Move modules/gzip to gitea.com/macaron/gzip (#9058)

* Move modules/gzip to gitea.com/macaron/gzip

* Fix vendor
tokarchuk/v1.17
Lunny Xiao 5 years ago committed by GitHub
parent ba4e8f221b
commit 9ff6312627
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
  1. 5
      go.mod
  2. 10
      go.sum
  3. 2
      integrations/lfs_getobject_test.go
  4. 131
      modules/gzip/gzip_test.go
  5. 2
      routers/routes/routes.go
  6. 9
      vendor/gitea.com/macaron/gzip/go.mod
  7. 42
      vendor/gitea.com/macaron/gzip/go.sum
  8. 0
      vendor/gitea.com/macaron/gzip/gzip.go
  9. 1
      vendor/github.com/klauspost/compress/LICENSE
  10. 32
      vendor/github.com/klauspost/compress/flate/copy.go
  11. 41
      vendor/github.com/klauspost/compress/flate/crc32_amd64.go
  12. 213
      vendor/github.com/klauspost/compress/flate/crc32_amd64.s
  13. 35
      vendor/github.com/klauspost/compress/flate/crc32_noasm.go
  14. 891
      vendor/github.com/klauspost/compress/flate/deflate.go
  15. 257
      vendor/github.com/klauspost/compress/flate/fast_encoder.go
  16. 472
      vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go
  17. 72
      vendor/github.com/klauspost/compress/flate/huffman_code.go
  18. 163
      vendor/github.com/klauspost/compress/flate/inflate.go
  19. 174
      vendor/github.com/klauspost/compress/flate/level1.go
  20. 199
      vendor/github.com/klauspost/compress/flate/level2.go
  21. 225
      vendor/github.com/klauspost/compress/flate/level3.go
  22. 210
      vendor/github.com/klauspost/compress/flate/level4.go
  23. 276
      vendor/github.com/klauspost/compress/flate/level5.go
  24. 279
      vendor/github.com/klauspost/compress/flate/level6.go
  25. 48
      vendor/github.com/klauspost/compress/flate/reverse_bits.go
  26. 856
      vendor/github.com/klauspost/compress/flate/snappy.go
  27. 252
      vendor/github.com/klauspost/compress/flate/stateless.go
  28. 292
      vendor/github.com/klauspost/compress/flate/token.go
  29. 2
      vendor/github.com/klauspost/compress/gzip/gunzip.go
  30. 26
      vendor/github.com/klauspost/compress/gzip/gzip.go
  31. 24
      vendor/github.com/klauspost/cpuid/.gitignore
  32. 8
      vendor/github.com/klauspost/cpuid/.travis.yml
  33. 22
      vendor/github.com/klauspost/cpuid/LICENSE
  34. 145
      vendor/github.com/klauspost/cpuid/README.md
  35. 1022
      vendor/github.com/klauspost/cpuid/cpuid.go
  36. 42
      vendor/github.com/klauspost/cpuid/cpuid_386.s
  37. 42
      vendor/github.com/klauspost/cpuid/cpuid_amd64.s
  38. 17
      vendor/github.com/klauspost/cpuid/detect_intel.go
  39. 23
      vendor/github.com/klauspost/cpuid/detect_ref.go
  40. 3
      vendor/github.com/klauspost/cpuid/generate.go
  41. 24
      vendor/github.com/klauspost/crc32/.gitignore
  42. 13
      vendor/github.com/klauspost/crc32/.travis.yml
  43. 28
      vendor/github.com/klauspost/crc32/LICENSE
  44. 87
      vendor/github.com/klauspost/crc32/README.md
  45. 207
      vendor/github.com/klauspost/crc32/crc32.go
  46. 230
      vendor/github.com/klauspost/crc32/crc32_amd64.go
  47. 319
      vendor/github.com/klauspost/crc32/crc32_amd64.s
  48. 43
      vendor/github.com/klauspost/crc32/crc32_amd64p32.go
  49. 67
      vendor/github.com/klauspost/crc32/crc32_amd64p32.s
  50. 89
      vendor/github.com/klauspost/crc32/crc32_generic.go
  51. 15
      vendor/github.com/klauspost/crc32/crc32_otherarch.go
  52. 91
      vendor/github.com/klauspost/crc32/crc32_s390x.go
  53. 249
      vendor/github.com/klauspost/crc32/crc32_s390x.s
  54. 8
      vendor/modules.txt

@ -9,6 +9,7 @@ require (
gitea.com/macaron/captcha v0.0.0-20190822015246-daa973478bae gitea.com/macaron/captcha v0.0.0-20190822015246-daa973478bae
gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175 gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175
gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439 gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439
gitea.com/macaron/gzip v0.0.0-20191118033930-0c4c5566a0e5
gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223 gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223
gitea.com/macaron/inject v0.0.0-20190805023432-d4c86e31027a gitea.com/macaron/inject v0.0.0-20190805023432-d4c86e31027a
gitea.com/macaron/macaron v1.3.3-0.20190821202302-9646c0587edb gitea.com/macaron/macaron v1.3.3-0.20190821202302-9646c0587edb
@ -55,9 +56,7 @@ require (
github.com/joho/godotenv v1.3.0 // indirect github.com/joho/godotenv v1.3.0 // indirect
github.com/kballard/go-shellquote v0.0.0-20170619183022-cd60e84ee657 github.com/kballard/go-shellquote v0.0.0-20170619183022-cd60e84ee657
github.com/keybase/go-crypto v0.0.0-20170605145657-00ac4db533f6 github.com/keybase/go-crypto v0.0.0-20170605145657-00ac4db533f6
github.com/klauspost/compress v0.0.0-20161025140425-8df558b6cb6f github.com/klauspost/compress v1.9.2
github.com/klauspost/cpuid v0.0.0-20160302075316-09cded8978dc // indirect
github.com/klauspost/crc32 v0.0.0-20161016154125-cb6bfca970f6 // indirect
github.com/lafriks/xormstore v1.3.2 github.com/lafriks/xormstore v1.3.2
github.com/lib/pq v1.2.0 github.com/lib/pq v1.2.0
github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96 github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96

@ -20,6 +20,8 @@ gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175 h1:ikzdAGB6SsUGByW5wKl
gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175/go.mod h1:rtOK4J20kpMD9XcNsnO5YA843YSTe/MUMbDj/TJ/Q7A= gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175/go.mod h1:rtOK4J20kpMD9XcNsnO5YA843YSTe/MUMbDj/TJ/Q7A=
gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439 h1:88c34YM29a1GlWLrLBaG/GTT2htDdJz1u3n9+lmPolg= gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439 h1:88c34YM29a1GlWLrLBaG/GTT2htDdJz1u3n9+lmPolg=
gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439/go.mod h1:IsQPHx73HnnqFBYiVHjg87q4XBZyGXXu77xANukvZuk= gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439/go.mod h1:IsQPHx73HnnqFBYiVHjg87q4XBZyGXXu77xANukvZuk=
gitea.com/macaron/gzip v0.0.0-20191118033930-0c4c5566a0e5 h1:G/a7r0r2jEelSynBlv1+PAEZQKfsdRHQUMb1PlNvemM=
gitea.com/macaron/gzip v0.0.0-20191118033930-0c4c5566a0e5/go.mod h1:jGHtoovArcQj+sw7NJxyPgjuRxOSG9a/oFu3VkLRTKQ=
gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223 h1:iZWwQif/LHMjBgfY/ua8CFVa4XMDfbbs7EZ0Q1dYguU= gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223 h1:iZWwQif/LHMjBgfY/ua8CFVa4XMDfbbs7EZ0Q1dYguU=
gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223/go.mod h1:+qsc10s4hBsHKU/9luGGumFh4m5FFVc7uih+8/mM1NY= gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223/go.mod h1:+qsc10s4hBsHKU/9luGGumFh4m5FFVc7uih+8/mM1NY=
gitea.com/macaron/inject v0.0.0-20190803172902-8375ba841591/go.mod h1:h6E4kLao1Yko6DOU6QDnQPcuoNzvbZqzj2mtPcEn1aM= gitea.com/macaron/inject v0.0.0-20190803172902-8375ba841591/go.mod h1:h6E4kLao1Yko6DOU6QDnQPcuoNzvbZqzj2mtPcEn1aM=
@ -334,12 +336,8 @@ github.com/keybase/go-crypto v0.0.0-20170605145657-00ac4db533f6/go.mod h1:ghbZsc
github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q= github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
github.com/kisielk/errcheck v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQLJ+jE2L00= github.com/kisielk/errcheck v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQLJ+jE2L00=
github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck= github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
github.com/klauspost/compress v0.0.0-20161025140425-8df558b6cb6f h1:tCnZKEmDovgV4jmsclh6CuKk9AMzTzyVWfejgkgccVg= github.com/klauspost/compress v1.9.2 h1:LfVyl+ZlLlLDeQ/d2AqfGIIH4qEDu0Ed2S5GyhCWIWY=
github.com/klauspost/compress v0.0.0-20161025140425-8df558b6cb6f/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A= github.com/klauspost/compress v1.9.2/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
github.com/klauspost/cpuid v0.0.0-20160302075316-09cded8978dc h1:WW8B7p7QBnFlqRVv/k6ro/S8Z7tCnYjJHcQNScx9YVs=
github.com/klauspost/cpuid v0.0.0-20160302075316-09cded8978dc/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
github.com/klauspost/crc32 v0.0.0-20161016154125-cb6bfca970f6 h1:KAZ1BW2TCmT6PRihDPpocIy1QTtsAsrx6TneU/4+CMg=
github.com/klauspost/crc32 v0.0.0-20161016154125-cb6bfca970f6/go.mod h1:+ZoRqAPRLkC4NPOvfYeR5KNOrY6TD+/sAC3HXPZgDYg=
github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ= github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ= github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc= github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=

@ -15,10 +15,10 @@ import (
"testing" "testing"
"code.gitea.io/gitea/models" "code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/gzip"
"code.gitea.io/gitea/modules/lfs" "code.gitea.io/gitea/modules/lfs"
"code.gitea.io/gitea/modules/setting" "code.gitea.io/gitea/modules/setting"
"gitea.com/macaron/gzip"
gzipp "github.com/klauspost/compress/gzip" gzipp "github.com/klauspost/compress/gzip"
"github.com/stretchr/testify/assert" "github.com/stretchr/testify/assert"
) )

@ -1,131 +0,0 @@
// Copyright 2019 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package gzip
import (
"archive/zip"
"bytes"
"io/ioutil"
"net/http"
"net/http/httptest"
"testing"
"gitea.com/macaron/macaron"
gzipp "github.com/klauspost/compress/gzip"
"github.com/stretchr/testify/assert"
)
func setup(sampleResponse []byte) (*macaron.Macaron, *[]byte) {
m := macaron.New()
m.Use(Middleware())
m.Get("/", func() *[]byte { return &sampleResponse })
return m, &sampleResponse
}
func reqNoAcceptGzip(t *testing.T, m *macaron.Macaron, sampleResponse *[]byte) {
// Request without accept gzip: Should not gzip
resp := httptest.NewRecorder()
req, err := http.NewRequest("GET", "/", nil)
assert.NoError(t, err)
m.ServeHTTP(resp, req)
_, ok := resp.HeaderMap[contentEncodingHeader]
assert.False(t, ok)
contentEncoding := resp.Header().Get(contentEncodingHeader)
assert.NotContains(t, contentEncoding, "gzip")
result := resp.Body.Bytes()
assert.Equal(t, *sampleResponse, result)
}
func reqAcceptGzip(t *testing.T, m *macaron.Macaron, sampleResponse *[]byte, expectGzip bool) {
// Request without accept gzip: Should not gzip
resp := httptest.NewRecorder()
req, err := http.NewRequest("GET", "/", nil)
assert.NoError(t, err)
req.Header.Set(acceptEncodingHeader, "gzip")
m.ServeHTTP(resp, req)
_, ok := resp.HeaderMap[contentEncodingHeader]
assert.Equal(t, ok, expectGzip)
contentEncoding := resp.Header().Get(contentEncodingHeader)
if expectGzip {
assert.Contains(t, contentEncoding, "gzip")
gzippReader, err := gzipp.NewReader(resp.Body)
assert.NoError(t, err)
result, err := ioutil.ReadAll(gzippReader)
assert.NoError(t, err)
assert.Equal(t, *sampleResponse, result)
} else {
assert.NotContains(t, contentEncoding, "gzip")
result := resp.Body.Bytes()
assert.Equal(t, *sampleResponse, result)
}
}
func TestMiddlewareSmall(t *testing.T) {
m, sampleResponse := setup([]byte("Small response"))
reqNoAcceptGzip(t, m, sampleResponse)
reqAcceptGzip(t, m, sampleResponse, false)
}
func TestMiddlewareLarge(t *testing.T) {
b := make([]byte, MinSize+1)
for i := range b {
b[i] = byte(i % 256)
}
m, sampleResponse := setup(b)
reqNoAcceptGzip(t, m, sampleResponse)
// This should be gzipped as we accept gzip
reqAcceptGzip(t, m, sampleResponse, true)
}
func TestMiddlewareGzip(t *testing.T) {
b := make([]byte, MinSize*10)
for i := range b {
b[i] = byte(i % 256)
}
outputBuffer := bytes.NewBuffer([]byte{})
gzippWriter := gzipp.NewWriter(outputBuffer)
gzippWriter.Write(b)
gzippWriter.Flush()
gzippWriter.Close()
output := outputBuffer.Bytes()
m, sampleResponse := setup(output)
reqNoAcceptGzip(t, m, sampleResponse)
// This should not be gzipped even though we accept gzip
reqAcceptGzip(t, m, sampleResponse, false)
}
func TestMiddlewareZip(t *testing.T) {
b := make([]byte, MinSize*10)
for i := range b {
b[i] = byte(i % 256)
}
outputBuffer := bytes.NewBuffer([]byte{})
zipWriter := zip.NewWriter(outputBuffer)
fileWriter, err := zipWriter.Create("default")
assert.NoError(t, err)
fileWriter.Write(b)
//fileWriter.Close()
zipWriter.Close()
output := outputBuffer.Bytes()
m, sampleResponse := setup(output)
reqNoAcceptGzip(t, m, sampleResponse)
// This should not be gzipped even though we accept gzip
reqAcceptGzip(t, m, sampleResponse, false)
}

@ -16,7 +16,6 @@ import (
"code.gitea.io/gitea/models" "code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/auth" "code.gitea.io/gitea/modules/auth"
"code.gitea.io/gitea/modules/context" "code.gitea.io/gitea/modules/context"
"code.gitea.io/gitea/modules/gzip"
"code.gitea.io/gitea/modules/lfs" "code.gitea.io/gitea/modules/lfs"
"code.gitea.io/gitea/modules/log" "code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/metrics" "code.gitea.io/gitea/modules/metrics"
@ -44,6 +43,7 @@ import (
"gitea.com/macaron/captcha" "gitea.com/macaron/captcha"
"gitea.com/macaron/cors" "gitea.com/macaron/cors"
"gitea.com/macaron/csrf" "gitea.com/macaron/csrf"
"gitea.com/macaron/gzip"
"gitea.com/macaron/i18n" "gitea.com/macaron/i18n"
"gitea.com/macaron/macaron" "gitea.com/macaron/macaron"
"gitea.com/macaron/session" "gitea.com/macaron/session"

@ -0,0 +1,9 @@
module gitea.com/macaron/gzip
go 1.12
require (
gitea.com/macaron/macaron v1.3.3-0.20190821202302-9646c0587edb
github.com/klauspost/compress v1.9.2
github.com/stretchr/testify v1.4.0
)

@ -0,0 +1,42 @@
gitea.com/macaron/inject v0.0.0-20190803172902-8375ba841591 h1:UbCTjPcLrNxR9LzKDjQBMT2zoxZuEnca1pZCpgeMuhQ=
gitea.com/macaron/inject v0.0.0-20190803172902-8375ba841591/go.mod h1:h6E4kLao1Yko6DOU6QDnQPcuoNzvbZqzj2mtPcEn1aM=
gitea.com/macaron/macaron v1.3.3-0.20190821202302-9646c0587edb h1:amL0md6orTj1tXY16ANzVU9FmzQB+W7aJwp8pVDbrmA=
gitea.com/macaron/macaron v1.3.3-0.20190821202302-9646c0587edb/go.mod h1:0coI+mSPSwbsyAbOuFllVS38awuk9mevhLD52l50Gjs=
github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e h1:JKmoR8x90Iww1ks85zJ1lfDGgIiMDuIptTOhJq+zKyg=
github.com/gopherjs/gopherjs v0.0.0-20181103185306-d547d1d9531e/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/jtolds/gls v4.2.1+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
github.com/klauspost/compress v1.9.2 h1:LfVyl+ZlLlLDeQ/d2AqfGIIH4qEDu0Ed2S5GyhCWIWY=
github.com/klauspost/compress v1.9.2/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
github.com/smartystreets/assertions v0.0.0-20190116191733-b6c0e53d7304 h1:Jpy1PXuP99tXNrhbq2BaPz9B+jNAvH1JPQQpG/9GCXY=
github.com/smartystreets/assertions v0.0.0-20190116191733-b6c0e53d7304/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
github.com/smartystreets/goconvey v0.0.0-20181108003508-044398e4856c/go.mod h1:XDJAKZRPZ1CvBcN2aX5YOUTYGHki24fSF0Iv48Ibg0s=
github.com/smartystreets/goconvey v0.0.0-20190731233626-505e41936337 h1:WN9BUFbdyOsSH/XohnWpXOlq9NBD5sGAB2FciQMUEe8=
github.com/smartystreets/goconvey v0.0.0-20190731233626-505e41936337/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/unknwon/com v0.0.0-20190804042917-757f69c95f3e h1:GSGeB9EAKY2spCABz6xOX5DbxZEXolK+nBSvmsQwRjM=
github.com/unknwon/com v0.0.0-20190804042917-757f69c95f3e/go.mod h1:tOOxU81rwgoCLoOVVPHb6T/wt8HZygqH5id+GNnlCXM=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 h1:HuIa8hRrWRSrqYzx1qI49NNxhdi2PrY7gxVSq1JjLDc=
golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/ini.v1 v1.44.0 h1:YRJzTUp0kSYWUVFF5XAbDFfyiqwsl0Vb9R8TVP5eRi0=
gopkg.in/ini.v1 v1.44.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

@ -1,4 +1,5 @@
Copyright (c) 2012 The Go Authors. All rights reserved. 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 Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are modification, are permitted provided that the following conditions are

@ -1,32 +0,0 @@
// Copyright 2012 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
// forwardCopy is like the built-in copy function except that it always goes
// forward from the start, even if the dst and src overlap.
// It is equivalent to:
// for i := 0; i < n; i++ {
// mem[dst+i] = mem[src+i]
// }
func forwardCopy(mem []byte, dst, src, n int) {
if dst <= src {
copy(mem[dst:dst+n], mem[src:src+n])
return
}
for {
if dst >= src+n {
copy(mem[dst:dst+n], mem[src:src+n])
return
}
// There is some forward overlap. The destination
// will be filled with a repeated pattern of mem[src:src+k].
// We copy one instance of the pattern here, then repeat.
// Each time around this loop k will double.
k := dst - src
copy(mem[dst:dst+k], mem[src:src+k])
n -= k
dst += k
}
}

@ -1,41 +0,0 @@
//+build !noasm
//+build !appengine
// Copyright 2015, Klaus Post, see LICENSE for details.
package flate
import (
"github.com/klauspost/cpuid"
)
// crc32sse returns a hash for the first 4 bytes of the slice
// len(a) must be >= 4.
//go:noescape
func crc32sse(a []byte) uint32
// crc32sseAll calculates hashes for each 4-byte set in a.
// dst must be east len(a) - 4 in size.
// The size is not checked by the assembly.
//go:noescape
func crc32sseAll(a []byte, dst []uint32)
// matchLenSSE4 returns the number of matching bytes in a and b
// up to length 'max'. Both slices must be at least 'max'
// bytes in size.
//
// TODO: drop the "SSE4" name, since it doesn't use any SSE instructions.
//
//go:noescape
func matchLenSSE4(a, b []byte, max int) int
// histogram accumulates a histogram of b in h.
// h must be at least 256 entries in length,
// and must be cleared before calling this function.
//go:noescape
func histogram(b []byte, h []int32)
// Detect SSE 4.2 feature.
func init() {
useSSE42 = cpuid.CPU.SSE42()
}

@ -1,213 +0,0 @@
//+build !noasm
//+build !appengine
// Copyright 2015, Klaus Post, see LICENSE for details.
// func crc32sse(a []byte) uint32
TEXT ·crc32sse(SB), 4, $0
MOVQ a+0(FP), R10
XORQ BX, BX
// CRC32 dword (R10), EBX
BYTE $0xF2; BYTE $0x41; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0x1a
MOVL BX, ret+24(FP)
RET
// func crc32sseAll(a []byte, dst []uint32)
TEXT ·crc32sseAll(SB), 4, $0
MOVQ a+0(FP), R8 // R8: src
MOVQ a_len+8(FP), R10 // input length
MOVQ dst+24(FP), R9 // R9: dst
SUBQ $4, R10
JS end
JZ one_crc
MOVQ R10, R13
SHRQ $2, R10 // len/4
ANDQ $3, R13 // len&3
XORQ BX, BX
ADDQ $1, R13
TESTQ R10, R10
JZ rem_loop
crc_loop:
MOVQ (R8), R11
XORQ BX, BX
XORQ DX, DX
XORQ DI, DI
MOVQ R11, R12
SHRQ $8, R11
MOVQ R12, AX
MOVQ R11, CX
SHRQ $16, R12
SHRQ $16, R11
MOVQ R12, SI
// CRC32 EAX, EBX
BYTE $0xF2; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0xd8
// CRC32 ECX, EDX
BYTE $0xF2; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0xd1
// CRC32 ESI, EDI
BYTE $0xF2; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0xfe
MOVL BX, (R9)
MOVL DX, 4(R9)
MOVL DI, 8(R9)
XORQ BX, BX
MOVL R11, AX
// CRC32 EAX, EBX
BYTE $0xF2; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0xd8
MOVL BX, 12(R9)
ADDQ $16, R9
ADDQ $4, R8
XORQ BX, BX
SUBQ $1, R10
JNZ crc_loop
rem_loop:
MOVL (R8), AX
// CRC32 EAX, EBX
BYTE $0xF2; BYTE $0x0f
BYTE $0x38; BYTE $0xf1; BYTE $0xd8
MOVL BX, (R9)
ADDQ $4, R9
ADDQ $1, R8
XORQ BX, BX
SUBQ $1, R13
JNZ rem_loop
end:
RET
one_crc:
MOVQ $1, R13
XORQ BX, BX
JMP rem_loop
// func matchLenSSE4(a, b []byte, max int) int
TEXT ·matchLenSSE4(SB), 4, $0
MOVQ a_base+0(FP), SI
MOVQ b_base+24(FP), DI
MOVQ DI, DX
MOVQ max+48(FP), CX
cmp8:
// As long as we are 8 or more bytes before the end of max, we can load and
// compare 8 bytes at a time. If those 8 bytes are equal, repeat.
CMPQ CX, $8
JLT cmp1
MOVQ (SI), AX
MOVQ (DI), BX
CMPQ AX, BX
JNE bsf
ADDQ $8, SI
ADDQ $8, DI
SUBQ $8, CX
JMP cmp8
bsf:
// If those 8 bytes were not equal, XOR the two 8 byte values, and return
// the index of the first byte that differs. The BSF instruction finds the
// least significant 1 bit, the amd64 architecture is little-endian, and
// the shift by 3 converts a bit index to a byte index.
XORQ AX, BX
BSFQ BX, BX
SHRQ $3, BX
ADDQ BX, DI
// Subtract off &b[0] to convert from &b[ret] to ret, and return.
SUBQ DX, DI
MOVQ DI, ret+56(FP)
RET
cmp1:
// In the slices' tail, compare 1 byte at a time.
CMPQ CX, $0
JEQ matchLenEnd
MOVB (SI), AX
MOVB (DI), BX
CMPB AX, BX
JNE matchLenEnd
ADDQ $1, SI
ADDQ $1, DI
SUBQ $1, CX
JMP cmp1
matchLenEnd:
// Subtract off &b[0] to convert from &b[ret] to ret, and return.
SUBQ DX, DI
MOVQ DI, ret+56(FP)
RET
// func histogram(b []byte, h []int32)
TEXT ·histogram(SB), 4, $0
MOVQ b+0(FP), SI // SI: &b
MOVQ b_len+8(FP), R9 // R9: len(b)
MOVQ h+24(FP), DI // DI: Histogram
MOVQ R9, R8
SHRQ $3, R8
JZ hist1
XORQ R11, R11
loop_hist8:
MOVQ (SI), R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
MOVB R10, R11
INCL (DI)(R11*4)
SHRQ $8, R10
INCL (DI)(R10*4)
ADDQ $8, SI
DECQ R8
JNZ loop_hist8
hist1:
ANDQ $7, R9
JZ end_hist
XORQ R10, R10
loop_hist1:
MOVB (SI), R10
INCL (DI)(R10*4)
INCQ SI
DECQ R9
JNZ loop_hist1
end_hist:
RET

@ -1,35 +0,0 @@
//+build !amd64 noasm appengine
// Copyright 2015, Klaus Post, see LICENSE for details.
package flate
func init() {
useSSE42 = false
}
// crc32sse should never be called.
func crc32sse(a []byte) uint32 {
panic("no assembler")
}
// crc32sseAll should never be called.
func crc32sseAll(a []byte, dst []uint32) {
panic("no assembler")
}
// matchLenSSE4 should never be called.
func matchLenSSE4(a, b []byte, max int) int {
panic("no assembler")
return 0
}
// histogram accumulates a histogram of b in h.
//
// len(h) must be >= 256, and h's elements must be all zeroes.
func histogram(b []byte, h []int32) {
h = h[:256]
for _, t := range b {
h[t]++
}
}

File diff suppressed because it is too large Load Diff

@ -0,0 +1,257 @@
// 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 (
"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 = 16 // 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 = 18 // Bits used in the big tables
bTableSize = 1 << bTableBits // Size of the table
allocHistory = maxMatchOffset * 10 // Size to preallocate for history.
bufferReset = (1 << 31) - allocHistory - maxStoreBlockSize // 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 {
// 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 load3232(b []byte, i int32) 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 load6432(b []byte, i int32) 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 hash(u uint32) uint32 {
return (u * 0x1e35a7bd) >> tableShift
}
type tableEntry struct {
val uint32
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) & 31)
}
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) & 31)
}
// 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) & 63))
}
// 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) & 63))
}
// 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) & 63))
}
// 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 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, ")"))
}
}
// 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) < int(maxMatchOffset*8) {
l := maxMatchOffset * 8
// Make it at least 1MB.
if l < 1<<20 {
l = 1 << 20
}
e.hist = make([]byte, 0, l)
}
// We offset current position so everything will be out of reach
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 {
b = b[:len(a)]
var checked int
if len(a) > 4 {
// Try 4 bytes first
if diff := load32(a, 0) ^ load32(b, 0); diff != 0 {
return bits.TrailingZeros32(diff) >> 3
}
// Switch to 8 byte matching.
checked = 4
a = a[4:]
b = b[4:]
for len(a) >= 8 {
b = b[:len(a)]
if diff := load64(a, 0) ^ load64(b, 0); 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 int(i) + checked
}
}
return len(a) + checked
}

@ -35,7 +35,7 @@ const (
) )
// The number of extra bits needed by length code X - LENGTH_CODES_START. // The number of extra bits needed by length code X - LENGTH_CODES_START.
var lengthExtraBits = []int8{ var lengthExtraBits = [32]int8{
/* 257 */ 0, 0, 0, /* 257 */ 0, 0, 0,
/* 260 */ 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, /* 260 */ 0, 0, 0, 0, 0, 1, 1, 1, 1, 2,
/* 270 */ 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, /* 270 */ 2, 2, 2, 3, 3, 3, 3, 4, 4, 4,
@ -43,14 +43,14 @@ var lengthExtraBits = []int8{
} }
// The length indicated by length code X - LENGTH_CODES_START. // The length indicated by length code X - LENGTH_CODES_START.
var lengthBase = []uint32{ var lengthBase = [32]uint8{
0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 0, 1, 2, 3, 4, 5, 6, 7, 8, 10,
12, 14, 16, 20, 24, 28, 32, 40, 48, 56, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
64, 80, 96, 112, 128, 160, 192, 224, 255, 64, 80, 96, 112, 128, 160, 192, 224, 255,
} }
// offset code word extra bits. // offset code word extra bits.
var offsetExtraBits = []int8{ var offsetExtraBits = [64]int8{
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13,
@ -58,7 +58,7 @@ var offsetExtraBits = []int8{
14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20,
} }
var offsetBase = []uint32{ var offsetBase = [64]uint32{
/* normal deflate */ /* normal deflate */
0x000000, 0x000001, 0x000002, 0x000003, 0x000004, 0x000000, 0x000001, 0x000002, 0x000003, 0x000004,
0x000006, 0x000008, 0x00000c, 0x000010, 0x000018, 0x000006, 0x000008, 0x00000c, 0x000010, 0x000018,
@ -85,26 +85,48 @@ type huffmanBitWriter struct {
// Data waiting to be written is bytes[0:nbytes] // Data waiting to be written is bytes[0:nbytes]
// and then the low nbits of bits. // and then the low nbits of bits.
bits uint64 bits uint64
nbits uint nbits uint16
bytes [bufferSize]byte nbytes uint8
codegenFreq [codegenCodeCount]int32
nbytes int
literalFreq []int32
offsetFreq []int32
codegen []uint8
literalEncoding *huffmanEncoder literalEncoding *huffmanEncoder
offsetEncoding *huffmanEncoder offsetEncoding *huffmanEncoder
codegenEncoding *huffmanEncoder codegenEncoding *huffmanEncoder
err error err error
lastHeader int
// Set between 0 (reused block can be up to 2x the size)
logReusePenalty uint
lastHuffMan bool
bytes [256]byte
literalFreq [lengthCodesStart + 32]uint16
offsetFreq [32]uint16
codegenFreq [codegenCodeCount]uint16
// codegen must have an extra space for the final symbol.
codegen [literalCount + offsetCodeCount + 1]uint8
} }
// Huffman reuse.
//
// The huffmanBitWriter supports reusing huffman tables and thereby combining block sections.
//
// This is controlled by several variables:
//
// If lastHeader is non-zero the Huffman table can be reused.
// This also indicates that a Huffman table has been generated that can output all
// possible symbols.
// It also indicates that an EOB has not yet been emitted, so if a new tabel is generated
// an EOB with the previous table must be written.
//
// If lastHuffMan is set, a table for outputting literals has been generated and offsets are invalid.
//
// An incoming block estimates the output size of a new table using a 'fresh' by calculating the
// optimal size and adding a penalty in 'logReusePenalty'.
// A Huffman table is not optimal, which is why we add a penalty, and generating a new table
// is slower both for compression and decompression.
func newHuffmanBitWriter(w io.Writer) *huffmanBitWriter { func newHuffmanBitWriter(w io.Writer) *huffmanBitWriter {
return &huffmanBitWriter{ return &huffmanBitWriter{
writer: w, writer: w,
literalFreq: make([]int32, maxNumLit), literalEncoding: newHuffmanEncoder(literalCount),
offsetFreq: make([]int32, offsetCodeCount),
codegen: make([]uint8, maxNumLit+offsetCodeCount+1),
literalEncoding: newHuffmanEncoder(maxNumLit),
codegenEncoding: newHuffmanEncoder(codegenCodeCount), codegenEncoding: newHuffmanEncoder(codegenCodeCount),
offsetEncoding: newHuffmanEncoder(offsetCodeCount), offsetEncoding: newHuffmanEncoder(offsetCodeCount),
} }
@ -113,7 +135,42 @@ func newHuffmanBitWriter(w io.Writer) *huffmanBitWriter {
func (w *huffmanBitWriter) reset(writer io.Writer) { func (w *huffmanBitWriter) reset(writer io.Writer) {
w.writer = writer w.writer = writer
w.bits, w.nbits, w.nbytes, w.err = 0, 0, 0, nil w.bits, w.nbits, w.nbytes, w.err = 0, 0, 0, nil
w.bytes = [bufferSize]byte{} w.bytes = [256]byte{}
w.lastHeader = 0
w.lastHuffMan = false
}
func (w *huffmanBitWriter) canReuse(t *tokens) (offsets, lits bool) {
offsets, lits = true, true
a := t.offHist[:offsetCodeCount]
b := w.offsetFreq[:len(a)]
for i := range a {
if b[i] == 0 && a[i] != 0 {
offsets = false
break
}
}
a = t.extraHist[:literalCount-256]
b = w.literalFreq[256:literalCount]
b = b[:len(a)]
for i := range a {
if b[i] == 0 && a[i] != 0 {
lits = false
break
}
}
if lits {
a = t.litHist[:]
b = w.literalFreq[:len(a)]
for i := range a {
if b[i] == 0 && a[i] != 0 {
lits = false
break
}
}
}
return
} }
func (w *huffmanBitWriter) flush() { func (w *huffmanBitWriter) flush() {
@ -144,30 +201,11 @@ func (w *huffmanBitWriter) write(b []byte) {
_, w.err = w.writer.Write(b) _, w.err = w.writer.Write(b)
} }
func (w *huffmanBitWriter) writeBits(b int32, nb uint) { func (w *huffmanBitWriter) writeBits(b int32, nb uint16) {
if w.err != nil { w.bits |= uint64(b) << (w.nbits & 63)
return
}
w.bits |= uint64(b) << w.nbits
w.nbits += nb w.nbits += nb
if w.nbits >= 48 { if w.nbits >= 48 {
bits := w.bits w.writeOutBits()
w.bits >>= 48
w.nbits -= 48
n := w.nbytes
bytes := w.bytes[n : n+6]
bytes[0] = byte(bits)
bytes[1] = byte(bits >> 8)
bytes[2] = byte(bits >> 16)
bytes[3] = byte(bits >> 24)
bytes[4] = byte(bits >> 32)
bytes[5] = byte(bits >> 40)
n += 6
if n >= bufferFlushSize {
w.write(w.bytes[:n])
n = 0
}
w.nbytes = n
} }
} }
@ -213,7 +251,7 @@ func (w *huffmanBitWriter) generateCodegen(numLiterals int, numOffsets int, litE
// a copy of the frequencies, and as the place where we put the result. // a copy of the frequencies, and as the place where we put the result.
// This is fine because the output is always shorter than the input used // This is fine because the output is always shorter than the input used
// so far. // so far.
codegen := w.codegen // cache codegen := w.codegen[:] // cache
// Copy the concatenated code sizes to codegen. Put a marker at the end. // Copy the concatenated code sizes to codegen. Put a marker at the end.
cgnl := codegen[:numLiterals] cgnl := codegen[:numLiterals]
for i := range cgnl { for i := range cgnl {
@ -292,30 +330,54 @@ func (w *huffmanBitWriter) generateCodegen(numLiterals int, numOffsets int, litE
codegen[outIndex] = badCode codegen[outIndex] = badCode
} }
// dynamicSize returns the size of dynamically encoded data in bits. func (w *huffmanBitWriter) codegens() int {
func (w *huffmanBitWriter) dynamicSize(litEnc, offEnc *huffmanEncoder, extraBits int) (size, numCodegens int) { numCodegens := len(w.codegenFreq)
for numCodegens > 4 && w.codegenFreq[codegenOrder[numCodegens-1]] == 0 {
numCodegens--
}
return numCodegens
}
func (w *huffmanBitWriter) headerSize() (size, numCodegens int) {
numCodegens = len(w.codegenFreq) numCodegens = len(w.codegenFreq)
for numCodegens > 4 && w.codegenFreq[codegenOrder[numCodegens-1]] == 0 { for numCodegens > 4 && w.codegenFreq[codegenOrder[numCodegens-1]] == 0 {
numCodegens-- numCodegens--
} }
header := 3 + 5 + 5 + 4 + (3 * numCodegens) + return 3 + 5 + 5 + 4 + (3 * numCodegens) +
w.codegenEncoding.bitLength(w.codegenFreq[:]) + w.codegenEncoding.bitLength(w.codegenFreq[:]) +
int(w.codegenFreq[16])*2 + int(w.codegenFreq[16])*2 +
int(w.codegenFreq[17])*3 + int(w.codegenFreq[17])*3 +
int(w.codegenFreq[18])*7 int(w.codegenFreq[18])*7, numCodegens
}
// dynamicSize returns the size of dynamically encoded data in bits.
func (w *huffmanBitWriter) dynamicSize(litEnc, offEnc *huffmanEncoder, extraBits int) (size, numCodegens int) {
header, numCodegens := w.headerSize()
size = header + size = header +
litEnc.bitLength(w.literalFreq) + litEnc.bitLength(w.literalFreq[:]) +
offEnc.bitLength(w.offsetFreq) + offEnc.bitLength(w.offsetFreq[:]) +
extraBits extraBits
return size, numCodegens return size, numCodegens
} }
// extraBitSize will return the number of bits that will be written
// as "extra" bits on matches.
func (w *huffmanBitWriter) extraBitSize() int {
total := 0
for i, n := range w.literalFreq[257:literalCount] {
total += int(n) * int(lengthExtraBits[i&31])
}
for i, n := range w.offsetFreq[:offsetCodeCount] {
total += int(n) * int(offsetExtraBits[i&31])
}
return total
}
// fixedSize returns the size of dynamically encoded data in bits. // fixedSize returns the size of dynamically encoded data in bits.
func (w *huffmanBitWriter) fixedSize(extraBits int) int { func (w *huffmanBitWriter) fixedSize(extraBits int) int {
return 3 + return 3 +
fixedLiteralEncoding.bitLength(w.literalFreq) + fixedLiteralEncoding.bitLength(w.literalFreq[:]) +
fixedOffsetEncoding.bitLength(w.offsetFreq) + fixedOffsetEncoding.bitLength(w.offsetFreq[:]) +
extraBits extraBits
} }
@ -333,30 +395,36 @@ func (w *huffmanBitWriter) storedSize(in []byte) (int, bool) {
} }
func (w *huffmanBitWriter) writeCode(c hcode) { func (w *huffmanBitWriter) writeCode(c hcode) {
if w.err != nil { // The function does not get inlined if we "& 63" the shift.
return
}
w.bits |= uint64(c.code) << w.nbits w.bits |= uint64(c.code) << w.nbits
w.nbits += uint(c.len) w.nbits += c.len
if w.nbits >= 48 { if w.nbits >= 48 {
w.writeOutBits()
}
}
// writeOutBits will write bits to the buffer.
func (w *huffmanBitWriter) writeOutBits() {
bits := w.bits bits := w.bits
w.bits >>= 48 w.bits >>= 48
w.nbits -= 48 w.nbits -= 48
n := w.nbytes n := w.nbytes
bytes := w.bytes[n : n+6] w.bytes[n] = byte(bits)
bytes[0] = byte(bits) w.bytes[n+1] = byte(bits >> 8)
bytes[1] = byte(bits >> 8) w.bytes[n+2] = byte(bits >> 16)
bytes[2] = byte(bits >> 16) w.bytes[n+3] = byte(bits >> 24)
bytes[3] = byte(bits >> 24) w.bytes[n+4] = byte(bits >> 32)
bytes[4] = byte(bits >> 32) w.bytes[n+5] = byte(bits >> 40)
bytes[5] = byte(bits >> 40)
n += 6 n += 6
if n >= bufferFlushSize { if n >= bufferFlushSize {
if w.err != nil {
n = 0
return
}
w.write(w.bytes[:n]) w.write(w.bytes[:n])
n = 0 n = 0
} }
w.nbytes = n w.nbytes = n
}
} }
// Write the header of a dynamic Huffman block to the output stream. // Write the header of a dynamic Huffman block to the output stream.
@ -412,6 +480,11 @@ func (w *huffmanBitWriter) writeStoredHeader(length int, isEof bool) {
if w.err != nil { if w.err != nil {
return return
} }
if w.lastHeader > 0 {
// We owe an EOB
w.writeCode(w.literalEncoding.codes[endBlockMarker])
w.lastHeader = 0
}
var flag int32 var flag int32
if isEof { if isEof {
flag = 1 flag = 1
@ -426,6 +499,12 @@ func (w *huffmanBitWriter) writeFixedHeader(isEof bool) {
if w.err != nil { if w.err != nil {
return return
} }
if w.lastHeader > 0 {
// We owe an EOB
w.writeCode(w.literalEncoding.codes[endBlockMarker])
w.lastHeader = 0
}
// Indicate that we are a fixed Huffman block // Indicate that we are a fixed Huffman block
var value int32 = 2 var value int32 = 2
if isEof { if isEof {
@ -439,29 +518,23 @@ func (w *huffmanBitWriter) writeFixedHeader(isEof bool) {
// is larger than the original bytes, the data will be written as a // is larger than the original bytes, the data will be written as a
// stored block. // stored block.
// If the input is nil, the tokens will always be Huffman encoded. // If the input is nil, the tokens will always be Huffman encoded.
func (w *huffmanBitWriter) writeBlock(tokens []token, eof bool, input []byte) { func (w *huffmanBitWriter) writeBlock(tokens *tokens, eof bool, input []byte) {
if w.err != nil { if w.err != nil {
return return
} }
tokens = append(tokens, endBlockMarker) tokens.AddEOB()
numLiterals, numOffsets := w.indexTokens(tokens) if w.lastHeader > 0 {
// We owe an EOB
w.writeCode(w.literalEncoding.codes[endBlockMarker])
w.lastHeader = 0
}
numLiterals, numOffsets := w.indexTokens(tokens, false)
w.generate(tokens)
var extraBits int var extraBits int
storedSize, storable := w.storedSize(input) storedSize, storable := w.storedSize(input)
if storable { if storable {
// We only bother calculating the costs of the extra bits required by extraBits = w.extraBitSize()
// the length of offset fields (which will be the same for both fixed
// and dynamic encoding), if we need to compare those two encodings
// against stored encoding.
for lengthCode := lengthCodesStart + 8; lengthCode < numLiterals; lengthCode++ {
// First eight length codes have extra size = 0.
extraBits += int(w.literalFreq[lengthCode]) * int(lengthExtraBits[lengthCode-lengthCodesStart])
}
for offsetCode := 4; offsetCode < numOffsets; offsetCode++ {
// First four offset codes have extra size = 0.
extraBits += int(w.offsetFreq[offsetCode]) * int(offsetExtraBits[offsetCode])
}
} }
// Figure out smallest code. // Figure out smallest code.
@ -500,7 +573,7 @@ func (w *huffmanBitWriter) writeBlock(tokens []token, eof bool, input []byte) {
} }
// Write the tokens. // Write the tokens.
w.writeTokens(tokens, literalEncoding.codes, offsetEncoding.codes) w.writeTokens(tokens.Slice(), literalEncoding.codes, offsetEncoding.codes)
} }
// writeBlockDynamic encodes a block using a dynamic Huffman table. // writeBlockDynamic encodes a block using a dynamic Huffman table.
@ -508,57 +581,103 @@ func (w *huffmanBitWriter) writeBlock(tokens []token, eof bool, input []byte) {
// histogram distribution. // histogram distribution.
// If input is supplied and the compression savings are below 1/16th of the // If input is supplied and the compression savings are below 1/16th of the
// input size the block is stored. // input size the block is stored.
func (w *huffmanBitWriter) writeBlockDynamic(tokens []token, eof bool, input []byte) { func (w *huffmanBitWriter) writeBlockDynamic(tokens *tokens, eof bool, input []byte, sync bool) {
if w.err != nil { if w.err != nil {
return return
} }
tokens = append(tokens, endBlockMarker) sync = sync || eof
numLiterals, numOffsets := w.indexTokens(tokens) if sync {
tokens.AddEOB()
}
// We cannot reuse pure huffman table.
if w.lastHuffMan && w.lastHeader > 0 {
// We will not try to reuse.
w.writeCode(w.literalEncoding.codes[endBlockMarker])
w.lastHeader = 0
w.lastHuffMan = false
}
if !sync {
tokens.Fill()
}
numLiterals, numOffsets := w.indexTokens(tokens, !sync)
var size int
// Check if we should reuse.
if w.lastHeader > 0 {
// Estimate size for using a new table
newSize := w.lastHeader + tokens.EstimatedBits()
// The estimated size is calculated as an optimal table.
// We add a penalty to make it more realistic and re-use a bit more.
newSize += newSize >> (w.logReusePenalty & 31)
extra := w.extraBitSize()
reuseSize, _ := w.dynamicSize(w.literalEncoding, w.offsetEncoding, extra)
// Check if a new table is better.
if newSize < reuseSize {
// Write the EOB we owe.
w.writeCode(w.literalEncoding.codes[endBlockMarker])
size = newSize
w.lastHeader = 0
} else {
size = reuseSize
}
// Check if we get a reasonable size decrease.
if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) {
w.writeStoredHeader(len(input), eof)
w.writeBytes(input)
w.lastHeader = 0
return
}
}
// We want a new block/table
if w.lastHeader == 0 {
w.generate(tokens)
// Generate codegen and codegenFrequencies, which indicates how to encode // Generate codegen and codegenFrequencies, which indicates how to encode
// the literalEncoding and the offsetEncoding. // the literalEncoding and the offsetEncoding.
w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, w.offsetEncoding) w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, w.offsetEncoding)
w.codegenEncoding.generate(w.codegenFreq[:], 7) w.codegenEncoding.generate(w.codegenFreq[:], 7)
size, numCodegens := w.dynamicSize(w.literalEncoding, w.offsetEncoding, 0) var numCodegens int
size, numCodegens = w.dynamicSize(w.literalEncoding, w.offsetEncoding, w.extraBitSize())
// Store bytes, if we don't get a reasonable improvement. // Store bytes, if we don't get a reasonable improvement.
if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) { if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) {
w.writeStoredHeader(len(input), eof) w.writeStoredHeader(len(input), eof)
w.writeBytes(input) w.writeBytes(input)
w.lastHeader = 0
return return
} }
// Write Huffman table. // Write Huffman table.
w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof) w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof)
w.lastHeader, _ = w.headerSize()
w.lastHuffMan = false
}
if sync {
w.lastHeader = 0
}
// Write the tokens. // Write the tokens.
w.writeTokens(tokens, w.literalEncoding.codes, w.offsetEncoding.codes) w.writeTokens(tokens.Slice(), w.literalEncoding.codes, w.offsetEncoding.codes)
} }
// indexTokens indexes a slice of tokens, and updates // indexTokens indexes a slice of tokens, and updates
// literalFreq and offsetFreq, and generates literalEncoding // literalFreq and offsetFreq, and generates literalEncoding
// and offsetEncoding. // and offsetEncoding.
// The number of literal and offset tokens is returned. // The number of literal and offset tokens is returned.
func (w *huffmanBitWriter) indexTokens(tokens []token) (numLiterals, numOffsets int) { func (w *huffmanBitWriter) indexTokens(t *tokens, filled bool) (numLiterals, numOffsets int) {
for i := range w.literalFreq { copy(w.literalFreq[:], t.litHist[:])
w.literalFreq[i] = 0 copy(w.literalFreq[256:], t.extraHist[:])
} copy(w.offsetFreq[:], t.offHist[:offsetCodeCount])
for i := range w.offsetFreq {
w.offsetFreq[i] = 0
}
for _, t := range tokens { if t.n == 0 {
if t < matchType { return
w.literalFreq[t.literal()]++
continue
} }
length := t.length() if filled {
offset := t.offset() return maxNumLit, maxNumDist
w.literalFreq[lengthCodesStart+lengthCode(length)]++
w.offsetFreq[offsetCode(offset)]++
} }
// get the number of literals // get the number of literals
numLiterals = len(w.literalFreq) numLiterals = len(w.literalFreq)
for w.literalFreq[numLiterals-1] == 0 { for w.literalFreq[numLiterals-1] == 0 {
@ -575,41 +694,85 @@ func (w *huffmanBitWriter) indexTokens(tokens []token) (numLiterals, numOffsets
w.offsetFreq[0] = 1 w.offsetFreq[0] = 1
numOffsets = 1 numOffsets = 1
} }
w.literalEncoding.generate(w.literalFreq, 15)
w.offsetEncoding.generate(w.offsetFreq, 15)
return return
} }
func (w *huffmanBitWriter) generate(t *tokens) {
w.literalEncoding.generate(w.literalFreq[:literalCount], 15)
w.offsetEncoding.generate(w.offsetFreq[:offsetCodeCount], 15)
}
// writeTokens writes a slice of tokens to the output. // writeTokens writes a slice of tokens to the output.
// codes for literal and offset encoding must be supplied. // codes for literal and offset encoding must be supplied.
func (w *huffmanBitWriter) writeTokens(tokens []token, leCodes, oeCodes []hcode) { func (w *huffmanBitWriter) writeTokens(tokens []token, leCodes, oeCodes []hcode) {
if w.err != nil { if w.err != nil {
return return
} }
if len(tokens) == 0 {
return
}
// Only last token should be endBlockMarker.
var deferEOB bool
if tokens[len(tokens)-1] == endBlockMarker {
tokens = tokens[:len(tokens)-1]
deferEOB = true
}
// Create slices up to the next power of two to avoid bounds checks.
lits := leCodes[:256]
offs := oeCodes[:32]
lengths := leCodes[lengthCodesStart:]
lengths = lengths[:32]
for _, t := range tokens { for _, t := range tokens {
if t < matchType { if t < matchType {
w.writeCode(leCodes[t.literal()]) w.writeCode(lits[t.literal()])
continue continue
} }
// Write the length // Write the length
length := t.length() length := t.length()
lengthCode := lengthCode(length) lengthCode := lengthCode(length)
w.writeCode(leCodes[lengthCode+lengthCodesStart]) if false {
extraLengthBits := uint(lengthExtraBits[lengthCode]) w.writeCode(lengths[lengthCode&31])
} else {
// inlined
c := lengths[lengthCode&31]
w.bits |= uint64(c.code) << (w.nbits & 63)
w.nbits += c.len
if w.nbits >= 48 {
w.writeOutBits()
}
}
extraLengthBits := uint16(lengthExtraBits[lengthCode&31])
if extraLengthBits > 0 { if extraLengthBits > 0 {
extraLength := int32(length - lengthBase[lengthCode]) extraLength := int32(length - lengthBase[lengthCode&31])
w.writeBits(extraLength, extraLengthBits) w.writeBits(extraLength, extraLengthBits)
} }
// Write the offset // Write the offset
offset := t.offset() offset := t.offset()
offsetCode := offsetCode(offset) offsetCode := offsetCode(offset)
w.writeCode(oeCodes[offsetCode]) if false {
extraOffsetBits := uint(offsetExtraBits[offsetCode]) w.writeCode(offs[offsetCode&31])
} else {
// inlined
c := offs[offsetCode&31]
w.bits |= uint64(c.code) << (w.nbits & 63)
w.nbits += c.len
if w.nbits >= 48 {
w.writeOutBits()
}
}
extraOffsetBits := uint16(offsetExtraBits[offsetCode&63])
if extraOffsetBits > 0 { if extraOffsetBits > 0 {
extraOffset := int32(offset - offsetBase[offsetCode]) extraOffset := int32(offset - offsetBase[offsetCode&63])
w.writeBits(extraOffset, extraOffsetBits) w.writeBits(extraOffset, extraOffsetBits)
} }
} }
if deferEOB {
w.writeCode(leCodes[endBlockMarker])
}
} }
// huffOffset is a static offset encoder used for huffman only encoding. // huffOffset is a static offset encoder used for huffman only encoding.
@ -620,82 +783,99 @@ func init() {
w := newHuffmanBitWriter(nil) w := newHuffmanBitWriter(nil)
w.offsetFreq[0] = 1 w.offsetFreq[0] = 1
huffOffset = newHuffmanEncoder(offsetCodeCount) huffOffset = newHuffmanEncoder(offsetCodeCount)
huffOffset.generate(w.offsetFreq, 15) huffOffset.generate(w.offsetFreq[:offsetCodeCount], 15)
} }
// writeBlockHuff encodes a block of bytes as either // writeBlockHuff encodes a block of bytes as either
// Huffman encoded literals or uncompressed bytes if the // Huffman encoded literals or uncompressed bytes if the
// results only gains very little from compression. // results only gains very little from compression.
func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte) { func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte, sync bool) {
if w.err != nil { if w.err != nil {
return return
} }
// Clear histogram // Clear histogram
for i := range w.literalFreq { for i := range w.literalFreq[:] {
w.literalFreq[i] = 0 w.literalFreq[i] = 0
} }
if !w.lastHuffMan {
for i := range w.offsetFreq[:] {
w.offsetFreq[i] = 0
}
}
// Add everything as literals // Add everything as literals
histogram(input, w.literalFreq) estBits := histogramSize(input, w.literalFreq[:], !eof && !sync) + 15
w.literalFreq[endBlockMarker] = 1 // Store bytes, if we don't get a reasonable improvement.
ssize, storable := w.storedSize(input)
if storable && ssize < (estBits+estBits>>4) {
w.writeStoredHeader(len(input), eof)
w.writeBytes(input)
return
}
const numLiterals = endBlockMarker + 1 if w.lastHeader > 0 {
const numOffsets = 1 size, _ := w.dynamicSize(w.literalEncoding, huffOffset, w.lastHeader)
estBits += estBits >> (w.logReusePenalty)
w.literalEncoding.generate(w.literalFreq, 15) if estBits < size {
// We owe an EOB
w.writeCode(w.literalEncoding.codes[endBlockMarker])
w.lastHeader = 0
}
}
// Figure out smallest code. const numLiterals = endBlockMarker + 1
// Always use dynamic Huffman or Store const numOffsets = 1
var numCodegens int if w.lastHeader == 0 {
w.literalFreq[endBlockMarker] = 1
w.literalEncoding.generate(w.literalFreq[:numLiterals], 15)
// Generate codegen and codegenFrequencies, which indicates how to encode // Generate codegen and codegenFrequencies, which indicates how to encode
// the literalEncoding and the offsetEncoding. // the literalEncoding and the offsetEncoding.
w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, huffOffset) w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, huffOffset)
w.codegenEncoding.generate(w.codegenFreq[:], 7) w.codegenEncoding.generate(w.codegenFreq[:], 7)
size, numCodegens := w.dynamicSize(w.literalEncoding, huffOffset, 0) numCodegens := w.codegens()
// Store bytes, if we don't get a reasonable improvement.
if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) {
w.writeStoredHeader(len(input), eof)
w.writeBytes(input)
return
}
// Huffman. // Huffman.
w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof) w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof)
w.lastHuffMan = true
w.lastHeader, _ = w.headerSize()
}
encoding := w.literalEncoding.codes[:257] encoding := w.literalEncoding.codes[:257]
n := w.nbytes
for _, t := range input { for _, t := range input {
// Bitwriting inlined, ~30% speedup // Bitwriting inlined, ~30% speedup
c := encoding[t] c := encoding[t]
w.bits |= uint64(c.code) << w.nbits w.bits |= uint64(c.code) << ((w.nbits) & 63)
w.nbits += uint(c.len) w.nbits += c.len
if w.nbits < 48 { if w.nbits >= 48 {
continue
}
// Store 6 bytes
bits := w.bits bits := w.bits
w.bits >>= 48 w.bits >>= 48
w.nbits -= 48 w.nbits -= 48
bytes := w.bytes[n : n+6] n := w.nbytes
bytes[0] = byte(bits) w.bytes[n] = byte(bits)
bytes[1] = byte(bits >> 8) w.bytes[n+1] = byte(bits >> 8)
bytes[2] = byte(bits >> 16) w.bytes[n+2] = byte(bits >> 16)
bytes[3] = byte(bits >> 24) w.bytes[n+3] = byte(bits >> 24)
bytes[4] = byte(bits >> 32) w.bytes[n+4] = byte(bits >> 32)
bytes[5] = byte(bits >> 40) w.bytes[n+5] = byte(bits >> 40)
n += 6 n += 6
if n < bufferFlushSize { if n >= bufferFlushSize {
continue
}
w.write(w.bytes[:n])
if w.err != nil { if w.err != nil {
return // Return early in the event of write failures n = 0
return
} }
w.write(w.bytes[:n])
n = 0 n = 0
} }
w.nbytes = n w.nbytes = n
}
}
if eof || sync {
w.writeCode(encoding[endBlockMarker]) w.writeCode(encoding[endBlockMarker])
w.lastHeader = 0
w.lastHuffMan = false
}
} }

@ -6,9 +6,16 @@ package flate
import ( import (
"math" "math"
"math/bits"
"sort" "sort"
) )
const (
maxBitsLimit = 16
// number of valid literals
literalCount = 286
)
// hcode is a huffman code with a bit code and bit length. // hcode is a huffman code with a bit code and bit length.
type hcode struct { type hcode struct {
code, len uint16 code, len uint16
@ -24,7 +31,7 @@ type huffmanEncoder struct {
type literalNode struct { type literalNode struct {
literal uint16 literal uint16
freq int32 freq uint16
} }
// A levelInfo describes the state of the constructed tree for a given depth. // A levelInfo describes the state of the constructed tree for a given depth.
@ -53,18 +60,24 @@ func (h *hcode) set(code uint16, length uint16) {
h.code = code h.code = code
} }
func maxNode() literalNode { return literalNode{math.MaxUint16, math.MaxInt32} } 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 { func newHuffmanEncoder(size int) *huffmanEncoder {
return &huffmanEncoder{codes: make([]hcode, size)} // 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 // Generates a HuffmanCode corresponding to the fixed literal table
func generateFixedLiteralEncoding() *huffmanEncoder { func generateFixedLiteralEncoding() *huffmanEncoder {
h := newHuffmanEncoder(maxNumLit) h := newHuffmanEncoder(literalCount)
codes := h.codes codes := h.codes
var ch uint16 var ch uint16
for ch = 0; ch < maxNumLit; ch++ { for ch = 0; ch < literalCount; ch++ {
var bits uint16 var bits uint16
var size uint16 var size uint16
switch { switch {
@ -105,7 +118,7 @@ func generateFixedOffsetEncoding() *huffmanEncoder {
var fixedLiteralEncoding *huffmanEncoder = generateFixedLiteralEncoding() var fixedLiteralEncoding *huffmanEncoder = generateFixedLiteralEncoding()
var fixedOffsetEncoding *huffmanEncoder = generateFixedOffsetEncoding() var fixedOffsetEncoding *huffmanEncoder = generateFixedOffsetEncoding()
func (h *huffmanEncoder) bitLength(freq []int32) int { func (h *huffmanEncoder) bitLength(freq []uint16) int {
var total int var total int
for i, f := range freq { for i, f := range freq {
if f != 0 { if f != 0 {
@ -115,8 +128,6 @@ func (h *huffmanEncoder) bitLength(freq []int32) int {
return total return total
} }
const maxBitsLimit = 16
// Return the number of literals assigned to each bit size in the Huffman encoding // Return the number of literals assigned to each bit size in the Huffman encoding
// //
// This method is only called when list.length >= 3 // This method is only called when list.length >= 3
@ -160,9 +171,9 @@ func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
// We initialize the levels as if we had already figured this out. // We initialize the levels as if we had already figured this out.
levels[level] = levelInfo{ levels[level] = levelInfo{
level: level, level: level,
lastFreq: list[1].freq, lastFreq: int32(list[1].freq),
nextCharFreq: list[2].freq, nextCharFreq: int32(list[2].freq),
nextPairFreq: list[0].freq + list[1].freq, nextPairFreq: int32(list[0].freq) + int32(list[1].freq),
} }
leafCounts[level][level] = 2 leafCounts[level][level] = 2
if level == 1 { if level == 1 {
@ -194,7 +205,12 @@ func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
l.lastFreq = l.nextCharFreq l.lastFreq = l.nextCharFreq
// Lower leafCounts are the same of the previous node. // Lower leafCounts are the same of the previous node.
leafCounts[level][level] = n leafCounts[level][level] = n
l.nextCharFreq = list[n].freq e := list[n]
if e.literal < math.MaxUint16 {
l.nextCharFreq = int32(e.freq)
} else {
l.nextCharFreq = math.MaxInt32
}
} else { } else {
// The next item on this row is a pair from the previous row. // The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two // nextPairFreq isn't valid until we generate two
@ -270,12 +286,12 @@ func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalN
// //
// freq An array of frequencies, in which frequency[i] gives the frequency of literal i. // 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. // maxBits The maximum number of bits to use for any literal.
func (h *huffmanEncoder) generate(freq []int32, maxBits int32) { func (h *huffmanEncoder) generate(freq []uint16, maxBits int32) {
if h.freqcache == nil { if h.freqcache == nil {
// Allocate a reusable buffer with the longest possible frequency table. // Allocate a reusable buffer with the longest possible frequency table.
// Possible lengths are codegenCodeCount, offsetCodeCount and maxNumLit. // Possible lengths are codegenCodeCount, offsetCodeCount and literalCount.
// The largest of these is maxNumLit, so we allocate for that case. // The largest of these is literalCount, so we allocate for that case.
h.freqcache = make([]literalNode, maxNumLit+1) h.freqcache = make([]literalNode, literalCount+1)
} }
list := h.freqcache[:len(freq)+1] list := h.freqcache[:len(freq)+1]
// Number of non-zero literals // Number of non-zero literals
@ -342,3 +358,27 @@ func (s byFreq) Less(i, j int) bool {
} }
func (s byFreq) Swap(i, j int) { s[i], s[j] = s[j], s[i] } func (s byFreq) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
// histogramSize accumulates a histogram of b in h.
// An estimated size in bits is returned.
// Unassigned values are assigned '1' in the histogram.
// len(h) must be >= 256, and h's elements must be all zeroes.
func histogramSize(b []byte, h []uint16, fill bool) int {
h = h[:256]
for _, t := range b {
h[t]++
}
invTotal := 1.0 / float64(len(b))
shannon := 0.0
single := math.Ceil(-math.Log2(invTotal))
for i, v := range h[:] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
} else if fill {
shannon += single
h[i] = 1
}
}
return int(shannon + 0.99)
}

@ -9,19 +9,24 @@ package flate
import ( import (
"bufio" "bufio"
"fmt"
"io" "io"
"math/bits"
"strconv" "strconv"
"sync" "sync"
) )
const ( const (
maxCodeLen = 16 // max length of Huffman code 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 // 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 // additional proviso in section 3.2.5 which implies that distance codes
// 30 and 31 should never occur in compressed data. // 30 and 31 should never occur in compressed data.
maxNumLit = 286 maxNumLit = 286
maxNumDist = 30 maxNumDist = 30
numCodes = 19 // number of codes in Huffman meta-code numCodes = 19 // number of codes in Huffman meta-code
debugDecode = false
) )
// Initialize the fixedHuffmanDecoder only once upon first use. // Initialize the fixedHuffmanDecoder only once upon first use.
@ -102,8 +107,8 @@ const (
type huffmanDecoder struct { type huffmanDecoder struct {
min int // the minimum code length min int // the minimum code length
chunks [huffmanNumChunks]uint32 // chunks as described above chunks *[huffmanNumChunks]uint16 // chunks as described above
links [][]uint32 // overflow links links [][]uint16 // overflow links
linkMask uint32 // mask the width of the link table linkMask uint32 // mask the width of the link table
} }
@ -112,21 +117,24 @@ type huffmanDecoder struct {
// tree (i.e., neither over-subscribed nor under-subscribed). The exception is a // 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 // degenerate case where the tree has only a single symbol with length 1. Empty
// trees are permitted. // trees are permitted.
func (h *huffmanDecoder) init(bits []int) bool { func (h *huffmanDecoder) init(lengths []int) bool {
// Sanity enables additional runtime tests during Huffman // Sanity enables additional runtime tests during Huffman
// table construction. It's intended to be used during // table construction. It's intended to be used during
// development to supplement the currently ad-hoc unit tests. // development to supplement the currently ad-hoc unit tests.
const sanity = false const sanity = false
if h.chunks == nil {
h.chunks = &[huffmanNumChunks]uint16{}
}
if h.min != 0 { if h.min != 0 {
*h = huffmanDecoder{} *h = huffmanDecoder{chunks: h.chunks, links: h.links}
} }
// Count number of codes of each length, // Count number of codes of each length,
// compute min and max length. // compute min and max length.
var count [maxCodeLen]int var count [maxCodeLen]int
var min, max int var min, max int
for _, n := range bits { for _, n := range lengths {
if n == 0 { if n == 0 {
continue continue
} }
@ -136,7 +144,7 @@ func (h *huffmanDecoder) init(bits []int) bool {
if n > max { if n > max {
max = n max = n
} }
count[n]++ count[n&maxCodeLenMask]++
} }
// Empty tree. The decompressor.huffSym function will fail later if the tree // Empty tree. The decompressor.huffSym function will fail later if the tree
@ -154,8 +162,8 @@ func (h *huffmanDecoder) init(bits []int) bool {
var nextcode [maxCodeLen]int var nextcode [maxCodeLen]int
for i := min; i <= max; i++ { for i := min; i <= max; i++ {
code <<= 1 code <<= 1
nextcode[i] = code nextcode[i&maxCodeLenMask] = code
code += count[i] code += count[i&maxCodeLenMask]
} }
// Check that the coding is complete (i.e., that we've // Check that the coding is complete (i.e., that we've
@ -164,37 +172,56 @@ func (h *huffmanDecoder) init(bits []int) bool {
// accept degenerate single-code codings. See also // accept degenerate single-code codings. See also
// TestDegenerateHuffmanCoding. // TestDegenerateHuffmanCoding.
if code != 1<<uint(max) && !(code == 1 && max == 1) { 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 return false
} }
h.min = min h.min = min
chunks := h.chunks[:]
for i := range chunks {
chunks[i] = 0
}
if max > huffmanChunkBits { if max > huffmanChunkBits {
numLinks := 1 << (uint(max) - huffmanChunkBits) numLinks := 1 << (uint(max) - huffmanChunkBits)
h.linkMask = uint32(numLinks - 1) h.linkMask = uint32(numLinks - 1)
// create link tables // create link tables
link := nextcode[huffmanChunkBits+1] >> 1 link := nextcode[huffmanChunkBits+1] >> 1
h.links = make([][]uint32, huffmanNumChunks-link) 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++ { for j := uint(link); j < huffmanNumChunks; j++ {
reverse := int(reverseByte[j>>8]) | int(reverseByte[j&0xff])<<8 reverse := int(bits.Reverse16(uint16(j)))
reverse >>= uint(16 - huffmanChunkBits) reverse >>= uint(16 - huffmanChunkBits)
off := j - uint(link) off := j - uint(link)
if sanity && h.chunks[reverse] != 0 { if sanity && h.chunks[reverse] != 0 {
panic("impossible: overwriting existing chunk") panic("impossible: overwriting existing chunk")
} }
h.chunks[reverse] = uint32(off<<huffmanValueShift | (huffmanChunkBits + 1)) h.chunks[reverse] = uint16(off<<huffmanValueShift | (huffmanChunkBits + 1))
h.links[off] = make([]uint32, numLinks) 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 bits { for i, n := range lengths {
if n == 0 { if n == 0 {
continue continue
} }
code := nextcode[n] code := nextcode[n]
nextcode[n]++ nextcode[n]++
chunk := uint32(i<<huffmanValueShift | n) chunk := uint16(i<<huffmanValueShift | n)
reverse := int(reverseByte[code>>8]) | int(reverseByte[code&0xff])<<8 reverse := int(bits.Reverse16(uint16(code)))
reverse >>= uint(16 - n) reverse >>= uint(16 - n)
if n <= huffmanChunkBits { if n <= huffmanChunkBits {
for off := reverse; off < len(h.chunks); off += 1 << uint(n) { for off := reverse; off < len(h.chunks); off += 1 << uint(n) {
@ -326,6 +353,9 @@ func (f *decompressor) nextBlock() {
f.huffmanBlock() f.huffmanBlock()
default: default:
// 3 is reserved. // 3 is reserved.
if debugDecode {
fmt.Println("reserved data block encountered")
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
} }
} }
@ -404,11 +434,17 @@ func (f *decompressor) readHuffman() error {
} }
nlit := int(f.b&0x1F) + 257 nlit := int(f.b&0x1F) + 257
if nlit > maxNumLit { if nlit > maxNumLit {
if debugDecode {
fmt.Println("nlit > maxNumLit", nlit)
}
return CorruptInputError(f.roffset) return CorruptInputError(f.roffset)
} }
f.b >>= 5 f.b >>= 5
ndist := int(f.b&0x1F) + 1 ndist := int(f.b&0x1F) + 1
if ndist > maxNumDist { if ndist > maxNumDist {
if debugDecode {
fmt.Println("ndist > maxNumDist", ndist)
}
return CorruptInputError(f.roffset) return CorruptInputError(f.roffset)
} }
f.b >>= 5 f.b >>= 5
@ -432,6 +468,9 @@ func (f *decompressor) readHuffman() error {
f.codebits[codeOrder[i]] = 0 f.codebits[codeOrder[i]] = 0
} }
if !f.h1.init(f.codebits[0:]) { if !f.h1.init(f.codebits[0:]) {
if debugDecode {
fmt.Println("init codebits failed")
}
return CorruptInputError(f.roffset) return CorruptInputError(f.roffset)
} }
@ -459,6 +498,9 @@ func (f *decompressor) readHuffman() error {
rep = 3 rep = 3
nb = 2 nb = 2
if i == 0 { if i == 0 {
if debugDecode {
fmt.Println("i==0")
}
return CorruptInputError(f.roffset) return CorruptInputError(f.roffset)
} }
b = f.bits[i-1] b = f.bits[i-1]
@ -473,6 +515,9 @@ func (f *decompressor) readHuffman() error {
} }
for f.nb < nb { for f.nb < nb {
if err := f.moreBits(); err != nil { if err := f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits:", err)
}
return err return err
} }
} }
@ -480,6 +525,9 @@ func (f *decompressor) readHuffman() error {
f.b >>= nb f.b >>= nb
f.nb -= nb f.nb -= nb
if i+rep > n { if i+rep > n {
if debugDecode {
fmt.Println("i+rep > n", i, rep, n)
}
return CorruptInputError(f.roffset) return CorruptInputError(f.roffset)
} }
for j := 0; j < rep; j++ { for j := 0; j < rep; j++ {
@ -489,6 +537,9 @@ func (f *decompressor) readHuffman() error {
} }
if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) { 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) return CorruptInputError(f.roffset)
} }
@ -566,12 +617,18 @@ readLiteral:
length = 258 length = 258
n = 0 n = 0
default: default:
if debugDecode {
fmt.Println(v, ">= maxNumLit")
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
return return
} }
if n > 0 { if n > 0 {
for f.nb < n { for f.nb < n {
if err = f.moreBits(); err != nil { if err = f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits n>0:", err)
}
f.err = err f.err = err
return return
} }
@ -585,15 +642,21 @@ readLiteral:
if f.hd == nil { if f.hd == nil {
for f.nb < 5 { for f.nb < 5 {
if err = f.moreBits(); err != nil { if err = f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits f.nb<5:", err)
}
f.err = err f.err = err
return return
} }
} }
dist = int(reverseByte[(f.b&0x1F)<<3]) dist = int(bits.Reverse8(uint8(f.b & 0x1F << 3)))
f.b >>= 5 f.b >>= 5
f.nb -= 5 f.nb -= 5
} else { } else {
if dist, err = f.huffSym(f.hd); err != nil { if dist, err = f.huffSym(f.hd); err != nil {
if debugDecode {
fmt.Println("huffsym:", err)
}
f.err = err f.err = err
return return
} }
@ -608,6 +671,9 @@ readLiteral:
extra := (dist & 1) << nb extra := (dist & 1) << nb
for f.nb < nb { for f.nb < nb {
if err = f.moreBits(); err != nil { if err = f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits f.nb<nb:", err)
}
f.err = err f.err = err
return return
} }
@ -617,12 +683,18 @@ readLiteral:
f.nb -= nb f.nb -= nb
dist = 1<<(nb+1) + 1 + extra dist = 1<<(nb+1) + 1 + extra
default: default:
if debugDecode {
fmt.Println("dist too big:", dist, maxNumDist)
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
return return
} }
// No check on length; encoding can be prescient. // No check on length; encoding can be prescient.
if dist > f.dict.histSize() { if dist > f.dict.histSize() {
if debugDecode {
fmt.Println("dist > f.dict.histSize():", dist, f.dict.histSize())
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
return return
} }
@ -661,15 +733,15 @@ func (f *decompressor) dataBlock() {
nr, err := io.ReadFull(f.r, f.buf[0:4]) nr, err := io.ReadFull(f.r, f.buf[0:4])
f.roffset += int64(nr) f.roffset += int64(nr)
if err != nil { if err != nil {
if err == io.EOF { f.err = noEOF(err)
err = io.ErrUnexpectedEOF
}
f.err = err
return return
} }
n := int(f.buf[0]) | int(f.buf[1])<<8 n := int(f.buf[0]) | int(f.buf[1])<<8
nn := int(f.buf[2]) | int(f.buf[3])<<8 nn := int(f.buf[2]) | int(f.buf[3])<<8
if uint16(nn) != uint16(^n) { if uint16(nn) != uint16(^n) {
if debugDecode {
fmt.Println("uint16(nn) != uint16(^n)", nn, ^n)
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
return return
} }
@ -697,10 +769,7 @@ func (f *decompressor) copyData() {
f.copyLen -= cnt f.copyLen -= cnt
f.dict.writeMark(cnt) f.dict.writeMark(cnt)
if err != nil { if err != nil {
if err == io.EOF { f.err = noEOF(err)
err = io.ErrUnexpectedEOF
}
f.err = err
return return
} }
@ -722,13 +791,18 @@ func (f *decompressor) finishBlock() {
f.step = (*decompressor).nextBlock 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 { func (f *decompressor) moreBits() error {
c, err := f.r.ReadByte() c, err := f.r.ReadByte()
if err != nil { if err != nil {
if err == io.EOF { return noEOF(err)
err = io.ErrUnexpectedEOF
}
return err
} }
f.roffset++ f.roffset++
f.b |= uint32(c) << f.nb f.b |= uint32(c) << f.nb
@ -743,25 +817,40 @@ func (f *decompressor) huffSym(h *huffmanDecoder) (int, error) {
// cases, the chunks slice will be 0 for the invalid sequence, leading it // cases, the chunks slice will be 0 for the invalid sequence, leading it
// satisfy the n == 0 check below. // satisfy the n == 0 check below.
n := uint(h.min) n := uint(h.min)
// 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 {
for f.nb < n { for nb < n {
if err := f.moreBits(); err != nil { c, err := f.r.ReadByte()
return 0, err if err != nil {
f.b = b
f.nb = nb
return 0, noEOF(err)
} }
f.roffset++
b |= uint32(c) << (nb & 31)
nb += 8
} }
chunk := h.chunks[f.b&(huffmanNumChunks-1)] chunk := h.chunks[b&(huffmanNumChunks-1)]
n = uint(chunk & huffmanCountMask) n = uint(chunk & huffmanCountMask)
if n > huffmanChunkBits { if n > huffmanChunkBits {
chunk = h.links[chunk>>huffmanValueShift][(f.b>>huffmanChunkBits)&h.linkMask] chunk = h.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&h.linkMask]
n = uint(chunk & huffmanCountMask) n = uint(chunk & huffmanCountMask)
} }
if n <= f.nb { if n <= nb {
if n == 0 { if n == 0 {
f.b = b
f.nb = nb
if debugDecode {
fmt.Println("huffsym: n==0")
}
f.err = CorruptInputError(f.roffset) f.err = CorruptInputError(f.roffset)
return 0, f.err return 0, f.err
} }
f.b >>= n f.b = b >> (n & 31)
f.nb -= n f.nb = nb - n
return int(chunk >> huffmanValueShift), nil return int(chunk >> huffmanValueShift), nil
} }
} }
@ -799,6 +888,8 @@ func (f *decompressor) Reset(r io.Reader, dict []byte) error {
r: makeReader(r), r: makeReader(r),
bits: f.bits, bits: f.bits,
codebits: f.codebits, codebits: f.codebits,
h1: f.h1,
h2: f.h2,
dict: f.dict, dict: f.dict,
step: (*decompressor).nextBlock, step: (*decompressor).nextBlock,
} }

@ -0,0 +1,174 @@
package flate
// 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
)
// 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, val: cv}
nextHash = hash(uint32(now))
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == candidate.val {
e.table[nextHash] = tableEntry{offset: nextS + e.cur, val: uint32(now)}
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, val: cv}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == candidate.val {
e.table[nextHash] = tableEntry{offset: nextS + e.cur, val: uint32(now)}
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
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 {
emitLiteral(dst, src[nextEmit:s])
}
// Save the match found
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[hash(cv)] = tableEntry{offset: s + e.cur, val: cv}
}
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, val: uint32(x)}
x >>= 16
currHash := hash(uint32(x))
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2, val: uint32(x)}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x) != candidate.val {
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:])
}
}

@ -0,0 +1,199 @@
package flate
// 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
)
// 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, val: cv}
nextHash = hash4u(uint32(now), bTableBits)
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == candidate.val {
e.table[nextHash] = tableEntry{offset: nextS + e.cur, val: uint32(now)}
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, val: cv}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && cv == candidate.val {
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 {
emitLiteral(dst, src[nextEmit:s])
}
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, val: cv}
}
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, int32(i))
nextHash := hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i, val: uint32(x)}
// Skip one
x >>= 16
nextHash = hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i + 2, val: uint32(x)}
// Skip one
x >>= 16
nextHash = hash4u(uint32(x), bTableBits)
e.table[nextHash] = tableEntry{offset: e.cur + i + 4, val: uint32(x)}
}
// 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, val: uint32(x)}
e.table[prevHash2] = tableEntry{offset: o + 1, val: uint32(x >> 8)}
currHash := hash4u(uint32(x>>16), bTableBits)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2, val: uint32(x >> 16)}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x>>16) != candidate.val {
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:])
}
}

@ -0,0 +1,225 @@
package flate
// fastEncL3
type fastEncL3 struct {
fastGen
table [tableSize]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
)
// 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 := hash(cv)
s = nextS
nextS = s + 1 + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash]
now := load3232(src, nextS)
e.table[nextHash] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur, val: cv}}
// Check both candidates
candidate = candidates.Cur
offset := s - (candidate.offset - e.cur)
if cv == candidate.val {
if offset > maxMatchOffset {
cv = now
// Previous will also be invalid, we have nothing.
continue
}
o2 := s - (candidates.Prev.offset - e.cur)
if cv != candidates.Prev.val || o2 > maxMatchOffset {
break
}
// Both match and are valid, pick longest.
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 cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset <= maxMatchOffset {
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 {
emitLiteral(dst, src[nextEmit:s])
}
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 := hash(cv)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + t, val: cv},
}
}
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-3 to s.
x := load6432(src, s-3)
prevHash := hash(uint32(x))
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 3, val: uint32(x)},
}
x >>= 8
prevHash = hash(uint32(x))
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 2, val: uint32(x)},
}
x >>= 8
prevHash = hash(uint32(x))
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 1, val: uint32(x)},
}
x >>= 8
currHash := hash(uint32(x))
candidates := e.table[currHash]
cv = uint32(x)
e.table[currHash] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur, val: cv},
}
// Check both candidates
candidate = candidates.Cur
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset <= maxMatchOffset {
continue
}
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset <= maxMatchOffset {
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:])
}
}

@ -0,0 +1,210 @@
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
)
// 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, val: uint32(cv)}
e.table[nextHashS] = entry
e.bTable[nextHashL] = entry
t = lCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == lCandidate.val {
// We got a long match. Use that.
break
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == sCandidate.val {
// 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 && lCandidate.val == 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 {
emitLiteral(dst, src[nextEmit:s])
}
if false {
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, val: uint32(cv)}
e.bTable[hash7(cv, tableBits)] = tableEntry{offset: s + e.cur, val: uint32(cv)}
}
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, val: uint32(cv)}
t2 := tableEntry{val: uint32(cv >> 8), offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hash4u(t2.val, tableBits)] = t2
i += 3
for ; i < s-1; i += 3 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur, val: uint32(cv)}
t2 := tableEntry{val: uint32(cv >> 8), offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hash4u(t2.val, 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, val: uint32(x)}
e.bTable[prevHashL] = tableEntry{offset: o, val: uint32(x)}
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:])
}
}

@ -0,0 +1,276 @@
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
)
// 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, val: uint32(cv)}
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) == lCandidate.Cur.val {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == lCandidate.Prev.val {
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) == lCandidate.Prev.val {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == sCandidate.val {
// 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, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if lCandidate.Cur.val == 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 && lCandidate.Prev.val == 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)
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
emitLiteral(dst, src[nextEmit:s])
}
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))
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, val: uint32(cv)}
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, val: uint32(cv)}
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, val: uint32(cv)}
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, val: uint32(cv)}
t2 := tableEntry{offset: t.offset + 1, val: uint32(cv >> 8)}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hash4u(t2.val, 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, val: uint32(x)}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o, val: uint32(x)}, 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:])
}
}

@ -0,0 +1,279 @@
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
)
// 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, val: uint32(cv)}
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) == lCandidate.Cur.val {
// Long candidate matches at least 4 bytes.
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
// Check the previous long candidate as well.
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == lCandidate.Prev.val {
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) == lCandidate.Prev.val {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == sCandidate.val {
// 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, val: uint32(next)}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, 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 lCandidate.Cur.val == 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 && lCandidate.Prev.val == 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)
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
emitLiteral(dst, src[nextEmit:s])
}
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, val: uint32(cv)}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur, val: uint32(cv)}, 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, val: uint32(cv)}
t2 := tableEntry{offset: t.offset + 1, val: uint32(cv >> 8)}
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:])
}
}

@ -1,48 +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
var reverseByte = [256]byte{
0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
}
func reverseUint16(v uint16) uint16 {
return uint16(reverseByte[v>>8]) | uint16(reverseByte[v&0xFF])<<8
}
func reverseBits(number uint16, bitLength byte) uint16 {
return reverseUint16(number << uint8(16-bitLength))
}

@ -1,856 +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
// emitLiteral writes a literal chunk and returns the number of bytes written.
func emitLiteral(dst *tokens, lit []byte) {
ol := int(dst.n)
for i, v := range lit {
dst.tokens[(i+ol)&maxStoreBlockSize] = token(v)
}
dst.n += uint16(len(lit))
}
// emitCopy writes a copy chunk and returns the number of bytes written.
func emitCopy(dst *tokens, offset, length int) {
dst.tokens[dst.n] = matchToken(uint32(length-3), uint32(offset-minOffsetSize))
dst.n++
}
type snappyEnc interface {
Encode(dst *tokens, src []byte)
Reset()
}
func newSnappy(level int) snappyEnc {
switch level {
case 1:
return &snappyL1{}
case 2:
return &snappyL2{snappyGen: snappyGen{cur: maxStoreBlockSize, prev: make([]byte, 0, maxStoreBlockSize)}}
case 3:
return &snappyL3{snappyGen: snappyGen{cur: maxStoreBlockSize, prev: make([]byte, 0, maxStoreBlockSize)}}
case 4:
return &snappyL4{snappyL3{snappyGen: snappyGen{cur: maxStoreBlockSize, prev: make([]byte, 0, maxStoreBlockSize)}}}
default:
panic("invalid level specified")
}
}
const (
tableBits = 14 // Bits used in the table
tableSize = 1 << tableBits // Size of the table
tableMask = tableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks.
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
)
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
}
func hash(u uint32) uint32 {
return (u * 0x1e35a7bd) >> tableShift
}
// snappyL1 encapsulates level 1 compression
type snappyL1 struct{}
func (e *snappyL1) Reset() {}
func (e *snappyL1) Encode(dst *tokens, src []byte) {
const (
inputMargin = 16 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
// 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
}
// Initialize the hash table.
//
// The table element type is uint16, as s < sLimit and sLimit < len(src)
// and len(src) <= maxStoreBlockSize and maxStoreBlockSize == 65535.
var table [tableSize]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))
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))
// TODO: < should be <=, and add a test for that.
if s-candidate < maxMatchOffset && 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.
emitLiteral(dst, 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 Snappy's:
// s = extendMatch(src, candidate+4, s+4)
s += 4
s1 := base + maxMatchLength
if s1 > len(src) {
s1 = len(src)
}
a := src[s:s1]
b := src[candidate+4:]
b = b[:len(a)]
l := len(a)
for i := range a {
if a[i] != b[i] {
l = i
break
}
}
s += l
// matchToken is flate's equivalent of Snappy's emitCopy.
dst.tokens[dst.n] = matchToken(uint32(s-base-baseMatchLength), uint32(base-candidate-baseMatchOffset))
dst.n++
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))
table[prevHash&tableMask] = uint16(s - 1)
currHash := hash(uint32(x >> 8))
candidate = int(table[currHash&tableMask])
table[currHash&tableMask] = uint16(s)
// TODO: >= should be >, and add a test for that.
if s-candidate >= maxMatchOffset || uint32(x>>8) != load32(src, candidate) {
nextHash = hash(uint32(x >> 16))
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
emitLiteral(dst, src[nextEmit:])
}
}
type tableEntry struct {
val uint32
offset int32
}
func load3232(b []byte, i int32) 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 load6432(b []byte, i int32) 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
}
// snappyGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type snappyGen struct {
prev []byte
cur int32
}
// snappyGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type snappyL2 struct {
snappyGen
table [tableSize]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 *snappyL2) Encode(dst *tokens, src []byte) {
const (
inputMargin = 16 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
// Ensure that e.cur doesn't wrap, mainly an issue on 32 bits.
if e.cur > 1<<30 {
for i := range e.table {
e.table[i] = tableEntry{}
}
e.cur = maxStoreBlockSize
}
// 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))
e.cur += maxStoreBlockSize
e.prev = e.prev[:0]
return
}
// 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.
nextEmit := int32(0)
s := int32(0)
cv := load3232(src, s)
nextHash := hash(cv)
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 := int32(32)
nextS := s
var candidate tableEntry
for {
s = nextS
bytesBetweenHashLookups := skip >> 5
nextS = s + bytesBetweenHashLookups
skip += bytesBetweenHashLookups
if nextS > sLimit {
goto emitRemainder
}
candidate = e.table[nextHash&tableMask]
now := load3232(src, nextS)
e.table[nextHash&tableMask] = tableEntry{offset: s + e.cur, val: cv}
nextHash = hash(now)
offset := s - (candidate.offset - e.cur)
if offset >= maxMatchOffset || cv != candidate.val {
// Out of range or not matched.
cv = now
continue
}
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.
emitLiteral(dst, 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.
// Extend the 4-byte match as long as possible.
//
s += 4
t := candidate.offset - e.cur + 4
l := e.matchlen(s, t, src)
// matchToken is flate's equivalent of Snappy's emitCopy. (length,offset)
dst.tokens[dst.n] = matchToken(uint32(l+4-baseMatchLength), uint32(s-t-baseMatchOffset))
dst.n++
s += l
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 := load6432(src, s-1)
prevHash := hash(uint32(x))
e.table[prevHash&tableMask] = tableEntry{offset: e.cur + s - 1, val: uint32(x)}
x >>= 8
currHash := hash(uint32(x))
candidate = e.table[currHash&tableMask]
e.table[currHash&tableMask] = tableEntry{offset: e.cur + s, val: uint32(x)}
offset := s - (candidate.offset - e.cur)
if offset >= maxMatchOffset || uint32(x) != candidate.val {
cv = uint32(x >> 8)
nextHash = hash(cv)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
emitLiteral(dst, src[nextEmit:])
}
e.cur += int32(len(src))
e.prev = e.prev[:len(src)]
copy(e.prev, src)
}
type tableEntryPrev struct {
Cur tableEntry
Prev tableEntry
}
// snappyL3
type snappyL3 struct {
snappyGen
table [tableSize]tableEntryPrev
}
// Encode uses a similar algorithm to level 2, will check up to two candidates.
func (e *snappyL3) Encode(dst *tokens, src []byte) {
const (
inputMargin = 16 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
// Ensure that e.cur doesn't wrap, mainly an issue on 32 bits.
if e.cur > 1<<30 {
for i := range e.table {
e.table[i] = tableEntryPrev{}
}
e.cur = maxStoreBlockSize
}
// 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))
e.cur += maxStoreBlockSize
e.prev = e.prev[:0]
return
}
// 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.
nextEmit := int32(0)
s := int32(0)
cv := load3232(src, s)
nextHash := hash(cv)
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 := int32(32)
nextS := s
var candidate tableEntry
for {
s = nextS
bytesBetweenHashLookups := skip >> 5
nextS = s + bytesBetweenHashLookups
skip += bytesBetweenHashLookups
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash&tableMask]
now := load3232(src, nextS)
e.table[nextHash&tableMask] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur, val: cv}}
nextHash = hash(now)
// Check both candidates
candidate = candidates.Cur
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
break
}
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
break
}
}
}
cv = 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.
emitLiteral(dst, 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.
// Extend the 4-byte match as long as possible.
//
s += 4
t := candidate.offset - e.cur + 4
l := e.matchlen(s, t, src)
// matchToken is flate's equivalent of Snappy's emitCopy. (length,offset)
dst.tokens[dst.n] = matchToken(uint32(l+4-baseMatchLength), uint32(s-t-baseMatchOffset))
dst.n++
s += l
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-2, 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 := load6432(src, s-2)
prevHash := hash(uint32(x))
e.table[prevHash&tableMask] = tableEntryPrev{
Prev: e.table[prevHash&tableMask].Cur,
Cur: tableEntry{offset: e.cur + s - 2, val: uint32(x)},
}
x >>= 8
prevHash = hash(uint32(x))
e.table[prevHash&tableMask] = tableEntryPrev{
Prev: e.table[prevHash&tableMask].Cur,
Cur: tableEntry{offset: e.cur + s - 1, val: uint32(x)},
}
x >>= 8
currHash := hash(uint32(x))
candidates := e.table[currHash&tableMask]
cv = uint32(x)
e.table[currHash&tableMask] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur, val: cv},
}
// Check both candidates
candidate = candidates.Cur
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
continue
}
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
continue
}
}
}
cv = uint32(x >> 8)
nextHash = hash(cv)
s++
break
}
}
emitRemainder:
if int(nextEmit) < len(src) {
emitLiteral(dst, src[nextEmit:])
}
e.cur += int32(len(src))
e.prev = e.prev[:len(src)]
copy(e.prev, src)
}
// snappyL4
type snappyL4 struct {
snappyL3
}
// Encode uses a similar algorithm to level 3,
// but will check up to two candidates if first isn't long enough.
func (e *snappyL4) Encode(dst *tokens, src []byte) {
const (
inputMargin = 16 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
matchLenGood = 12
)
// Ensure that e.cur doesn't wrap, mainly an issue on 32 bits.
if e.cur > 1<<30 {
for i := range e.table {
e.table[i] = tableEntryPrev{}
}
e.cur = maxStoreBlockSize
}
// 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))
e.cur += maxStoreBlockSize
e.prev = e.prev[:0]
return
}
// 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.
nextEmit := int32(0)
s := int32(0)
cv := load3232(src, s)
nextHash := hash(cv)
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 := int32(32)
nextS := s
var candidate tableEntry
var candidateAlt tableEntry
for {
s = nextS
bytesBetweenHashLookups := skip >> 5
nextS = s + bytesBetweenHashLookups
skip += bytesBetweenHashLookups
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash&tableMask]
now := load3232(src, nextS)
e.table[nextHash&tableMask] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur, val: cv}}
nextHash = hash(now)
// Check both candidates
candidate = candidates.Cur
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
offset = s - (candidates.Prev.offset - e.cur)
if cv == candidates.Prev.val && offset < maxMatchOffset {
candidateAlt = candidates.Prev
}
break
}
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
break
}
}
}
cv = 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.
emitLiteral(dst, 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.
// Extend the 4-byte match as long as possible.
//
s += 4
t := candidate.offset - e.cur + 4
l := e.matchlen(s, t, src)
// Try alternative candidate if match length < matchLenGood.
if l < matchLenGood-4 && candidateAlt.offset != 0 {
t2 := candidateAlt.offset - e.cur + 4
l2 := e.matchlen(s, t2, src)
if l2 > l {
l = l2
t = t2
}
}
// matchToken is flate's equivalent of Snappy's emitCopy. (length,offset)
dst.tokens[dst.n] = matchToken(uint32(l+4-baseMatchLength), uint32(s-t-baseMatchOffset))
dst.n++
s += l
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-2, 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 := load6432(src, s-2)
prevHash := hash(uint32(x))
e.table[prevHash&tableMask] = tableEntryPrev{
Prev: e.table[prevHash&tableMask].Cur,
Cur: tableEntry{offset: e.cur + s - 2, val: uint32(x)},
}
x >>= 8
prevHash = hash(uint32(x))
e.table[prevHash&tableMask] = tableEntryPrev{
Prev: e.table[prevHash&tableMask].Cur,
Cur: tableEntry{offset: e.cur + s - 1, val: uint32(x)},
}
x >>= 8
currHash := hash(uint32(x))
candidates := e.table[currHash&tableMask]
cv = uint32(x)
e.table[currHash&tableMask] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur, val: cv},
}
// Check both candidates
candidate = candidates.Cur
candidateAlt = tableEntry{}
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
offset = s - (candidates.Prev.offset - e.cur)
if cv == candidates.Prev.val && offset < maxMatchOffset {
candidateAlt = candidates.Prev
}
continue
}
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if cv == candidate.val {
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset {
continue
}
}
}
cv = uint32(x >> 8)
nextHash = hash(cv)
s++
break
}
}
emitRemainder:
if int(nextEmit) < len(src) {
emitLiteral(dst, src[nextEmit:])
}
e.cur += int32(len(src))
e.prev = e.prev[:len(src)]
copy(e.prev, src)
}
func (e *snappyGen) matchlen(s, t int32, src []byte) int32 {
s1 := int(s) + maxMatchLength - 4
if s1 > len(src) {
s1 = len(src)
}
// If we are inside the current block
if t >= 0 {
b := src[t:]
a := src[s:s1]
b = b[:len(a)]
// Extend the match to be as long as possible.
for i := range a {
if a[i] != b[i] {
return int32(i)
}
}
return int32(len(a))
}
// We found a match in the previous block.
tp := int32(len(e.prev)) + t
if tp < 0 {
return 0
}
// Extend the match to be as long as possible.
a := src[s:s1]
b := e.prev[tp:]
if len(b) > len(a) {
b = b[:len(a)]
}
a = a[:len(b)]
for i := range b {
if a[i] != b[i] {
return int32(i)
}
}
n := int32(len(b))
a = src[s+n : s1]
b = src[:len(a)]
for i := range a {
if a[i] != b[i] {
return int32(i) + n
}
}
return int32(len(a)) + n
}
// Reset the encoding table.
func (e *snappyGen) Reset() {
e.prev = e.prev[:0]
e.cur += maxMatchOffset + 1
}

@ -0,0 +1,252 @@
package flate
import (
"io"
"math"
)
const (
maxStatelessBlock = math.MaxInt16
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)
}
func (s *statelessWriter) Write(p []byte) (n int, err error) {
err = StatelessDeflate(s.dst, p, false)
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}
}
// StatelessDeflate allows to compress directly to a Writer without retaining state.
// When returning everything will be flushed.
func StatelessDeflate(out io.Writer, in []byte, eof bool) error {
var dst tokens
bw := newHuffmanBitWriter(out)
if eof && len(in) == 0 {
// Just write an EOF block.
// Could be faster...
bw.writeStoredHeader(0, true)
bw.flush()
return bw.err
}
for len(in) > 0 {
todo := in
if len(todo) > maxStatelessBlock {
todo = todo[:maxStatelessBlock]
}
in = in[len(todo):]
// Compress
statelessEnc(&dst, todo)
isEof := eof && len(in) == 0
if dst.n == 0 {
bw.writeStoredHeader(len(todo), isEof)
if bw.err != nil {
return bw.err
}
bw.writeBytes(todo)
} else if int(dst.n) > len(todo)-len(todo)>>4 {
// If we removed less than 1/16th, huffman compress the block.
bw.writeBlockHuff(isEof, todo, false)
} else {
bw.writeBlockDynamic(&dst, isEof, todo, false)
}
if bw.err != nil {
return bw.err
}
dst.Reset()
}
if !eof {
// Align.
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) {
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) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
s := int16(1)
nextEmit := int16(0)
// 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 {
emitLiteral(dst, src[nextEmit:s])
}
// 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:])
}
}

@ -4,7 +4,13 @@
package flate package flate
import "fmt" import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
)
const ( const (
// 2 bits: type 0 = literal 1=EOF 2=Match 3=Unused // 2 bits: type 0 = literal 1=EOF 2=Match 3=Unused
@ -19,7 +25,7 @@ const (
// The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH) // The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH)
// is lengthCodes[length - MIN_MATCH_LENGTH] // is lengthCodes[length - MIN_MATCH_LENGTH]
var lengthCodes = [...]uint32{ var lengthCodes = [256]uint8{
0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 12, 12, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15,
@ -48,7 +54,37 @@ var lengthCodes = [...]uint32{
27, 27, 27, 27, 27, 28, 27, 27, 27, 27, 27, 28,
} }
var offsetCodes = [...]uint32{ // 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, 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, 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, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
@ -67,49 +103,265 @@ var offsetCodes = [...]uint32{
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 token uint32
type tokens struct { type tokens struct {
tokens [maxStoreBlockSize + 1]token nLits int
extraHist [32]uint16 // codes 256->maxnumlit
offHist [32]uint16 // offset codes
litHist [256]uint16 // codes 0->255
n uint16 // Must be able to contain maxStoreBlockSize 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.nLits = 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.nLits++
}
}
for i, v := range t.extraHist[:literalCount-256] {
if v == 0 {
t.nLits++
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.tokens[t.n] = tok
t.litHist[tok]++
t.n++
continue
}
t.AddMatch(uint32(tok.length()), tok.offset())
}
} }
// Convert a literal into a literal token. // emitLiteral writes a literal chunk and returns the number of bytes written.
func literalToken(literal uint32) token { return token(literalType + literal) } func emitLiteral(dst *tokens, lit []byte) {
ol := int(dst.n)
for i, v := range lit {
dst.tokens[(i+ol)&maxStoreBlockSize] = token(v)
dst.litHist[v]++
}
dst.n += uint16(len(lit))
dst.nLits += len(lit)
}
// Convert a < xlength, xoffset > pair into a match token. func (t *tokens) AddLiteral(lit byte) {
func matchToken(xlength uint32, xoffset uint32) token { t.tokens[t.n] = token(lit)
return token(matchType + xlength<<lengthShift + xoffset) t.litHist[lit]++
t.n++
t.nLits++
} }
func matchTokend(xlength uint32, xoffset uint32) token { // EstimatedBits will return an minimum size estimated by an *optimal*
if xlength > maxMatchLength || xoffset > maxMatchOffset { // compression of the block.
panic(fmt.Sprintf("Invalid match: len: %d, offset: %d\n", xlength, xoffset)) // The size of the block
return token(matchType) func (t *tokens) EstimatedBits() int {
shannon := float64(0)
bits := int(0)
nMatches := 0
if t.nLits > 0 {
invTotal := 1.0 / float64(t.nLits)
for _, v := range t.litHist[:] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
}
}
// Just add 15 for EOB
shannon += 15
for _, v := range t.extraHist[1 : literalCount-256] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
bits += int(lengthExtraBits[v&31]) * int(v)
nMatches += int(v)
}
}
}
if nMatches > 0 {
invTotal := 1.0 / float64(nMatches)
for _, v := range t.offHist[:offsetCodeCount] {
if v > 0 {
n := float64(v)
shannon += math.Ceil(-math.Log2(n*invTotal) * n)
bits += int(offsetExtraBits[v&31]) * int(n)
}
}
} }
return token(matchType + xlength<<lengthShift + xoffset)
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 debugDecode {
if xlength >= maxMatchLength+baseMatchLength {
panic(fmt.Errorf("invalid length: %v", xlength))
}
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
t.nLits++
lengthCode := lengthCodes1[uint8(xlength)] & 31
t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset)
t.extraHist[lengthCode]++
t.offHist[offsetCode(xoffset)&31]++
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 debugDecode {
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oc := offsetCode(xoffset) & 31
for xlength > 0 {
xl := xlength
if xl > 258 {
// We need to have at least baseMatchLength left over for next loop.
xl = 258 - baseMatchLength
}
xlength -= xl
xl -= 3
t.nLits++
lengthCode := lengthCodes1[uint8(xl)] & 31
t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
t.extraHist[lengthCode]++
t.offHist[oc]++
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 // Returns the type of a token
func (t token) typ() uint32 { return uint32(t) & typeMask } func (t token) typ() uint32 { return uint32(t) & typeMask }
// Returns the literal of a literal token // Returns the literal of a literal token
func (t token) literal() uint32 { return uint32(t - literalType) } func (t token) literal() uint8 { return uint8(t) }
// Returns the extra offset of a match token // Returns the extra offset of a match token
func (t token) offset() uint32 { return uint32(t) & offsetMask } func (t token) offset() uint32 { return uint32(t) & offsetMask }
func (t token) length() uint32 { return uint32((t - matchType) >> lengthShift) } func (t token) length() uint8 { return uint8(t >> lengthShift) }
func lengthCode(len uint32) uint32 { return lengthCodes[len] } // The code is never more than 8 bits, but is returned as uint32 for convenience.
func lengthCode(len uint8) uint32 { return uint32(lengthCodes[len]) }
// Returns the offset code corresponding to a specific offset // Returns the offset code corresponding to a specific offset
func offsetCode(off uint32) uint32 { func offsetCode(off uint32) uint32 {
if false {
if off < uint32(len(offsetCodes)) { if off < uint32(len(offsetCodes)) {
return offsetCodes[off] return offsetCodes[off&255]
} else if off>>7 < uint32(len(offsetCodes)) { } else if off>>7 < uint32(len(offsetCodes)) {
return offsetCodes[off>>7] + 14 return offsetCodes[(off>>7)&255] + 14
} else { } else {
return offsetCodes[off>>14] + 28 return offsetCodes[(off>>14)&255] + 28
}
}
if off < uint32(len(offsetCodes)) {
return offsetCodes[uint8(off)]
} }
return offsetCodes14[uint8(off>>7)]
} }

@ -10,11 +10,11 @@ import (
"bufio" "bufio"
"encoding/binary" "encoding/binary"
"errors" "errors"
"hash/crc32"
"io" "io"
"time" "time"
"github.com/klauspost/compress/flate" "github.com/klauspost/compress/flate"
"github.com/klauspost/crc32"
) )
const ( const (

@ -7,10 +7,10 @@ package gzip
import ( import (
"errors" "errors"
"fmt" "fmt"
"hash/crc32"
"io" "io"
"github.com/klauspost/compress/flate" "github.com/klauspost/compress/flate"
"github.com/klauspost/crc32"
) )
// These constants are copied from the flate package, so that code that imports // These constants are copied from the flate package, so that code that imports
@ -22,6 +22,13 @@ const (
DefaultCompression = flate.DefaultCompression DefaultCompression = flate.DefaultCompression
ConstantCompression = flate.ConstantCompression ConstantCompression = flate.ConstantCompression
HuffmanOnly = flate.HuffmanOnly 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. // A Writer is an io.WriteCloser.
@ -59,7 +66,7 @@ func NewWriter(w io.Writer) *Writer {
// integer value between BestSpeed and BestCompression inclusive. The error // integer value between BestSpeed and BestCompression inclusive. The error
// returned will be nil if the level is valid. // returned will be nil if the level is valid.
func NewWriterLevel(w io.Writer, level int) (*Writer, error) { func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
if level < HuffmanOnly || level > BestCompression { if level < StatelessCompression || level > BestCompression {
return nil, fmt.Errorf("gzip: invalid compression level: %d", level) return nil, fmt.Errorf("gzip: invalid compression level: %d", level)
} }
z := new(Writer) z := new(Writer)
@ -69,9 +76,12 @@ func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
func (z *Writer) init(w io.Writer, level int) { func (z *Writer) init(w io.Writer, level int) {
compressor := z.compressor compressor := z.compressor
if level != StatelessCompression {
if compressor != nil { if compressor != nil {
compressor.Reset(w) compressor.Reset(w)
} }
}
*z = Writer{ *z = Writer{
Header: Header{ Header: Header{
OS: 255, // unknown OS: 255, // unknown
@ -189,12 +199,16 @@ func (z *Writer) Write(p []byte) (int, error) {
return n, z.err return n, z.err
} }
} }
if z.compressor == nil {
if z.compressor == nil && z.level != StatelessCompression {
z.compressor, _ = flate.NewWriter(z.w, z.level) z.compressor, _ = flate.NewWriter(z.w, z.level)
} }
} }
z.size += uint32(len(p)) z.size += uint32(len(p))
z.digest = crc32.Update(z.digest, crc32.IEEETable, p) z.digest = crc32.Update(z.digest, crc32.IEEETable, p)
if z.level == StatelessCompression {
return len(p), flate.StatelessDeflate(z.w, p, false)
}
n, z.err = z.compressor.Write(p) n, z.err = z.compressor.Write(p)
return n, z.err return n, z.err
} }
@ -211,7 +225,7 @@ func (z *Writer) Flush() error {
if z.err != nil { if z.err != nil {
return z.err return z.err
} }
if z.closed { if z.closed || z.level == StatelessCompression {
return nil return nil
} }
if !z.wroteHeader { if !z.wroteHeader {
@ -240,7 +254,11 @@ func (z *Writer) Close() error {
return z.err return z.err
} }
} }
if z.level == StatelessCompression {
z.err = flate.StatelessDeflate(z.w, nil, true)
} else {
z.err = z.compressor.Close() z.err = z.compressor.Close()
}
if z.err != nil { if z.err != nil {
return z.err return z.err
} }

@ -1,24 +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

@ -1,8 +0,0 @@
language: go
go:
- 1.3
- 1.4
- 1.5
- 1.6
- tip

@ -1,22 +0,0 @@
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.

@ -1,145 +0,0 @@
# cpuid
Package cpuid provides information about the CPU running the current program.
CPU features are detected on startup, and kept for fast access through the life of the application.
Currently x86 / x64 (AMD64) is supported, and no external C (cgo) code is used, which should make the library very easy to use.
You can access the CPU information by accessing the shared CPU variable of the cpuid library.
Package home: https://github.com/klauspost/cpuid
[![GoDoc][1]][2] [![Build Status][3]][4]
[1]: https://godoc.org/github.com/klauspost/cpuid?status.svg
[2]: https://godoc.org/github.com/klauspost/cpuid
[3]: https://travis-ci.org/klauspost/cpuid.svg
[4]: https://travis-ci.org/klauspost/cpuid
# features
## CPU Instructions
* **CMOV** (i686 CMOV)
* **NX** (NX (No-Execute) bit)
* **AMD3DNOW** (AMD 3DNOW)
* **AMD3DNOWEXT** (AMD 3DNowExt)
* **MMX** (standard MMX)
* **MMXEXT** (SSE integer functions or AMD MMX ext)
* **SSE** (SSE functions)
* **SSE2** (P4 SSE functions)
* **SSE3** (Prescott SSE3 functions)
* **SSSE3** (Conroe SSSE3 functions)
* **SSE4** (Penryn SSE4.1 functions)
* **SSE4A** (AMD Barcelona microarchitecture SSE4a instructions)
* **SSE42** (Nehalem SSE4.2 functions)
* **AVX** (AVX functions)
* **AVX2** (AVX2 functions)
* **FMA3** (Intel FMA 3)
* **FMA4** (Bulldozer FMA4 functions)
* **XOP** (Bulldozer XOP functions)
* **F16C** (Half-precision floating-point conversion)
* **BMI1** (Bit Manipulation Instruction Set 1)
* **BMI2** (Bit Manipulation Instruction Set 2)
* **TBM** (AMD Trailing Bit Manipulation)
* **LZCNT** (LZCNT instruction)
* **POPCNT** (POPCNT instruction)
* **AESNI** (Advanced Encryption Standard New Instructions)
* **CLMUL** (Carry-less Multiplication)
* **HTT** (Hyperthreading (enabled))
* **HLE** (Hardware Lock Elision)
* **RTM** (Restricted Transactional Memory)
* **RDRAND** (RDRAND instruction is available)
* **RDSEED** (RDSEED instruction is available)
* **ADX** (Intel ADX (Multi-Precision Add-Carry Instruction Extensions))
* **SHA** (Intel SHA Extensions)
* **AVX512F** (AVX-512 Foundation)
* **AVX512DQ** (AVX-512 Doubleword and Quadword Instructions)
* **AVX512IFMA** (AVX-512 Integer Fused Multiply-Add Instructions)
* **AVX512PF** (AVX-512 Prefetch Instructions)
* **AVX512ER** (AVX-512 Exponential and Reciprocal Instructions)
* **AVX512CD** (AVX-512 Conflict Detection Instructions)
* **AVX512BW** (AVX-512 Byte and Word Instructions)
* **AVX512VL** (AVX-512 Vector Length Extensions)
* **AVX512VBMI** (AVX-512 Vector Bit Manipulation Instructions)
* **MPX** (Intel MPX (Memory Protection Extensions))
* **ERMS** (Enhanced REP MOVSB/STOSB)
* **RDTSCP** (RDTSCP Instruction)
* **CX16** (CMPXCHG16B Instruction)
* **SGX** (Software Guard Extensions, with activation details)
## Performance
* **RDTSCP()** Returns current cycle count. Can be used for benchmarking.
* **SSE2SLOW** (SSE2 is supported, but usually not faster)
* **SSE3SLOW** (SSE3 is supported, but usually not faster)
* **ATOM** (Atom processor, some SSSE3 instructions are slower)
* **Cache line** (Probable size of a cache line).
* **L1, L2, L3 Cache size** on newer Intel/AMD CPUs.
## Cpu Vendor/VM
* **Intel**
* **AMD**
* **VIA**
* **Transmeta**
* **NSC**
* **KVM** (Kernel-based Virtual Machine)
* **MSVM** (Microsoft Hyper-V or Windows Virtual PC)
* **VMware**
* **XenHVM**
# installing
```go get github.com/klauspost/cpuid```
# example
```Go
package main
import (
"fmt"
"github.com/klauspost/cpuid"
)
func main() {
// Print basic CPU information:
fmt.Println("Name:", cpuid.CPU.BrandName)
fmt.Println("PhysicalCores:", cpuid.CPU.PhysicalCores)
fmt.Println("ThreadsPerCore:", cpuid.CPU.ThreadsPerCore)
fmt.Println("LogicalCores:", cpuid.CPU.LogicalCores)
fmt.Println("Family", cpuid.CPU.Family, "Model:", cpuid.CPU.Model)
fmt.Println("Features:", cpuid.CPU.Features)
fmt.Println("Cacheline bytes:", cpuid.CPU.CacheLine)
fmt.Println("L1 Data Cache:", cpuid.CPU.Cache.L1D, "bytes")
fmt.Println("L1 Instruction Cache:", cpuid.CPU.Cache.L1D, "bytes")
fmt.Println("L2 Cache:", cpuid.CPU.Cache.L2, "bytes")
fmt.Println("L3 Cache:", cpuid.CPU.Cache.L3, "bytes")
// Test if we have a specific feature:
if cpuid.CPU.SSE() {
fmt.Println("We have Streaming SIMD Extensions")
}
}
```
Sample output:
```
>go run main.go
Name: Intel(R) Core(TM) i5-2540M CPU @ 2.60GHz
PhysicalCores: 2
ThreadsPerCore: 2
LogicalCores: 4
Family 6 Model: 42
Features: CMOV,MMX,MMXEXT,SSE,SSE2,SSE3,SSSE3,SSE4.1,SSE4.2,AVX,AESNI,CLMUL
Cacheline bytes: 64
We have Streaming SIMD Extensions
```
# private package
In the "private" folder you can find an autogenerated version of the library you can include in your own packages.
For this purpose all exports are removed, and functions and constants are lowercased.
This is not a recommended way of using the library, but provided for convenience, if it is difficult for you to use external packages.
# license
This code is published under an MIT license. See LICENSE file for more information.

File diff suppressed because it is too large Load Diff

@ -1,42 +0,0 @@
// Copyright (c) 2015 Klaus Post, released under MIT License. See LICENSE file.
// +build 386,!gccgo
// func asmCpuid(op uint32) (eax, ebx, ecx, edx uint32)
TEXT ·asmCpuid(SB), 7, $0
XORL CX, CX
MOVL op+0(FP), AX
CPUID
MOVL AX, eax+4(FP)
MOVL BX, ebx+8(FP)
MOVL CX, ecx+12(FP)
MOVL DX, edx+16(FP)
RET
// func asmCpuidex(op, op2 uint32) (eax, ebx, ecx, edx uint32)
TEXT ·asmCpuidex(SB), 7, $0
MOVL op+0(FP), AX
MOVL op2+4(FP), CX
CPUID
MOVL AX, eax+8(FP)
MOVL BX, ebx+12(FP)
MOVL CX, ecx+16(FP)
MOVL DX, edx+20(FP)
RET
// func xgetbv(index uint32) (eax, edx uint32)
TEXT ·asmXgetbv(SB), 7, $0
MOVL index+0(FP), CX
BYTE $0x0f; BYTE $0x01; BYTE $0xd0 // XGETBV
MOVL AX, eax+4(FP)
MOVL DX, edx+8(FP)
RET
// func asmRdtscpAsm() (eax, ebx, ecx, edx uint32)
TEXT ·asmRdtscpAsm(SB), 7, $0
BYTE $0x0F; BYTE $0x01; BYTE $0xF9 // RDTSCP
MOVL AX, eax+0(FP)
MOVL BX, ebx+4(FP)
MOVL CX, ecx+8(FP)
MOVL DX, edx+12(FP)
RET

@ -1,42 +0,0 @@
// Copyright (c) 2015 Klaus Post, released under MIT License. See LICENSE file.
//+build amd64,!gccgo
// func asmCpuid(op uint32) (eax, ebx, ecx, edx uint32)
TEXT ·asmCpuid(SB), 7, $0
XORQ CX, CX
MOVL op+0(FP), AX
CPUID
MOVL AX, eax+8(FP)
MOVL BX, ebx+12(FP)
MOVL CX, ecx+16(FP)
MOVL DX, edx+20(FP)
RET
// func asmCpuidex(op, op2 uint32) (eax, ebx, ecx, edx uint32)
TEXT ·asmCpuidex(SB), 7, $0
MOVL op+0(FP), AX
MOVL op2+4(FP), CX
CPUID
MOVL AX, eax+8(FP)
MOVL BX, ebx+12(FP)
MOVL CX, ecx+16(FP)
MOVL DX, edx+20(FP)
RET
// func asmXgetbv(index uint32) (eax, edx uint32)
TEXT ·asmXgetbv(SB), 7, $0
MOVL index+0(FP), CX
BYTE $0x0f; BYTE $0x01; BYTE $0xd0 // XGETBV
MOVL AX, eax+8(FP)
MOVL DX, edx+12(FP)
RET
// func asmRdtscpAsm() (eax, ebx, ecx, edx uint32)
TEXT ·asmRdtscpAsm(SB), 7, $0
BYTE $0x0F; BYTE $0x01; BYTE $0xF9 // RDTSCP
MOVL AX, eax+0(FP)
MOVL BX, ebx+4(FP)
MOVL CX, ecx+8(FP)
MOVL DX, edx+12(FP)
RET

@ -1,17 +0,0 @@
// Copyright (c) 2015 Klaus Post, released under MIT License. See LICENSE file.
// +build 386,!gccgo amd64,!gccgo
package cpuid
func asmCpuid(op uint32) (eax, ebx, ecx, edx uint32)
func asmCpuidex(op, op2 uint32) (eax, ebx, ecx, edx uint32)
func asmXgetbv(index uint32) (eax, edx uint32)
func asmRdtscpAsm() (eax, ebx, ecx, edx uint32)
func initCPU() {
cpuid = asmCpuid
cpuidex = asmCpuidex
xgetbv = asmXgetbv
rdtscpAsm = asmRdtscpAsm
}

@ -1,23 +0,0 @@
// Copyright (c) 2015 Klaus Post, released under MIT License. See LICENSE file.
// +build !amd64,!386 gccgo
package cpuid
func initCPU() {
cpuid = func(op uint32) (eax, ebx, ecx, edx uint32) {
return 0, 0, 0, 0
}
cpuidex = func(op, op2 uint32) (eax, ebx, ecx, edx uint32) {
return 0, 0, 0, 0
}
xgetbv = func(index uint32) (eax, edx uint32) {
return 0, 0
}
rdtscpAsm = func() (eax, ebx, ecx, edx uint32) {
return 0, 0, 0, 0
}
}

@ -1,3 +0,0 @@
package cpuid
//go:generate go run private-gen.go

@ -1,24 +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

@ -1,13 +0,0 @@
language: go
go:
- 1.3
- 1.4
- 1.5
- 1.6
- 1.7
- tip
script:
- go test -v .
- go test -v -race .

@ -1,28 +0,0 @@
Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2015 Klaus Post
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.

@ -1,87 +0,0 @@
# crc32
CRC32 hash with x64 optimizations
This package is a drop-in replacement for the standard library `hash/crc32` package, that features SSE 4.2 optimizations on x64 platforms, for a 10x speedup.
[![Build Status](https://travis-ci.org/klauspost/crc32.svg?branch=master)](https://travis-ci.org/klauspost/crc32)
# usage
Install using `go get github.com/klauspost/crc32`. This library is based on Go 1.5 code and requires Go 1.3 or newer.
Replace `import "hash/crc32"` with `import "github.com/klauspost/crc32"` and you are good to go.
# changes
* Oct 20, 2016: Changes have been merged to upstream Go. Package updated to match.
* Dec 4, 2015: Uses the "slice-by-8" trick more extensively, which gives a 1.5 to 2.5x speedup if assembler is unavailable.
# performance
For *Go 1.7* performance is equivalent to the standard library. So if you use this package for Go 1.7 you can switch back.
For IEEE tables (the most common), there is approximately a factor 10 speedup with "CLMUL" (Carryless multiplication) instruction:
```
benchmark old ns/op new ns/op delta
BenchmarkCrc32KB 99955 10258 -89.74%
benchmark old MB/s new MB/s speedup
BenchmarkCrc32KB 327.83 3194.20 9.74x
```
For other tables and "CLMUL" capable machines the performance is the same as the standard library.
Here are some detailed benchmarks, comparing to go 1.5 standard library with and without assembler enabled.
```
Std: Standard Go 1.5 library
Crc: Indicates IEEE type CRC.
40B: Size of each slice encoded.
NoAsm: Assembler was disabled (ie. not an AMD64 or SSE 4.2+ capable machine).
Castagnoli: Castagnoli CRC type.
BenchmarkStdCrc40B-4 10000000 158 ns/op 252.88 MB/s
BenchmarkCrc40BNoAsm-4 20000000 105 ns/op 377.38 MB/s (slice8)
BenchmarkCrc40B-4 20000000 105 ns/op 378.77 MB/s (slice8)
BenchmarkStdCrc1KB-4 500000 3604 ns/op 284.10 MB/s
BenchmarkCrc1KBNoAsm-4 1000000 1463 ns/op 699.79 MB/s (slice8)
BenchmarkCrc1KB-4 3000000 396 ns/op 2583.69 MB/s (asm)
BenchmarkStdCrc8KB-4 200000 11417 ns/op 717.48 MB/s (slice8)
BenchmarkCrc8KBNoAsm-4 200000 11317 ns/op 723.85 MB/s (slice8)
BenchmarkCrc8KB-4 500000 2919 ns/op 2805.73 MB/s (asm)
BenchmarkStdCrc32KB-4 30000 45749 ns/op 716.24 MB/s (slice8)
BenchmarkCrc32KBNoAsm-4 30000 45109 ns/op 726.42 MB/s (slice8)
BenchmarkCrc32KB-4 100000 11497 ns/op 2850.09 MB/s (asm)
BenchmarkStdNoAsmCastagnol40B-4 10000000 161 ns/op 246.94 MB/s
BenchmarkStdCastagnoli40B-4 50000000 28.4 ns/op 1410.69 MB/s (asm)
BenchmarkCastagnoli40BNoAsm-4 20000000 100 ns/op 398.01 MB/s (slice8)
BenchmarkCastagnoli40B-4 50000000 28.2 ns/op 1419.54 MB/s (asm)
BenchmarkStdNoAsmCastagnoli1KB-4 500000 3622 ns/op 282.67 MB/s
BenchmarkStdCastagnoli1KB-4 10000000 144 ns/op 7099.78 MB/s (asm)
BenchmarkCastagnoli1KBNoAsm-4 1000000 1475 ns/op 694.14 MB/s (slice8)
BenchmarkCastagnoli1KB-4 10000000 146 ns/op 6993.35 MB/s (asm)
BenchmarkStdNoAsmCastagnoli8KB-4 50000 28781 ns/op 284.63 MB/s
BenchmarkStdCastagnoli8KB-4 1000000 1029 ns/op 7957.89 MB/s (asm)
BenchmarkCastagnoli8KBNoAsm-4 200000 11410 ns/op 717.94 MB/s (slice8)
BenchmarkCastagnoli8KB-4 1000000 1000 ns/op 8188.71 MB/s (asm)
BenchmarkStdNoAsmCastagnoli32KB-4 10000 115426 ns/op 283.89 MB/s
BenchmarkStdCastagnoli32KB-4 300000 4065 ns/op 8059.13 MB/s (asm)
BenchmarkCastagnoli32KBNoAsm-4 30000 45171 ns/op 725.41 MB/s (slice8)
BenchmarkCastagnoli32KB-4 500000 4077 ns/op 8035.89 MB/s (asm)
```
The IEEE assembler optimizations has been submitted and will be part of the Go 1.6 standard library.
However, the improved use of slice-by-8 has not, but will probably be submitted for Go 1.7.
# license
Standard Go license. Changes are Copyright (c) 2015 Klaus Post under same conditions.

@ -1,207 +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 crc32 implements the 32-bit cyclic redundancy check, or CRC-32,
// checksum. See http://en.wikipedia.org/wiki/Cyclic_redundancy_check for
// information.
//
// Polynomials are represented in LSB-first form also known as reversed representation.
//
// See http://en.wikipedia.org/wiki/Mathematics_of_cyclic_redundancy_checks#Reversed_representations_and_reciprocal_polynomials
// for information.
package crc32
import (
"hash"
"sync"
)
// The size of a CRC-32 checksum in bytes.
const Size = 4
// Predefined polynomials.
const (
// IEEE is by far and away the most common CRC-32 polynomial.
// Used by ethernet (IEEE 802.3), v.42, fddi, gzip, zip, png, ...
IEEE = 0xedb88320
// Castagnoli's polynomial, used in iSCSI.
// Has better error detection characteristics than IEEE.
// http://dx.doi.org/10.1109/26.231911
Castagnoli = 0x82f63b78
// Koopman's polynomial.
// Also has better error detection characteristics than IEEE.
// http://dx.doi.org/10.1109/DSN.2002.1028931
Koopman = 0xeb31d82e
)
// Table is a 256-word table representing the polynomial for efficient processing.
type Table [256]uint32
// This file makes use of functions implemented in architecture-specific files.
// The interface that they implement is as follows:
//
// // archAvailableIEEE reports whether an architecture-specific CRC32-IEEE
// // algorithm is available.
// archAvailableIEEE() bool
//
// // archInitIEEE initializes the architecture-specific CRC3-IEEE algorithm.
// // It can only be called if archAvailableIEEE() returns true.
// archInitIEEE()
//
// // archUpdateIEEE updates the given CRC32-IEEE. It can only be called if
// // archInitIEEE() was previously called.
// archUpdateIEEE(crc uint32, p []byte) uint32
//
// // archAvailableCastagnoli reports whether an architecture-specific
// // CRC32-C algorithm is available.
// archAvailableCastagnoli() bool
//
// // archInitCastagnoli initializes the architecture-specific CRC32-C
// // algorithm. It can only be called if archAvailableCastagnoli() returns
// // true.
// archInitCastagnoli()
//
// // archUpdateCastagnoli updates the given CRC32-C. It can only be called
// // if archInitCastagnoli() was previously called.
// archUpdateCastagnoli(crc uint32, p []byte) uint32
// castagnoliTable points to a lazily initialized Table for the Castagnoli
// polynomial. MakeTable will always return this value when asked to make a
// Castagnoli table so we can compare against it to find when the caller is
// using this polynomial.
var castagnoliTable *Table
var castagnoliTable8 *slicing8Table
var castagnoliArchImpl bool
var updateCastagnoli func(crc uint32, p []byte) uint32
var castagnoliOnce sync.Once
func castagnoliInit() {
castagnoliTable = simpleMakeTable(Castagnoli)
castagnoliArchImpl = archAvailableCastagnoli()
if castagnoliArchImpl {
archInitCastagnoli()
updateCastagnoli = archUpdateCastagnoli
} else {
// Initialize the slicing-by-8 table.
castagnoliTable8 = slicingMakeTable(Castagnoli)
updateCastagnoli = func(crc uint32, p []byte) uint32 {
return slicingUpdate(crc, castagnoliTable8, p)
}
}
}
// IEEETable is the table for the IEEE polynomial.
var IEEETable = simpleMakeTable(IEEE)
// ieeeTable8 is the slicing8Table for IEEE
var ieeeTable8 *slicing8Table
var ieeeArchImpl bool
var updateIEEE func(crc uint32, p []byte) uint32
var ieeeOnce sync.Once
func ieeeInit() {
ieeeArchImpl = archAvailableIEEE()
if ieeeArchImpl {
archInitIEEE()
updateIEEE = archUpdateIEEE
} else {
// Initialize the slicing-by-8 table.
ieeeTable8 = slicingMakeTable(IEEE)
updateIEEE = func(crc uint32, p []byte) uint32 {
return slicingUpdate(crc, ieeeTable8, p)
}
}
}
// MakeTable returns a Table constructed from the specified polynomial.
// The contents of this Table must not be modified.
func MakeTable(poly uint32) *Table {
switch poly {
case IEEE:
ieeeOnce.Do(ieeeInit)
return IEEETable
case Castagnoli:
castagnoliOnce.Do(castagnoliInit)
return castagnoliTable
}
return simpleMakeTable(poly)
}
// digest represents the partial evaluation of a checksum.
type digest struct {
crc uint32
tab *Table
}
// New creates a new hash.Hash32 computing the CRC-32 checksum
// using the polynomial represented by the Table.
// Its Sum method will lay the value out in big-endian byte order.
func New(tab *Table) hash.Hash32 {
if tab == IEEETable {
ieeeOnce.Do(ieeeInit)
}
return &digest{0, tab}
}
// NewIEEE creates a new hash.Hash32 computing the CRC-32 checksum
// using the IEEE polynomial.
// Its Sum method will lay the value out in big-endian byte order.
func NewIEEE() hash.Hash32 { return New(IEEETable) }
func (d *digest) Size() int { return Size }
func (d *digest) BlockSize() int { return 1 }
func (d *digest) Reset() { d.crc = 0 }
// Update returns the result of adding the bytes in p to the crc.
func Update(crc uint32, tab *Table, p []byte) uint32 {
switch tab {
case castagnoliTable:
return updateCastagnoli(crc, p)
case IEEETable:
// Unfortunately, because IEEETable is exported, IEEE may be used without a
// call to MakeTable. We have to make sure it gets initialized in that case.
ieeeOnce.Do(ieeeInit)
return updateIEEE(crc, p)
default:
return simpleUpdate(crc, tab, p)
}
}
func (d *digest) Write(p []byte) (n int, err error) {
switch d.tab {
case castagnoliTable:
d.crc = updateCastagnoli(d.crc, p)
case IEEETable:
// We only create digest objects through New() which takes care of
// initialization in this case.
d.crc = updateIEEE(d.crc, p)
default:
d.crc = simpleUpdate(d.crc, d.tab, p)
}
return len(p), nil
}
func (d *digest) Sum32() uint32 { return d.crc }
func (d *digest) Sum(in []byte) []byte {
s := d.Sum32()
return append(in, byte(s>>24), byte(s>>16), byte(s>>8), byte(s))
}
// Checksum returns the CRC-32 checksum of data
// using the polynomial represented by the Table.
func Checksum(data []byte, tab *Table) uint32 { return Update(0, tab, data) }
// ChecksumIEEE returns the CRC-32 checksum of data
// using the IEEE polynomial.
func ChecksumIEEE(data []byte) uint32 {
ieeeOnce.Do(ieeeInit)
return updateIEEE(0, data)
}

@ -1,230 +0,0 @@
// Copyright 2011 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,!gccgo
// AMD64-specific hardware-assisted CRC32 algorithms. See crc32.go for a
// description of the interface that each architecture-specific file
// implements.
package crc32
import "unsafe"
// This file contains the code to call the SSE 4.2 version of the Castagnoli
// and IEEE CRC.
// haveSSE41/haveSSE42/haveCLMUL are defined in crc_amd64.s and use
// CPUID to test for SSE 4.1, 4.2 and CLMUL support.
func haveSSE41() bool
func haveSSE42() bool
func haveCLMUL() bool
// castagnoliSSE42 is defined in crc32_amd64.s and uses the SSE4.2 CRC32
// instruction.
//go:noescape
func castagnoliSSE42(crc uint32, p []byte) uint32
// castagnoliSSE42Triple is defined in crc32_amd64.s and uses the SSE4.2 CRC32
// instruction.
//go:noescape
func castagnoliSSE42Triple(
crcA, crcB, crcC uint32,
a, b, c []byte,
rounds uint32,
) (retA uint32, retB uint32, retC uint32)
// ieeeCLMUL is defined in crc_amd64.s and uses the PCLMULQDQ
// instruction as well as SSE 4.1.
//go:noescape
func ieeeCLMUL(crc uint32, p []byte) uint32
var sse42 = haveSSE42()
var useFastIEEE = haveCLMUL() && haveSSE41()
const castagnoliK1 = 168
const castagnoliK2 = 1344
type sse42Table [4]Table
var castagnoliSSE42TableK1 *sse42Table
var castagnoliSSE42TableK2 *sse42Table
func archAvailableCastagnoli() bool {
return sse42
}
func archInitCastagnoli() {
if !sse42 {
panic("arch-specific Castagnoli not available")
}
castagnoliSSE42TableK1 = new(sse42Table)
castagnoliSSE42TableK2 = new(sse42Table)
// See description in updateCastagnoli.
// t[0][i] = CRC(i000, O)
// t[1][i] = CRC(0i00, O)
// t[2][i] = CRC(00i0, O)
// t[3][i] = CRC(000i, O)
// where O is a sequence of K zeros.
var tmp [castagnoliK2]byte
for b := 0; b < 4; b++ {
for i := 0; i < 256; i++ {
val := uint32(i) << uint32(b*8)
castagnoliSSE42TableK1[b][i] = castagnoliSSE42(val, tmp[:castagnoliK1])
castagnoliSSE42TableK2[b][i] = castagnoliSSE42(val, tmp[:])
}
}
}
// castagnoliShift computes the CRC32-C of K1 or K2 zeroes (depending on the
// table given) with the given initial crc value. This corresponds to
// CRC(crc, O) in the description in updateCastagnoli.
func castagnoliShift(table *sse42Table, crc uint32) uint32 {
return table[3][crc>>24] ^
table[2][(crc>>16)&0xFF] ^
table[1][(crc>>8)&0xFF] ^
table[0][crc&0xFF]
}
func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
if !sse42 {
panic("not available")
}
// This method is inspired from the algorithm in Intel's white paper:
// "Fast CRC Computation for iSCSI Polynomial Using CRC32 Instruction"
// The same strategy of splitting the buffer in three is used but the
// combining calculation is different; the complete derivation is explained
// below.
//
// -- The basic idea --
//
// The CRC32 instruction (available in SSE4.2) can process 8 bytes at a
// time. In recent Intel architectures the instruction takes 3 cycles;
// however the processor can pipeline up to three instructions if they
// don't depend on each other.
//
// Roughly this means that we can process three buffers in about the same
// time we can process one buffer.
//
// The idea is then to split the buffer in three, CRC the three pieces
// separately and then combine the results.
//
// Combining the results requires precomputed tables, so we must choose a
// fixed buffer length to optimize. The longer the length, the faster; but
// only buffers longer than this length will use the optimization. We choose
// two cutoffs and compute tables for both:
// - one around 512: 168*3=504
// - one around 4KB: 1344*3=4032
//
// -- The nitty gritty --
//
// Let CRC(I, X) be the non-inverted CRC32-C of the sequence X (with
// initial non-inverted CRC I). This function has the following properties:
// (a) CRC(I, AB) = CRC(CRC(I, A), B)
// (b) CRC(I, A xor B) = CRC(I, A) xor CRC(0, B)
//
// Say we want to compute CRC(I, ABC) where A, B, C are three sequences of
// K bytes each, where K is a fixed constant. Let O be the sequence of K zero
// bytes.
//
// CRC(I, ABC) = CRC(I, ABO xor C)
// = CRC(I, ABO) xor CRC(0, C)
// = CRC(CRC(I, AB), O) xor CRC(0, C)
// = CRC(CRC(I, AO xor B), O) xor CRC(0, C)
// = CRC(CRC(I, AO) xor CRC(0, B), O) xor CRC(0, C)
// = CRC(CRC(CRC(I, A), O) xor CRC(0, B), O) xor CRC(0, C)
//
// The castagnoliSSE42Triple function can compute CRC(I, A), CRC(0, B),
// and CRC(0, C) efficiently. We just need to find a way to quickly compute
// CRC(uvwx, O) given a 4-byte initial value uvwx. We can precompute these
// values; since we can't have a 32-bit table, we break it up into four
// 8-bit tables:
//
// CRC(uvwx, O) = CRC(u000, O) xor
// CRC(0v00, O) xor
// CRC(00w0, O) xor
// CRC(000x, O)
//
// We can compute tables corresponding to the four terms for all 8-bit
// values.
crc = ^crc
// If a buffer is long enough to use the optimization, process the first few
// bytes to align the buffer to an 8 byte boundary (if necessary).
if len(p) >= castagnoliK1*3 {
delta := int(uintptr(unsafe.Pointer(&p[0])) & 7)
if delta != 0 {
delta = 8 - delta
crc = castagnoliSSE42(crc, p[:delta])
p = p[delta:]
}
}
// Process 3*K2 at a time.
for len(p) >= castagnoliK2*3 {
// Compute CRC(I, A), CRC(0, B), and CRC(0, C).
crcA, crcB, crcC := castagnoliSSE42Triple(
crc, 0, 0,
p, p[castagnoliK2:], p[castagnoliK2*2:],
castagnoliK2/24)
// CRC(I, AB) = CRC(CRC(I, A), O) xor CRC(0, B)
crcAB := castagnoliShift(castagnoliSSE42TableK2, crcA) ^ crcB
// CRC(I, ABC) = CRC(CRC(I, AB), O) xor CRC(0, C)
crc = castagnoliShift(castagnoliSSE42TableK2, crcAB) ^ crcC
p = p[castagnoliK2*3:]
}
// Process 3*K1 at a time.
for len(p) >= castagnoliK1*3 {
// Compute CRC(I, A), CRC(0, B), and CRC(0, C).
crcA, crcB, crcC := castagnoliSSE42Triple(
crc, 0, 0,
p, p[castagnoliK1:], p[castagnoliK1*2:],
castagnoliK1/24)
// CRC(I, AB) = CRC(CRC(I, A), O) xor CRC(0, B)
crcAB := castagnoliShift(castagnoliSSE42TableK1, crcA) ^ crcB
// CRC(I, ABC) = CRC(CRC(I, AB), O) xor CRC(0, C)
crc = castagnoliShift(castagnoliSSE42TableK1, crcAB) ^ crcC
p = p[castagnoliK1*3:]
}
// Use the simple implementation for what's left.
crc = castagnoliSSE42(crc, p)
return ^crc
}
func archAvailableIEEE() bool {
return useFastIEEE
}
var archIeeeTable8 *slicing8Table
func archInitIEEE() {
if !useFastIEEE {
panic("not available")
}
// We still use slicing-by-8 for small buffers.
archIeeeTable8 = slicingMakeTable(IEEE)
}
func archUpdateIEEE(crc uint32, p []byte) uint32 {
if !useFastIEEE {
panic("not available")
}
if len(p) >= 64 {
left := len(p) & 15
do := len(p) - left
crc = ^ieeeCLMUL(^crc, p[:do])
p = p[do:]
}
if len(p) == 0 {
return crc
}
return slicingUpdate(crc, archIeeeTable8, p)
}

@ -1,319 +0,0 @@
// Copyright 2011 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 gc
#define NOSPLIT 4
#define RODATA 8
// castagnoliSSE42 updates the (non-inverted) crc with the given buffer.
//
// func castagnoliSSE42(crc uint32, p []byte) uint32
TEXT ·castagnoliSSE42(SB), NOSPLIT, $0
MOVL crc+0(FP), AX // CRC value
MOVQ p+8(FP), SI // data pointer
MOVQ p_len+16(FP), CX // len(p)
// If there are fewer than 8 bytes to process, skip alignment.
CMPQ CX, $8
JL less_than_8
MOVQ SI, BX
ANDQ $7, BX
JZ aligned
// Process the first few bytes to 8-byte align the input.
// BX = 8 - BX. We need to process this many bytes to align.
SUBQ $1, BX
XORQ $7, BX
BTQ $0, BX
JNC align_2
CRC32B (SI), AX
DECQ CX
INCQ SI
align_2:
BTQ $1, BX
JNC align_4
// CRC32W (SI), AX
BYTE $0x66; BYTE $0xf2; BYTE $0x0f; BYTE $0x38; BYTE $0xf1; BYTE $0x06
SUBQ $2, CX
ADDQ $2, SI
align_4:
BTQ $2, BX
JNC aligned
// CRC32L (SI), AX
BYTE $0xf2; BYTE $0x0f; BYTE $0x38; BYTE $0xf1; BYTE $0x06
SUBQ $4, CX
ADDQ $4, SI
aligned:
// The input is now 8-byte aligned and we can process 8-byte chunks.
CMPQ CX, $8
JL less_than_8
CRC32Q (SI), AX
ADDQ $8, SI
SUBQ $8, CX
JMP aligned
less_than_8:
// We may have some bytes left over; process 4 bytes, then 2, then 1.
BTQ $2, CX
JNC less_than_4
// CRC32L (SI), AX
BYTE $0xf2; BYTE $0x0f; BYTE $0x38; BYTE $0xf1; BYTE $0x06
ADDQ $4, SI
less_than_4:
BTQ $1, CX
JNC less_than_2
// CRC32W (SI), AX
BYTE $0x66; BYTE $0xf2; BYTE $0x0f; BYTE $0x38; BYTE $0xf1; BYTE $0x06
ADDQ $2, SI
less_than_2:
BTQ $0, CX
JNC done
CRC32B (SI), AX
done:
MOVL AX, ret+32(FP)
RET
// castagnoliSSE42Triple updates three (non-inverted) crcs with (24*rounds)
// bytes from each buffer.
//
// func castagnoliSSE42Triple(
// crc1, crc2, crc3 uint32,
// a, b, c []byte,
// rounds uint32,
// ) (retA uint32, retB uint32, retC uint32)
TEXT ·castagnoliSSE42Triple(SB), NOSPLIT, $0
MOVL crcA+0(FP), AX
MOVL crcB+4(FP), CX
MOVL crcC+8(FP), DX
MOVQ a+16(FP), R8 // data pointer
MOVQ b+40(FP), R9 // data pointer
MOVQ c+64(FP), R10 // data pointer
MOVL rounds+88(FP), R11
loop:
CRC32Q (R8), AX
CRC32Q (R9), CX
CRC32Q (R10), DX
CRC32Q 8(R8), AX
CRC32Q 8(R9), CX
CRC32Q 8(R10), DX
CRC32Q 16(R8), AX
CRC32Q 16(R9), CX
CRC32Q 16(R10), DX
ADDQ $24, R8
ADDQ $24, R9
ADDQ $24, R10
DECQ R11
JNZ loop
MOVL AX, retA+96(FP)
MOVL CX, retB+100(FP)
MOVL DX, retC+104(FP)
RET
// func haveSSE42() bool
TEXT ·haveSSE42(SB), NOSPLIT, $0
XORQ AX, AX
INCL AX
CPUID
SHRQ $20, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// func haveCLMUL() bool
TEXT ·haveCLMUL(SB), NOSPLIT, $0
XORQ AX, AX
INCL AX
CPUID
SHRQ $1, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// func haveSSE41() bool
TEXT ·haveSSE41(SB), NOSPLIT, $0
XORQ AX, AX
INCL AX
CPUID
SHRQ $19, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// CRC32 polynomial data
//
// These constants are lifted from the
// Linux kernel, since they avoid the costly
// PSHUFB 16 byte reversal proposed in the
// original Intel paper.
DATA r2r1kp<>+0(SB)/8, $0x154442bd4
DATA r2r1kp<>+8(SB)/8, $0x1c6e41596
DATA r4r3kp<>+0(SB)/8, $0x1751997d0
DATA r4r3kp<>+8(SB)/8, $0x0ccaa009e
DATA rupolykp<>+0(SB)/8, $0x1db710641
DATA rupolykp<>+8(SB)/8, $0x1f7011641
DATA r5kp<>+0(SB)/8, $0x163cd6124
GLOBL r2r1kp<>(SB), RODATA, $16
GLOBL r4r3kp<>(SB), RODATA, $16
GLOBL rupolykp<>(SB), RODATA, $16
GLOBL r5kp<>(SB), RODATA, $8
// Based on http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
// len(p) must be at least 64, and must be a multiple of 16.
// func ieeeCLMUL(crc uint32, p []byte) uint32
TEXT ·ieeeCLMUL(SB), NOSPLIT, $0
MOVL crc+0(FP), X0 // Initial CRC value
MOVQ p+8(FP), SI // data pointer
MOVQ p_len+16(FP), CX // len(p)
MOVOU (SI), X1
MOVOU 16(SI), X2
MOVOU 32(SI), X3
MOVOU 48(SI), X4
PXOR X0, X1
ADDQ $64, SI // buf+=64
SUBQ $64, CX // len-=64
CMPQ CX, $64 // Less than 64 bytes left
JB remain64
MOVOA r2r1kp<>+0(SB), X0
loopback64:
MOVOA X1, X5
MOVOA X2, X6
MOVOA X3, X7
MOVOA X4, X8
PCLMULQDQ $0, X0, X1
PCLMULQDQ $0, X0, X2
PCLMULQDQ $0, X0, X3
PCLMULQDQ $0, X0, X4
// Load next early
MOVOU (SI), X11
MOVOU 16(SI), X12
MOVOU 32(SI), X13
MOVOU 48(SI), X14
PCLMULQDQ $0x11, X0, X5
PCLMULQDQ $0x11, X0, X6
PCLMULQDQ $0x11, X0, X7
PCLMULQDQ $0x11, X0, X8
PXOR X5, X1
PXOR X6, X2
PXOR X7, X3
PXOR X8, X4
PXOR X11, X1
PXOR X12, X2
PXOR X13, X3
PXOR X14, X4
ADDQ $0x40, DI
ADDQ $64, SI // buf+=64
SUBQ $64, CX // len-=64
CMPQ CX, $64 // Less than 64 bytes left?
JGE loopback64
// Fold result into a single register (X1)
remain64:
MOVOA r4r3kp<>+0(SB), X0
MOVOA X1, X5
PCLMULQDQ $0, X0, X1
PCLMULQDQ $0x11, X0, X5
PXOR X5, X1
PXOR X2, X1
MOVOA X1, X5
PCLMULQDQ $0, X0, X1
PCLMULQDQ $0x11, X0, X5
PXOR X5, X1
PXOR X3, X1
MOVOA X1, X5
PCLMULQDQ $0, X0, X1
PCLMULQDQ $0x11, X0, X5
PXOR X5, X1
PXOR X4, X1
// If there is less than 16 bytes left we are done
CMPQ CX, $16
JB finish
// Encode 16 bytes
remain16:
MOVOU (SI), X10
MOVOA X1, X5
PCLMULQDQ $0, X0, X1
PCLMULQDQ $0x11, X0, X5
PXOR X5, X1
PXOR X10, X1
SUBQ $16, CX
ADDQ $16, SI
CMPQ CX, $16
JGE remain16
finish:
// Fold final result into 32 bits and return it
PCMPEQB X3, X3
PCLMULQDQ $1, X1, X0
PSRLDQ $8, X1
PXOR X0, X1
MOVOA X1, X2
MOVQ r5kp<>+0(SB), X0
// Creates 32 bit mask. Note that we don't care about upper half.
PSRLQ $32, X3
PSRLDQ $4, X2
PAND X3, X1
PCLMULQDQ $0, X0, X1
PXOR X2, X1
MOVOA rupolykp<>+0(SB), X0
MOVOA X1, X2
PAND X3, X1
PCLMULQDQ $0x10, X0, X1
PAND X3, X1
PCLMULQDQ $0, X0, X1
PXOR X2, X1
// PEXTRD $1, X1, AX (SSE 4.1)
BYTE $0x66; BYTE $0x0f; BYTE $0x3a
BYTE $0x16; BYTE $0xc8; BYTE $0x01
MOVL AX, ret+32(FP)
RET

@ -1,43 +0,0 @@
// Copyright 2011 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,!gccgo
package crc32
// This file contains the code to call the SSE 4.2 version of the Castagnoli
// CRC.
// haveSSE42 is defined in crc32_amd64p32.s and uses CPUID to test for SSE 4.2
// support.
func haveSSE42() bool
// castagnoliSSE42 is defined in crc32_amd64p32.s and uses the SSE4.2 CRC32
// instruction.
//go:noescape
func castagnoliSSE42(crc uint32, p []byte) uint32
var sse42 = haveSSE42()
func archAvailableCastagnoli() bool {
return sse42
}
func archInitCastagnoli() {
if !sse42 {
panic("not available")
}
// No initialization necessary.
}
func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
if !sse42 {
panic("not available")
}
return castagnoliSSE42(crc, p)
}
func archAvailableIEEE() bool { return false }
func archInitIEEE() { panic("not available") }
func archUpdateIEEE(crc uint32, p []byte) uint32 { panic("not available") }

@ -1,67 +0,0 @@
// Copyright 2011 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 gc
#define NOSPLIT 4
#define RODATA 8
// func castagnoliSSE42(crc uint32, p []byte) uint32
TEXT ·castagnoliSSE42(SB), NOSPLIT, $0
MOVL crc+0(FP), AX // CRC value
MOVL p+4(FP), SI // data pointer
MOVL p_len+8(FP), CX // len(p)
NOTL AX
// If there's less than 8 bytes to process, we do it byte-by-byte.
CMPQ CX, $8
JL cleanup
// Process individual bytes until the input is 8-byte aligned.
startup:
MOVQ SI, BX
ANDQ $7, BX
JZ aligned
CRC32B (SI), AX
DECQ CX
INCQ SI
JMP startup
aligned:
// The input is now 8-byte aligned and we can process 8-byte chunks.
CMPQ CX, $8
JL cleanup
CRC32Q (SI), AX
ADDQ $8, SI
SUBQ $8, CX
JMP aligned
cleanup:
// We may have some bytes left over that we process one at a time.
CMPQ CX, $0
JE done
CRC32B (SI), AX
INCQ SI
DECQ CX
JMP cleanup
done:
NOTL AX
MOVL AX, ret+16(FP)
RET
// func haveSSE42() bool
TEXT ·haveSSE42(SB), NOSPLIT, $0
XORQ AX, AX
INCL AX
CPUID
SHRQ $20, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET

@ -1,89 +0,0 @@
// Copyright 2011 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.
// This file contains CRC32 algorithms that are not specific to any architecture
// and don't use hardware acceleration.
//
// The simple (and slow) CRC32 implementation only uses a 256*4 bytes table.
//
// The slicing-by-8 algorithm is a faster implementation that uses a bigger
// table (8*256*4 bytes).
package crc32
// simpleMakeTable allocates and constructs a Table for the specified
// polynomial. The table is suitable for use with the simple algorithm
// (simpleUpdate).
func simpleMakeTable(poly uint32) *Table {
t := new(Table)
simplePopulateTable(poly, t)
return t
}
// simplePopulateTable constructs a Table for the specified polynomial, suitable
// for use with simpleUpdate.
func simplePopulateTable(poly uint32, t *Table) {
for i := 0; i < 256; i++ {
crc := uint32(i)
for j := 0; j < 8; j++ {
if crc&1 == 1 {
crc = (crc >> 1) ^ poly
} else {
crc >>= 1
}
}
t[i] = crc
}
}
// simpleUpdate uses the simple algorithm to update the CRC, given a table that
// was previously computed using simpleMakeTable.
func simpleUpdate(crc uint32, tab *Table, p []byte) uint32 {
crc = ^crc
for _, v := range p {
crc = tab[byte(crc)^v] ^ (crc >> 8)
}
return ^crc
}
// Use slicing-by-8 when payload >= this value.
const slicing8Cutoff = 16
// slicing8Table is array of 8 Tables, used by the slicing-by-8 algorithm.
type slicing8Table [8]Table
// slicingMakeTable constructs a slicing8Table for the specified polynomial. The
// table is suitable for use with the slicing-by-8 algorithm (slicingUpdate).
func slicingMakeTable(poly uint32) *slicing8Table {
t := new(slicing8Table)
simplePopulateTable(poly, &t[0])
for i := 0; i < 256; i++ {
crc := t[0][i]
for j := 1; j < 8; j++ {
crc = t[0][crc&0xFF] ^ (crc >> 8)
t[j][i] = crc
}
}
return t
}
// slicingUpdate uses the slicing-by-8 algorithm to update the CRC, given a
// table that was previously computed using slicingMakeTable.
func slicingUpdate(crc uint32, tab *slicing8Table, p []byte) uint32 {
if len(p) >= slicing8Cutoff {
crc = ^crc
for len(p) > 8 {
crc ^= uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24
crc = tab[0][p[7]] ^ tab[1][p[6]] ^ tab[2][p[5]] ^ tab[3][p[4]] ^
tab[4][crc>>24] ^ tab[5][(crc>>16)&0xFF] ^
tab[6][(crc>>8)&0xFF] ^ tab[7][crc&0xFF]
p = p[8:]
}
crc = ^crc
}
if len(p) == 0 {
return crc
}
return simpleUpdate(crc, &tab[0], p)
}

@ -1,15 +0,0 @@
// Copyright 2011 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 !amd64,!amd64p32,!s390x
package crc32
func archAvailableIEEE() bool { return false }
func archInitIEEE() { panic("not available") }
func archUpdateIEEE(crc uint32, p []byte) uint32 { panic("not available") }
func archAvailableCastagnoli() bool { return false }
func archInitCastagnoli() { panic("not available") }
func archUpdateCastagnoli(crc uint32, p []byte) uint32 { panic("not available") }

@ -1,91 +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.
// +build s390x
package crc32
const (
vxMinLen = 64
vxAlignMask = 15 // align to 16 bytes
)
// hasVectorFacility reports whether the machine has the z/Architecture
// vector facility installed and enabled.
func hasVectorFacility() bool
var hasVX = hasVectorFacility()
// vectorizedCastagnoli implements CRC32 using vector instructions.
// It is defined in crc32_s390x.s.
//go:noescape
func vectorizedCastagnoli(crc uint32, p []byte) uint32
// vectorizedIEEE implements CRC32 using vector instructions.
// It is defined in crc32_s390x.s.
//go:noescape
func vectorizedIEEE(crc uint32, p []byte) uint32
func archAvailableCastagnoli() bool {
return hasVX
}
var archCastagnoliTable8 *slicing8Table
func archInitCastagnoli() {
if !hasVX {
panic("not available")
}
// We still use slicing-by-8 for small buffers.
archCastagnoliTable8 = slicingMakeTable(Castagnoli)
}
// archUpdateCastagnoli calculates the checksum of p using
// vectorizedCastagnoli.
func archUpdateCastagnoli(crc uint32, p []byte) uint32 {
if !hasVX {
panic("not available")
}
// Use vectorized function if data length is above threshold.
if len(p) >= vxMinLen {
aligned := len(p) & ^vxAlignMask
crc = vectorizedCastagnoli(crc, p[:aligned])
p = p[aligned:]
}
if len(p) == 0 {
return crc
}
return slicingUpdate(crc, archCastagnoliTable8, p)
}
func archAvailableIEEE() bool {
return hasVX
}
var archIeeeTable8 *slicing8Table
func archInitIEEE() {
if !hasVX {
panic("not available")
}
// We still use slicing-by-8 for small buffers.
archIeeeTable8 = slicingMakeTable(IEEE)
}
// archUpdateIEEE calculates the checksum of p using vectorizedIEEE.
func archUpdateIEEE(crc uint32, p []byte) uint32 {
if !hasVX {
panic("not available")
}
// Use vectorized function if data length is above threshold.
if len(p) >= vxMinLen {
aligned := len(p) & ^vxAlignMask
crc = vectorizedIEEE(crc, p[:aligned])
p = p[aligned:]
}
if len(p) == 0 {
return crc
}
return slicingUpdate(crc, archIeeeTable8, p)
}

@ -1,249 +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.
// +build s390x
#include "textflag.h"
// Vector register range containing CRC-32 constants
#define CONST_PERM_LE2BE V9
#define CONST_R2R1 V10
#define CONST_R4R3 V11
#define CONST_R5 V12
#define CONST_RU_POLY V13
#define CONST_CRC_POLY V14
// The CRC-32 constant block contains reduction constants to fold and
// process particular chunks of the input data stream in parallel.
//
// Note that the constant definitions below are extended in order to compute
// intermediate results with a single VECTOR GALOIS FIELD MULTIPLY instruction.
// The rightmost doubleword can be 0 to prevent contribution to the result or
// can be multiplied by 1 to perform an XOR without the need for a separate
// VECTOR EXCLUSIVE OR instruction.
//
// The polynomials used are bit-reflected:
//
// IEEE: P'(x) = 0x0edb88320
// Castagnoli: P'(x) = 0x082f63b78
// IEEE polynomial constants
DATA ·crcleconskp+0(SB)/8, $0x0F0E0D0C0B0A0908 // LE-to-BE mask
DATA ·crcleconskp+8(SB)/8, $0x0706050403020100
DATA ·crcleconskp+16(SB)/8, $0x00000001c6e41596 // R2
DATA ·crcleconskp+24(SB)/8, $0x0000000154442bd4 // R1
DATA ·crcleconskp+32(SB)/8, $0x00000000ccaa009e // R4
DATA ·crcleconskp+40(SB)/8, $0x00000001751997d0 // R3
DATA ·crcleconskp+48(SB)/8, $0x0000000000000000
DATA ·crcleconskp+56(SB)/8, $0x0000000163cd6124 // R5
DATA ·crcleconskp+64(SB)/8, $0x0000000000000000
DATA ·crcleconskp+72(SB)/8, $0x00000001F7011641 // u'
DATA ·crcleconskp+80(SB)/8, $0x0000000000000000
DATA ·crcleconskp+88(SB)/8, $0x00000001DB710641 // P'(x) << 1
GLOBL ·crcleconskp(SB), RODATA, $144
// Castagonli Polynomial constants
DATA ·crccleconskp+0(SB)/8, $0x0F0E0D0C0B0A0908 // LE-to-BE mask
DATA ·crccleconskp+8(SB)/8, $0x0706050403020100
DATA ·crccleconskp+16(SB)/8, $0x000000009e4addf8 // R2
DATA ·crccleconskp+24(SB)/8, $0x00000000740eef02 // R1
DATA ·crccleconskp+32(SB)/8, $0x000000014cd00bd6 // R4
DATA ·crccleconskp+40(SB)/8, $0x00000000f20c0dfe // R3
DATA ·crccleconskp+48(SB)/8, $0x0000000000000000
DATA ·crccleconskp+56(SB)/8, $0x00000000dd45aab8 // R5
DATA ·crccleconskp+64(SB)/8, $0x0000000000000000
DATA ·crccleconskp+72(SB)/8, $0x00000000dea713f1 // u'
DATA ·crccleconskp+80(SB)/8, $0x0000000000000000
DATA ·crccleconskp+88(SB)/8, $0x0000000105ec76f0 // P'(x) << 1
GLOBL ·crccleconskp(SB), RODATA, $144
// func hasVectorFacility() bool
TEXT ·hasVectorFacility(SB), NOSPLIT, $24-1
MOVD $x-24(SP), R1
XC $24, 0(R1), 0(R1) // clear the storage
MOVD $2, R0 // R0 is the number of double words stored -1
WORD $0xB2B01000 // STFLE 0(R1)
XOR R0, R0 // reset the value of R0
MOVBZ z-8(SP), R1
AND $0x40, R1
BEQ novector
vectorinstalled:
// check if the vector instruction has been enabled
VLEIB $0, $0xF, V16
VLGVB $0, V16, R1
CMPBNE R1, $0xF, novector
MOVB $1, ret+0(FP) // have vx
RET
novector:
MOVB $0, ret+0(FP) // no vx
RET
// The CRC-32 function(s) use these calling conventions:
//
// Parameters:
//
// R2: Initial CRC value, typically ~0; and final CRC (return) value.
// R3: Input buffer pointer, performance might be improved if the
// buffer is on a doubleword boundary.
// R4: Length of the buffer, must be 64 bytes or greater.
//
// Register usage:
//
// R5: CRC-32 constant pool base pointer.
// V0: Initial CRC value and intermediate constants and results.
// V1..V4: Data for CRC computation.
// V5..V8: Next data chunks that are fetched from the input buffer.
//
// V9..V14: CRC-32 constants.
// func vectorizedIEEE(crc uint32, p []byte) uint32
TEXT ·vectorizedIEEE(SB), NOSPLIT, $0
MOVWZ crc+0(FP), R2 // R2 stores the CRC value
MOVD p+8(FP), R3 // data pointer
MOVD p_len+16(FP), R4 // len(p)
MOVD $·crcleconskp(SB), R5
BR vectorizedBody<>(SB)
// func vectorizedCastagnoli(crc uint32, p []byte) uint32
TEXT ·vectorizedCastagnoli(SB), NOSPLIT, $0
MOVWZ crc+0(FP), R2 // R2 stores the CRC value
MOVD p+8(FP), R3 // data pointer
MOVD p_len+16(FP), R4 // len(p)
// R5: crc-32 constant pool base pointer, constant is used to reduce crc
MOVD $·crccleconskp(SB), R5
BR vectorizedBody<>(SB)
TEXT vectorizedBody<>(SB), NOSPLIT, $0
XOR $0xffffffff, R2 // NOTW R2
VLM 0(R5), CONST_PERM_LE2BE, CONST_CRC_POLY
// Load the initial CRC value into the rightmost word of V0
VZERO V0
VLVGF $3, R2, V0
// Crash if the input size is less than 64-bytes.
CMP R4, $64
BLT crash
// Load a 64-byte data chunk and XOR with CRC
VLM 0(R3), V1, V4 // 64-bytes into V1..V4
// Reflect the data if the CRC operation is in the bit-reflected domain
VPERM V1, V1, CONST_PERM_LE2BE, V1
VPERM V2, V2, CONST_PERM_LE2BE, V2
VPERM V3, V3, CONST_PERM_LE2BE, V3
VPERM V4, V4, CONST_PERM_LE2BE, V4
VX V0, V1, V1 // V1 ^= CRC
ADD $64, R3 // BUF = BUF + 64
ADD $(-64), R4
// Check remaining buffer size and jump to proper folding method
CMP R4, $64
BLT less_than_64bytes
fold_64bytes_loop:
// Load the next 64-byte data chunk into V5 to V8
VLM 0(R3), V5, V8
VPERM V5, V5, CONST_PERM_LE2BE, V5
VPERM V6, V6, CONST_PERM_LE2BE, V6
VPERM V7, V7, CONST_PERM_LE2BE, V7
VPERM V8, V8, CONST_PERM_LE2BE, V8
// Perform a GF(2) multiplication of the doublewords in V1 with
// the reduction constants in V0. The intermediate result is
// then folded (accumulated) with the next data chunk in V5 and
// stored in V1. Repeat this step for the register contents
// in V2, V3, and V4 respectively.
VGFMAG CONST_R2R1, V1, V5, V1
VGFMAG CONST_R2R1, V2, V6, V2
VGFMAG CONST_R2R1, V3, V7, V3
VGFMAG CONST_R2R1, V4, V8, V4
// Adjust buffer pointer and length for next loop
ADD $64, R3 // BUF = BUF + 64
ADD $(-64), R4 // LEN = LEN - 64
CMP R4, $64
BGE fold_64bytes_loop
less_than_64bytes:
// Fold V1 to V4 into a single 128-bit value in V1
VGFMAG CONST_R4R3, V1, V2, V1
VGFMAG CONST_R4R3, V1, V3, V1
VGFMAG CONST_R4R3, V1, V4, V1
// Check whether to continue with 64-bit folding
CMP R4, $16
BLT final_fold
fold_16bytes_loop:
VL 0(R3), V2 // Load next data chunk
VPERM V2, V2, CONST_PERM_LE2BE, V2
VGFMAG CONST_R4R3, V1, V2, V1 // Fold next data chunk
// Adjust buffer pointer and size for folding next data chunk
ADD $16, R3
ADD $-16, R4
// Process remaining data chunks
CMP R4, $16
BGE fold_16bytes_loop
final_fold:
VLEIB $7, $0x40, V9
VSRLB V9, CONST_R4R3, V0
VLEIG $0, $1, V0
VGFMG V0, V1, V1
VLEIB $7, $0x20, V9 // Shift by words
VSRLB V9, V1, V2 // Store remaining bits in V2
VUPLLF V1, V1 // Split rightmost doubleword
VGFMAG CONST_R5, V1, V2, V1 // V1 = (V1 * R5) XOR V2
// The input values to the Barret reduction are the degree-63 polynomial
// in V1 (R(x)), degree-32 generator polynomial, and the reduction
// constant u. The Barret reduction result is the CRC value of R(x) mod
// P(x).
//
// The Barret reduction algorithm is defined as:
//
// 1. T1(x) = floor( R(x) / x^32 ) GF2MUL u
// 2. T2(x) = floor( T1(x) / x^32 ) GF2MUL P(x)
// 3. C(x) = R(x) XOR T2(x) mod x^32
//
// Note: To compensate the division by x^32, use the vector unpack
// instruction to move the leftmost word into the leftmost doubleword
// of the vector register. The rightmost doubleword is multiplied
// with zero to not contribute to the intermedate results.
// T1(x) = floor( R(x) / x^32 ) GF2MUL u
VUPLLF V1, V2
VGFMG CONST_RU_POLY, V2, V2
// Compute the GF(2) product of the CRC polynomial in VO with T1(x) in
// V2 and XOR the intermediate result, T2(x), with the value in V1.
// The final result is in the rightmost word of V2.
VUPLLF V2, V2
VGFMAG CONST_CRC_POLY, V2, V1, V2
done:
VLGVF $2, V2, R2
XOR $0xffffffff, R2 // NOTW R2
MOVWZ R2, ret + 32(FP)
RET
crash:
MOVD $0, (R0) // input size is less than 64-bytes

@ -12,6 +12,8 @@ gitea.com/macaron/captcha
gitea.com/macaron/cors gitea.com/macaron/cors
# gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439 # gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439
gitea.com/macaron/csrf gitea.com/macaron/csrf
# gitea.com/macaron/gzip v0.0.0-20191118033930-0c4c5566a0e5
gitea.com/macaron/gzip
# gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223 # gitea.com/macaron/i18n v0.0.0-20190822004228-474e714e2223
gitea.com/macaron/i18n gitea.com/macaron/i18n
# gitea.com/macaron/inject v0.0.0-20190805023432-d4c86e31027a # gitea.com/macaron/inject v0.0.0-20190805023432-d4c86e31027a
@ -259,13 +261,9 @@ github.com/keybase/go-crypto/openpgp/errors
github.com/keybase/go-crypto/openpgp/packet github.com/keybase/go-crypto/openpgp/packet
github.com/keybase/go-crypto/openpgp/s2k github.com/keybase/go-crypto/openpgp/s2k
github.com/keybase/go-crypto/rsa github.com/keybase/go-crypto/rsa
# github.com/klauspost/compress v0.0.0-20161025140425-8df558b6cb6f # github.com/klauspost/compress v1.9.2
github.com/klauspost/compress/flate github.com/klauspost/compress/flate
github.com/klauspost/compress/gzip github.com/klauspost/compress/gzip
# github.com/klauspost/cpuid v0.0.0-20160302075316-09cded8978dc
github.com/klauspost/cpuid
# github.com/klauspost/crc32 v0.0.0-20161016154125-cb6bfca970f6
github.com/klauspost/crc32
# github.com/kr/pretty v0.1.0 # github.com/kr/pretty v0.1.0
github.com/kr/pretty github.com/kr/pretty
# github.com/kr/text v0.1.0 # github.com/kr/text v0.1.0

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