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

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

* Fix vendor

go.mod

@@ -9,6 +9,7 @@ require (
 	gitea.com/macaron/captcha v0.0.0-20190822015246-daa973478bae
 	gitea.com/macaron/cors v0.0.0-20190821152825-7dcef4a17175
 	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/inject v0.0.0-20190805023432-d4c86e31027a
 	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/kballard/go-shellquote v0.0.0-20170619183022-cd60e84ee657
 	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/lib/pq v1.2.0
 	github.com/lunny/dingtalk_webhook v0.0.0-20171025031554-e3534c89ef96

go.sum

@@ -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/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/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/go.mod h1:+qsc10s4hBsHKU/9luGGumFh4m5FFVc7uih+8/mM1NY=
 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 v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQLJ+jE2L00=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
-github.com/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 v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=

integrations/lfs_getobject_test.go

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

modules/gzip/gzip_test.go

@@ -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)
-}

routers/routes/routes.go

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

vendor/gitea.com/macaron/gzip/go.mod

@@ -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
+)

vendor/gitea.com/macaron/gzip/go.sum

@@ -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=

vendor/github.com/klauspost/compress/LICENSE

@@ -1,4 +1,5 @@
 Copyright (c) 2012 The Go Authors. All rights reserved.
+Copyright (c) 2019 Klaus Post. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are

vendor/github.com/klauspost/compress/flate/copy.go

@@ -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
-	}
-}

vendor/github.com/klauspost/compress/flate/crc32_amd64.go

@@ -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()
-}

vendor/github.com/klauspost/compress/flate/crc32_amd64.s

@@ -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

vendor/github.com/klauspost/compress/flate/crc32_noasm.go

@@ -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]++
-	}
-}

vendor/github.com/klauspost/compress/flate/fast_encoder.go

@@ -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
+}

vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go

@@ -35,7 +35,7 @@ const (
 )
 
 // The number of extra bits needed by length code X - LENGTH_CODES_START.
-var lengthExtraBits = []int8{
+var lengthExtraBits = [32]int8{
 	/* 257 */ 0, 0, 0,
 	/* 260 */ 0, 0, 0, 0, 0, 1, 1, 1, 1, 2,
 	/* 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.
-var lengthBase = []uint32{
+var lengthBase = [32]uint8{
 	0, 1, 2, 3, 4, 5, 6, 7, 8, 10,
 	12, 14, 16, 20, 24, 28, 32, 40, 48, 56,
 	64, 80, 96, 112, 128, 160, 192, 224, 255,
 }
 
 // offset code word extra bits.
-var offsetExtraBits = []int8{
+var offsetExtraBits = [64]int8{
 	0, 0, 0, 0, 1, 1, 2, 2, 3, 3,
 	4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
 	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,
 }
 
-var offsetBase = []uint32{
+var offsetBase = [64]uint32{
 	/* normal deflate */
 	0x000000, 0x000001, 0x000002, 0x000003, 0x000004,
 	0x000006, 0x000008, 0x00000c, 0x000010, 0x000018,
@@ -85,26 +85,48 @@ type huffmanBitWriter struct {
 	// Data waiting to be written is bytes[0:nbytes]
 	// and then the low nbits of bits.
 	bits            uint64
-	nbits           uint
+	nbits           uint16
-	bytes           [bufferSize]byte
+	nbytes          uint8
-	codegenFreq     [codegenCodeCount]int32
-	nbytes          int
-	literalFreq     []int32
-	offsetFreq      []int32
-	codegen         []uint8
 	literalEncoding *huffmanEncoder
 	offsetEncoding  *huffmanEncoder
 	codegenEncoding *huffmanEncoder
 	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 {
 	return &huffmanBitWriter{
 		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),
 		offsetEncoding:  newHuffmanEncoder(offsetCodeCount),
 	}
@@ -113,7 +135,42 @@ func newHuffmanBitWriter(w io.Writer) *huffmanBitWriter {
 func (w *huffmanBitWriter) reset(writer io.Writer) {
 	w.writer = writer
 	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() {
@@ -144,30 +201,11 @@ func (w *huffmanBitWriter) write(b []byte) {
 	_, 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
 	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.
 	// This is fine because the output is always shorter than the input used
 	// so far.
-	codegen := w.codegen // cache
+	codegen := w.codegen[:] // cache
 	// Copy the concatenated code sizes to codegen. Put a marker at the end.
 	cgnl := codegen[:numLiterals]
 	for i := range cgnl {
@@ -292,30 +330,54 @@ func (w *huffmanBitWriter) generateCodegen(numLiterals int, numOffsets int, litE
 	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)
 	for numCodegens > 4 && w.codegenFreq[codegenOrder[numCodegens-1]] == 0 {
 		numCodegens--
 	}
-	header := 3 + 5 + 5 + 4 + (3 * numCodegens) +
+	return 3 + 5 + 5 + 4 + (3 * numCodegens) +
 		w.codegenEncoding.bitLength(w.codegenFreq[:]) +
 		int(w.codegenFreq[16])*2 +
 		int(w.codegenFreq[17])*3 +
-		int(w.codegenFreq[18])*7
+		int(w.codegenFreq[18])*7, numCodegens
-	size = header +
+}
-		litEnc.bitLength(w.literalFreq) +
-		offEnc.bitLength(w.offsetFreq) +
-		extraBits
 
+// 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 +
+		litEnc.bitLength(w.literalFreq[:]) +
+		offEnc.bitLength(w.offsetFreq[:]) +
+		extraBits
 	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.
 func (w *huffmanBitWriter) fixedSize(extraBits int) int {
 	return 3 +
-		fixedLiteralEncoding.bitLength(w.literalFreq) +
+		fixedLiteralEncoding.bitLength(w.literalFreq[:]) +
-		fixedOffsetEncoding.bitLength(w.offsetFreq) +
+		fixedOffsetEncoding.bitLength(w.offsetFreq[:]) +
 		extraBits
 }
 
@@ -333,31 +395,37 @@ func (w *huffmanBitWriter) storedSize(in []byte) (int, bool) {
 }
 
 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.nbits += uint(c.len)
+	w.nbits += c.len
 	if w.nbits >= 48 {
+		w.writeOutBits()
+	}
+}
+
+// writeOutBits will write bits to the buffer.
+func (w *huffmanBitWriter) writeOutBits() {
 	bits := w.bits
 	w.bits >>= 48
 	w.nbits -= 48
 	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
 	if n >= bufferFlushSize {
+		if w.err != nil {
+			n = 0
+			return
+		}
 		w.write(w.bytes[:n])
 		n = 0
 	}
 	w.nbytes = n
 }
-}
 
 // 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 {
 		return
 	}
+	if w.lastHeader > 0 {
+		// We owe an EOB
+		w.writeCode(w.literalEncoding.codes[endBlockMarker])
+		w.lastHeader = 0
+	}
 	var flag int32
 	if isEof {
 		flag = 1
@@ -426,6 +499,12 @@ func (w *huffmanBitWriter) writeFixedHeader(isEof bool) {
 	if w.err != nil {
 		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
 	var value int32 = 2
 	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
 // stored block.
 // 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 {
 		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
 	storedSize, storable := w.storedSize(input)
 	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.
@@ -500,7 +573,7 @@ func (w *huffmanBitWriter) writeBlock(tokens []token, eof bool, input []byte) {
 	}
 
 	// 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.
@@ -508,57 +581,103 @@ func (w *huffmanBitWriter) writeBlock(tokens []token, eof bool, input []byte) {
 // histogram distribution.
 // If input is supplied and the compression savings are below 1/16th of the
 // 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 {
 		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
 		// the literalEncoding and the offsetEncoding.
 		w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, w.offsetEncoding)
 		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.
 		if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) {
 			w.writeStoredHeader(len(input), eof)
 			w.writeBytes(input)
+			w.lastHeader = 0
 			return
 		}
 
 		// Write Huffman table.
 		w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof)
+		w.lastHeader, _ = w.headerSize()
+		w.lastHuffMan = false
+	}
 
+	if sync {
+		w.lastHeader = 0
+	}
 	// 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
 // literalFreq and offsetFreq, and generates literalEncoding
 // and offsetEncoding.
 // 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
 	numLiterals = len(w.literalFreq)
 	for w.literalFreq[numLiterals-1] == 0 {
@@ -575,41 +694,85 @@ func (w *huffmanBitWriter) indexTokens(tokens []token) (numLiterals, numOffsets
 		w.offsetFreq[0] = 1
 		numOffsets = 1
 	}
-	w.literalEncoding.generate(w.literalFreq, 15)
-	w.offsetEncoding.generate(w.offsetFreq, 15)
 	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.
 // codes for literal and offset encoding must be supplied.
 func (w *huffmanBitWriter) writeTokens(tokens []token, leCodes, oeCodes []hcode) {
 	if w.err != nil {
 		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 {
 		if t < matchType {
-			w.writeCode(leCodes[t.literal()])
+			w.writeCode(lits[t.literal()])
 			continue
 		}
+
 		// Write the length
 		length := t.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 {
-			extraLength := int32(length - lengthBase[lengthCode])
+			extraLength := int32(length - lengthBase[lengthCode&31])
 			w.writeBits(extraLength, extraLengthBits)
 		}
 		// Write the offset
 		offset := t.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 {
-			extraOffset := int32(offset - offsetBase[offsetCode])
+			extraOffset := int32(offset - offsetBase[offsetCode&63])
 			w.writeBits(extraOffset, extraOffsetBits)
 		}
 	}
+	if deferEOB {
+		w.writeCode(leCodes[endBlockMarker])
+	}
 }
 
 // huffOffset is a static offset encoder used for huffman only encoding.
@@ -620,82 +783,99 @@ func init() {
 	w := newHuffmanBitWriter(nil)
 	w.offsetFreq[0] = 1
 	huffOffset = newHuffmanEncoder(offsetCodeCount)
-	huffOffset.generate(w.offsetFreq, 15)
+	huffOffset.generate(w.offsetFreq[:offsetCodeCount], 15)
 }
 
 // writeBlockHuff encodes a block of bytes as either
 // Huffman encoded literals or uncompressed bytes if the
 // 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 {
 		return
 	}
 
 	// Clear histogram
-	for i := range w.literalFreq {
+	for i := range w.literalFreq[:] {
 		w.literalFreq[i] = 0
 	}
+	if !w.lastHuffMan {
+		for i := range w.offsetFreq[:] {
+			w.offsetFreq[i] = 0
+		}
+	}
 
 	// Add everything as literals
-	histogram(input, w.literalFreq)
+	estBits := histogramSize(input, w.literalFreq[:], !eof && !sync) + 15
-
-	w.literalFreq[endBlockMarker] = 1
-
-	const numLiterals = endBlockMarker + 1
-	const numOffsets = 1
-
-	w.literalEncoding.generate(w.literalFreq, 15)
-
-	// Figure out smallest code.
-	// Always use dynamic Huffman or Store
-	var numCodegens int
-
-	// Generate codegen and codegenFrequencies, which indicates how to encode
-	// the literalEncoding and the offsetEncoding.
-	w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, huffOffset)
-	w.codegenEncoding.generate(w.codegenFreq[:], 7)
-	size, numCodegens := w.dynamicSize(w.literalEncoding, huffOffset, 0)
 
 	// Store bytes, if we don't get a reasonable improvement.
-	if ssize, storable := w.storedSize(input); storable && ssize < (size+size>>4) {
+	ssize, storable := w.storedSize(input)
+	if storable && ssize < (estBits+estBits>>4) {
 		w.writeStoredHeader(len(input), eof)
 		w.writeBytes(input)
 		return
 	}
 
+	if w.lastHeader > 0 {
+		size, _ := w.dynamicSize(w.literalEncoding, huffOffset, w.lastHeader)
+		estBits += estBits >> (w.logReusePenalty)
+
+		if estBits < size {
+			// We owe an EOB
+			w.writeCode(w.literalEncoding.codes[endBlockMarker])
+			w.lastHeader = 0
+		}
+	}
+
+	const numLiterals = endBlockMarker + 1
+	const numOffsets = 1
+	if w.lastHeader == 0 {
+		w.literalFreq[endBlockMarker] = 1
+		w.literalEncoding.generate(w.literalFreq[:numLiterals], 15)
+
+		// Generate codegen and codegenFrequencies, which indicates how to encode
+		// the literalEncoding and the offsetEncoding.
+		w.generateCodegen(numLiterals, numOffsets, w.literalEncoding, huffOffset)
+		w.codegenEncoding.generate(w.codegenFreq[:], 7)
+		numCodegens := w.codegens()
+
 		// Huffman.
 		w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof)
+		w.lastHuffMan = true
+		w.lastHeader, _ = w.headerSize()
+	}
+
 	encoding := w.literalEncoding.codes[:257]
-	n := w.nbytes
 	for _, t := range input {
 		// Bitwriting inlined, ~30% speedup
 		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
 			w.bits >>= 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
-		if n < bufferFlushSize {
+			if n >= bufferFlushSize {
-			continue
+				if w.err != nil {
+					n = 0
+					return
 				}
 				w.write(w.bytes[:n])
-		if w.err != nil {
-			return // Return early in the event of write failures
-		}
 				n = 0
 			}
 			w.nbytes = n
-	w.writeCode(encoding[endBlockMarker])
+		}
+	}
+	if eof || sync {
+		w.writeCode(encoding[endBlockMarker])
+		w.lastHeader = 0
+		w.lastHuffMan = false
+	}
 }

vendor/github.com/klauspost/compress/flate/huffman_code.go

@@ -6,9 +6,16 @@ package flate
 
 import (
 	"math"
+	"math/bits"
 	"sort"
 )
 
+const (
+	maxBitsLimit = 16
+	// number of valid literals
+	literalCount = 286
+)
+
 // hcode is a huffman code with a bit code and bit length.
 type hcode struct {
 	code, len uint16
@@ -24,7 +31,7 @@ type huffmanEncoder struct {
 
 type literalNode struct {
 	literal uint16
-	freq    int32
+	freq    uint16
 }
 
 // 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
 }
 
-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 {
-	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
 func generateFixedLiteralEncoding() *huffmanEncoder {
-	h := newHuffmanEncoder(maxNumLit)
+	h := newHuffmanEncoder(literalCount)
 	codes := h.codes
 	var ch uint16
-	for ch = 0; ch < maxNumLit; ch++ {
+	for ch = 0; ch < literalCount; ch++ {
 		var bits uint16
 		var size uint16
 		switch {
@@ -105,7 +118,7 @@ func generateFixedOffsetEncoding() *huffmanEncoder {
 var fixedLiteralEncoding *huffmanEncoder = generateFixedLiteralEncoding()
 var fixedOffsetEncoding *huffmanEncoder = generateFixedOffsetEncoding()
 
-func (h *huffmanEncoder) bitLength(freq []int32) int {
+func (h *huffmanEncoder) bitLength(freq []uint16) int {
 	var total int
 	for i, f := range freq {
 		if f != 0 {
@@ -115,8 +128,6 @@ func (h *huffmanEncoder) bitLength(freq []int32) int {
 	return total
 }
 
-const maxBitsLimit = 16
-
 // Return the number of literals assigned to each bit size in the Huffman encoding
 //
 // 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.
 		levels[level] = levelInfo{
 			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
 		if level == 1 {
@@ -194,7 +205,12 @@ func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
 			l.lastFreq = l.nextCharFreq
 			// Lower leafCounts are the same of the previous node.
 			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 {
 			// The next item on this row is a pair from the previous row.
 			// 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.
 // 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 {
 		// 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]
 	// 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] }
+
+// 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)
+}

vendor/github.com/klauspost/compress/flate/inflate.go

@@ -9,19 +9,24 @@ package flate
 
 import (
 	"bufio"
+	"fmt"
 	"io"
+	"math/bits"
 	"strconv"
 	"sync"
 )
 
 const (
 	maxCodeLen     = 16 // max length of Huffman code
+	maxCodeLenMask = 15 // mask for max length of Huffman code
 	// The next three numbers come from the RFC section 3.2.7, with the
 	// additional proviso in section 3.2.5 which implies that distance codes
 	// 30 and 31 should never occur in compressed data.
 	maxNumLit  = 286
 	maxNumDist = 30
 	numCodes   = 19 // number of codes in Huffman meta-code
+
+	debugDecode = false
 )
 
 // Initialize the fixedHuffmanDecoder only once upon first use.
@@ -102,8 +107,8 @@ const (
 
 type huffmanDecoder struct {
 	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
 }
 
@@ -112,21 +117,24 @@ type huffmanDecoder struct {
 // tree (i.e., neither over-subscribed nor under-subscribed). The exception is a
 // degenerate case where the tree has only a single symbol with length 1. Empty
 // trees are permitted.
-func (h *huffmanDecoder) init(bits []int) bool {
+func (h *huffmanDecoder) init(lengths []int) bool {
 	// Sanity enables additional runtime tests during Huffman
 	// table construction. It's intended to be used during
 	// development to supplement the currently ad-hoc unit tests.
 	const sanity = false
 
+	if h.chunks == nil {
+		h.chunks = &[huffmanNumChunks]uint16{}
+	}
 	if h.min != 0 {
-		*h = huffmanDecoder{}
+		*h = huffmanDecoder{chunks: h.chunks, links: h.links}
 	}
 
 	// Count number of codes of each length,
 	// compute min and max length.
 	var count [maxCodeLen]int
 	var min, max int
-	for _, n := range bits {
+	for _, n := range lengths {
 		if n == 0 {
 			continue
 		}
@@ -136,7 +144,7 @@ func (h *huffmanDecoder) init(bits []int) bool {
 		if n > max {
 			max = n
 		}
-		count[n]++
+		count[n&maxCodeLenMask]++
 	}
 
 	// 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
 	for i := min; i <= max; i++ {
 		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
@@ -164,37 +172,56 @@ func (h *huffmanDecoder) init(bits []int) bool {
 	// accept degenerate single-code codings. See also
 	// TestDegenerateHuffmanCoding.
 	if code != 1<<uint(max) && !(code == 1 && max == 1) {
+		if debugDecode {
+			fmt.Println("coding failed, code, max:", code, max, code == 1<<uint(max), code == 1 && max == 1, "(one should be true)")
+		}
 		return false
 	}
 
 	h.min = min
+	chunks := h.chunks[:]
+	for i := range chunks {
+		chunks[i] = 0
+	}
+
 	if max > huffmanChunkBits {
 		numLinks := 1 << (uint(max) - huffmanChunkBits)
 		h.linkMask = uint32(numLinks - 1)
 
 		// create link tables
 		link := nextcode[huffmanChunkBits+1] >> 1
-		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++ {
-			reverse := int(reverseByte[j>>8]) | int(reverseByte[j&0xff])<<8
+			reverse := int(bits.Reverse16(uint16(j)))
 			reverse >>= uint(16 - huffmanChunkBits)
 			off := j - uint(link)
 			if sanity && h.chunks[reverse] != 0 {
 				panic("impossible: overwriting existing chunk")
 			}
-			h.chunks[reverse] = 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 {
 			continue
 		}
 		code := 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)
 		if n <= huffmanChunkBits {
 			for off := reverse; off < len(h.chunks); off += 1 << uint(n) {
@@ -326,6 +353,9 @@ func (f *decompressor) nextBlock() {
 		f.huffmanBlock()
 	default:
 		// 3 is reserved.
+		if debugDecode {
+			fmt.Println("reserved data block encountered")
+		}
 		f.err = CorruptInputError(f.roffset)
 	}
 }
@@ -404,11 +434,17 @@ func (f *decompressor) readHuffman() error {
 	}
 	nlit := int(f.b&0x1F) + 257
 	if nlit > maxNumLit {
+		if debugDecode {
+			fmt.Println("nlit > maxNumLit", nlit)
+		}
 		return CorruptInputError(f.roffset)
 	}
 	f.b >>= 5
 	ndist := int(f.b&0x1F) + 1
 	if ndist > maxNumDist {
+		if debugDecode {
+			fmt.Println("ndist > maxNumDist", ndist)
+		}
 		return CorruptInputError(f.roffset)
 	}
 	f.b >>= 5
@@ -432,6 +468,9 @@ func (f *decompressor) readHuffman() error {
 		f.codebits[codeOrder[i]] = 0
 	}
 	if !f.h1.init(f.codebits[0:]) {
+		if debugDecode {
+			fmt.Println("init codebits failed")
+		}
 		return CorruptInputError(f.roffset)
 	}
 
@@ -459,6 +498,9 @@ func (f *decompressor) readHuffman() error {
 			rep = 3
 			nb = 2
 			if i == 0 {
+				if debugDecode {
+					fmt.Println("i==0")
+				}
 				return CorruptInputError(f.roffset)
 			}
 			b = f.bits[i-1]
@@ -473,6 +515,9 @@ func (f *decompressor) readHuffman() error {
 		}
 		for f.nb < nb {
 			if err := f.moreBits(); err != nil {
+				if debugDecode {
+					fmt.Println("morebits:", err)
+				}
 				return err
 			}
 		}
@@ -480,6 +525,9 @@ func (f *decompressor) readHuffman() error {
 		f.b >>= nb
 		f.nb -= nb
 		if i+rep > n {
+			if debugDecode {
+				fmt.Println("i+rep > n", i, rep, n)
+			}
 			return CorruptInputError(f.roffset)
 		}
 		for j := 0; j < rep; j++ {
@@ -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 debugDecode {
+			fmt.Println("init2 failed")
+		}
 		return CorruptInputError(f.roffset)
 	}
 
@@ -566,12 +617,18 @@ readLiteral:
 			length = 258
 			n = 0
 		default:
+			if debugDecode {
+				fmt.Println(v, ">= maxNumLit")
+			}
 			f.err = CorruptInputError(f.roffset)
 			return
 		}
 		if n > 0 {
 			for f.nb < n {
 				if err = f.moreBits(); err != nil {
+					if debugDecode {
+						fmt.Println("morebits n>0:", err)
+					}
 					f.err = err
 					return
 				}
@@ -585,15 +642,21 @@ readLiteral:
 		if f.hd == nil {
 			for f.nb < 5 {
 				if err = f.moreBits(); err != nil {
+					if debugDecode {
+						fmt.Println("morebits f.nb<5:", err)
+					}
 					f.err = err
 					return
 				}
 			}
-			dist = int(reverseByte[(f.b&0x1F)<<3])
+			dist = int(bits.Reverse8(uint8(f.b & 0x1F << 3)))
 			f.b >>= 5
 			f.nb -= 5
 		} else {
 			if dist, err = f.huffSym(f.hd); err != nil {
+				if debugDecode {
+					fmt.Println("huffsym:", err)
+				}
 				f.err = err
 				return
 			}
@@ -608,6 +671,9 @@ readLiteral:
 			extra := (dist & 1) << nb
 			for f.nb < nb {
 				if err = f.moreBits(); err != nil {
+					if debugDecode {
+						fmt.Println("morebits f.nb<nb:", err)
+					}
 					f.err = err
 					return
 				}
@@ -617,12 +683,18 @@ readLiteral:
 			f.nb -= nb
 			dist = 1<<(nb+1) + 1 + extra
 		default:
+			if debugDecode {
+				fmt.Println("dist too big:", dist, maxNumDist)
+			}
 			f.err = CorruptInputError(f.roffset)
 			return
 		}
 
 		// No check on length; encoding can be prescient.
 		if dist > f.dict.histSize() {
+			if debugDecode {
+				fmt.Println("dist > f.dict.histSize():", dist, f.dict.histSize())
+			}
 			f.err = CorruptInputError(f.roffset)
 			return
 		}
@@ -661,15 +733,15 @@ func (f *decompressor) dataBlock() {
 	nr, err := io.ReadFull(f.r, f.buf[0:4])
 	f.roffset += int64(nr)
 	if err != nil {
-		if err == io.EOF {
+		f.err = noEOF(err)
-			err = io.ErrUnexpectedEOF
-		}
-		f.err = err
 		return
 	}
 	n := int(f.buf[0]) | int(f.buf[1])<<8
 	nn := int(f.buf[2]) | int(f.buf[3])<<8
 	if uint16(nn) != uint16(^n) {
+		if debugDecode {
+			fmt.Println("uint16(nn) != uint16(^n)", nn, ^n)
+		}
 		f.err = CorruptInputError(f.roffset)
 		return
 	}
@@ -697,10 +769,7 @@ func (f *decompressor) copyData() {
 	f.copyLen -= cnt
 	f.dict.writeMark(cnt)
 	if err != nil {
-		if err == io.EOF {
+		f.err = noEOF(err)
-			err = io.ErrUnexpectedEOF
-		}
-		f.err = err
 		return
 	}
 
@@ -722,13 +791,18 @@ func (f *decompressor) finishBlock() {
 	f.step = (*decompressor).nextBlock
 }
 
+// noEOF returns err, unless err == io.EOF, in which case it returns io.ErrUnexpectedEOF.
+func noEOF(e error) error {
+	if e == io.EOF {
+		return io.ErrUnexpectedEOF
+	}
+	return e
+}
+
 func (f *decompressor) moreBits() error {
 	c, err := f.r.ReadByte()
 	if err != nil {
-		if err == io.EOF {
+		return noEOF(err)
-			err = io.ErrUnexpectedEOF
-		}
-		return err
 	}
 	f.roffset++
 	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
 	// satisfy the n == 0 check below.
 	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 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)
 		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)
 		}
-		if n <= f.nb {
+		if n <= nb {
 			if n == 0 {
+				f.b = b
+				f.nb = nb
+				if debugDecode {
+					fmt.Println("huffsym: n==0")
+				}
 				f.err = CorruptInputError(f.roffset)
 				return 0, f.err
 			}
-			f.b >>= n
+			f.b = b >> (n & 31)
-			f.nb -= n
+			f.nb = nb - n
 			return int(chunk >> huffmanValueShift), nil
 		}
 	}
@@ -799,6 +888,8 @@ func (f *decompressor) Reset(r io.Reader, dict []byte) error {
 		r:        makeReader(r),
 		bits:     f.bits,
 		codebits: f.codebits,
+		h1:       f.h1,
+		h2:       f.h2,
 		dict:     f.dict,
 		step:     (*decompressor).nextBlock,
 	}

vendor/github.com/klauspost/compress/flate/level1.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/level2.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/level3.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/level4.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/level5.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/level6.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/reverse_bits.go

@@ -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))
-}

vendor/github.com/klauspost/compress/flate/snappy.go

@@ -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
-}

vendor/github.com/klauspost/compress/flate/stateless.go

@@ -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:])
+	}
+}

vendor/github.com/klauspost/compress/flate/token.go

@@ -4,7 +4,13 @@
 
 package flate
 
-import "fmt"
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"math"
+)
 
 const (
 	// 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)
 // is lengthCodes[length - MIN_MATCH_LENGTH]
-var lengthCodes = [...]uint32{
+var lengthCodes = [256]uint8{
 	0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
 	9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
 	13, 13, 13, 13, 14, 14, 14, 14, 15, 15,
@@ -48,7 +54,37 @@ var lengthCodes = [...]uint32{
 	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,
 	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,
@@ -67,49 +103,265 @@ var offsetCodes = [...]uint32{
 	15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
 }
 
+// offsetCodes14 are offsetCodes, but with 14 added.
+var offsetCodes14 = [256]uint32{
+	14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
+	22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
+	24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
+	25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
+	26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+	26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
+	27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+	27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
+	28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+	28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+	28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+	28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
+	29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+	29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+	29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+	29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
+}
+
 type token uint32
 
 type tokens struct {
-	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
+	tokens    [maxStoreBlockSize + 1]token
 }
 
-// Convert a literal into a literal token.
+func (t *tokens) Reset() {
-func literalToken(literal uint32) token { return token(literalType + literal) }
+	if t.n == 0 {
-
+		return
-// Convert a < xlength, xoffset > pair into a match token.
+	}
-func matchToken(xlength uint32, xoffset uint32) token {
+	t.n = 0
-	return token(matchType + xlength<<lengthShift + xoffset)
+	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 matchTokend(xlength uint32, xoffset uint32) token {
+func (t *tokens) Fill() {
-	if xlength > maxMatchLength || xoffset > maxMatchOffset {
+	if t.n == 0 {
-		panic(fmt.Sprintf("Invalid match: len: %d, offset: %d\n", xlength, xoffset))
+		return
-		return token(matchType)
 	}
-	return token(matchType + xlength<<lengthShift + xoffset)
+	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())
+	}
+}
+
+// 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.litHist[v]++
+	}
+	dst.n += uint16(len(lit))
+	dst.nLits += len(lit)
+}
+
+func (t *tokens) AddLiteral(lit byte) {
+	t.tokens[t.n] = token(lit)
+	t.litHist[lit]++
+	t.n++
+	t.nLits++
+}
+
+// EstimatedBits will return an minimum size estimated by an *optimal*
+// compression of the block.
+// The size of the block
+func (t *tokens) EstimatedBits() int {
+	shannon := 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 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
 func (t token) typ() uint32 { return uint32(t) & typeMask }
 
 // 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
 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
 func offsetCode(off uint32) uint32 {
+	if false {
 		if off < uint32(len(offsetCodes)) {
-		return offsetCodes[off]
+			return offsetCodes[off&255]
 		} else if off>>7 < uint32(len(offsetCodes)) {
-		return offsetCodes[off>>7] + 14
+			return offsetCodes[(off>>7)&255] + 14
 		} 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)]
+}

vendor/github.com/klauspost/compress/gzip/gunzip.go

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

vendor/github.com/klauspost/compress/gzip/gzip.go

@@ -7,10 +7,10 @@ package gzip
 import (
 	"errors"
 	"fmt"
+	"hash/crc32"
 	"io"
 
 	"github.com/klauspost/compress/flate"
-	"github.com/klauspost/crc32"
 )
 
 // These constants are copied from the flate package, so that code that imports
@@ -22,6 +22,13 @@ const (
 	DefaultCompression  = flate.DefaultCompression
 	ConstantCompression = flate.ConstantCompression
 	HuffmanOnly         = flate.HuffmanOnly
+
+	// StatelessCompression will do compression but without maintaining any state
+	// between Write calls.
+	// There will be no memory kept between Write calls,
+	// but compression and speed will be suboptimal.
+	// Because of this, the size of actual Write calls will affect output size.
+	StatelessCompression = -3
 )
 
 // A Writer is an io.WriteCloser.
@@ -59,7 +66,7 @@ func NewWriter(w io.Writer) *Writer {
 // integer value between BestSpeed and BestCompression inclusive. The error
 // returned will be nil if the level is valid.
 func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
-	if level < HuffmanOnly || level > BestCompression {
+	if level < StatelessCompression || level > BestCompression {
 		return nil, fmt.Errorf("gzip: invalid compression level: %d", level)
 	}
 	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) {
 	compressor := z.compressor
+	if level != StatelessCompression {
 		if compressor != nil {
 			compressor.Reset(w)
 		}
+	}
+
 	*z = Writer{
 		Header: Header{
 			OS: 255, // unknown
@@ -189,12 +199,16 @@ func (z *Writer) Write(p []byte) (int, error) {
 				return n, z.err
 			}
 		}
-		if z.compressor == nil {
+
+		if z.compressor == nil && z.level != StatelessCompression {
 			z.compressor, _ = flate.NewWriter(z.w, z.level)
 		}
 	}
 	z.size += uint32(len(p))
 	z.digest = crc32.Update(z.digest, crc32.IEEETable, p)
+	if z.level == StatelessCompression {
+		return len(p), flate.StatelessDeflate(z.w, p, false)
+	}
 	n, z.err = z.compressor.Write(p)
 	return n, z.err
 }
@@ -211,7 +225,7 @@ func (z *Writer) Flush() error {
 	if z.err != nil {
 		return z.err
 	}
-	if z.closed {
+	if z.closed || z.level == StatelessCompression {
 		return nil
 	}
 	if !z.wroteHeader {
@@ -240,7 +254,11 @@ func (z *Writer) Close() error {
 			return z.err
 		}
 	}
+	if z.level == StatelessCompression {
+		z.err = flate.StatelessDeflate(z.w, nil, true)
+	} else {
 		z.err = z.compressor.Close()
+	}
 	if z.err != nil {
 		return z.err
 	}

vendor/github.com/klauspost/cpuid/.gitignore

@@ -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

vendor/github.com/klauspost/cpuid/.travis.yml

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

vendor/github.com/klauspost/cpuid/LICENSE

@@ -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.
-

vendor/github.com/klauspost/cpuid/README.md

@@ -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.

vendor/github.com/klauspost/cpuid/cpuid_386.s

@@ -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

vendor/github.com/klauspost/cpuid/cpuid_amd64.s

@@ -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

vendor/github.com/klauspost/cpuid/detect_intel.go

@@ -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
-}

vendor/github.com/klauspost/cpuid/detect_ref.go

@@ -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
-	}
-}

vendor/github.com/klauspost/cpuid/generate.go

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

vendor/github.com/klauspost/crc32/.gitignore

@@ -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

vendor/github.com/klauspost/crc32/.travis.yml

@@ -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 .

vendor/github.com/klauspost/crc32/LICENSE

@@ -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.

vendor/github.com/klauspost/crc32/README.md

@@ -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.

vendor/github.com/klauspost/crc32/crc32.go

@@ -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)
-}

vendor/github.com/klauspost/crc32/crc32_amd64.go

@@ -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)
-}

vendor/github.com/klauspost/crc32/crc32_amd64.s

@@ -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

vendor/github.com/klauspost/crc32/crc32_amd64p32.go

@@ -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") }

vendor/github.com/klauspost/crc32/crc32_amd64p32.s

@@ -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
-

vendor/github.com/klauspost/crc32/crc32_generic.go

@@ -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)
-}

vendor/github.com/klauspost/crc32/crc32_otherarch.go

@@ -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") }

vendor/github.com/klauspost/crc32/crc32_s390x.go

@@ -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)
-}

vendor/github.com/klauspost/crc32/crc32_s390x.s

@@ -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

vendor/modules.txt

@@ -12,6 +12,8 @@ gitea.com/macaron/captcha
 gitea.com/macaron/cors
 # gitea.com/macaron/csrf v0.0.0-20190822024205-3dc5a4474439
 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
 # 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/s2k
 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/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
 # github.com/kr/text v0.1.0