i*2+offsetIdx+1] = byte(length >> 8)
}
}
return s.Out, nil
}
// compress4Xp will compress 4 streams using separate goroutines.
func (s *Scratch) compress4Xp(src []byte) ([]byte, error) {
if len(src) < 12 {
return nil, ErrIncompressible
}
// Add placeholder for output length
s.Out = s.Out[:6]
segmentSize := (len(src) + 3) / 4
var wg sync.WaitGroup
var errs [4]error
wg.Add(4)
for i := 0; i < 4; i++ {
toDo := src
if len(toDo) > segmentSize {
toDo = toDo[:segmentSize]
}
src = src[len(toDo):]
// Separate goroutine for each block.
go func(i int) {
s.tmpOut[i], errs[i] = s.compress1xDo(s.tmpOut[i][:0], toDo)
wg.Done()
}(i)
}
wg.Wait()
for i := 0; i < 4; i++ {
if errs[i] != nil {
return nil, errs[i]
}
o := s.tmpOut[i]
if len(o) > math.MaxUint16 {
// We cannot store the size in the jump table
return nil, ErrIncompressible
}
// Write compressed length as little endian before block.
if i < 3 {
// Last length is not written.
s.Out[i*2] = byte(len(o))
s.Out[i*2+1] = byte(len(o) >> 8)
}
// Write output.
s.Out = append(s.Out, o...)
}
return s.Out, nil
}
// countSimple will create a simple histogram in s.count.
// Returns the biggest count.
// Does not update s.clearCount.
func (s *Scratch) countSimple(in []byte) (max int, reuse bool) {
reuse = true
for _, v := range in {
s.count[v]++
}
m := uint32(0)
if len(s.prevTable) > 0 {
for i, v := range s.count[:] {
if v > m {
m = v
}
if v > 0 {
s.symbolLen = uint16(i) + 1
if i >= len(s.prevTable) {
reuse = false
} else {
if s.prevTable[i].nBits == 0 {
reuse = false
}
}
}
}
return int(m), reuse
}
for i, v := range s.count[:] {
if v > m {
m = v
}
if v > 0 {
s.symbolLen = uint16(i) + 1
}
}
return int(m), false
}
func (s *Scratch) canUseTable(c cTable) bool {
if len(c) < int(s.symbolLen) {
return false
}
for i, v := range s.count[:s.symbolLen] {
if v != 0 && c[i].nBits == 0 {
return false
}
}
return true
}
//lint:ignore U1000 used for debugging
func (s *Scratch) validateTable(c cTable) bool {
if len(c) < int(s.symbolLen) {
return false
}
for i, v := range s.count[:s.symbolLen] {
if v != 0 {
if c[i].nBits == 0 {
return false
}
if c[i].nBits > s.actualTableLog {
return false
}
}
}
return true
}
// minTableLog provides the minimum logSize to safely represent a distribution.
func (s *Scratch) minTableLog() uint8 {
minBitsSrc := highBit32(uint32(s.br.remain())) + 1
minBitsSymbols := highBit32(uint32(s.symbolLen-1)) + 2
if minBitsSrc < minBitsSymbols {
return uint8(minBitsSrc)
}
return uint8(minBitsSymbols)
}
// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog
func (s *Scratch) optimalTableLog() {
tableLog := s.TableLog
minBits := s.minTableLog()
maxBitsSrc := uint8(highBit32(uint32(s.br.remain()-1))) - 1
if maxBitsSrc < tableLog {
// Accuracy can be reduced
tableLog = maxBitsSrc
}
if minBits > tableLog {
tableLog = minBits
}
// Need a minimum to safely represent all symbol values
if tableLog < minTablelog {
tableLog = minTablelog
}
if tableLog > tableLogMax {
tableLog = tableLogMax
}
s.actualTableLog = tableLog
}
type cTableEntry struct {
val uint16
nBits uint8
// We have 8 bits extra
}
const huffNodesMask = huffNodesLen - 1
func (s *Scratch) buildCTable() error {
s.optimalTableLog()
s.huffSort()
if cap(s.cTable) < maxSymbolValue+1 {
s.cTable = make([]cTableEntry, s.symbolLen, maxSymbolValue+1)
} else {
s.cTable = s.cTable[:s.symbolLen]
for i := range s.cTable {
s.cTable[i] = cTableEntry{}
}
}
var startNode = int16(s.symbolLen)
nonNullRank := s.symbolLen - 1
nodeNb := startNode
huffNode := s.nodes[1 : huffNodesLen+1]
// This overlays the slice above, but allows "-1" index lookups.
// Different from reference implementation.
huffNode0 := s.nodes[0 : huffNodesLen+1]
for huffNode[nonNullRank].count == 0 {
nonNullRank--
}
lowS := int16(nonNullRank)
nodeRoot := nodeNb + lowS - 1
lowN := nodeNb
huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS-1].count
huffNode[lowS].parent, huffNode[lowS-1].parent = uint16(nodeNb), uint16(nodeNb)
nodeNb++
lowS -= 2
for n := nodeNb; n <= nodeRoot; n++ {
huffNode[n].count = 1 << 30
}
// fake entry, strong barrier
huffNode0[0].count = 1 << 31
// create parents
for nodeNb <= nodeRoot {
var n1, n2 int16
if huffNode0[lowS+1].count < huffNode0[lowN+1].count {
n1 = lowS
lowS--
} else {
n1 = lowN
lowN++
}
if huffNode0[lowS+1].count < huffNode0[lowN+1].count {
n2 = lowS
lowS--
} else {
n2 = lowN
lowN++
}
huffNode[nodeNb].count = huffNode0[n1+1].count + huffNode0[n2+1].count
huffNode0[n1+1].parent, huffNode0[n2+1].parent = uint16(nodeNb), uint16(nodeNb)
nodeNb++
}
// distribute weights (unlimited tree height)
huffNode[nodeRoot].nbBits = 0
for n := nodeRoot - 1; n >= startNode; n-- {
huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1
}
for n := uint16(0); n <= nonNullRank; n++ {
huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1
}
s.actualTableLog = s.setMaxHeight(int(nonNullRank))
maxNbBits := s.actualTableLog
// fill result into tree (val, nbBits)
if maxNbBits > tableLogMax {
return fmt.Errorf("internal error: maxNbBits (%d) > tableLogMax (%d)", maxNbBits, tableLogMax)
}
var nbPerRank [tableLogMax + 1]uint16
var valPerRank [16]uint16
for _, v := range huffNode[:nonNullRank+1] {
nbPerRank[v.nbBits]++
}
// determine stating value per rank
{
min := uint16(0)
for n := maxNbBits; n > 0; n-- {
// get starting value within each rank
valPerRank[n] = min
min += nbPerRank[n]
min >>= 1
}
}
// push nbBits per symbol, symbol order
for _, v := range huffNode[:nonNullRank+1] {
s.cTable[v.symbol].nBits = v.nbBits
}
// assign value within rank, symbol order
t := s.cTable[:s.symbolLen]
for n, val := range t {
nbits := val.nBits & 15
v := valPerRank[nbits]
t[n].val = v
valPerRank[nbits] = v + 1
}
return nil
}
// huffSort will sort symbols, decreasing order.
func (s *Scratch) huffSort() {
type rankPos struct {
base uint32
current uint32
}
// Clear nodes
nodes := s.nodes[:huffNodesLen+1]
s.nodes = nodes
nodes = nodes[1 : huffNodesLen+1]
// Sort into buckets based on length of symbol count.
var rank [32]rankPos
for _, v := range s.count[:s.symbolLen] {
r := highBit32(v+1) & 31
rank[r].base++
}
// maxBitLength is log2(BlockSizeMax) + 1
const maxBitLength = 18 + 1
for n := maxBitLength; n > 0; n-- {
rank[n-1].base += rank[n].base
}
for n := range rank[:maxBitLength] {
rank[n].current = rank[n].base
}
for n, c := range s.count[:s.symbolLen] {
r := (highBit32(c+1) + 1) & 31
pos := rank[r].current
rank[r].current++
prev := nodes[(pos-1)&huffNodesMask]
for pos > rank[r].base && c > prev.count {
nodes[pos&huffNodesMask] = prev
pos--
prev = nodes[(pos-1)&huffNodesMask]
}
nodes[pos&huffNodesMask] = nodeElt{count: c, symbol: byte(n)}
}
}
func (s *Scratch) setMaxHeight(lastNonNull int) uint8 {
maxNbBits := s.actualTableLog
huffNode := s.nodes[1 : huffNodesLen+1]
//huffNode = huffNode[: huffNodesLen]
largestBits := huffNode[lastNonNull].nbBits
// early exit : no elt > maxNbBits
if largestBits <= maxNbBits {
return largestBits
}
totalCost := int(0)
baseCost := int(1) << (largestBits - maxNbBits)
n := uint32(lastNonNull)
for huffNode[n].nbBits > maxNbBits {
totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits))
huffNode[n].nbBits = maxNbBits
n--
}
// n stops at huffNode[n].nbBits <= maxNbBits
for huffNode[n].nbBits == maxNbBits {
n--
}
// n end at index of smallest symbol using < maxNbBits
// renorm totalCost
totalCost >>= largestBits - maxNbBits /* note : totalCost is necessarily a multiple of baseCost */
// repay normalized cost
{
const noSymbol = 0xF0F0F0F0
var rankLast [tableLogMax + 2]uint32
for i := range rankLast[:] {
rankLast[i] = noSymbol
}
// Get pos of last (smallest) symbol per rank
{
currentNbBits := maxNbBits
for pos := int(n); pos >= 0; pos-- {
if huffNode[pos].nbBits >= currentNbBits {
continue
}
currentNbBits = huffNode[pos].nbBits // < maxNbBits
rankLast[maxNbBits-currentNbBits] = uint32(pos)
}
}
for totalCost > 0 {
nBitsToDecrease := uint8(highBit32(uint32(totalCost))) + 1
for ; nBitsToDecrease > 1; nBitsToDecrease-- {
highPos := rankLast[nBitsToDecrease]
lowPos := rankLast[nBitsToDecrease-1]
if highPos == noSymbol {
continue
}
if lowPos == noSymbol {
break
}
highTotal := huffNode[highPos].count
lowTotal := 2 * huffNode[lowPos].count
if highTotal <= lowTotal {
break
}
}
// only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !)
// HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary
// FIXME: try to remove
for (nBitsToDecrease <= tableLogMax) && (rankLast[nBitsToDecrease] == noSymbol) {
nBitsToDecrease++
}
totalCost -= 1 << (nBitsToDecrease - 1)
if rankLast[nBitsToDecrease-1] == noSymbol {
// this rank is no longer empty
rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease]
}
huffNode[rankLast[nBitsToDecrease]].nbBits++
if rankLast[nBitsToDecrease] == 0 {
/* special case, reached largest symbol */
rankLast[nBitsToDecrease] = noSymbol
} else {
rankLast[nBitsToDecrease]--
if huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease {
rankLast[nBitsToDecrease] = noSymbol /* this rank is now empty */
}
}
}
for totalCost < 0 { /* Sometimes, cost correction overshoot */
if rankLast[1] == noSymbol { /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0 (using maxNbBits) */
for huffNode[n].nbBits == maxNbBits {
n--
}
huffNode[n+1].nbBits--
rankLast[1] = n + 1
totalCost++
continue
}
huffNode[rankLast[1]+1].nbBits--
rankLast[1]++
totalCost++
}
}
return maxNbBits
}
type nodeElt struct {
count uint32
parent uint16
symbol byte
nbBits uint8
}

File diff suppressed because it is too large Load Diff

@ -1,222 +0,0 @@
//go:build amd64 && !appengine && !noasm && gc
// +build amd64,!appengine,!noasm,gc
// This file contains the specialisation of Decoder.Decompress4X
// and Decoder.Decompress1X that use an asm implementation of thir main loops.
package huff0
import (
"errors"
"fmt"
"github.com/klauspost/compress/internal/cpuinfo"
)
// decompress4x_main_loop_x86 is an x86 assembler implementation
// of Decompress4X when tablelog > 8.
//go:noescape
func decompress4x_main_loop_amd64(ctx *decompress4xContext)
// decompress4x_8b_loop_x86 is an x86 assembler implementation
// of Decompress4X when tablelog <= 8 which decodes 4 entries
// per loop.
//go:noescape
func decompress4x_8b_main_loop_amd64(ctx *decompress4xContext)
// fallback8BitSize is the size where using Go version is faster.
const fallback8BitSize = 800
type decompress4xContext struct {
pbr *[4]bitReaderShifted
peekBits uint8
out *byte
dstEvery int
tbl *dEntrySingle
decoded int
limit *byte
}
// Decompress4X will decompress a 4X encoded stream.
// The length of the supplied input must match the end of a block exactly.
// The *capacity* of the dst slice must match the destination size of
// the uncompressed data exactly.
func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if len(src) < 6+(4*1) {
return nil, errors.New("input too small")
}
use8BitTables := d.actualTableLog <= 8
if cap(dst) < fallback8BitSize && use8BitTables {
return d.decompress4X8bit(dst, src)
}
var br [4]bitReaderShifted
// Decode "jump table"
start := 6
for i := 0; i < 3; i++ {
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
if start+length >= len(src) {
return nil, errors.New("truncated input (or invalid offset)")
}
err := br[i].init(src[start : start+length])
if err != nil {
return nil, err
}
start += length
}
err := br[3].init(src[start:])
if err != nil {
return nil, err
}
// destination, offset to match first output
dstSize := cap(dst)
dst = dst[:dstSize]
out := dst
dstEvery := (dstSize + 3) / 4
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
single := d.dt.single[:tlSize]
var decoded int
if len(out) > 4*4 && !(br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4) {
ctx := decompress4xContext{
pbr: &br,
peekBits: uint8((64 - d.actualTableLog) & 63), // see: bitReaderShifted.peekBitsFast()
out: &out[0],
dstEvery: dstEvery,
tbl: &single[0],
limit: &out[dstEvery-4], // Always stop decoding when first buffer gets here to avoid writing OOB on last.
}
if use8BitTables {
decompress4x_8b_main_loop_amd64(&ctx)
} else {
decompress4x_main_loop_amd64(&ctx)
}
decoded = ctx.decoded
out = out[decoded/4:]
}
// Decode remaining.
remainBytes := dstEvery - (decoded / 4)
for i := range br {
offset := dstEvery * i
endsAt := offset + remainBytes
if endsAt > len(out) {
endsAt = len(out)
}
br := &br[i]
bitsLeft := br.remaining()
for bitsLeft > 0 {
br.fill()
if offset >= endsAt {
return nil, errors.New("corruption detected: stream overrun 4")
}
// Read value and increment offset.
val := br.peekBitsFast(d.actualTableLog)
v := single[val&tlMask].entry
nBits := uint8(v)
br.advance(nBits)
bitsLeft -= uint(nBits)
out[offset] = uint8(v >> 8)
offset++
}
if offset != endsAt {
return nil, fmt.Errorf("corruption detected: short output block %d, end %d != %d", i, offset, endsAt)
}
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
return nil, err
}
}
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
return dst, nil
}
// decompress4x_main_loop_x86 is an x86 assembler implementation
// of Decompress1X when tablelog > 8.
//go:noescape
func decompress1x_main_loop_amd64(ctx *decompress1xContext)
// decompress4x_main_loop_x86 is an x86 with BMI2 assembler implementation
// of Decompress1X when tablelog > 8.
//go:noescape
func decompress1x_main_loop_bmi2(ctx *decompress1xContext)
type decompress1xContext struct {
pbr *bitReaderShifted
peekBits uint8
out *byte
outCap int
tbl *dEntrySingle
decoded int
}
// Error reported by asm implementations
const error_max_decoded_size_exeeded = -1
// Decompress1X will decompress a 1X encoded stream.
// The cap of the output buffer will be the maximum decompressed size.
// The length of the supplied input must match the end of a block exactly.
func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
var br bitReaderShifted
err := br.init(src)
if err != nil {
return dst, err
}
maxDecodedSize := cap(dst)
dst = dst[:maxDecodedSize]
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
if maxDecodedSize >= 4 {
ctx := decompress1xContext{
pbr: &br,
out: &dst[0],
outCap: maxDecodedSize,
peekBits: uint8((64 - d.actualTableLog) & 63), // see: bitReaderShifted.peekBitsFast()
tbl: &d.dt.single[0],
}
if cpuinfo.HasBMI2() {
decompress1x_main_loop_bmi2(&ctx)
} else {
decompress1x_main_loop_amd64(&ctx)
}
if ctx.decoded == error_max_decoded_size_exeeded {
return nil, ErrMaxDecodedSizeExceeded
}
dst = dst[:ctx.decoded]
}
// br < 8, so uint8 is fine
bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
for bitsLeft > 0 {
br.fill()
if len(dst) >= maxDecodedSize {
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
nBits := uint8(v.entry)
br.advance(nBits)
bitsLeft -= nBits
dst = append(dst, uint8(v.entry>>8))
}
return dst, br.close()
}

@ -1,847 +0,0 @@
// Code generated by command: go run gen.go -out ../decompress_amd64.s -pkg=huff0. DO NOT EDIT.
//go:build amd64 && !appengine && !noasm && gc
// +build amd64,!appengine,!noasm,gc
// func decompress4x_main_loop_amd64(ctx *decompress4xContext)
TEXT ·decompress4x_main_loop_amd64(SB), $0-8
XORQ DX, DX
// Preload values
MOVQ ctx+0(FP), AX
MOVBQZX 8(AX), DI
MOVQ 16(AX), SI
MOVQ 48(AX), BX
MOVQ 24(AX), R9
MOVQ 32(AX), R10
MOVQ (AX), R11
// Main loop
main_loop:
MOVQ SI, R8
CMPQ R8, BX
SETGE DL
// br0.fillFast32()
MOVQ 32(R11), R12
MOVBQZX 40(R11), R13
CMPQ R13, $0x20
JBE skip_fill0
MOVQ 24(R11), AX
SUBQ $0x20, R13
SUBQ $0x04, AX
MOVQ (R11), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R14*1), R14
MOVQ R13, CX
SHLQ CL, R14
MOVQ AX, 24(R11)
ORQ R14, R12
// exhausted = exhausted || (br0.off < 4)
CMPQ AX, $0x04
SETLT AL
ORB AL, DL
skip_fill0:
// val0 := br0.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br0.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R12, R14
SHRQ CL, R14
// v1 := table[val1&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (R8)
// update the bitreader structure
MOVQ R12, 32(R11)
MOVB R13, 40(R11)
ADDQ R9, R8
// br1.fillFast32()
MOVQ 80(R11), R12
MOVBQZX 88(R11), R13
CMPQ R13, $0x20
JBE skip_fill1
MOVQ 72(R11), AX
SUBQ $0x20, R13
SUBQ $0x04, AX
MOVQ 48(R11), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R14*1), R14
MOVQ R13, CX
SHLQ CL, R14
MOVQ AX, 72(R11)
ORQ R14, R12
// exhausted = exhausted || (br1.off < 4)
CMPQ AX, $0x04
SETLT AL
ORB AL, DL
skip_fill1:
// val0 := br1.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br1.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R12, R14
SHRQ CL, R14
// v1 := table[val1&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (R8)
// update the bitreader structure
MOVQ R12, 80(R11)
MOVB R13, 88(R11)
ADDQ R9, R8
// br2.fillFast32()
MOVQ 128(R11), R12
MOVBQZX 136(R11), R13
CMPQ R13, $0x20
JBE skip_fill2
MOVQ 120(R11), AX
SUBQ $0x20, R13
SUBQ $0x04, AX
MOVQ 96(R11), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R14*1), R14
MOVQ R13, CX
SHLQ CL, R14
MOVQ AX, 120(R11)
ORQ R14, R12
// exhausted = exhausted || (br2.off < 4)
CMPQ AX, $0x04
SETLT AL
ORB AL, DL
skip_fill2:
// val0 := br2.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br2.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R12, R14
SHRQ CL, R14
// v1 := table[val1&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (R8)
// update the bitreader structure
MOVQ R12, 128(R11)
MOVB R13, 136(R11)
ADDQ R9, R8
// br3.fillFast32()
MOVQ 176(R11), R12
MOVBQZX 184(R11), R13
CMPQ R13, $0x20
JBE skip_fill3
MOVQ 168(R11), AX
SUBQ $0x20, R13
SUBQ $0x04, AX
MOVQ 144(R11), R14
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (AX)(R14*1), R14
MOVQ R13, CX
SHLQ CL, R14
MOVQ AX, 168(R11)
ORQ R14, R12
// exhausted = exhausted || (br3.off < 4)
CMPQ AX, $0x04
SETLT AL
ORB AL, DL
skip_fill3:
// val0 := br3.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br3.peekTopBits(peekBits)
MOVQ DI, CX
MOVQ R12, R14
SHRQ CL, R14
// v1 := table[val1&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v1.entry))
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// these two writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
MOVW AX, (R8)
// update the bitreader structure
MOVQ R12, 176(R11)
MOVB R13, 184(R11)
ADDQ $0x02, SI
TESTB DL, DL
JZ main_loop
MOVQ ctx+0(FP), AX
SUBQ 16(AX), SI
SHLQ $0x02, SI
MOVQ SI, 40(AX)
RET
// func decompress4x_8b_main_loop_amd64(ctx *decompress4xContext)
TEXT ·decompress4x_8b_main_loop_amd64(SB), $0-8
XORQ DX, DX
// Preload values
MOVQ ctx+0(FP), CX
MOVBQZX 8(CX), DI
MOVQ 16(CX), BX
MOVQ 48(CX), SI
MOVQ 24(CX), R9
MOVQ 32(CX), R10
MOVQ (CX), R11
// Main loop
main_loop:
MOVQ BX, R8
CMPQ R8, SI
SETGE DL
// br0.fillFast32()
MOVQ 32(R11), R12
MOVBQZX 40(R11), R13
CMPQ R13, $0x20
JBE skip_fill0
MOVQ 24(R11), R14
SUBQ $0x20, R13
SUBQ $0x04, R14
MOVQ (R11), R15
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R14)(R15*1), R15
MOVQ R13, CX
SHLQ CL, R15
MOVQ R14, 24(R11)
ORQ R15, R12
// exhausted = exhausted || (br0.off < 4)
CMPQ R14, $0x04
SETLT AL
ORB AL, DL
skip_fill0:
// val0 := br0.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br0.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v1 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// val2 := br0.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v2 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// val3 := br0.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v3 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br0.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (R8)
// update the bitreader structure
MOVQ R12, 32(R11)
MOVB R13, 40(R11)
ADDQ R9, R8
// br1.fillFast32()
MOVQ 80(R11), R12
MOVBQZX 88(R11), R13
CMPQ R13, $0x20
JBE skip_fill1
MOVQ 72(R11), R14
SUBQ $0x20, R13
SUBQ $0x04, R14
MOVQ 48(R11), R15
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R14)(R15*1), R15
MOVQ R13, CX
SHLQ CL, R15
MOVQ R14, 72(R11)
ORQ R15, R12
// exhausted = exhausted || (br1.off < 4)
CMPQ R14, $0x04
SETLT AL
ORB AL, DL
skip_fill1:
// val0 := br1.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br1.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v1 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// val2 := br1.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v2 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// val3 := br1.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v3 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br1.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (R8)
// update the bitreader structure
MOVQ R12, 80(R11)
MOVB R13, 88(R11)
ADDQ R9, R8
// br2.fillFast32()
MOVQ 128(R11), R12
MOVBQZX 136(R11), R13
CMPQ R13, $0x20
JBE skip_fill2
MOVQ 120(R11), R14
SUBQ $0x20, R13
SUBQ $0x04, R14
MOVQ 96(R11), R15
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R14)(R15*1), R15
MOVQ R13, CX
SHLQ CL, R15
MOVQ R14, 120(R11)
ORQ R15, R12
// exhausted = exhausted || (br2.off < 4)
CMPQ R14, $0x04
SETLT AL
ORB AL, DL
skip_fill2:
// val0 := br2.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br2.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v1 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// val2 := br2.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v2 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// val3 := br2.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v3 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br2.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (R8)
// update the bitreader structure
MOVQ R12, 128(R11)
MOVB R13, 136(R11)
ADDQ R9, R8
// br3.fillFast32()
MOVQ 176(R11), R12
MOVBQZX 184(R11), R13
CMPQ R13, $0x20
JBE skip_fill3
MOVQ 168(R11), R14
SUBQ $0x20, R13
SUBQ $0x04, R14
MOVQ 144(R11), R15
// b.value |= uint64(low) << (b.bitsRead & 63)
MOVL (R14)(R15*1), R15
MOVQ R13, CX
SHLQ CL, R15
MOVQ R14, 168(R11)
ORQ R15, R12
// exhausted = exhausted || (br3.off < 4)
CMPQ R14, $0x04
SETLT AL
ORB AL, DL
skip_fill3:
// val0 := br3.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v0 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v0.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
// val1 := br3.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v1 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v1.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// val2 := br3.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v2 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v2.entry)
MOVB CH, AH
SHLQ CL, R12
ADDB CL, R13
// val3 := br3.peekTopBits(peekBits)
MOVQ R12, R14
MOVQ DI, CX
SHRQ CL, R14
// v3 := table[val0&mask]
MOVW (R10)(R14*2), CX
// br3.advance(uint8(v3.entry)
MOVB CH, AL
SHLQ CL, R12
ADDB CL, R13
BSWAPL AX
// these four writes get coalesced
// out[id * dstEvery + 0] = uint8(v0.entry >> 8)
// out[id * dstEvery + 1] = uint8(v1.entry >> 8)
// out[id * dstEvery + 3] = uint8(v2.entry >> 8)
// out[id * dstEvery + 4] = uint8(v3.entry >> 8)
MOVL AX, (R8)
// update the bitreader structure
MOVQ R12, 176(R11)
MOVB R13, 184(R11)
ADDQ $0x04, BX
TESTB DL, DL
JZ main_loop
MOVQ ctx+0(FP), AX
SUBQ 16(AX), BX
SHLQ $0x02, BX
MOVQ BX, 40(AX)
RET
// func decompress1x_main_loop_amd64(ctx *decompress1xContext)
TEXT ·decompress1x_main_loop_amd64(SB), $0-8
MOVQ ctx+0(FP), CX
MOVQ 16(CX), DX
MOVQ 24(CX), BX
CMPQ BX, $0x04
JB error_max_decoded_size_exeeded
LEAQ (DX)(BX*1), BX
MOVQ (CX), SI
MOVQ (SI), R8
MOVQ 24(SI), R9
MOVQ 32(SI), R10
MOVBQZX 40(SI), R11
MOVQ 32(CX), SI
MOVBQZX 8(CX), DI
JMP loop_condition
main_loop:
// Check if we have room for 4 bytes in the output buffer
LEAQ 4(DX), CX
CMPQ CX, BX
JGE error_max_decoded_size_exeeded
// Decode 4 values
CMPQ R11, $0x20
JL bitReader_fillFast_1_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), R12
MOVQ R11, CX
SHLQ CL, R12
ORQ R12, R10
bitReader_fillFast_1_end:
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
BSWAPL AX
CMPQ R11, $0x20
JL bitReader_fillFast_2_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), R12
MOVQ R11, CX
SHLQ CL, R12
ORQ R12, R10
bitReader_fillFast_2_end:
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
MOVQ DI, CX
MOVQ R10, R12
SHRQ CL, R12
MOVW (SI)(R12*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLQ CL, R10
BSWAPL AX
// Store the decoded values
MOVL AX, (DX)
ADDQ $0x04, DX
loop_condition:
CMPQ R9, $0x08
JGE main_loop
// Update ctx structure
MOVQ ctx+0(FP), AX
SUBQ 16(AX), DX
MOVQ DX, 40(AX)
MOVQ (AX), AX
MOVQ R9, 24(AX)
MOVQ R10, 32(AX)
MOVB R11, 40(AX)
RET
// Report error
error_max_decoded_size_exeeded:
MOVQ ctx+0(FP), AX
MOVQ $-1, CX
MOVQ CX, 40(AX)
RET
// func decompress1x_main_loop_bmi2(ctx *decompress1xContext)
// Requires: BMI2
TEXT ·decompress1x_main_loop_bmi2(SB), $0-8
MOVQ ctx+0(FP), CX
MOVQ 16(CX), DX
MOVQ 24(CX), BX
CMPQ BX, $0x04
JB error_max_decoded_size_exeeded
LEAQ (DX)(BX*1), BX
MOVQ (CX), SI
MOVQ (SI), R8
MOVQ 24(SI), R9
MOVQ 32(SI), R10
MOVBQZX 40(SI), R11
MOVQ 32(CX), SI
MOVBQZX 8(CX), DI
JMP loop_condition
main_loop:
// Check if we have room for 4 bytes in the output buffer
LEAQ 4(DX), CX
CMPQ CX, BX
JGE error_max_decoded_size_exeeded
// Decode 4 values
CMPQ R11, $0x20
JL bitReader_fillFast_1_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), CX
SHLXQ R11, CX, CX
ORQ CX, R10
bitReader_fillFast_1_end:
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
BSWAPL AX
CMPQ R11, $0x20
JL bitReader_fillFast_2_end
SUBQ $0x20, R11
SUBQ $0x04, R9
MOVL (R8)(R9*1), CX
SHLXQ R11, CX, CX
ORQ CX, R10
bitReader_fillFast_2_end:
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AH
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
SHRXQ DI, R10, CX
MOVW (SI)(CX*2), CX
MOVB CH, AL
MOVBQZX CL, CX
ADDQ CX, R11
SHLXQ CX, R10, R10
BSWAPL AX
// Store the decoded values
MOVL AX, (DX)
ADDQ $0x04, DX
loop_condition:
CMPQ R9, $0x08
JGE main_loop
// Update ctx structure
MOVQ ctx+0(FP), AX
SUBQ 16(AX), DX
MOVQ DX, 40(AX)
MOVQ (AX), AX
MOVQ R9, 24(AX)
MOVQ R10, 32(AX)
MOVB R11, 40(AX)
RET
// Report error
error_max_decoded_size_exeeded:
MOVQ ctx+0(FP), AX
MOVQ $-1, CX
MOVQ CX, 40(AX)
RET

@ -1,295 +0,0 @@
//go:build !amd64 || appengine || !gc || noasm
// +build !amd64 appengine !gc noasm
// This file contains a generic implementation of Decoder.Decompress4X.
package huff0
import (
"errors"
"fmt"
)
// Decompress4X will decompress a 4X encoded stream.
// The length of the supplied input must match the end of a block exactly.
// The *capacity* of the dst slice must match the destination size of
// the uncompressed data exactly.
func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if len(src) < 6+(4*1) {
return nil, errors.New("input too small")
}
if use8BitTables && d.actualTableLog <= 8 {
return d.decompress4X8bit(dst, src)
}
var br [4]bitReaderShifted
// Decode "jump table"
start := 6
for i := 0; i < 3; i++ {
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
if start+length >= len(src) {
return nil, errors.New("truncated input (or invalid offset)")
}
err := br[i].init(src[start : start+length])
if err != nil {
return nil, err
}
start += length
}
err := br[3].init(src[start:])
if err != nil {
return nil, err
}
// destination, offset to match first output
dstSize := cap(dst)
dst = dst[:dstSize]
out := dst
dstEvery := (dstSize + 3) / 4
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
single := d.dt.single[:tlSize]
// Use temp table to avoid bound checks/append penalty.
buf := d.buffer()
var off uint8
var decoded int
// Decode 2 values from each decoder/loop.
const bufoff = 256
for {
if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
break
}
{
const stream = 0
const stream2 = 1
br[stream].fillFast()
br[stream2].fillFast()
val := br[stream].peekBitsFast(d.actualTableLog)
val2 := br[stream2].peekBitsFast(d.actualTableLog)
v := single[val&tlMask]
v2 := single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off] = uint8(v.entry >> 8)
buf[stream2][off] = uint8(v2.entry >> 8)
val = br[stream].peekBitsFast(d.actualTableLog)
val2 = br[stream2].peekBitsFast(d.actualTableLog)
v = single[val&tlMask]
v2 = single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off+1] = uint8(v.entry >> 8)
buf[stream2][off+1] = uint8(v2.entry >> 8)
}
{
const stream = 2
const stream2 = 3
br[stream].fillFast()
br[stream2].fillFast()
val := br[stream].peekBitsFast(d.actualTableLog)
val2 := br[stream2].peekBitsFast(d.actualTableLog)
v := single[val&tlMask]
v2 := single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off] = uint8(v.entry >> 8)
buf[stream2][off] = uint8(v2.entry >> 8)
val = br[stream].peekBitsFast(d.actualTableLog)
val2 = br[stream2].peekBitsFast(d.actualTableLog)
v = single[val&tlMask]
v2 = single[val2&tlMask]
br[stream].advance(uint8(v.entry))
br[stream2].advance(uint8(v2.entry))
buf[stream][off+1] = uint8(v.entry >> 8)
buf[stream2][off+1] = uint8(v2.entry >> 8)
}
off += 2
if off == 0 {
if bufoff > dstEvery {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 1")
}
copy(out, buf[0][:])
copy(out[dstEvery:], buf[1][:])
copy(out[dstEvery*2:], buf[2][:])
copy(out[dstEvery*3:], buf[3][:])
out = out[bufoff:]
decoded += bufoff * 4
// There must at least be 3 buffers left.
if len(out) < dstEvery*3 {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 2")
}
}
}
if off > 0 {
ioff := int(off)
if len(out) < dstEvery*3+ioff {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 3")
}
copy(out, buf[0][:off])
copy(out[dstEvery:], buf[1][:off])
copy(out[dstEvery*2:], buf[2][:off])
copy(out[dstEvery*3:], buf[3][:off])
decoded += int(off) * 4
out = out[off:]
}
// Decode remaining.
remainBytes := dstEvery - (decoded / 4)
for i := range br {
offset := dstEvery * i
endsAt := offset + remainBytes
if endsAt > len(out) {
endsAt = len(out)
}
br := &br[i]
bitsLeft := br.remaining()
for bitsLeft > 0 {
br.fill()
if offset >= endsAt {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 4")
}
// Read value and increment offset.
val := br.peekBitsFast(d.actualTableLog)
v := single[val&tlMask].entry
nBits := uint8(v)
br.advance(nBits)
bitsLeft -= uint(nBits)
out[offset] = uint8(v >> 8)
offset++
}
if offset != endsAt {
d.bufs.Put(buf)
return nil, fmt.Errorf("corruption detected: short output block %d, end %d != %d", i, offset, endsAt)
}
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
return nil, err
}
}
d.bufs.Put(buf)
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
return dst, nil
}
// Decompress1X will decompress a 1X encoded stream.
// The cap of the output buffer will be the maximum decompressed size.
// The length of the supplied input must match the end of a block exactly.
func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
if len(d.dt.single) == 0 {
return nil, errors.New("no table loaded")
}
if use8BitTables && d.actualTableLog <= 8 {
return d.decompress1X8Bit(dst, src)
}
var br bitReaderShifted
err := br.init(src)
if err != nil {
return dst, err
}
maxDecodedSize := cap(dst)
dst = dst[:0]
// Avoid bounds check by always having full sized table.
const tlSize = 1 << tableLogMax
const tlMask = tlSize - 1
dt := d.dt.single[:tlSize]
// Use temp table to avoid bound checks/append penalty.
bufs := d.buffer()
buf := &bufs[0]
var off uint8
for br.off >= 8 {
br.fillFast()
v := dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+0] = uint8(v.entry >> 8)
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+1] = uint8(v.entry >> 8)
// Refill
br.fillFast()
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+2] = uint8(v.entry >> 8)
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
br.advance(uint8(v.entry))
buf[off+3] = uint8(v.entry >> 8)
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
}
}
if len(dst)+int(off) > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:off]...)
// br < 8, so uint8 is fine
bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
for bitsLeft > 0 {
br.fill()
if false && br.bitsRead >= 32 {
if br.off >= 4 {
v := br.in[br.off-4:]
v = v[:4]
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
br.value = (br.value << 32) | uint64(low)
br.bitsRead -= 32
br.off -= 4
} else {
for br.off > 0 {
br.value = (br.value << 8) | uint64(br.in[br.off-1])
br.bitsRead -= 8
br.off--
}
}
}
if len(dst) >= maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
nBits := uint8(v.entry)
br.advance(nBits)
bitsLeft -= nBits
dst = append(dst, uint8(v.entry>>8))
}
d.bufs.Put(bufs)
return dst, br.close()
}

@ -1,337 +0,0 @@
// Package huff0 provides fast huffman encoding as used in zstd.
//
// See README.md at https://github.com/klauspost/compress/tree/master/huff0 for details.
package huff0
import (
"errors"
"fmt"
"math"
"math/bits"
"sync"
"github.com/klauspost/compress/fse"
)
const (
maxSymbolValue = 255
// zstandard limits tablelog to 11, see:
// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#huffman-tree-description
tableLogMax = 11
tableLogDefault = 11
minTablelog = 5
huffNodesLen = 512
// BlockSizeMax is maximum input size for a single block uncompressed.
BlockSizeMax = 1<<18 - 1
)
var (
// ErrIncompressible is returned when input is judged to be too hard to compress.
ErrIncompressible = errors.New("input is not compressible")
// ErrUseRLE is returned from the compressor when the input is a single byte value repeated.
ErrUseRLE = errors.New("input is single value repeated")
// ErrTooBig is return if input is too large for a single block.
ErrTooBig = errors.New("input too big")
// ErrMaxDecodedSizeExceeded is return if input is too large for a single block.
ErrMaxDecodedSizeExceeded = errors.New("maximum output size exceeded")
)
type ReusePolicy uint8
const (
// ReusePolicyAllow will allow reuse if it produces smaller output.
ReusePolicyAllow ReusePolicy = iota
// ReusePolicyPrefer will re-use aggressively if possible.
// This will not check if a new table will produce smaller output,
// except if the current table is impossible to use or
// compressed output is bigger than input.
ReusePolicyPrefer
// ReusePolicyNone will disable re-use of tables.
// This is slightly faster than ReusePolicyAllow but may produce larger output.
ReusePolicyNone
// ReusePolicyMust must allow reuse and produce smaller output.
ReusePolicyMust
)
type Scratch struct {
count [maxSymbolValue + 1]uint32
// Per block parameters.
// These can be used to override compression parameters of the block.
// Do not touch, unless you know what you are doing.
// Out is output buffer.
// If the scratch is re-used before the caller is done processing the output,
// set this field to nil.
// Otherwise the output buffer will be re-used for next Compression/Decompression step
// and allocation will be avoided.
Out []byte
// OutTable will contain the table data only, if a new table has been generated.
// Slice of the returned data.
OutTable []byte
// OutData will contain the compressed data.
// Slice of the returned data.
OutData []byte
// MaxDecodedSize will set the maximum allowed output size.
// This value will automatically be set to BlockSizeMax if not set.
// Decoders will return ErrMaxDecodedSizeExceeded is this limit is exceeded.
MaxDecodedSize int
br byteReader
// MaxSymbolValue will override the maximum symbol value of the next block.
MaxSymbolValue uint8
// TableLog will attempt to override the tablelog for the next block.
// Must be <= 11 and >= 5.
TableLog uint8
// Reuse will specify the reuse policy
Reuse ReusePolicy
// WantLogLess allows to specify a log 2 reduction that should at least be achieved,
// otherwise the block will be returned as incompressible.
// The reduction should then at least be (input size >> WantLogLess)
// If WantLogLess == 0 any improvement will do.
WantLogLess uint8
symbolLen uint16 // Length of active part of the symbol table.
maxCount int // count of the most probable symbol
clearCount bool // clear count
actualTableLog uint8 // Selected tablelog.
prevTableLog uint8 // Tablelog for previous table
prevTable cTable // Table used for previous compression.
cTable cTable // compression table
dt dTable // decompression table
nodes []nodeElt
tmpOut [4][]byte
fse *fse.Scratch
decPool sync.Pool // *[4][256]byte buffers.
huffWeight [maxSymbolValue + 1]byte
}
// TransferCTable will transfer the previously used compression table.
func (s *Scratch) TransferCTable(src *Scratch) {
if cap(s.prevTable) < len(src.prevTable) {
s.prevTable = make(cTable, 0, maxSymbolValue+1)
}
s.prevTable = s.prevTable[:len(src.prevTable)]
copy(s.prevTable, src.prevTable)
s.prevTableLog = src.prevTableLog
}
func (s *Scratch) prepare(in []byte) (*Scratch, error) {
if len(in) > BlockSizeMax {
return nil, ErrTooBig
}
if s == nil {
s = &Scratch{}
}
if s.MaxSymbolValue == 0 {
s.MaxSymbolValue = maxSymbolValue
}
if s.TableLog == 0 {
s.TableLog = tableLogDefault
}
if s.TableLog > tableLogMax || s.TableLog < minTablelog {
return nil, fmt.Errorf(" invalid tableLog %d (%d -> %d)", s.TableLog, minTablelog, tableLogMax)
}
if s.MaxDecodedSize <= 0 || s.MaxDecodedSize > BlockSizeMax {
s.MaxDecodedSize = BlockSizeMax
}
if s.clearCount && s.maxCount == 0 {
for i := range s.count {
s.count[i] = 0
}
s.clearCount = false
}
if cap(s.Out) == 0 {
s.Out = make([]byte, 0, len(in))
}
s.Out = s.Out[:0]
s.OutTable = nil
s.OutData = nil
if cap(s.nodes) < huffNodesLen+1 {
s.nodes = make([]nodeElt, 0, huffNodesLen+1)
}
s.nodes = s.nodes[:0]
if s.fse == nil {
s.fse = &fse.Scratch{}
}
s.br.init(in)
return s, nil
}
type cTable []cTableEntry
func (c cTable) write(s *Scratch) error {
var (
// precomputed conversion table
bitsToWeight [tableLogMax + 1]byte
huffLog = s.actualTableLog
// last weight is not saved.
maxSymbolValue = uint8(s.symbolLen - 1)
huffWeight = s.huffWeight[:256]
)
const (
maxFSETableLog = 6
)
// convert to weight
bitsToWeight[0] = 0
for n := uint8(1); n < huffLog+1; n++ {
bitsToWeight[n] = huffLog + 1 - n
}
// Acquire histogram for FSE.
hist := s.fse.Histogram()
hist = hist[:256]
for i := range hist[:16] {
hist[i] = 0
}
for n := uint8(0); n < maxSymbolValue; n++ {
v := bitsToWeight[c[n].nBits] & 15
huffWeight[n] = v
hist[v]++
}
// FSE compress if feasible.
if maxSymbolValue >= 2 {
huffMaxCnt := uint32(0)
huffMax := uint8(0)
for i, v := range hist[:16] {
if v == 0 {
continue
}
huffMax = byte(i)
if v > huffMaxCnt {
huffMaxCnt = v
}
}
s.fse.HistogramFinished(huffMax, int(huffMaxCnt))
s.fse.TableLog = maxFSETableLog
b, err := fse.Compress(huffWeight[:maxSymbolValue], s.fse)
if err == nil && len(b) < int(s.symbolLen>>1) {
s.Out = append(s.Out, uint8(len(b)))
s.Out = append(s.Out, b...)
return nil
}
// Unable to compress (RLE/uncompressible)
}
// write raw values as 4-bits (max : 15)
if maxSymbolValue > (256 - 128) {
// should not happen : likely means source cannot be compressed
return ErrIncompressible
}
op := s.Out
// special case, pack weights 4 bits/weight.
op = append(op, 128|(maxSymbolValue-1))
// be sure it doesn't cause msan issue in final combination
huffWeight[maxSymbolValue] = 0
for n := uint16(0); n < uint16(maxSymbolValue); n += 2 {
op = append(op, (huffWeight[n]<<4)|huffWeight[n+1])
}
s.Out = op
return nil
}
func (c cTable) estTableSize(s *Scratch) (sz int, err error) {
var (
// precomputed conversion table
bitsToWeight [tableLogMax + 1]byte
huffLog = s.actualTableLog
// last weight is not saved.
maxSymbolValue = uint8(s.symbolLen - 1)
huffWeight = s.huffWeight[:256]
)
const (
maxFSETableLog = 6
)
// convert to weight
bitsToWeight[0] = 0
for n := uint8(1); n < huffLog+1; n++ {
bitsToWeight[n] = huffLog + 1 - n
}
// Acquire histogram for FSE.
hist := s.fse.Histogram()
hist = hist[:256]
for i := range hist[:16] {
hist[i] = 0
}
for n := uint8(0); n < maxSymbolValue; n++ {
v := bitsToWeight[c[n].nBits] & 15
huffWeight[n] = v
hist[v]++
}
// FSE compress if feasible.
if maxSymbolValue >= 2 {
huffMaxCnt := uint32(0)
huffMax := uint8(0)
for i, v := range hist[:16] {
if v == 0 {
continue
}
huffMax = byte(i)
if v > huffMaxCnt {
huffMaxCnt = v
}
}
s.fse.HistogramFinished(huffMax, int(huffMaxCnt))
s.fse.TableLog = maxFSETableLog
b, err := fse.Compress(huffWeight[:maxSymbolValue], s.fse)
if err == nil && len(b) < int(s.symbolLen>>1) {
sz += 1 + len(b)
return sz, nil
}
// Unable to compress (RLE/uncompressible)
}
// write raw values as 4-bits (max : 15)
if maxSymbolValue > (256 - 128) {
// should not happen : likely means source cannot be compressed
return 0, ErrIncompressible
}
// special case, pack weights 4 bits/weight.
sz += 1 + int(maxSymbolValue/2)
return sz, nil
}
// estimateSize returns the estimated size in bytes of the input represented in the
// histogram supplied.
func (c cTable) estimateSize(hist []uint32) int {
nbBits := uint32(7)
for i, v := range c[:len(hist)] {
nbBits += uint32(v.nBits) * hist[i]
}
return int(nbBits >> 3)
}
// minSize returns the minimum possible size considering the shannon limit.
func (s *Scratch) minSize(total int) int {
nbBits := float64(7)
fTotal := float64(total)
for _, v := range s.count[:s.symbolLen] {
n := float64(v)
if n > 0 {
nbBits += math.Log2(fTotal/n) * n
}
}
return int(nbBits) >> 3
}
func highBit32(val uint32) (n uint32) {
return uint32(bits.Len32(val) - 1)
}

@ -1,34 +0,0 @@
// Package cpuinfo gives runtime info about the current CPU.
//
// This is a very limited module meant for use internally
// in this project. For more versatile solution check
// https://github.com/klauspost/cpuid.
package cpuinfo
// HasBMI1 checks whether an x86 CPU supports the BMI1 extension.
func HasBMI1() bool {
return hasBMI1
}
// HasBMI2 checks whether an x86 CPU supports the BMI2 extension.
func HasBMI2() bool {
return hasBMI2
}
// DisableBMI2 will disable BMI2, for testing purposes.
// Call returned function to restore previous state.
func DisableBMI2() func() {
old := hasBMI2
hasBMI2 = false
return func() {
hasBMI2 = old
}
}
// HasBMI checks whether an x86 CPU supports both BMI1 and BMI2 extensions.
func HasBMI() bool {
return HasBMI1() && HasBMI2()
}
var hasBMI1 bool
var hasBMI2 bool

@ -1,11 +0,0 @@
//go:build amd64 && !appengine && !noasm && gc
// +build amd64,!appengine,!noasm,gc
package cpuinfo
// go:noescape
func x86extensions() (bmi1, bmi2 bool)
func init() {
hasBMI1, hasBMI2 = x86extensions()
}

@ -1,36 +0,0 @@
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#include "funcdata.h"
#include "go_asm.h"
TEXT ·x86extensions(SB), NOSPLIT, $0
// 1. determine max EAX value
XORQ AX, AX
CPUID
CMPQ AX, $7
JB unsupported
// 2. EAX = 7, ECX = 0 --- see Table 3-8 "Information Returned by CPUID Instruction"
MOVQ $7, AX
MOVQ $0, CX
CPUID
BTQ $3, BX // bit 3 = BMI1
SETCS AL
BTQ $8, BX // bit 8 = BMI2
SETCS AH
MOVB AL, bmi1+0(FP)
MOVB AH, bmi2+1(FP)
RET
unsupported:
XORQ AX, AX
MOVB AL, bmi1+0(FP)
MOVB AL, bmi2+1(FP)
RET

@ -1,27 +0,0 @@
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@ -1,264 +0,0 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
import (
"encoding/binary"
"errors"
"io"
)
var (
// ErrCorrupt reports that the input is invalid.
ErrCorrupt = errors.New("snappy: corrupt input")
// ErrTooLarge reports that the uncompressed length is too large.
ErrTooLarge = errors.New("snappy: decoded block is too large")
// ErrUnsupported reports that the input isn't supported.
ErrUnsupported = errors.New("snappy: unsupported input")
errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length")
)
// DecodedLen returns the length of the decoded block.
func DecodedLen(src []byte) (int, error) {
v, _, err := decodedLen(src)
return v, err
}
// decodedLen returns the length of the decoded block and the number of bytes
// that the length header occupied.
func decodedLen(src []byte) (blockLen, headerLen int, err error) {
v, n := binary.Uvarint(src)
if n <= 0 || v > 0xffffffff {
return 0, 0, ErrCorrupt
}
const wordSize = 32 << (^uint(0) >> 32 & 1)
if wordSize == 32 && v > 0x7fffffff {
return 0, 0, ErrTooLarge
}
return int(v), n, nil
}
const (
decodeErrCodeCorrupt = 1
decodeErrCodeUnsupportedLiteralLength = 2
)
// Decode returns the decoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire decoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Decode handles the Snappy block format, not the Snappy stream format.
func Decode(dst, src []byte) ([]byte, error) {
dLen, s, err := decodedLen(src)
if err != nil {
return nil, err
}
if dLen <= len(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
switch decode(dst, src[s:]) {
case 0:
return dst, nil
case decodeErrCodeUnsupportedLiteralLength:
return nil, errUnsupportedLiteralLength
}
return nil, ErrCorrupt
}
// NewReader returns a new Reader that decompresses from r, using the framing
// format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
func NewReader(r io.Reader) *Reader {
return &Reader{
r: r,
decoded: make([]byte, maxBlockSize),
buf: make([]byte, maxEncodedLenOfMaxBlockSize+checksumSize),
}
}
// Reader is an io.Reader that can read Snappy-compressed bytes.
//
// Reader handles the Snappy stream format, not the Snappy block format.
type Reader struct {
r io.Reader
err error
decoded []byte
buf []byte
// decoded[i:j] contains decoded bytes that have not yet been passed on.
i, j int
readHeader bool
}
// Reset discards any buffered data, resets all state, and switches the Snappy
// reader to read from r. This permits reusing a Reader rather than allocating
// a new one.
func (r *Reader) Reset(reader io.Reader) {
r.r = reader
r.err = nil
r.i = 0
r.j = 0
r.readHeader = false
}
func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) {
if _, r.err = io.ReadFull(r.r, p); r.err != nil {
if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) {
r.err = ErrCorrupt
}
return false
}
return true
}
func (r *Reader) fill() error {
for r.i >= r.j {
if !r.readFull(r.buf[:4], true) {
return r.err
}
chunkType := r.buf[0]
if !r.readHeader {
if chunkType != chunkTypeStreamIdentifier {
r.err = ErrCorrupt
return r.err
}
r.readHeader = true
}
chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16
if chunkLen > len(r.buf) {
r.err = ErrUnsupported
return r.err
}
// The chunk types are specified at
// https://github.com/google/snappy/blob/master/framing_format.txt
switch chunkType {
case chunkTypeCompressedData:
// Section 4.2. Compressed data (chunk type 0x00).
if chunkLen < checksumSize {
r.err = ErrCorrupt
return r.err
}
buf := r.buf[:chunkLen]
if !r.readFull(buf, false) {
return r.err
}
checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
buf = buf[checksumSize:]
n, err := DecodedLen(buf)
if err != nil {
r.err = err
return r.err
}
if n > len(r.decoded) {
r.err = ErrCorrupt
return r.err
}
if _, err := Decode(r.decoded, buf); err != nil {
r.err = err
return r.err
}
if crc(r.decoded[:n]) != checksum {
r.err = ErrCorrupt
return r.err
}
r.i, r.j = 0, n
continue
case chunkTypeUncompressedData:
// Section 4.3. Uncompressed data (chunk type 0x01).
if chunkLen < checksumSize {
r.err = ErrCorrupt
return r.err
}
buf := r.buf[:checksumSize]
if !r.readFull(buf, false) {
return r.err
}
checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24
// Read directly into r.decoded instead of via r.buf.
n := chunkLen - checksumSize
if n > len(r.decoded) {
r.err = ErrCorrupt
return r.err
}
if !r.readFull(r.decoded[:n], false) {
return r.err
}
if crc(r.decoded[:n]) != checksum {
r.err = ErrCorrupt
return r.err
}
r.i, r.j = 0, n
continue
case chunkTypeStreamIdentifier:
// Section 4.1. Stream identifier (chunk type 0xff).
if chunkLen != len(magicBody) {
r.err = ErrCorrupt
return r.err
}
if !r.readFull(r.buf[:len(magicBody)], false) {
return r.err
}
for i := 0; i < len(magicBody); i++ {
if r.buf[i] != magicBody[i] {
r.err = ErrCorrupt
return r.err
}
}
continue
}
if chunkType <= 0x7f {
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
r.err = ErrUnsupported
return r.err
}
// Section 4.4 Padding (chunk type 0xfe).
// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
if !r.readFull(r.buf[:chunkLen], false) {
return r.err
}
}
return nil
}
// Read satisfies the io.Reader interface.
func (r *Reader) Read(p []byte) (int, error) {
if r.err != nil {
return 0, r.err
}
if err := r.fill(); err != nil {
return 0, err
}
n := copy(p, r.decoded[r.i:r.j])
r.i += n
return n, nil
}
// ReadByte satisfies the io.ByteReader interface.
func (r *Reader) ReadByte() (byte, error) {
if r.err != nil {
return 0, r.err
}
if err := r.fill(); err != nil {
return 0, err
}
c := r.decoded[r.i]
r.i++
return c, nil
}

@ -1,113 +0,0 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
// decode writes the decoding of src to dst. It assumes that the varint-encoded
// length of the decompressed bytes has already been read, and that len(dst)
// equals that length.
//
// It returns 0 on success or a decodeErrCodeXxx error code on failure.
func decode(dst, src []byte) int {
var d, s, offset, length int
for s < len(src) {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-1])
case x == 61:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length <= 0 {
return decodeErrCodeUnsupportedLiteralLength
}
if length > len(dst)-d || length > len(src)-s {
return decodeErrCodeCorrupt
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 4 + int(src[s-2])>>2&0x7
offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || d < offset || length > len(dst)-d {
return decodeErrCodeCorrupt
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset >= length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
return decodeErrCodeCorrupt
}
return 0
}

@ -1,289 +0,0 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
import (
"encoding/binary"
"errors"
"io"
)
// Encode returns the encoded form of src. The returned slice may be a sub-
// slice of dst if dst was large enough to hold the entire encoded block.
// Otherwise, a newly allocated slice will be returned.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// Encode handles the Snappy block format, not the Snappy stream format.
func Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if len(dst) < n {
dst = make([]byte, n)
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
for len(src) > 0 {
p := src
src = nil
if len(p) > maxBlockSize {
p, src = p[:maxBlockSize], p[maxBlockSize:]
}
if len(p) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], p)
} else {
d += encodeBlock(dst[d:], p)
}
}
return dst[:d]
}
// inputMargin is the minimum number of extra input bytes to keep, inside
// encodeBlock's inner loop. On some architectures, this margin lets us
// implement a fast path for emitLiteral, where the copy of short (<= 16 byte)
// literals can be implemented as a single load to and store from a 16-byte
// register. That literal's actual length can be as short as 1 byte, so this
// can copy up to 15 bytes too much, but that's OK as subsequent iterations of
// the encoding loop will fix up the copy overrun, and this inputMargin ensures
// that we don't overrun the dst and src buffers.
const inputMargin = 16 - 1
// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
// could be encoded with a copy tag. This is the minimum with respect to the
// algorithm used by encodeBlock, not a minimum enforced by the file format.
//
// The encoded output must start with at least a 1 byte literal, as there are
// no previous bytes to copy. A minimal (1 byte) copy after that, generated
// from an emitCopy call in encodeBlock's main loop, would require at least
// another inputMargin bytes, for the reason above: we want any emitLiteral
// calls inside encodeBlock's main loop to use the fast path if possible, which
// requires being able to overrun by inputMargin bytes. Thus,
// minNonLiteralBlockSize equals 1 + 1 + inputMargin.
//
// The C++ code doesn't use this exact threshold, but it could, as discussed at
// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion
// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an
// optimization. It should not affect the encoded form. This is tested by
// TestSameEncodingAsCppShortCopies.
const minNonLiteralBlockSize = 1 + 1 + inputMargin
// MaxEncodedLen returns the maximum length of a snappy block, given its
// uncompressed length.
//
// It will return a negative value if srcLen is too large to encode.
func MaxEncodedLen(srcLen int) int {
n := uint64(srcLen)
if n > 0xffffffff {
return -1
}
// Compressed data can be defined as:
// compressed := item* literal*
// item := literal* copy
//
// The trailing literal sequence has a space blowup of at most 62/60
// since a literal of length 60 needs one tag byte + one extra byte
// for length information.
//
// Item blowup is trickier to measure. Suppose the "copy" op copies
// 4 bytes of data. Because of a special check in the encoding code,
// we produce a 4-byte copy only if the offset is < 65536. Therefore
// the copy op takes 3 bytes to encode, and this type of item leads
// to at most the 62/60 blowup for representing literals.
//
// Suppose the "copy" op copies 5 bytes of data. If the offset is big
// enough, it will take 5 bytes to encode the copy op. Therefore the
// worst case here is a one-byte literal followed by a five-byte copy.
// That is, 6 bytes of input turn into 7 bytes of "compressed" data.
//
// This last factor dominates the blowup, so the final estimate is:
n = 32 + n + n/6
if n > 0xffffffff {
return -1
}
return int(n)
}
var errClosed = errors.New("snappy: Writer is closed")
// NewWriter returns a new Writer that compresses to w.
//
// The Writer returned does not buffer writes. There is no need to Flush or
// Close such a Writer.
//
// Deprecated: the Writer returned is not suitable for many small writes, only
// for few large writes. Use NewBufferedWriter instead, which is efficient
// regardless of the frequency and shape of the writes, and remember to Close
// that Writer when done.
func NewWriter(w io.Writer) *Writer {
return &Writer{
w: w,
obuf: make([]byte, obufLen),
}
}
// NewBufferedWriter returns a new Writer that compresses to w, using the
// framing format described at
// https://github.com/google/snappy/blob/master/framing_format.txt
//
// The Writer returned buffers writes. Users must call Close to guarantee all
// data has been forwarded to the underlying io.Writer. They may also call
// Flush zero or more times before calling Close.
func NewBufferedWriter(w io.Writer) *Writer {
return &Writer{
w: w,
ibuf: make([]byte, 0, maxBlockSize),
obuf: make([]byte, obufLen),
}
}
// Writer is an io.Writer that can write Snappy-compressed bytes.
//
// Writer handles the Snappy stream format, not the Snappy block format.
type Writer struct {
w io.Writer
err error
// ibuf is a buffer for the incoming (uncompressed) bytes.
//
// Its use is optional. For backwards compatibility, Writers created by the
// NewWriter function have ibuf == nil, do not buffer incoming bytes, and
// therefore do not need to be Flush'ed or Close'd.
ibuf []byte
// obuf is a buffer for the outgoing (compressed) bytes.
obuf []byte
// wroteStreamHeader is whether we have written the stream header.
wroteStreamHeader bool
}
// Reset discards the writer's state and switches the Snappy writer to write to
// w. This permits reusing a Writer rather than allocating a new one.
func (w *Writer) Reset(writer io.Writer) {
w.w = writer
w.err = nil
if w.ibuf != nil {
w.ibuf = w.ibuf[:0]
}
w.wroteStreamHeader = false
}
// Write satisfies the io.Writer interface.
func (w *Writer) Write(p []byte) (nRet int, errRet error) {
if w.ibuf == nil {
// Do not buffer incoming bytes. This does not perform or compress well
// if the caller of Writer.Write writes many small slices. This
// behavior is therefore deprecated, but still supported for backwards
// compatibility with code that doesn't explicitly Flush or Close.
return w.write(p)
}
// The remainder of this method is based on bufio.Writer.Write from the
// standard library.
for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil {
var n int
if len(w.ibuf) == 0 {
// Large write, empty buffer.
// Write directly from p to avoid copy.
n, _ = w.write(p)
} else {
n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
w.ibuf = w.ibuf[:len(w.ibuf)+n]
w.Flush()
}
nRet += n
p = p[n:]
}
if w.err != nil {
return nRet, w.err
}
n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p)
w.ibuf = w.ibuf[:len(w.ibuf)+n]
nRet += n
return nRet, nil
}
func (w *Writer) write(p []byte) (nRet int, errRet error) {
if w.err != nil {
return 0, w.err
}
for len(p) > 0 {
obufStart := len(magicChunk)
if !w.wroteStreamHeader {
w.wroteStreamHeader = true
copy(w.obuf, magicChunk)
obufStart = 0
}
var uncompressed []byte
if len(p) > maxBlockSize {
uncompressed, p = p[:maxBlockSize], p[maxBlockSize:]
} else {
uncompressed, p = p, nil
}
checksum := crc(uncompressed)
// Compress the buffer, discarding the result if the improvement
// isn't at least 12.5%.
compressed := Encode(w.obuf[obufHeaderLen:], uncompressed)
chunkType := uint8(chunkTypeCompressedData)
chunkLen := 4 + len(compressed)
obufEnd := obufHeaderLen + len(compressed)
if len(compressed) >= len(uncompressed)-len(uncompressed)/8 {
chunkType = chunkTypeUncompressedData
chunkLen = 4 + len(uncompressed)
obufEnd = obufHeaderLen
}
// Fill in the per-chunk header that comes before the body.
w.obuf[len(magicChunk)+0] = chunkType
w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0)
w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8)
w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16)
w.obuf[len(magicChunk)+4] = uint8(checksum >> 0)
w.obuf[len(magicChunk)+5] = uint8(checksum >> 8)
w.obuf[len(magicChunk)+6] = uint8(checksum >> 16)
w.obuf[len(magicChunk)+7] = uint8(checksum >> 24)
if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil {
w.err = err
return nRet, err
}
if chunkType == chunkTypeUncompressedData {
if _, err := w.w.Write(uncompressed); err != nil {
w.err = err
return nRet, err
}
}
nRet += len(uncompressed)
}
return nRet, nil
}
// Flush flushes the Writer to its underlying io.Writer.
func (w *Writer) Flush() error {
if w.err != nil {
return w.err
}
if len(w.ibuf) == 0 {
return nil
}
w.write(w.ibuf)
w.ibuf = w.ibuf[:0]
return w.err
}
// Close calls Flush and then closes the Writer.
func (w *Writer) Close() error {
w.Flush()
ret := w.err
if w.err == nil {
w.err = errClosed
}
return ret
}

@ -1,236 +0,0 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package snapref
func load32(b []byte, i int) uint32 {
b = b[i : i+4 : len(b)] // Help the compiler eliminate bounds checks on the next line.
return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
}
func load64(b []byte, i int) uint64 {
b = b[i : i+8 : len(b)] // Help the compiler eliminate bounds checks on the next line.
return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 |
uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
// dst is long enough to hold the encoded bytes
// 1 <= len(lit) && len(lit) <= 65536
func emitLiteral(dst, lit []byte) int {
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[0] = 60<<2 | tagLiteral
dst[1] = uint8(n)
i = 2
default:
dst[0] = 61<<2 | tagLiteral
dst[1] = uint8(n)
dst[2] = uint8(n >> 8)
i = 3
}
return i + copy(dst[i:], lit)
}
// emitCopy writes a copy chunk and returns the number of bytes written.
//
// It assumes that:
// dst is long enough to hold the encoded bytes
// 1 <= offset && offset <= 65535
// 4 <= length && length <= 65535
func emitCopy(dst []byte, offset, length int) int {
i := 0
// The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The
// threshold for this loop is a little higher (at 68 = 64 + 4), and the
// length emitted down below is is a little lower (at 60 = 64 - 4), because
// it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed
// by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as
// a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as
// 3+3 bytes). The magic 4 in the 64±4 is because the minimum length for a
// tagCopy1 op is 4 bytes, which is why a length 3 copy has to be an
// encodes-as-3-bytes tagCopy2 instead of an encodes-as-2-bytes tagCopy1.
for length >= 68 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[i+0] = 63<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
i += 3
length -= 64
}
if length > 64 {
// Emit a length 60 copy, encoded as 3 bytes.
dst[i+0] = 59<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
i += 3
length -= 60
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy2
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
return i + 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[i+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
dst[i+1] = uint8(offset)
return i + 2
}
// extendMatch returns the largest k such that k <= len(src) and that
// src[i:i+k-j] and src[j:k] have the same contents.
//
// It assumes that:
// 0 <= i && i < j && j <= len(src)
func extendMatch(src []byte, i, j int) int {
for ; j < len(src) && src[i] == src[j]; i, j = i+1, j+1 {
}
return j
}
func hash(u, shift uint32) uint32 {
return (u * 0x1e35a7bd) >> shift
}
// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlock(dst, src []byte) (d int) {
// Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive.
// The table element type is uint16, as s < sLimit and sLimit < len(src)
// and len(src) <= maxBlockSize and maxBlockSize == 65536.
const (
maxTableSize = 1 << 14
// tableMask is redundant, but helps the compiler eliminate bounds
// checks.
tableMask = maxTableSize - 1
)
shift := uint32(32 - 8)
for tableSize := 1 << 8; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 {
shift--
}
// In Go, all array elements are zero-initialized, so there is no advantage
// to a smaller tableSize per se. However, it matches the C++ algorithm,
// and in the asm versions of this code, we can get away with zeroing only
// the first tableSize elements.
var table [maxTableSize]uint16
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
nextHash := hash(load32(src, s), shift)
for {
// Copied from the C++ snappy implementation:
//
// Heuristic match skipping: If 32 bytes are scanned with no matches
// found, start looking only at every other byte. If 32 more bytes are
// scanned (or skipped), look at every third byte, etc.. When a match
// is found, immediately go back to looking at every byte. This is a
// small loss (~5% performance, ~0.1% density) for compressible data
// due to more bookkeeping, but for non-compressible data (such as
// JPEG) it's a huge win since the compressor quickly "realizes" the
// data is incompressible and doesn't bother looking for matches
// everywhere.
//
// The "skip" variable keeps track of how many bytes there are since
// the last match; dividing it by 32 (ie. right-shifting by five) gives
// the number of bytes to move ahead for each iteration.
skip := 32
nextS := s
candidate := 0
for {
s = nextS
bytesBetweenHashLookups := skip >> 5
nextS = s + bytesBetweenHashLookups
skip += bytesBetweenHashLookups
if nextS > sLimit {
goto emitRemainder
}
candidate = int(table[nextHash&tableMask])
table[nextHash&tableMask] = uint16(s)
nextHash = hash(load32(src, nextS), shift)
if load32(src, s) == load32(src, candidate) {
break
}
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteral(dst[d:], src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
// Extend the 4-byte match as long as possible.
//
// This is an inlined version of:
// s = extendMatch(src, candidate+4, s+4)
s += 4
for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 {
}
d += emitCopy(dst[d:], base-candidate, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s. If
// another emitCopy is not our next move, also calculate nextHash
// at s+1. At least on GOARCH=amd64, these three hash calculations
// are faster as one load64 call (with some shifts) instead of
// three load32 calls.
x := load64(src, s-1)
prevHash := hash(uint32(x>>0), shift)
table[prevHash&tableMask] = uint16(s - 1)
currHash := hash(uint32(x>>8), shift)
candidate = int(table[currHash&tableMask])
table[currHash&tableMask] = uint16(s)
if uint32(x>>8) != load32(src, candidate) {
nextHash = hash(uint32(x>>16), shift)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}

@ -1,98 +0,0 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package snapref implements the Snappy compression format. It aims for very
// high speeds and reasonable compression.
//
// There are actually two Snappy formats: block and stream. They are related,
// but different: trying to decompress block-compressed data as a Snappy stream
// will fail, and vice versa. The block format is the Decode and Encode
// functions and the stream format is the Reader and Writer types.
//
// The block format, the more common case, is used when the complete size (the
// number of bytes) of the original data is known upfront, at the time
// compression starts. The stream format, also known as the framing format, is
// for when that isn't always true.
//
// The canonical, C++ implementation is at https://github.com/google/snappy and
// it only implements the block format.
package snapref
import (
"hash/crc32"
)
/*
Each encoded block begins with the varint-encoded length of the decoded data,
followed by a sequence of chunks. Chunks begin and end on byte boundaries. The
first byte of each chunk is broken into its 2 least and 6 most significant bits
called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag.
Zero means a literal tag. All other values mean a copy tag.
For literal tags:
- If m < 60, the next 1 + m bytes are literal bytes.
- Otherwise, let n be the little-endian unsigned integer denoted by the next
m - 59 bytes. The next 1 + n bytes after that are literal bytes.
For copy tags, length bytes are copied from offset bytes ago, in the style of
Lempel-Ziv compression algorithms. In particular:
- For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12).
The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10
of the offset. The next byte is bits 0-7 of the offset.
- For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65).
The length is 1 + m. The offset is the little-endian unsigned integer
denoted by the next 2 bytes.
- For l == 3, this tag is a legacy format that is no longer issued by most
encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in
[1, 65). The length is 1 + m. The offset is the little-endian unsigned
integer denoted by the next 4 bytes.
*/
const (
tagLiteral = 0x00
tagCopy1 = 0x01
tagCopy2 = 0x02
tagCopy4 = 0x03
)
const (
checksumSize = 4
chunkHeaderSize = 4
magicChunk = "\xff\x06\x00\x00" + magicBody
magicBody = "sNaPpY"
// maxBlockSize is the maximum size of the input to encodeBlock. It is not
// part of the wire format per se, but some parts of the encoder assume
// that an offset fits into a uint16.
//
// Also, for the framing format (Writer type instead of Encode function),
// https://github.com/google/snappy/blob/master/framing_format.txt says
// that "the uncompressed data in a chunk must be no longer than 65536
// bytes".
maxBlockSize = 65536
// maxEncodedLenOfMaxBlockSize equals MaxEncodedLen(maxBlockSize), but is
// hard coded to be a const instead of a variable, so that obufLen can also
// be a const. Their equivalence is confirmed by
// TestMaxEncodedLenOfMaxBlockSize.
maxEncodedLenOfMaxBlockSize = 76490
obufHeaderLen = len(magicChunk) + checksumSize + chunkHeaderSize
obufLen = obufHeaderLen + maxEncodedLenOfMaxBlockSize
)
const (
chunkTypeCompressedData = 0x00
chunkTypeUncompressedData = 0x01
chunkTypePadding = 0xfe
chunkTypeStreamIdentifier = 0xff
)
var crcTable = crc32.MakeTable(crc32.Castagnoli)
// crc implements the checksum specified in section 3 of
// https://github.com/google/snappy/blob/master/framing_format.txt
func crc(b []byte) uint32 {
c := crc32.Update(0, crcTable, b)
return uint32(c>>15|c<<17) + 0xa282ead8
}

@ -1,15 +0,0 @@
testdata/bench
# These explicitly listed benchmark data files are for an obsolete version of
# snappy_test.go.
testdata/alice29.txt
testdata/asyoulik.txt
testdata/fireworks.jpeg
testdata/geo.protodata
testdata/html
testdata/html_x_4
testdata/kppkn.gtb
testdata/lcet10.txt
testdata/paper-100k.pdf
testdata/plrabn12.txt
testdata/urls.10K

@ -1,28 +0,0 @@
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@ -1,965 +0,0 @@
# S2 Compression
S2 is an extension of [Snappy](https://github.com/google/snappy).
S2 is aimed for high throughput, which is why it features concurrent compression for bigger payloads.
Decoding is compatible with Snappy compressed content, but content compressed with S2 cannot be decompressed by Snappy.
This means that S2 can seamlessly replace Snappy without converting compressed content.
S2 can produce Snappy compatible output, faster and better than Snappy.
If you want full benefit of the changes you should use s2 without Snappy compatibility.
S2 is designed to have high throughput on content that cannot be compressed.
This is important, so you don't have to worry about spending CPU cycles on already compressed data.
## Benefits over Snappy
* Better compression
* Adjustable compression (3 levels)
* Concurrent stream compression
* Faster decompression, even for Snappy compatible content
* Concurrent Snappy/S2 stream decompression
* Ability to quickly skip forward in compressed stream
* Random seeking with indexes
* Compatible with reading Snappy compressed content
* Smaller block size overhead on incompressible blocks
* Block concatenation
* Uncompressed stream mode
* Automatic stream size padding
* Snappy compatible block compression
## Drawbacks over Snappy
* Not optimized for 32 bit systems
* Streams use slightly more memory due to larger blocks and concurrency (configurable)
# Usage
Installation: `go get -u github.com/klauspost/compress/s2`
Full package documentation:
[![godoc][1]][2]
[1]: https://godoc.org/github.com/klauspost/compress?status.svg
[2]: https://godoc.org/github.com/klauspost/compress/s2
## Compression
```Go
func EncodeStream(src io.Reader, dst io.Writer) error {
enc := s2.NewWriter(dst)
_, err := io.Copy(enc, src)
if err != nil {
enc.Close()
return err
}
// Blocks until compression is done.
return enc.Close()
}
```
You should always call `enc.Close()`, otherwise you will leak resources and your encode will be incomplete.
For the best throughput, you should attempt to reuse the `Writer` using the `Reset()` method.
The Writer in S2 is always buffered, therefore `NewBufferedWriter` in Snappy can be replaced with `NewWriter` in S2.
It is possible to flush any buffered data using the `Flush()` method.
This will block until all data sent to the encoder has been written to the output.
S2 also supports the `io.ReaderFrom` interface, which will consume all input from a reader.
As a final method to compress data, if you have a single block of data you would like to have encoded as a stream,
a slightly more efficient method is to use the `EncodeBuffer` method.
This will take ownership of the buffer until the stream is closed.
```Go
func EncodeStream(src []byte, dst io.Writer) error {
enc := s2.NewWriter(dst)
// The encoder owns the buffer until Flush or Close is called.
err := enc.EncodeBuffer(buf)
if err != nil {
enc.Close()
return err
}
// Blocks until compression is done.
return enc.Close()
}
```
Each call to `EncodeBuffer` will result in discrete blocks being created without buffering,
so it should only be used a single time per stream.
If you need to write several blocks, you should use the regular io.Writer interface.
## Decompression
```Go
func DecodeStream(src io.Reader, dst io.Writer) error {
dec := s2.NewReader(src)
_, err := io.Copy(dst, dec)
return err
}
```
Similar to the Writer, a Reader can be reused using the `Reset` method.
For the best possible throughput, there is a `EncodeBuffer(buf []byte)` function available.
However, it requires that the provided buffer isn't used after it is handed over to S2 and until the stream is flushed or closed.
For smaller data blocks, there is also a non-streaming interface: `Encode()`, `EncodeBetter()` and `Decode()`.
Do however note that these functions (similar to Snappy) does not provide validation of data,
so data corruption may be undetected. Stream encoding provides CRC checks of data.
It is possible to efficiently skip forward in a compressed stream using the `Skip()` method.
For big skips the decompressor is able to skip blocks without decompressing them.
## Single Blocks
Similar to Snappy S2 offers single block compression.
Blocks do not offer the same flexibility and safety as streams,
but may be preferable for very small payloads, less than 100K.
Using a simple `dst := s2.Encode(nil, src)` will compress `src` and return the compressed result.
It is possible to provide a destination buffer.
If the buffer has a capacity of `s2.MaxEncodedLen(len(src))` it will be used.
If not a new will be allocated.
Alternatively `EncodeBetter`/`EncodeBest` can also be used for better, but slightly slower compression.
Similarly to decompress a block you can use `dst, err := s2.Decode(nil, src)`.
Again an optional destination buffer can be supplied.
The `s2.DecodedLen(src)` can be used to get the minimum capacity needed.
If that is not satisfied a new buffer will be allocated.
Block function always operate on a single goroutine since it should only be used for small payloads.
# Commandline tools
Some very simply commandline tools are provided; `s2c` for compression and `s2d` for decompression.
Binaries can be downloaded on the [Releases Page](https://github.com/klauspost/compress/releases).
Installing then requires Go to be installed. To install them, use:
`go install github.com/klauspost/compress/s2/cmd/s2c@latest && go install github.com/klauspost/compress/s2/cmd/s2d@latest`
To build binaries to the current folder use:
`go build github.com/klauspost/compress/s2/cmd/s2c && go build github.com/klauspost/compress/s2/cmd/s2d`
## s2c
```
Usage: s2c [options] file1 file2
Compresses all files supplied as input separately.
Output files are written as 'filename.ext.s2' or 'filename.ext.snappy'.
By default output files will be overwritten.
Use - as the only file name to read from stdin and write to stdout.
Wildcards are accepted: testdir/*.txt will compress all files in testdir ending with .txt
Directories can be wildcards as well. testdir/*/*.txt will match testdir/subdir/b.txt
File names beginning with 'http://' and 'https://' will be downloaded and compressed.
Only http response code 200 is accepted.
Options:
-bench int
Run benchmark n times. No output will be written
-blocksize string
Max block size. Examples: 64K, 256K, 1M, 4M. Must be power of two and <= 4MB (default "4M")
-c Write all output to stdout. Multiple input files will be concatenated
-cpu int
Compress using this amount of threads (default 32)
-faster
Compress faster, but with a minor compression loss
-help
Display help
-index
Add seek index (default true)
-o string
Write output to another file. Single input file only
-pad string
Pad size to a multiple of this value, Examples: 500, 64K, 256K, 1M, 4M, etc (default "1")
-q Don't write any output to terminal, except errors
-rm
Delete source file(s) after successful compression
-safe
Do not overwrite output files
-slower
Compress more, but a lot slower
-snappy
Generate Snappy compatible output stream
-verify
Verify written files
```
## s2d
```
Usage: s2d [options] file1 file2
Decompresses all files supplied as input. Input files must end with '.s2' or '.snappy'.
Output file names have the extension removed. By default output files will be overwritten.
Use - as the only file name to read from stdin and write to stdout.
Wildcards are accepted: testdir/*.txt will compress all files in testdir ending with .txt
Directories can be wildcards as well. testdir/*/*.txt will match testdir/subdir/b.txt
File names beginning with 'http://' and 'https://' will be downloaded and decompressed.
Extensions on downloaded files are ignored. Only http response code 200 is accepted.
Options:
-bench int
Run benchmark n times. No output will be written
-c Write all output to stdout. Multiple input files will be concatenated
-help
Display help
-o string
Write output to another file. Single input file only
-offset string
Start at offset. Examples: 92, 64K, 256K, 1M, 4M. Requires Index
-q Don't write any output to terminal, except errors
-rm
Delete source file(s) after successful decompression
-safe
Do not overwrite output files
-tail string
Return last of compressed file. Examples: 92, 64K, 256K, 1M, 4M. Requires Index
-verify
Verify files, but do not write output
```
## s2sx: self-extracting archives
s2sx allows creating self-extracting archives with no dependencies.
By default, executables are created for the same platforms as the host os,
but this can be overridden with `-os` and `-arch` parameters.
Extracted files have 0666 permissions, except when untar option used.
```
Usage: s2sx [options] file1 file2
Compresses all files supplied as input separately.
If files have '.s2' extension they are assumed to be compressed already.
Output files are written as 'filename.s2sx' and with '.exe' for windows targets.
If output is big, an additional file with ".more" is written. This must be included as well.
By default output files will be overwritten.
Wildcards are accepted: testdir/*.txt will compress all files in testdir ending with .txt
Directories can be wildcards as well. testdir/*/*.txt will match testdir/subdir/b.txt
Options:
-arch string
Destination architecture (default "amd64")
-c Write all output to stdout. Multiple input files will be concatenated
-cpu int
Compress using this amount of threads (default 32)
-help
Display help
-max string
Maximum executable size. Rest will be written to another file. (default "1G")
-os string
Destination operating system (default "windows")
-q Don't write any output to terminal, except errors
-rm
Delete source file(s) after successful compression
-safe
Do not overwrite output files
-untar
Untar on destination
```
Available platforms are:
* darwin-amd64
* darwin-arm64
* linux-amd64
* linux-arm
* linux-arm64
* linux-mips64
* linux-ppc64le
* windows-386
* windows-amd64
By default, there is a size limit of 1GB for the output executable.
When this is exceeded the remaining file content is written to a file called
output+`.more`. This file must be included for a successful extraction and
placed alongside the executable for a successful extraction.
This file *must* have the same name as the executable, so if the executable is renamed,
so must the `.more` file.
This functionality is disabled with stdin/stdout.
### Self-extracting TAR files
If you wrap a TAR file you can specify `-untar` to make it untar on the destination host.
Files are extracted to the current folder with the path specified in the tar file.
Note that tar files are not validated before they are wrapped.
For security reasons files that move below the root folder are not allowed.
# Performance
This section will focus on comparisons to Snappy.
This package is solely aimed at replacing Snappy as a high speed compression package.
If you are mainly looking for better compression [zstandard](https://github.com/klauspost/compress/tree/master/zstd#zstd)
gives better compression, but typically at speeds slightly below "better" mode in this package.
Compression is increased compared to Snappy, mostly around 5-20% and the throughput is typically 25-40% increased (single threaded) compared to the Snappy Go implementation.
Streams are concurrently compressed. The stream will be distributed among all available CPU cores for the best possible throughput.
A "better" compression mode is also available. This allows to trade a bit of speed for a minor compression gain.
The content compressed in this mode is fully compatible with the standard decoder.
Snappy vs S2 **compression** speed on 16 core (32 thread) computer, using all threads and a single thread (1 CPU):
| File | S2 speed | S2 Throughput | S2 % smaller | S2 "better" | "better" throughput | "better" % smaller |
|-----------------------------------------------------------------------------------------------------|----------|---------------|--------------|-------------|---------------------|--------------------|
| [rawstudio-mint14.tar](https://files.klauspost.com/compress/rawstudio-mint14.7z) | 12.70x | 10556 MB/s | 7.35% | 4.15x | 3455 MB/s | 12.79% |
| (1 CPU) | 1.14x | 948 MB/s | - | 0.42x | 349 MB/s | - |
| [github-june-2days-2019.json](https://files.klauspost.com/compress/github-june-2days-2019.json.zst) | 17.13x | 14484 MB/s | 31.60% | 10.09x | 8533 MB/s | 37.71% |
| (1 CPU) | 1.33x | 1127 MB/s | - | 0.70x | 589 MB/s | - |
| [github-ranks-backup.bin](https://files.klauspost.com/compress/github-ranks-backup.bin.zst) | 15.14x | 12000 MB/s | -5.79% | 6.59x | 5223 MB/s | 5.80% |
| (1 CPU) | 1.11x | 877 MB/s | - | 0.47x | 370 MB/s | - |
| [consensus.db.10gb](https://files.klauspost.com/compress/consensus.db.10gb.zst) | 14.62x | 12116 MB/s | 15.90% | 5.35x | 4430 MB/s | 16.08% |
| (1 CPU) | 1.38x | 1146 MB/s | - | 0.38x | 312 MB/s | - |
| [adresser.json](https://files.klauspost.com/compress/adresser.json.zst) | 8.83x | 17579 MB/s | 43.86% | 6.54x | 13011 MB/s | 47.23% |
| (1 CPU) | 1.14x | 2259 MB/s | - | 0.74x | 1475 MB/s | - |
| [gob-stream](https://files.klauspost.com/compress/gob-stream.7z) | 16.72x | 14019 MB/s | 24.02% | 10.11x | 8477 MB/s | 30.48% |
| (1 CPU) | 1.24x | 1043 MB/s | - | 0.70x | 586 MB/s | - |
| [10gb.tar](http://mattmahoney.net/dc/10gb.html) | 13.33x | 9254 MB/s | 1.84% | 6.75x | 4686 MB/s | 6.72% |
| (1 CPU) | 0.97x | 672 MB/s | - | 0.53x | 366 MB/s | - |
| sharnd.out.2gb | 2.11x | 12639 MB/s | 0.01% | 1.98x | 11833 MB/s | 0.01% |
| (1 CPU) | 0.93x | 5594 MB/s | - | 1.34x | 8030 MB/s | - |
| [enwik9](http://mattmahoney.net/dc/textdata.html) | 19.34x | 8220 MB/s | 3.98% | 7.87x | 3345 MB/s | 15.82% |
| (1 CPU) | 1.06x | 452 MB/s | - | 0.50x | 213 MB/s | - |
| [silesia.tar](http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip) | 10.48x | 6124 MB/s | 5.67% | 3.76x | 2197 MB/s | 12.60% |
| (1 CPU) | 0.97x | 568 MB/s | - | 0.46x | 271 MB/s | - |
| [enwik10](https://encode.su/threads/3315-enwik10-benchmark-results) | 21.07x | 9020 MB/s | 6.36% | 6.91x | 2959 MB/s | 16.95% |
| (1 CPU) | 1.07x | 460 MB/s | - | 0.51x | 220 MB/s | - |
### Legend
* `S2 speed`: Speed of S2 compared to Snappy, using 16 cores and 1 core.
* `S2 throughput`: Throughput of S2 in MB/s.
* `S2 % smaller`: How many percent of the Snappy output size is S2 better.
* `S2 "better"`: Speed when enabling "better" compression mode in S2 compared to Snappy.
* `"better" throughput`: Speed when enabling "better" compression mode in S2 compared to Snappy.
* `"better" % smaller`: How many percent of the Snappy output size is S2 better when using "better" compression.
There is a good speedup across the board when using a single thread and a significant speedup when using multiple threads.
Machine generated data gets by far the biggest compression boost, with size being being reduced by up to 45% of Snappy size.
The "better" compression mode sees a good improvement in all cases, but usually at a performance cost.
Incompressible content (`sharnd.out.2gb`, 2GB random data) sees the smallest speedup.
This is likely dominated by synchronization overhead, which is confirmed by the fact that single threaded performance is higher (see above).
## Decompression
S2 attempts to create content that is also fast to decompress, except in "better" mode where the smallest representation is used.
S2 vs Snappy **decompression** speed. Both operating on single core:
| File | S2 Throughput | vs. Snappy | Better Throughput | vs. Snappy |
|-----------------------------------------------------------------------------------------------------|---------------|------------|-------------------|------------|
| [rawstudio-mint14.tar](https://files.klauspost.com/compress/rawstudio-mint14.7z) | 2117 MB/s | 1.14x | 1738 MB/s | 0.94x |
| [github-june-2days-2019.json](https://files.klauspost.com/compress/github-june-2days-2019.json.zst) | 2401 MB/s | 1.25x | 2307 MB/s | 1.20x |
| [github-ranks-backup.bin](https://files.klauspost.com/compress/github-ranks-backup.bin.zst) | 2075 MB/s | 0.98x | 1764 MB/s | 0.83x |
| [consensus.db.10gb](https://files.klauspost.com/compress/consensus.db.10gb.zst) | 2967 MB/s | 1.05x | 2885 MB/s | 1.02x |
| [adresser.json](https://files.klauspost.com/compress/adresser.json.zst) | 4141 MB/s | 1.07x | 4184 MB/s | 1.08x |
| [gob-stream](https://files.klauspost.com/compress/gob-stream.7z) | 2264 MB/s | 1.12x | 2185 MB/s | 1.08x |
| [10gb.tar](http://mattmahoney.net/dc/10gb.html) | 1525 MB/s | 1.03x | 1347 MB/s | 0.91x |
| sharnd.out.2gb | 3813 MB/s | 0.79x | 3900 MB/s | 0.81x |
| [enwik9](http://mattmahoney.net/dc/textdata.html) | 1246 MB/s | 1.29x | 967 MB/s | 1.00x |
| [silesia.tar](http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip) | 1433 MB/s | 1.12x | 1203 MB/s | 0.94x |
| [enwik10](https://encode.su/threads/3315-enwik10-benchmark-results) | 1284 MB/s | 1.32x | 1010 MB/s | 1.04x |
### Legend
* `S2 Throughput`: Decompression speed of S2 encoded content.
* `Better Throughput`: Decompression speed of S2 "better" encoded content.
* `vs Snappy`: Decompression speed of S2 "better" mode compared to Snappy and absolute speed.
While the decompression code hasn't changed, there is a significant speedup in decompression speed.
S2 prefers longer matches and will typically only find matches that are 6 bytes or longer.
While this reduces compression a bit, it improves decompression speed.
The "better" compression mode will actively look for shorter matches, which is why it has a decompression speed quite similar to Snappy.
Without assembly decompression is also very fast; single goroutine decompression speed. No assembly:
| File | S2 Throughput | S2 throughput |
|--------------------------------|--------------|---------------|
| consensus.db.10gb.s2 | 1.84x | 2289.8 MB/s |
| 10gb.tar.s2 | 1.30x | 867.07 MB/s |
| rawstudio-mint14.tar.s2 | 1.66x | 1329.65 MB/s |
| github-june-2days-2019.json.s2 | 2.36x | 1831.59 MB/s |
| github-ranks-backup.bin.s2 | 1.73x | 1390.7 MB/s |
| enwik9.s2 | 1.67x | 681.53 MB/s |
| adresser.json.s2 | 3.41x | 4230.53 MB/s |
| silesia.tar.s2 | 1.52x | 811.58 |
Even though S2 typically compresses better than Snappy, decompression speed is always better.
### Concurrent Stream Decompression
For full stream decompression S2 offers a [DecodeConcurrent](https://pkg.go.dev/github.com/klauspost/compress/s2#Reader.DecodeConcurrent)
that will decode a full stream using multiple goroutines.
Example scaling, AMD Ryzen 3950X, 16 cores, decompression using `s2d -bench=3 <input>`, best of 3:
| Input | `-cpu=1` | `-cpu=2` | `-cpu=4` | `-cpu=8` | `-cpu=16` |
|-------------------------------------------|------------|------------|------------|------------|-------------|
| enwik10.snappy | 1098.6MB/s | 1819.8MB/s | 3625.6MB/s | 6910.6MB/s | 10818.2MB/s |
| enwik10.s2 | 1303.5MB/s | 2606.1MB/s | 4847.9MB/s | 8878.4MB/s | 9592.1MB/s |
| sofia-air-quality-dataset.tar.snappy | 1302.0MB/s | 2165.0MB/s | 4244.5MB/s | 8241.0MB/s | 12920.5MB/s |
| sofia-air-quality-dataset.tar.s2 | 1399.2MB/s | 2463.2MB/s | 5196.5MB/s | 9639.8MB/s | 11439.5MB/s |
| sofia-air-quality-dataset.tar.s2 (no asm) | 837.5MB/s | 1652.6MB/s | 3183.6MB/s | 5945.0MB/s | 9620.7MB/s |
Scaling can be expected to be pretty linear until memory bandwidth is saturated.
For now the DecodeConcurrent can only be used for full streams without seeking or combining with regular reads.
## Block compression
When compressing blocks no concurrent compression is performed just as Snappy.
This is because blocks are for smaller payloads and generally will not benefit from concurrent compression.
An important change is that incompressible blocks will not be more than at most 10 bytes bigger than the input.
In rare, worst case scenario Snappy blocks could be significantly bigger than the input.
### Mixed content blocks
The most reliable is a wide dataset.
For this we use [`webdevdata.org-2015-01-07-subset`](https://files.klauspost.com/compress/webdevdata.org-2015-01-07-4GB-subset.7z),
53927 files, total input size: 4,014,735,833 bytes. Single goroutine used.
| * | Input | Output | Reduction | MB/s |
|-------------------|------------|------------|-----------|--------|
| S2 | 4014735833 | 1059723369 | 73.60% | **934.34** |
| S2 Better | 4014735833 | 969670507 | 75.85% | 532.70 |
| S2 Best | 4014735833 | 906625668 | **77.85%** | 46.84 |
| Snappy | 4014735833 | 1128706759 | 71.89% | 762.59 |
| S2, Snappy Output | 4014735833 | 1093821420 | 72.75% | 908.60 |
| LZ4 | 4014735833 | 1079259294 | 73.12% | 526.94 |
S2 delivers both the best single threaded throughput with regular mode and the best compression rate with "best".
"Better" mode provides the same compression speed as LZ4 with better compression ratio.
When outputting Snappy compatible output it still delivers better throughput (150MB/s more) and better compression.
As can be seen from the other benchmarks decompression should also be easier on the S2 generated output.
Though they cannot be compared due to different decompression speeds here are the speed/size comparisons for
other Go compressors:
| * | Input | Output | Reduction | MB/s |
|-------------------|------------|------------|-----------|--------|
| Zstd Fastest (Go) | 4014735833 | 794608518 | 80.21% | 236.04 |
| Zstd Best (Go) | 4014735833 | 704603356 | 82.45% | 35.63 |
| Deflate (Go) l1 | 4014735833 | 871294239 | 78.30% | 214.04 |
| Deflate (Go) l9 | 4014735833 | 730389060 | 81.81% | 41.17 |
### Standard block compression
Benchmarking single block performance is subject to a lot more variation since it only tests a limited number of file patterns.
So individual benchmarks should only be seen as a guideline and the overall picture is more important.
These micro-benchmarks are with data in cache and trained branch predictors. For a more realistic benchmark see the mixed content above.
Block compression. Parallel benchmark running on 16 cores, 16 goroutines.
AMD64 assembly is use for both S2 and Snappy.
| Absolute Perf | Snappy size | S2 Size | Snappy Speed | S2 Speed | Snappy dec | S2 dec |
|-----------------------|-------------|---------|--------------|-------------|-------------|-------------|
| html | 22843 | 21111 | 16246 MB/s | 17438 MB/s | 40972 MB/s | 49263 MB/s |
| urls.10K | 335492 | 287326 | 7943 MB/s | 9693 MB/s | 22523 MB/s | 26484 MB/s |
| fireworks.jpeg | 123034 | 123100 | 349544 MB/s | 273889 MB/s | 718321 MB/s | 827552 MB/s |
| fireworks.jpeg (200B) | 146 | 155 | 8869 MB/s | 17773 MB/s | 33691 MB/s | 52421 MB/s |
| paper-100k.pdf | 85304 | 84459 | 167546 MB/s | 101263 MB/s | 326905 MB/s | 291944 MB/s |
| html_x_4 | 92234 | 21113 | 15194 MB/s | 50670 MB/s | 30843 MB/s | 32217 MB/s |
| alice29.txt | 88034 | 85975 | 5936 MB/s | 6139 MB/s | 12882 MB/s | 20044 MB/s |
| asyoulik.txt | 77503 | 79650 | 5517 MB/s | 6366 MB/s | 12735 MB/s | 22806 MB/s |
| lcet10.txt | 234661 | 220670 | 6235 MB/s | 6067 MB/s | 14519 MB/s | 18697 MB/s |
| plrabn12.txt | 319267 | 317985 | 5159 MB/s | 5726 MB/s | 11923 MB/s | 19901 MB/s |
| geo.protodata | 23335 | 18690 | 21220 MB/s | 26529 MB/s | 56271 MB/s | 62540 MB/s |
| kppkn.gtb | 69526 | 65312 | 9732 MB/s | 8559 MB/s | 18491 MB/s | 18969 MB/s |
| alice29.txt (128B) | 80 | 82 | 6691 MB/s | 15489 MB/s | 31883 MB/s | 38874 MB/s |
| alice29.txt (1000B) | 774 | 774 | 12204 MB/s | 13000 MB/s | 48056 MB/s | 52341 MB/s |
| alice29.txt (10000B) | 6648 | 6933 | 10044 MB/s | 12806 MB/s | 32378 MB/s | 46322 MB/s |
| alice29.txt (20000B) | 12686 | 13574 | 7733 MB/s | 11210 MB/s | 30566 MB/s | 58969 MB/s |
| Relative Perf | Snappy size | S2 size improved | S2 Speed | S2 Dec Speed |
|-----------------------|-------------|------------------|----------|--------------|
| html | 22.31% | 7.58% | 1.07x | 1.20x |
| urls.10K | 47.78% | 14.36% | 1.22x | 1.18x |
| fireworks.jpeg | 99.95% | -0.05% | 0.78x | 1.15x |
| fireworks.jpeg (200B) | 73.00% | -6.16% | 2.00x | 1.56x |
| paper-100k.pdf | 83.30% | 0.99% | 0.60x | 0.89x |
| html_x_4 | 22.52% | 77.11% | 3.33x | 1.04x |
| alice29.txt | 57.88% | 2.34% | 1.03x | 1.56x |
| asyoulik.txt | 61.91% | -2.77% | 1.15x | 1.79x |
| lcet10.txt | 54.99% | 5.96% | 0.97x | 1.29x |
| plrabn12.txt | 66.26% | 0.40% | 1.11x | 1.67x |
| geo.protodata | 19.68% | 19.91% | 1.25x | 1.11x |
| kppkn.gtb | 37.72% | 6.06% | 0.88x | 1.03x |
| alice29.txt (128B) | 62.50% | -2.50% | 2.31x | 1.22x |
| alice29.txt (1000B) | 77.40% | 0.00% | 1.07x | 1.09x |
| alice29.txt (10000B) | 66.48% | -4.29% | 1.27x | 1.43x |
| alice29.txt (20000B) | 63.43% | -7.00% | 1.45x | 1.93x |
Speed is generally at or above Snappy. Small blocks gets a significant speedup, although at the expense of size.
Decompression speed is better than Snappy, except in one case.
Since payloads are very small the variance in terms of size is rather big, so they should only be seen as a general guideline.
Size is on average around Snappy, but varies on content type.
In cases where compression is worse, it usually is compensated by a speed boost.
### Better compression
Benchmarking single block performance is subject to a lot more variation since it only tests a limited number of file patterns.
So individual benchmarks should only be seen as a guideline and the overall picture is more important.
| Absolute Perf | Snappy size | Better Size | Snappy Speed | Better Speed | Snappy dec | Better dec |
|-----------------------|-------------|-------------|--------------|--------------|-------------|-------------|
| html | 22843 | 19833 | 16246 MB/s | 7731 MB/s | 40972 MB/s | 40292 MB/s |
| urls.10K | 335492 | 253529 | 7943 MB/s | 3980 MB/s | 22523 MB/s | 20981 MB/s |
| fireworks.jpeg | 123034 | 123100 | 349544 MB/s | 9760 MB/s | 718321 MB/s | 823698 MB/s |
| fireworks.jpeg (200B) | 146 | 142 | 8869 MB/s | 594 MB/s | 33691 MB/s | 30101 MB/s |
| paper-100k.pdf | 85304 | 82915 | 167546 MB/s | 7470 MB/s | 326905 MB/s | 198869 MB/s |
| html_x_4 | 92234 | 19841 | 15194 MB/s | 23403 MB/s | 30843 MB/s | 30937 MB/s |
| alice29.txt | 88034 | 73218 | 5936 MB/s | 2945 MB/s | 12882 MB/s | 16611 MB/s |
| asyoulik.txt | 77503 | 66844 | 5517 MB/s | 2739 MB/s | 12735 MB/s | 14975 MB/s |
| lcet10.txt | 234661 | 190589 | 6235 MB/s | 3099 MB/s | 14519 MB/s | 16634 MB/s |
| plrabn12.txt | 319267 | 270828 | 5159 MB/s | 2600 MB/s | 11923 MB/s | 13382 MB/s |
| geo.protodata | 23335 | 18278 | 21220 MB/s | 11208 MB/s | 56271 MB/s | 57961 MB/s |
| kppkn.gtb | 69526 | 61851 | 9732 MB/s | 4556 MB/s | 18491 MB/s | 16524 MB/s |
| alice29.txt (128B) | 80 | 81 | 6691 MB/s | 529 MB/s | 31883 MB/s | 34225 MB/s |
| alice29.txt (1000B) | 774 | 748 | 12204 MB/s | 1943 MB/s | 48056 MB/s | 42068 MB/s |
| alice29.txt (10000B) | 6648 | 6234 | 10044 MB/s | 2949 MB/s | 32378 MB/s | 28813 MB/s |
| alice29.txt (20000B) | 12686 | 11584 | 7733 MB/s | 2822 MB/s | 30566 MB/s | 27315 MB/s |
| Relative Perf | Snappy size | Better size | Better Speed | Better dec |
|-----------------------|-------------|-------------|--------------|------------|
| html | 22.31% | 13.18% | 0.48x | 0.98x |
| urls.10K | 47.78% | 24.43% | 0.50x | 0.93x |
| fireworks.jpeg | 99.95% | -0.05% | 0.03x | 1.15x |
| fireworks.jpeg (200B) | 73.00% | 2.74% | 0.07x | 0.89x |
| paper-100k.pdf | 83.30% | 2.80% | 0.07x | 0.61x |
| html_x_4 | 22.52% | 78.49% | 0.04x | 1.00x |
| alice29.txt | 57.88% | 16.83% | 1.54x | 1.29x |
| asyoulik.txt | 61.91% | 13.75% | 0.50x | 1.18x |
| lcet10.txt | 54.99% | 18.78% | 0.50x | 1.15x |
| plrabn12.txt | 66.26% | 15.17% | 0.50x | 1.12x |
| geo.protodata | 19.68% | 21.67% | 0.50x | 1.03x |
| kppkn.gtb | 37.72% | 11.04% | 0.53x | 0.89x |
| alice29.txt (128B) | 62.50% | -1.25% | 0.47x | 1.07x |
| alice29.txt (1000B) | 77.40% | 3.36% | 0.08x | 0.88x |
| alice29.txt (10000B) | 66.48% | 6.23% | 0.16x | 0.89x |
| alice29.txt (20000B) | 63.43% | 8.69% | 0.29x | 0.89x |
Except for the mostly incompressible JPEG image compression is better and usually in the
double digits in terms of percentage reduction over Snappy.
The PDF sample shows a significant slowdown compared to Snappy, as this mode tries harder
to compress the data. Very small blocks are also not favorable for better compression, so throughput is way down.
This mode aims to provide better compression at the expense of performance and achieves that
without a huge performance penalty, except on very small blocks.
Decompression speed suffers a little compared to the regular S2 mode,
but still manages to be close to Snappy in spite of increased compression.
# Best compression mode
S2 offers a "best" compression mode.
This will compress as much as possible with little regard to CPU usage.
Mainly for offline compression, but where decompression speed should still
be high and compatible with other S2 compressed data.
Some examples compared on 16 core CPU, amd64 assembly used:
```
* enwik10
Default... 10000000000 -> 4761467548 [47.61%]; 1.098s, 8685.6MB/s
Better... 10000000000 -> 4219438251 [42.19%]; 1.925s, 4954.2MB/s
Best... 10000000000 -> 3627364337 [36.27%]; 43.051s, 221.5MB/s
* github-june-2days-2019.json
Default... 6273951764 -> 1043196283 [16.63%]; 431ms, 13882.3MB/s
Better... 6273951764 -> 949146808 [15.13%]; 547ms, 10938.4MB/s
Best... 6273951764 -> 832855506 [13.27%]; 9.455s, 632.8MB/s
* nyc-taxi-data-10M.csv
Default... 3325605752 -> 1095998837 [32.96%]; 324ms, 9788.7MB/s
Better... 3325605752 -> 954776589 [28.71%]; 491ms, 6459.4MB/s
Best... 3325605752 -> 779098746 [23.43%]; 8.29s, 382.6MB/s
* 10gb.tar
Default... 10065157632 -> 5916578242 [58.78%]; 1.028s, 9337.4MB/s
Better... 10065157632 -> 5649207485 [56.13%]; 1.597s, 6010.6MB/s
Best... 10065157632 -> 5208719802 [51.75%]; 32.78s, 292.8MB/
* consensus.db.10gb
Default... 10737418240 -> 4562648848 [42.49%]; 882ms, 11610.0MB/s
Better... 10737418240 -> 4542428129 [42.30%]; 1.533s, 6679.7MB/s
Best... 10737418240 -> 4244773384 [39.53%]; 42.96s, 238.4MB/s
```
Decompression speed should be around the same as using the 'better' compression mode.
# Snappy Compatibility
S2 now offers full compatibility with Snappy.
This means that the efficient encoders of S2 can be used to generate fully Snappy compatible output.
There is a [snappy](https://github.com/klauspost/compress/tree/master/snappy) package that can be used by
simply changing imports from `github.com/golang/snappy` to `github.com/klauspost/compress/snappy`.
This uses "better" mode for all operations.
If you would like more control, you can use the s2 package as described below:
## Blocks
Snappy compatible blocks can be generated with the S2 encoder.
Compression and speed is typically a bit better `MaxEncodedLen` is also smaller for smaller memory usage. Replace
| Snappy | S2 replacement |
|----------------------------|-------------------------|
| snappy.Encode(...) | s2.EncodeSnappy(...) |
| snappy.MaxEncodedLen(...) | s2.MaxEncodedLen(...) |
`s2.EncodeSnappy` can be replaced with `s2.EncodeSnappyBetter` or `s2.EncodeSnappyBest` to get more efficiently compressed snappy compatible output.
`s2.ConcatBlocks` is compatible with snappy blocks.
Comparison of [`webdevdata.org-2015-01-07-subset`](https://files.klauspost.com/compress/webdevdata.org-2015-01-07-4GB-subset.7z),
53927 files, total input size: 4,014,735,833 bytes. amd64, single goroutine used:
| Encoder | Size | MB/s | Reduction |
|-----------------------|------------|------------|------------
| snappy.Encode | 1128706759 | 725.59 | 71.89% |
| s2.EncodeSnappy | 1093823291 | **899.16** | 72.75% |
| s2.EncodeSnappyBetter | 1001158548 | 578.49 | 75.06% |
| s2.EncodeSnappyBest | 944507998 | 66.00 | **76.47%**|
## Streams
For streams, replace `enc = snappy.NewBufferedWriter(w)` with `enc = s2.NewWriter(w, s2.WriterSnappyCompat())`.
All other options are available, but note that block size limit is different for snappy.
Comparison of different streams, AMD Ryzen 3950x, 16 cores. Size and throughput:
| File | snappy.NewWriter | S2 Snappy | S2 Snappy, Better | S2 Snappy, Best |
|-----------------------------|--------------------------|---------------------------|--------------------------|-------------------------|
| nyc-taxi-data-10M.csv | 1316042016 - 539.47MB/s | 1307003093 - 10132.73MB/s | 1174534014 - 5002.44MB/s | 1115904679 - 177.97MB/s |
| enwik10 (xml) | 5088294643 - 451.13MB/s | 5175840939 - 9440.69MB/s | 4560784526 - 4487.21MB/s | 4340299103 - 158.92MB/s |
| 10gb.tar (mixed) | 6056946612 - 729.73MB/s | 6208571995 - 9978.05MB/s | 5741646126 - 4919.98MB/s | 5548973895 - 180.44MB/s |
| github-june-2days-2019.json | 1525176492 - 933.00MB/s | 1476519054 - 13150.12MB/s | 1400547532 - 5803.40MB/s | 1321887137 - 204.29MB/s |
| consensus.db.10gb (db) | 5412897703 - 1102.14MB/s | 5354073487 - 13562.91MB/s | 5335069899 - 5294.73MB/s | 5201000954 - 175.72MB/s |
# Decompression
All decompression functions map directly to equivalent s2 functions.
| Snappy | S2 replacement |
|------------------------|--------------------|
| snappy.Decode(...) | s2.Decode(...) |
| snappy.DecodedLen(...) | s2.DecodedLen(...) |
| snappy.NewReader(...) | s2.NewReader(...) |
Features like [quick forward skipping without decompression](https://pkg.go.dev/github.com/klauspost/compress/s2#Reader.Skip)
are also available for Snappy streams.
If you know you are only decompressing snappy streams, setting [`ReaderMaxBlockSize(64<<10)`](https://pkg.go.dev/github.com/klauspost/compress/s2#ReaderMaxBlockSize)
on your Reader will reduce memory consumption.
# Concatenating blocks and streams.
Concatenating streams will concatenate the output of both without recompressing them.
While this is inefficient in terms of compression it might be usable in certain scenarios.
The 10 byte 'stream identifier' of the second stream can optionally be stripped, but it is not a requirement.
Blocks can be concatenated using the `ConcatBlocks` function.
Snappy blocks/streams can safely be concatenated with S2 blocks and streams.
Streams with indexes (see below) will currently not work on concatenated streams.
# Stream Seek Index
S2 and Snappy streams can have indexes. These indexes will allow random seeking within the compressed data.
The index can either be appended to the stream as a skippable block or returned for separate storage.
When the index is appended to a stream it will be skipped by regular decoders,
so the output remains compatible with other decoders.
## Creating an Index
To automatically add an index to a stream, add `WriterAddIndex()` option to your writer.
Then the index will be added to the stream when `Close()` is called.
```
// Add Index to stream...
enc := s2.NewWriter(w, s2.WriterAddIndex())
io.Copy(enc, r)
enc.Close()
```
If you want to store the index separately, you can use `CloseIndex()` instead of the regular `Close()`.
This will return the index. Note that `CloseIndex()` should only be called once, and you shouldn't call `Close()`.
```
// Get index for separate storage...
enc := s2.NewWriter(w)
io.Copy(enc, r)
index, err := enc.CloseIndex()
```
The `index` can then be used needing to read from the stream.
This means the index can be used without needing to seek to the end of the stream
or for manually forwarding streams. See below.
Finally, an existing S2/Snappy stream can be indexed using the `s2.IndexStream(r io.Reader)` function.
## Using Indexes
To use indexes there is a `ReadSeeker(random bool, index []byte) (*ReadSeeker, error)` function available.
Calling ReadSeeker will return an [io.ReadSeeker](https://pkg.go.dev/io#ReadSeeker) compatible version of the reader.
If 'random' is specified the returned io.Seeker can be used for random seeking, otherwise only forward seeking is supported.
Enabling random seeking requires the original input to support the [io.Seeker](https://pkg.go.dev/io#Seeker) interface.
```
dec := s2.NewReader(r)
rs, err := dec.ReadSeeker(false, nil)
rs.Seek(wantOffset, io.SeekStart)
```
Get a seeker to seek forward. Since no index is provided, the index is read from the stream.
This requires that an index was added and that `r` supports the [io.Seeker](https://pkg.go.dev/io#Seeker) interface.
A custom index can be specified which will be used if supplied.
When using a custom index, it will not be read from the input stream.
```
dec := s2.NewReader(r)
rs, err := dec.ReadSeeker(false, index)
rs.Seek(wantOffset, io.SeekStart)
```
This will read the index from `index`. Since we specify non-random (forward only) seeking `r` does not have to be an io.Seeker
```
dec := s2.NewReader(r)
rs, err := dec.ReadSeeker(true, index)
rs.Seek(wantOffset, io.SeekStart)
```
Finally, since we specify that we want to do random seeking `r` must be an io.Seeker.
The returned [ReadSeeker](https://pkg.go.dev/github.com/klauspost/compress/s2#ReadSeeker) contains a shallow reference to the existing Reader,
meaning changes performed to one is reflected in the other.
To check if a stream contains an index at the end, the `(*Index).LoadStream(rs io.ReadSeeker) error` can be used.
## Manually Forwarding Streams
Indexes can also be read outside the decoder using the [Index](https://pkg.go.dev/github.com/klauspost/compress/s2#Index) type.
This can be used for parsing indexes, either separate or in streams.
In some cases it may not be possible to serve a seekable stream.
This can for instance be an HTTP stream, where the Range request
is sent at the start of the stream.
With a little bit of extra code it is still possible to use indexes
to forward to specific offset with a single forward skip.
It is possible to load the index manually like this:
```
var index s2.Index
_, err = index.Load(idxBytes)
```
This can be used to figure out how much to offset the compressed stream:
```
compressedOffset, uncompressedOffset, err := index.Find(wantOffset)
```
The `compressedOffset` is the number of bytes that should be skipped
from the beginning of the compressed file.
The `uncompressedOffset` will then be offset of the uncompressed bytes returned
when decoding from that position. This will always be <= wantOffset.
When creating a decoder it must be specified that it should *not* expect a stream identifier
at the beginning of the stream. Assuming the io.Reader `r` has been forwarded to `compressedOffset`
we create the decoder like this:
```
dec := s2.NewReader(r, s2.ReaderIgnoreStreamIdentifier())
```
We are not completely done. We still need to forward the stream the uncompressed bytes we didn't want.
This is done using the regular "Skip" function:
```
err = dec.Skip(wantOffset - uncompressedOffset)
```
This will ensure that we are at exactly the offset we want, and reading from `dec` will start at the requested offset.
## Index Format:
Each block is structured as a snappy skippable block, with the chunk ID 0x99.
The block can be read from the front, but contains information so it can be read from the back as well.
Numbers are stored as fixed size little endian values or [zigzag encoded](https://developers.google.com/protocol-buffers/docs/encoding#signed_integers) [base 128 varints](https://developers.google.com/protocol-buffers/docs/encoding),
with un-encoded value length of 64 bits, unless other limits are specified.
| Content | Format |
|---------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------|
| ID, `[1]byte` | Always 0x99. |
| Data Length, `[3]byte` | 3 byte little-endian length of the chunk in bytes, following this. |
| Header `[6]byte` | Header, must be `[115, 50, 105, 100, 120, 0]` or in text: "s2idx\x00". |
| UncompressedSize, Varint | Total Uncompressed size. |
| CompressedSize, Varint | Total Compressed size if known. Should be -1 if unknown. |
| EstBlockSize, Varint | Block Size, used for guessing uncompressed offsets. Must be >= 0. |
| Entries, Varint | Number of Entries in index, must be < 65536 and >=0. |
| HasUncompressedOffsets `byte` | 0 if no uncompressed offsets are present, 1 if present. Other values are invalid. |
| UncompressedOffsets, [Entries]VarInt | Uncompressed offsets. See below how to decode. |
| CompressedOffsets, [Entries]VarInt | Compressed offsets. See below how to decode. |
| Block Size, `[4]byte` | Little Endian total encoded size (including header and trailer). Can be used for searching backwards to start of block. |
| Trailer `[6]byte` | Trailer, must be `[0, 120, 100, 105, 50, 115]` or in text: "\x00xdi2s". Can be used for identifying block from end of stream. |
For regular streams the uncompressed offsets are fully predictable,
so `HasUncompressedOffsets` allows to specify that compressed blocks all have
exactly `EstBlockSize` bytes of uncompressed content.
Entries *must* be in order, starting with the lowest offset,
and there *must* be no uncompressed offset duplicates.
Entries *may* point to the start of a skippable block,
but it is then not allowed to also have an entry for the next block since
that would give an uncompressed offset duplicate.
There is no requirement for all blocks to be represented in the index.
In fact there is a maximum of 65536 block entries in an index.
The writer can use any method to reduce the number of entries.
An implicit block start at 0,0 can be assumed.
### Decoding entries:
```
// Read Uncompressed entries.
// Each assumes EstBlockSize delta from previous.
for each entry {
uOff = 0
if HasUncompressedOffsets == 1 {
uOff = ReadVarInt // Read value from stream
}
// Except for the first entry, use previous values.
if entryNum == 0 {
entry[entryNum].UncompressedOffset = uOff
continue
}
// Uncompressed uses previous offset and adds EstBlockSize
entry[entryNum].UncompressedOffset = entry[entryNum-1].UncompressedOffset + EstBlockSize + uOff
}
// Guess that the first block will be 50% of uncompressed size.
// Integer truncating division must be used.
CompressGuess := EstBlockSize / 2
// Read Compressed entries.
// Each assumes CompressGuess delta from previous.
// CompressGuess is adjusted for each value.
for each entry {
cOff = ReadVarInt // Read value from stream
// Except for the first entry, use previous values.
if entryNum == 0 {
entry[entryNum].CompressedOffset = cOff
continue
}
// Compressed uses previous and our estimate.
entry[entryNum].CompressedOffset = entry[entryNum-1].CompressedOffset + CompressGuess + cOff
// Adjust compressed offset for next loop, integer truncating division must be used.
CompressGuess += cOff/2
}
```
To decode from any given uncompressed offset `(wantOffset)`:
* Iterate entries until `entry[n].UncompressedOffset > wantOffset`.
* Start decoding from `entry[n-1].CompressedOffset`.
* Discard `entry[n-1].UncompressedOffset - wantOffset` bytes from the decoded stream.
See [using indexes](https://github.com/klauspost/compress/tree/master/s2#using-indexes) for functions that perform the operations with a simpler interface.
# Format Extensions
* Frame [Stream identifier](https://github.com/google/snappy/blob/master/framing_format.txt#L68) changed from `sNaPpY` to `S2sTwO`.
* [Framed compressed blocks](https://github.com/google/snappy/blob/master/format_description.txt) can be up to 4MB (up from 64KB).
* Compressed blocks can have an offset of `0`, which indicates to repeat the last seen offset.
Repeat offsets must be encoded as a [2.2.1. Copy with 1-byte offset (01)](https://github.com/google/snappy/blob/master/format_description.txt#L89), where the offset is 0.
The length is specified by reading the 3-bit length specified in the tag and decode using this table:
| Length | Actual Length |
|--------|----------------------|
| 0 | 4 |
| 1 | 5 |
| 2 | 6 |
| 3 | 7 |
| 4 | 8 |
| 5 | 8 + read 1 byte |
| 6 | 260 + read 2 bytes |
| 7 | 65540 + read 3 bytes |
This allows any repeat offset + length to be represented by 2 to 5 bytes.
Lengths are stored as little endian values.
The first copy of a block cannot be a repeat offset and the offset is not carried across blocks in streams.
Default streaming block size is 1MB.
# LICENSE
This code is based on the [Snappy-Go](https://github.com/golang/snappy) implementation.
Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

File diff suppressed because it is too large Load Diff

@ -1,568 +0,0 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#define R_TMP0 AX
#define R_TMP1 BX
#define R_LEN CX
#define R_OFF DX
#define R_SRC SI
#define R_DST DI
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// The asm code generally follows the pure Go code in decode_other.go, except
// where marked with a "!!!".
// func decode(dst, src []byte) int
//
// All local variables fit into registers. The non-zero stack size is only to
// spill registers and push args when issuing a CALL. The register allocation:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x (shared)
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (marked with a "+") are set at the start of the
// function, and after a CALL returns, and are not otherwise modified.
//
// The d variable is implicitly R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $48-56
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DST
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SRC
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
XORQ R_OFF, R_OFF
loop:
// for s < len(src)
CMPQ R_SRC, R_SEND
JEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBLZX (R_SRC), R_LEN
MOVL R_LEN, R_TMP1
ANDL $3, R_TMP1
CMPL R_TMP1, $1
JAE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
SHRL $2, R_LEN
CMPL R_LEN, $60
JAE tagLit60Plus
// case x < 60:
// s++
INCQ R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == x and x fits in a uint32, where x is the variable
// used in the pure Go decode_other.go code.
// length = int(x) + 1
//
// Unlike the pure Go code, we don't need to check if length <= 0 because
// R_LEN can hold 64 bits, so the increment cannot overflow.
INCQ R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVQ R_DEND, R_TMP0
SUBQ R_DST, R_TMP0
MOVQ R_SEND, R_TMP1
SUBQ R_SRC, R_TMP1
// !!! Try a faster technique for short (16 or fewer bytes) copies.
//
// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
// goto callMemmove // Fall back on calling runtime·memmove.
// }
//
// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
// against 21 instead of 16, because it cannot assume that all of its input
// is contiguous in memory and so it needs to leave enough source bytes to
// read the next tag without refilling buffers, but Go's Decode assumes
// contiguousness (the src argument is a []byte).
CMPQ R_LEN, $16
JGT callMemmove
CMPQ R_TMP0, $16
JLT callMemmove
CMPQ R_TMP1, $16
JLT callMemmove
// !!! Implement the copy from src to dst as a 16-byte load and store.
// (Decode's documentation says that dst and src must not overlap.)
//
// This always copies 16 bytes, instead of only length bytes, but that's
// OK. If the input is a valid Snappy encoding then subsequent iterations
// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
// non-nil error), so the overrun will be ignored.
//
// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
// 16-byte loads and stores. This technique probably wouldn't be as
// effective on architectures that are fussier about alignment.
MOVOU 0(R_SRC), X0
MOVOU X0, 0(R_DST)
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
JMP loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMPQ R_LEN, R_TMP0
JGT errCorrupt
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVQ R_DST, 0(SP)
MOVQ R_SRC, 8(SP)
MOVQ R_LEN, 16(SP)
MOVQ R_DST, 24(SP)
MOVQ R_SRC, 32(SP)
MOVQ R_LEN, 40(SP)
MOVQ R_OFF, 48(SP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVQ 24(SP), R_DST
MOVQ 32(SP), R_SRC
MOVQ 40(SP), R_LEN
MOVQ 48(SP), R_OFF
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
JMP loop
tagLit60Plus:
// !!! This fragment does the
//
// s += x - 58; if uint(s) > uint(len(src)) { etc }
//
// checks. In the asm version, we code it once instead of once per switch case.
ADDQ R_LEN, R_SRC
SUBQ $58, R_SRC
CMPQ R_SRC, R_SEND
JA errCorrupt
// case x == 60:
CMPL R_LEN, $61
JEQ tagLit61
JA tagLit62Plus
// x = uint32(src[s-1])
MOVBLZX -1(R_SRC), R_LEN
JMP doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVWLZX -2(R_SRC), R_LEN
JMP doLit
tagLit62Plus:
CMPL R_LEN, $62
JA tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
// We read one byte, safe to read one back, since we are just reading tag.
// x = binary.LittleEndian.Uint32(src[s-1:]) >> 8
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
JMP doLit
tagLit63:
// case x == 63:
// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
MOVL -4(R_SRC), R_LEN
JMP doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADDQ $5, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-5])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVLQZX -4(R_SRC), R_OFF
JMP doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-3])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVWQZX -2(R_SRC), R_OFF
JMP doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMPQ R_TMP1, $2
JEQ tagCopy2
JA tagCopy4
// case tagCopy1:
// s += 2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// length = 4 + int(src[s-2])>>2&0x7
MOVBQZX -1(R_SRC), R_TMP1
MOVQ R_LEN, R_TMP0
SHRQ $2, R_LEN
ANDQ $0xe0, R_TMP0
ANDQ $7, R_LEN
SHLQ $3, R_TMP0
ADDQ $4, R_LEN
ORQ R_TMP1, R_TMP0
// check if repeat code, ZF set by ORQ.
JZ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (length)
MOVQ R_TMP0, R_OFF
JMP doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMPQ R_LEN, $9
JL doCopyRepeat
// Read additional bytes for length.
JE repeatLen1
// Rare, so the extra branch shouldn't hurt too much.
CMPQ R_LEN, $10
JE repeatLen2
JMP repeatLen3
// Read repeat lengths.
repeatLen1:
// s ++
ADDQ $1, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = src[s-1] + 8
MOVBQZX -1(R_SRC), R_LEN
ADDL $8, R_LEN
JMP doCopyRepeat
repeatLen2:
// s +=2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + (1 << 8)
MOVWQZX -2(R_SRC), R_LEN
ADDL $260, R_LEN
JMP doCopyRepeat
repeatLen3:
// s +=3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + (1 << 16)
// Read one byte further back (just part of the tag, shifted out)
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
ADDL $65540, R_LEN
JMP doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVQ R_DST, R_TMP1
SUBQ R_DBASE, R_TMP1
CMPQ R_TMP1, R_OFF
JLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMPQ R_OFF, $0
JLE errCorrupt
// if length > len(dst)-d { etc }
MOVQ R_DEND, R_TMP1
SUBQ R_DST, R_TMP1
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVQ R_DEND, R_TMP2
SUBQ R_DST, R_TMP2
MOVQ R_DST, R_TMP3
SUBQ R_OFF, R_TMP3
// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
//
// First, try using two 8-byte load/stores, similar to the doLit technique
// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
// and not one 16-byte load/store, and the first store has to be before the
// second load, due to the overlap if offset is in the range [8, 16).
//
// if length > 16 || offset < 8 || len(dst)-d < 16 {
// goto slowForwardCopy
// }
// copy 16 bytes
// d += length
CMPQ R_LEN, $16
JGT slowForwardCopy
CMPQ R_OFF, $8
JLT slowForwardCopy
CMPQ R_TMP2, $16
JLT slowForwardCopy
MOVQ 0(R_TMP3), R_TMP0
MOVQ R_TMP0, 0(R_DST)
MOVQ 8(R_TMP3), R_TMP1
MOVQ R_TMP1, 8(R_DST)
ADDQ R_LEN, R_DST
JMP loop
slowForwardCopy:
// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
// can still try 8-byte load stores, provided we can overrun up to 10 extra
// bytes. As above, the overrun will be fixed up by subsequent iterations
// of the outermost loop.
//
// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
// commentary says:
//
// ----
//
// The main part of this loop is a simple copy of eight bytes at a time
// until we've copied (at least) the requested amount of bytes. However,
// if d and d-offset are less than eight bytes apart (indicating a
// repeating pattern of length < 8), we first need to expand the pattern in
// order to get the correct results. For instance, if the buffer looks like
// this, with the eight-byte <d-offset> and <d> patterns marked as
// intervals:
//
// abxxxxxxxxxxxx
// [------] d-offset
// [------] d
//
// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
// once, after which we can move <d> two bytes without moving <d-offset>:
//
// ababxxxxxxxxxx
// [------] d-offset
// [------] d
//
// and repeat the exercise until the two no longer overlap.
//
// This allows us to do very well in the special case of one single byte
// repeated many times, without taking a big hit for more general cases.
//
// The worst case of extra writing past the end of the match occurs when
// offset == 1 and length == 1; the last copy will read from byte positions
// [0..7] and write to [4..11], whereas it was only supposed to write to
// position 1. Thus, ten excess bytes.
//
// ----
//
// That "10 byte overrun" worst case is confirmed by Go's
// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
// and finishSlowForwardCopy algorithm.
//
// if length > len(dst)-d-10 {
// goto verySlowForwardCopy
// }
SUBQ $10, R_TMP2
CMPQ R_LEN, R_TMP2
JGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVQ R_OFF, R_TMP2
makeOffsetAtLeast8:
// !!! As above, expand the pattern so that offset >= 8 and we can use
// 8-byte load/stores.
//
// for offset < 8 {
// copy 8 bytes from dst[d-offset:] to dst[d:]
// length -= offset
// d += offset
// offset += offset
// // The two previous lines together means that d-offset, and therefore
// // R_TMP3, is unchanged.
// }
CMPQ R_TMP2, $8
JGE fixUpSlowForwardCopy
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_DST)
SUBQ R_TMP2, R_LEN
ADDQ R_TMP2, R_DST
ADDQ R_TMP2, R_TMP2
JMP makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST being
// &dst[d]) so that d ends up at the right place when we jump back to the
// top of the loop. Before we do that, though, we save R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVQ R_DST, R_TMP0
ADDQ R_LEN, R_DST
finishSlowForwardCopy:
// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
// length means that we overrun, but as above, that will be fixed up by
// subsequent iterations of the outermost loop.
CMPQ R_LEN, $0
JLE loop
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_TMP0)
ADDQ $8, R_TMP3
ADDQ $8, R_TMP0
SUBQ $8, R_LEN
JMP finishSlowForwardCopy
verySlowForwardCopy:
// verySlowForwardCopy is a simple implementation of forward copy. In C
// parlance, this is a do/while loop instead of a while loop, since we know
// that length > 0. In Go syntax:
//
// for {
// dst[d] = dst[d - offset]
// d++
// length--
// if length == 0 {
// break
// }
// }
MOVB (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
INCQ R_TMP3
INCQ R_DST
DECQ R_LEN
JNZ verySlowForwardCopy
JMP loop
// The code above handles copy tags.
// ----------------------------------------
end:
// This is the end of the "for s < len(src)".
//
// if d != len(dst) { etc }
CMPQ R_DST, R_DEND
JNE errCorrupt
// return 0
MOVQ $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVQ $1, ret+48(FP)
RET

@ -1,574 +0,0 @@
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
#define R_TMP0 R2
#define R_TMP1 R3
#define R_LEN R4
#define R_OFF R5
#define R_SRC R6
#define R_DST R7
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// TEST_SRC will check if R_SRC is <= SRC_END
#define TEST_SRC() \
CMP R_SEND, R_SRC \
BGT errCorrupt
// MOVD R_SRC, R_TMP1
// SUB R_SBASE, R_TMP1, R_TMP1
// CMP R_SLEN, R_TMP1
// BGT errCorrupt
// The asm code generally follows the pure Go code in decode_other.go, except
// where marked with a "!!!".
// func decode(dst, src []byte) int
//
// All local variables fit into registers. The non-zero stack size is only to
// spill registers and push args when issuing a CALL. The register allocation:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (marked with a "+") are set at the start of the
// function, and after a CALL returns, and are not otherwise modified.
//
// The d variable is implicitly R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $56-64
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DST
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SRC
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
MOVD $0, R_OFF
loop:
// for s < len(src)
CMP R_SEND, R_SRC
BEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBU (R_SRC), R_LEN
MOVW R_LEN, R_TMP1
ANDW $3, R_TMP1
MOVW $1, R1
CMPW R1, R_TMP1
BGE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
MOVW $60, R1
LSRW $2, R_LEN, R_LEN
CMPW R_LEN, R1
BLS tagLit60Plus
// case x < 60:
// s++
ADD $1, R_SRC, R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == x and x fits in a uint32, where x is the variable
// used in the pure Go decode_other.go code.
// length = int(x) + 1
//
// Unlike the pure Go code, we don't need to check if length <= 0 because
// R_LEN can hold 64 bits, so the increment cannot overflow.
ADD $1, R_LEN, R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVD R_DEND, R_TMP0
SUB R_DST, R_TMP0, R_TMP0
MOVD R_SEND, R_TMP1
SUB R_SRC, R_TMP1, R_TMP1
// !!! Try a faster technique for short (16 or fewer bytes) copies.
//
// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
// goto callMemmove // Fall back on calling runtime·memmove.
// }
//
// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
// against 21 instead of 16, because it cannot assume that all of its input
// is contiguous in memory and so it needs to leave enough source bytes to
// read the next tag without refilling buffers, but Go's Decode assumes
// contiguousness (the src argument is a []byte).
CMP $16, R_LEN
BGT callMemmove
CMP $16, R_TMP0
BLT callMemmove
CMP $16, R_TMP1
BLT callMemmove
// !!! Implement the copy from src to dst as a 16-byte load and store.
// (Decode's documentation says that dst and src must not overlap.)
//
// This always copies 16 bytes, instead of only length bytes, but that's
// OK. If the input is a valid Snappy encoding then subsequent iterations
// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
// non-nil error), so the overrun will be ignored.
//
// Note that on arm64, it is legal and cheap to issue unaligned 8-byte or
// 16-byte loads and stores. This technique probably wouldn't be as
// effective on architectures that are fussier about alignment.
LDP 0(R_SRC), (R_TMP2, R_TMP3)
STP (R_TMP2, R_TMP3), 0(R_DST)
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMP R_TMP0, R_LEN
BGT errCorrupt
CMP R_TMP1, R_LEN
BGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVD R_DST, 8(RSP)
MOVD R_SRC, 16(RSP)
MOVD R_LEN, 24(RSP)
MOVD R_DST, 32(RSP)
MOVD R_SRC, 40(RSP)
MOVD R_LEN, 48(RSP)
MOVD R_OFF, 56(RSP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVD 32(RSP), R_DST
MOVD 40(RSP), R_SRC
MOVD 48(RSP), R_LEN
MOVD 56(RSP), R_OFF
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B loop
tagLit60Plus:
// !!! This fragment does the
//
// s += x - 58; if uint(s) > uint(len(src)) { etc }
//
// checks. In the asm version, we code it once instead of once per switch case.
ADD R_LEN, R_SRC, R_SRC
SUB $58, R_SRC, R_SRC
TEST_SRC()
// case x == 60:
MOVW $61, R1
CMPW R1, R_LEN
BEQ tagLit61
BGT tagLit62Plus
// x = uint32(src[s-1])
MOVBU -1(R_SRC), R_LEN
B doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVHU -2(R_SRC), R_LEN
B doLit
tagLit62Plus:
CMPW $62, R_LEN
BHI tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
MOVHU -3(R_SRC), R_LEN
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP1<<16, R_LEN
B doLit
tagLit63:
// case x == 63:
// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
MOVWU -4(R_SRC), R_LEN
B doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADD $5, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
MOVD R_SRC, R_TMP1
SUB R_SBASE, R_TMP1, R_TMP1
CMP R_SLEN, R_TMP1
BGT errCorrupt
// length = 1 + int(src[s-5])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVWU -4(R_SRC), R_OFF
B doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = 1 + int(src[s-3])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVHU -2(R_SRC), R_OFF
B doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMP $2, R_TMP1
BEQ tagCopy2
BGT tagCopy4
// case tagCopy1:
// s += 2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// Calculate offset in R_TMP0 in case it is a repeat.
MOVD R_LEN, R_TMP0
AND $0xe0, R_TMP0
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP0<<3, R_TMP1, R_TMP0
// length = 4 + int(src[s-2])>>2&0x7
MOVD $7, R1
AND R_LEN>>2, R1, R_LEN
ADD $4, R_LEN, R_LEN
// check if repeat code with offset 0.
CMP $0, R_TMP0
BEQ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (offset)
MOVD R_TMP0, R_OFF
B doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMP $9, R_LEN
BLT doCopyRepeat
BEQ repeatLen1
CMP $10, R_LEN
BEQ repeatLen2
repeatLen3:
// s +=3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + 65540
MOVBU -1(R_SRC), R_TMP0
MOVHU -3(R_SRC), R_LEN
ORR R_TMP0<<16, R_LEN, R_LEN
ADD $65540, R_LEN, R_LEN
B doCopyRepeat
repeatLen2:
// s +=2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + 260
MOVHU -2(R_SRC), R_LEN
ADD $260, R_LEN, R_LEN
B doCopyRepeat
repeatLen1:
// s +=1
ADD $1, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = src[s-1] + 8
MOVBU -1(R_SRC), R_LEN
ADD $8, R_LEN, R_LEN
B doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVD R_DST, R_TMP1
SUB R_DBASE, R_TMP1, R_TMP1
CMP R_OFF, R_TMP1
BLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMP $0, R_OFF
BLE errCorrupt
// if length > len(dst)-d { etc }
MOVD R_DEND, R_TMP1
SUB R_DST, R_TMP1, R_TMP1
CMP R_TMP1, R_LEN
BGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVD R_DEND, R_TMP2
SUB R_DST, R_TMP2, R_TMP2
MOVD R_DST, R_TMP3
SUB R_OFF, R_TMP3, R_TMP3
// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
//
// First, try using two 8-byte load/stores, similar to the doLit technique
// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
// and not one 16-byte load/store, and the first store has to be before the
// second load, due to the overlap if offset is in the range [8, 16).
//
// if length > 16 || offset < 8 || len(dst)-d < 16 {
// goto slowForwardCopy
// }
// copy 16 bytes
// d += length
CMP $16, R_LEN
BGT slowForwardCopy
CMP $8, R_OFF
BLT slowForwardCopy
CMP $16, R_TMP2
BLT slowForwardCopy
MOVD 0(R_TMP3), R_TMP0
MOVD R_TMP0, 0(R_DST)
MOVD 8(R_TMP3), R_TMP1
MOVD R_TMP1, 8(R_DST)
ADD R_LEN, R_DST, R_DST
B loop
slowForwardCopy:
// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
// can still try 8-byte load stores, provided we can overrun up to 10 extra
// bytes. As above, the overrun will be fixed up by subsequent iterations
// of the outermost loop.
//
// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
// commentary says:
//
// ----
//
// The main part of this loop is a simple copy of eight bytes at a time
// until we've copied (at least) the requested amount of bytes. However,
// if d and d-offset are less than eight bytes apart (indicating a
// repeating pattern of length < 8), we first need to expand the pattern in
// order to get the correct results. For instance, if the buffer looks like
// this, with the eight-byte <d-offset> and <d> patterns marked as
// intervals:
//
// abxxxxxxxxxxxx
// [------] d-offset
// [------] d
//
// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
// once, after which we can move <d> two bytes without moving <d-offset>:
//
// ababxxxxxxxxxx
// [------] d-offset
// [------] d
//
// and repeat the exercise until the two no longer overlap.
//
// This allows us to do very well in the special case of one single byte
// repeated many times, without taking a big hit for more general cases.
//
// The worst case of extra writing past the end of the match occurs when
// offset == 1 and length == 1; the last copy will read from byte positions
// [0..7] and write to [4..11], whereas it was only supposed to write to
// position 1. Thus, ten excess bytes.
//
// ----
//
// That "10 byte overrun" worst case is confirmed by Go's
// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
// and finishSlowForwardCopy algorithm.
//
// if length > len(dst)-d-10 {
// goto verySlowForwardCopy
// }
SUB $10, R_TMP2, R_TMP2
CMP R_TMP2, R_LEN
BGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVD R_OFF, R_TMP2
makeOffsetAtLeast8:
// !!! As above, expand the pattern so that offset >= 8 and we can use
// 8-byte load/stores.
//
// for offset < 8 {
// copy 8 bytes from dst[d-offset:] to dst[d:]
// length -= offset
// d += offset
// offset += offset
// // The two previous lines together means that d-offset, and therefore
// // R_TMP3, is unchanged.
// }
CMP $8, R_TMP2
BGE fixUpSlowForwardCopy
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_DST)
SUB R_TMP2, R_LEN, R_LEN
ADD R_TMP2, R_DST, R_DST
ADD R_TMP2, R_TMP2, R_TMP2
B makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST being
// &dst[d]) so that d ends up at the right place when we jump back to the
// top of the loop. Before we do that, though, we save R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVD R_DST, R_TMP0
ADD R_LEN, R_DST, R_DST
finishSlowForwardCopy:
// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
// length means that we overrun, but as above, that will be fixed up by
// subsequent iterations of the outermost loop.
MOVD $0, R1
CMP R1, R_LEN
BLE loop
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_TMP0)
ADD $8, R_TMP3, R_TMP3
ADD $8, R_TMP0, R_TMP0
SUB $8, R_LEN, R_LEN
B finishSlowForwardCopy
verySlowForwardCopy:
// verySlowForwardCopy is a simple implementation of forward copy. In C
// parlance, this is a do/while loop instead of a while loop, since we know
// that length > 0. In Go syntax:
//
// for {
// dst[d] = dst[d - offset]
// d++
// length--
// if length == 0 {
// break
// }
// }
MOVB (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
ADD $1, R_TMP3, R_TMP3
ADD $1, R_DST, R_DST
SUB $1, R_LEN, R_LEN
CBNZ R_LEN, verySlowForwardCopy
B loop
// The code above handles copy tags.
// ----------------------------------------
end:
// This is the end of the "for s < len(src)".
//
// if d != len(dst) { etc }
CMP R_DEND, R_DST
BNE errCorrupt
// return 0
MOVD $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVD $1, R_TMP0
MOVD R_TMP0, ret+48(FP)
RET

@ -1,17 +0,0 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (amd64 || arm64) && !appengine && gc && !noasm
// +build amd64 arm64
// +build !appengine
// +build gc
// +build !noasm
package s2
// decode has the same semantics as in decode_other.go.
//
//go:noescape
func s2Decode(dst, src []byte) int

@ -1,267 +0,0 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (!amd64 && !arm64) || appengine || !gc || noasm
// +build !amd64,!arm64 appengine !gc noasm
package s2
import (
"fmt"
"strconv"
)
// decode writes the decoding of src to dst. It assumes that the varint-encoded
// length of the decompressed bytes has already been read, and that len(dst)
// equals that length.
//
// It returns 0 on success or a decodeErrCodeXxx error code on failure.
func s2Decode(dst, src []byte) int {
const debug = false
if debug {
fmt.Println("Starting decode, dst len:", len(dst))
}
var d, s, length int
offset := 0
// As long as we can read at least 5 bytes...
for s < len(src)-5 {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
x = uint32(src[s-1])
case x == 61:
s += 3
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
length = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
s += 3
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || d < offset || length > len(dst)-d {
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
// Remaining with extra checks...
for s < len(src) {
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-1])
case x == 61:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-2]) | uint32(src[s-1])<<8
case x == 62:
s += 4
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
case x == 63:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-3])>>2
offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
case tagCopy4:
s += 5
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = 1 + int(src[s-5])>>2
offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
}
if offset <= 0 || d < offset || length > len(dst)-d {
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
return decodeErrCodeCorrupt
}
return 0
}

File diff suppressed because it is too large Load Diff

@ -1,456 +0,0 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"bytes"
"encoding/binary"
"math/bits"
)
func load32(b []byte, i int) uint32 {
return binary.LittleEndian.Uint32(b[i:])
}
func load64(b []byte, i int) uint64 {
return binary.LittleEndian.Uint64(b[i:])
}
// hash6 returns the hash of the lowest 6 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash6(u uint64, h uint8) uint32 {
const prime6bytes = 227718039650203
return uint32(((u << (64 - 48)) * prime6bytes) >> ((64 - h) & 63))
}
func encodeGo(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if len(dst) < n {
dst = make([]byte, n)
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockGo(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// encodeBlockGo encodes a non-empty src to a guaranteed-large-enough dst. It
// assumes that the varint-encoded length of the decompressed bytes has already
// been written.
//
// It also assumes that:
// len(dst) >= MaxEncodedLen(len(src)) &&
// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
func encodeBlockGo(dst, src []byte) (d int) {
// Initialize the hash table.
const (
tableBits = 14
maxTableSize = 1 << tableBits
debug = false
)
var table [maxTableSize]uint32
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteral(dst[d:], src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
if debug {
// Validate match.
if s <= candidate {
panic("s <= candidate")
}
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
if nextEmit > 0 {
// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
d += emitRepeat(dst[d:], repeat, s-base)
} else {
// First match, cannot be repeat.
d += emitCopy(dst[d:], repeat, s-base)
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards.
// The top bytes will be rechecked to get the full match.
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteral(dst[d:], src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopy(dst[d:], repeat, s-base)
if debug {
// Validate match.
if s <= candidate {
panic("s <= candidate")
}
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if debug && s == candidate {
panic("s == candidate")
}
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
func encodeBlockSnappyGo(dst, src []byte) (d int) {
// Initialize the hash table.
const (
tableBits = 14
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint32
// sLimit is when to stop looking for offset/length copies. The inputMargin
// lets us use a fast path for emitLiteral in the main loop, while we are
// looking for copies.
sLimit := len(src) - inputMargin
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// nextEmit is where in src the next emitLiteral should start from.
nextEmit := 0
// The encoded form must start with a literal, as there are no previous
// bytes to copy, so we start looking for hash matches at s == 1.
s := 1
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteral(dst[d:], src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeat(dst[d:], repeat, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// A 4-byte match has been found. We'll later see if more than 4 bytes
// match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
// them as literal bytes.
d += emitLiteral(dst[d:], src[nextEmit:s])
// Call emitCopy, and then see if another emitCopy could be our next
// move. Repeat until we find no match for the input immediately after
// what was consumed by the last emitCopy call.
//
// If we exit this loop normally then we need to call emitLiteral next,
// though we don't yet know how big the literal will be. We handle that
// by proceeding to the next iteration of the main loop. We also can
// exit this loop via goto if we get close to exhausting the input.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
base := s
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeat(dst[d:], repeat, s-base)
if false {
// Validate match.
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}

Some files were not shown because too many files have changed in this diff Show More

Loading…
Cancel
Save