parent
694f44660f
commit
8d2059a201
@ -0,0 +1,24 @@
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kind: pipeline
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name: go1-1-2
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steps:
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- name: test
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image: golang:1.12
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environment:
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GOPROXY: https://goproxy.cn
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commands:
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- go build -v
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- go test -v -race -coverprofile=coverage.txt -covermode=atomic
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---
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kind: pipeline
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name: go1-1-3
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steps:
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- name: test
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image: golang:1.13
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environment:
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GOPROXY: https://goproxy.cn
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commands:
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- go build -v
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- go test -v -race -coverprofile=coverage.txt -covermode=atomic
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@ -0,0 +1,19 @@
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# gzip
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Middleware gzip provides gzip comparess middleware for [Macaron](https://gitea.com/macaron/macaron).
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### Installation
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go get gitea.com/macaron/gzip
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## Getting Help
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- [API Reference](https://godoc.org/gitea.com/macaron/gzip)
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## Credits
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This package is a modified version of [go-macaron gzip](github.com/go-macaron/gzip).
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## License
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This project is under the Apache License, Version 2.0. See the [LICENSE](LICENSE) file for the full license text.
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@ -0,0 +1,274 @@
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// +build generate
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//go:generate go run $GOFILE && gofmt -w inflate_gen.go
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package main
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import (
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"os"
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"strings"
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)
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func main() {
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f, err := os.Create("inflate_gen.go")
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if err != nil {
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panic(err)
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}
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defer f.Close()
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types := []string{"*bytes.Buffer", "*bytes.Reader", "*bufio.Reader", "*strings.Reader"}
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names := []string{"BytesBuffer", "BytesReader", "BufioReader", "StringsReader"}
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imports := []string{"bytes", "bufio", "io", "strings", "math/bits"}
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f.WriteString(`// Code generated by go generate gen_inflate.go. DO NOT EDIT.
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package flate
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import (
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`)
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for _, imp := range imports {
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f.WriteString("\t\"" + imp + "\"\n")
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}
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f.WriteString(")\n\n")
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template := `
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// Decode a single Huffman block from f.
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// hl and hd are the Huffman states for the lit/length values
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// and the distance values, respectively. If hd == nil, using the
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// fixed distance encoding associated with fixed Huffman blocks.
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func (f *decompressor) $FUNCNAME$() {
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const (
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stateInit = iota // Zero value must be stateInit
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stateDict
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)
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fr := f.r.($TYPE$)
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moreBits := func() error {
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c, err := fr.ReadByte()
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if err != nil {
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return noEOF(err)
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}
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f.roffset++
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f.b |= uint32(c) << f.nb
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f.nb += 8
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return nil
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}
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switch f.stepState {
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case stateInit:
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goto readLiteral
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case stateDict:
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goto copyHistory
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}
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readLiteral:
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// Read literal and/or (length, distance) according to RFC section 3.2.3.
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{
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var v int
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{
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// Inlined v, err := f.huffSym(f.hl)
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// Since a huffmanDecoder can be empty or be composed of a degenerate tree
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// with single element, huffSym must error on these two edge cases. In both
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// cases, the chunks slice will be 0 for the invalid sequence, leading it
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// satisfy the n == 0 check below.
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n := uint(f.hl.maxRead)
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// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
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// but is smart enough to keep local variables in registers, so use nb and b,
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// inline call to moreBits and reassign b,nb back to f on return.
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nb, b := f.nb, f.b
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for {
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for nb < n {
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c, err := fr.ReadByte()
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if err != nil {
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f.b = b
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f.nb = nb
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f.err = noEOF(err)
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return
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}
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f.roffset++
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b |= uint32(c) << (nb & 31)
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nb += 8
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}
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chunk := f.hl.chunks[b&(huffmanNumChunks-1)]
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n = uint(chunk & huffmanCountMask)
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if n > huffmanChunkBits {
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chunk = f.hl.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&f.hl.linkMask]
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n = uint(chunk & huffmanCountMask)
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}
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if n <= nb {
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if n == 0 {
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f.b = b
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f.nb = nb
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if debugDecode {
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fmt.Println("huffsym: n==0")
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}
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f.err = CorruptInputError(f.roffset)
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return
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}
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f.b = b >> (n & 31)
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f.nb = nb - n
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v = int(chunk >> huffmanValueShift)
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break
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}
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}
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}
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var n uint // number of bits extra
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var length int
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var err error
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switch {
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case v < 256:
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f.dict.writeByte(byte(v))
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if f.dict.availWrite() == 0 {
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f.toRead = f.dict.readFlush()
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f.step = (*decompressor).$FUNCNAME$
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f.stepState = stateInit
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return
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}
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goto readLiteral
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case v == 256:
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f.finishBlock()
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return
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// otherwise, reference to older data
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case v < 265:
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length = v - (257 - 3)
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n = 0
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case v < 269:
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length = v*2 - (265*2 - 11)
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n = 1
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case v < 273:
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length = v*4 - (269*4 - 19)
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n = 2
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case v < 277:
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length = v*8 - (273*8 - 35)
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n = 3
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case v < 281:
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length = v*16 - (277*16 - 67)
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n = 4
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case v < 285:
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length = v*32 - (281*32 - 131)
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n = 5
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case v < maxNumLit:
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length = 258
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n = 0
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default:
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if debugDecode {
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fmt.Println(v, ">= maxNumLit")
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}
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f.err = CorruptInputError(f.roffset)
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return
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}
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if n > 0 {
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for f.nb < n {
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if err = moreBits(); err != nil {
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if debugDecode {
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fmt.Println("morebits n>0:", err)
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}
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f.err = err
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return
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}
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}
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length += int(f.b & uint32(1<<n-1))
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f.b >>= n
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f.nb -= n
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}
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var dist int
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if f.hd == nil {
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for f.nb < 5 {
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if err = moreBits(); err != nil {
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if debugDecode {
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fmt.Println("morebits f.nb<5:", err)
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}
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f.err = err
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return
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}
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}
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dist = int(bits.Reverse8(uint8(f.b & 0x1F << 3)))
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f.b >>= 5
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f.nb -= 5
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} else {
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if dist, err = f.huffSym(f.hd); err != nil {
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if debugDecode {
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fmt.Println("huffsym:", err)
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}
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f.err = err
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return
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}
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}
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switch {
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case dist < 4:
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dist++
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case dist < maxNumDist:
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nb := uint(dist-2) >> 1
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// have 1 bit in bottom of dist, need nb more.
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extra := (dist & 1) << nb
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for f.nb < nb {
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if err = moreBits(); err != nil {
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if debugDecode {
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fmt.Println("morebits f.nb<nb:", err)
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}
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f.err = err
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return
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}
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}
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extra |= int(f.b & uint32(1<<nb-1))
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f.b >>= nb
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f.nb -= nb
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dist = 1<<(nb+1) + 1 + extra
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default:
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if debugDecode {
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fmt.Println("dist too big:", dist, maxNumDist)
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}
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f.err = CorruptInputError(f.roffset)
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return
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}
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// No check on length; encoding can be prescient.
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if dist > f.dict.histSize() {
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if debugDecode {
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fmt.Println("dist > f.dict.histSize():", dist, f.dict.histSize())
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}
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f.err = CorruptInputError(f.roffset)
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return
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}
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f.copyLen, f.copyDist = length, dist
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goto copyHistory
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}
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copyHistory:
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// Perform a backwards copy according to RFC section 3.2.3.
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{
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cnt := f.dict.tryWriteCopy(f.copyDist, f.copyLen)
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if cnt == 0 {
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cnt = f.dict.writeCopy(f.copyDist, f.copyLen)
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}
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f.copyLen -= cnt
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if f.dict.availWrite() == 0 || f.copyLen > 0 {
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f.toRead = f.dict.readFlush()
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f.step = (*decompressor).$FUNCNAME$ // We need to continue this work
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f.stepState = stateDict
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return
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}
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goto readLiteral
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}
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}
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`
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for i, t := range types {
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s := strings.Replace(template, "$FUNCNAME$", "huffman"+names[i], -1)
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s = strings.Replace(s, "$TYPE$", t, -1)
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f.WriteString(s)
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}
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f.WriteString("func (f *decompressor) huffmanBlockDecoder() func() {\n")
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f.WriteString("\tswitch f.r.(type) {\n")
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for i, t := range types {
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f.WriteString("\t\tcase " + t + ":\n")
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f.WriteString("\t\t\treturn f.huffman" + names[i] + "\n")
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}
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f.WriteString("\t\tdefault:\n")
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f.WriteString("\t\t\treturn f.huffmanBlockGeneric")
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f.WriteString("\t}\n}\n")
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}
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@ -0,0 +1,178 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package flate
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// Sort sorts data.
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// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
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// data.Less and data.Swap. The sort is not guaranteed to be stable.
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func sortByFreq(data []literalNode) {
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n := len(data)
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quickSortByFreq(data, 0, n, maxDepth(n))
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}
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func quickSortByFreq(data []literalNode, a, b, maxDepth int) {
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for b-a > 12 { // Use ShellSort for slices <= 12 elements
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if maxDepth == 0 {
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heapSort(data, a, b)
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return
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}
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maxDepth--
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mlo, mhi := doPivotByFreq(data, a, b)
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// Avoiding recursion on the larger subproblem guarantees
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// a stack depth of at most lg(b-a).
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if mlo-a < b-mhi {
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quickSortByFreq(data, a, mlo, maxDepth)
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||||
a = mhi // i.e., quickSortByFreq(data, mhi, b)
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||||
} else {
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quickSortByFreq(data, mhi, b, maxDepth)
|
||||
b = mlo // i.e., quickSortByFreq(data, a, mlo)
|
||||
}
|
||||
}
|
||||
if b-a > 1 {
|
||||
// Do ShellSort pass with gap 6
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// It could be written in this simplified form cause b-a <= 12
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for i := a + 6; i < b; i++ {
|
||||
if data[i].freq == data[i-6].freq && data[i].literal < data[i-6].literal || data[i].freq < data[i-6].freq {
|
||||
data[i], data[i-6] = data[i-6], data[i]
|
||||
}
|
||||
}
|
||||
insertionSortByFreq(data, a, b)
|
||||
}
|
||||
}
|
||||
|
||||
// siftDownByFreq implements the heap property on data[lo, hi).
|
||||
// first is an offset into the array where the root of the heap lies.
|
||||
func siftDownByFreq(data []literalNode, lo, hi, first int) {
|
||||
root := lo
|
||||
for {
|
||||
child := 2*root + 1
|
||||
if child >= hi {
|
||||
break
|
||||
}
|
||||
if child+1 < hi && (data[first+child].freq == data[first+child+1].freq && data[first+child].literal < data[first+child+1].literal || data[first+child].freq < data[first+child+1].freq) {
|
||||
child++
|
||||
}
|
||||
if data[first+root].freq == data[first+child].freq && data[first+root].literal > data[first+child].literal || data[first+root].freq > data[first+child].freq {
|
||||
return
|
||||
}
|
||||
data[first+root], data[first+child] = data[first+child], data[first+root]
|
||||
root = child
|
||||
}
|
||||
}
|
||||
func doPivotByFreq(data []literalNode, lo, hi int) (midlo, midhi int) {
|
||||
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
|
||||
if hi-lo > 40 {
|
||||
// Tukey's ``Ninther,'' median of three medians of three.
|
||||
s := (hi - lo) / 8
|
||||
medianOfThreeSortByFreq(data, lo, lo+s, lo+2*s)
|
||||
medianOfThreeSortByFreq(data, m, m-s, m+s)
|
||||
medianOfThreeSortByFreq(data, hi-1, hi-1-s, hi-1-2*s)
|
||||
}
|
||||
medianOfThreeSortByFreq(data, lo, m, hi-1)
|
||||
|
||||
// Invariants are:
|
||||
// data[lo] = pivot (set up by ChoosePivot)
|
||||
// data[lo < i < a] < pivot
|
||||
// data[a <= i < b] <= pivot
|
||||
// data[b <= i < c] unexamined
|
||||
// data[c <= i < hi-1] > pivot
|
||||
// data[hi-1] >= pivot
|
||||
pivot := lo
|
||||
a, c := lo+1, hi-1
|
||||
|
||||
for ; a < c && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ {
|
||||
}
|
||||
b := a
|
||||
for {
|
||||
for ; b < c && (data[pivot].freq == data[b].freq && data[pivot].literal > data[b].literal || data[pivot].freq > data[b].freq); b++ { // data[b] <= pivot
|
||||
}
|
||||
for ; b < c && (data[pivot].freq == data[c-1].freq && data[pivot].literal < data[c-1].literal || data[pivot].freq < data[c-1].freq); c-- { // data[c-1] > pivot
|
||||
}
|
||||
if b >= c {
|
||||
break
|
||||
}
|
||||
// data[b] > pivot; data[c-1] <= pivot
|
||||
data[b], data[c-1] = data[c-1], data[b]
|
||||
b++
|
||||
c--
|
||||
}
|
||||
// If hi-c<3 then there are duplicates (by property of median of nine).
|
||||
// Let's be a bit more conservative, and set border to 5.
|
||||
protect := hi-c < 5
|
||||
if !protect && hi-c < (hi-lo)/4 {
|
||||
// Lets test some points for equality to pivot
|
||||
dups := 0
|
||||
if data[pivot].freq == data[hi-1].freq && data[pivot].literal > data[hi-1].literal || data[pivot].freq > data[hi-1].freq { // data[hi-1] = pivot
|
||||
data[c], data[hi-1] = data[hi-1], data[c]
|
||||
c++
|
||||
dups++
|
||||
}
|
||||
if data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq { // data[b-1] = pivot
|
||||
b--
|
||||
dups++
|
||||
}
|
||||
// m-lo = (hi-lo)/2 > 6
|
||||
// b-lo > (hi-lo)*3/4-1 > 8
|
||||
// ==> m < b ==> data[m] <= pivot
|
||||
if data[m].freq == data[pivot].freq && data[m].literal > data[pivot].literal || data[m].freq > data[pivot].freq { // data[m] = pivot
|
||||
data[m], data[b-1] = data[b-1], data[m]
|
||||
b--
|
||||
dups++
|
||||
}
|
||||
// if at least 2 points are equal to pivot, assume skewed distribution
|
||||
protect = dups > 1
|
||||
}
|
||||
if protect {
|
||||
// Protect against a lot of duplicates
|
||||
// Add invariant:
|
||||
// data[a <= i < b] unexamined
|
||||
// data[b <= i < c] = pivot
|
||||
for {
|
||||
for ; a < b && (data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq); b-- { // data[b] == pivot
|
||||
}
|
||||
for ; a < b && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ { // data[a] < pivot
|
||||
}
|
||||
if a >= b {
|
||||
break
|
||||
}
|
||||
// data[a] == pivot; data[b-1] < pivot
|
||||
data[a], data[b-1] = data[b-1], data[a]
|
||||
a++
|
||||
b--
|
||||
}
|
||||
}
|
||||
// Swap pivot into middle
|
||||
data[pivot], data[b-1] = data[b-1], data[pivot]
|
||||
return b - 1, c
|
||||
}
|
||||
|
||||
// Insertion sort
|
||||
func insertionSortByFreq(data []literalNode, a, b int) {
|
||||
for i := a + 1; i < b; i++ {
|
||||
for j := i; j > a && (data[j].freq == data[j-1].freq && data[j].literal < data[j-1].literal || data[j].freq < data[j-1].freq); j-- {
|
||||
data[j], data[j-1] = data[j-1], data[j]
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// quickSortByFreq, loosely following Bentley and McIlroy,
|
||||
// ``Engineering a Sort Function,'' SP&E November 1993.
|
||||
|
||||
// medianOfThreeSortByFreq moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
|
||||
func medianOfThreeSortByFreq(data []literalNode, m1, m0, m2 int) {
|
||||
// sort 3 elements
|
||||
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
|
||||
data[m1], data[m0] = data[m0], data[m1]
|
||||
}
|
||||
// data[m0] <= data[m1]
|
||||
if data[m2].freq == data[m1].freq && data[m2].literal < data[m1].literal || data[m2].freq < data[m1].freq {
|
||||
data[m2], data[m1] = data[m1], data[m2]
|
||||
// data[m0] <= data[m2] && data[m1] < data[m2]
|
||||
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
|
||||
data[m1], data[m0] = data[m0], data[m1]
|
||||
}
|
||||
}
|
||||
// now data[m0] <= data[m1] <= data[m2]
|
||||
}
|
@ -0,0 +1,201 @@
|
||||
// Copyright 2009 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package flate
|
||||
|
||||
// Sort sorts data.
|
||||
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
|
||||
// data.Less and data.Swap. The sort is not guaranteed to be stable.
|
||||
func sortByLiteral(data []literalNode) {
|
||||
n := len(data)
|
||||
quickSort(data, 0, n, maxDepth(n))
|
||||
}
|
||||
|
||||
func quickSort(data []literalNode, a, b, maxDepth int) {
|
||||
for b-a > 12 { // Use ShellSort for slices <= 12 elements
|
||||
if maxDepth == 0 {
|
||||
heapSort(data, a, b)
|
||||
return
|
||||
}
|
||||
maxDepth--
|
||||
mlo, mhi := doPivot(data, a, b)
|
||||
// Avoiding recursion on the larger subproblem guarantees
|
||||
// a stack depth of at most lg(b-a).
|
||||
if mlo-a < b-mhi {
|
||||
quickSort(data, a, mlo, maxDepth)
|
||||
a = mhi // i.e., quickSort(data, mhi, b)
|
||||
} else {
|
||||
quickSort(data, mhi, b, maxDepth)
|
||||
b = mlo // i.e., quickSort(data, a, mlo)
|
||||
}
|
||||
}
|
||||
if b-a > 1 {
|
||||
// Do ShellSort pass with gap 6
|
||||
// It could be written in this simplified form cause b-a <= 12
|
||||
for i := a + 6; i < b; i++ {
|
||||
if data[i].literal < data[i-6].literal {
|
||||
data[i], data[i-6] = data[i-6], data[i]
|
||||
}
|
||||
}
|
||||
insertionSort(data, a, b)
|
||||
}
|
||||
}
|
||||
func heapSort(data []literalNode, a, b int) {
|
||||
first := a
|
||||
lo := 0
|
||||
hi := b - a
|
||||
|
||||
// Build heap with greatest element at top.
|
||||
for i := (hi - 1) / 2; i >= 0; i-- {
|
||||
siftDown(data, i, hi, first)
|
||||
}
|
||||
|
||||
// Pop elements, largest first, into end of data.
|
||||
for i := hi - 1; i >= 0; i-- {
|
||||
data[first], data[first+i] = data[first+i], data[first]
|
||||
siftDown(data, lo, i, first)
|
||||
}
|
||||
}
|
||||
|
||||
// siftDown implements the heap property on data[lo, hi).
|
||||
// first is an offset into the array where the root of the heap lies.
|
||||
func siftDown(data []literalNode, lo, hi, first int) {
|
||||
root := lo
|
||||
for {
|
||||
child := 2*root + 1
|
||||
if child >= hi {
|
||||
break
|
||||
}
|
||||
if child+1 < hi && data[first+child].literal < data[first+child+1].literal {
|
||||
child++
|
||||
}
|
||||
if data[first+root].literal > data[first+child].literal {
|
||||
return
|
||||
}
|
||||
data[first+root], data[first+child] = data[first+child], data[first+root]
|
||||
root = child
|
||||
}
|
||||
}
|
||||
func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) {
|
||||
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
|
||||
if hi-lo > 40 {
|
||||
// Tukey's ``Ninther,'' median of three medians of three.
|
||||
s := (hi - lo) / 8
|
||||
medianOfThree(data, lo, lo+s, lo+2*s)
|
||||
medianOfThree(data, m, m-s, m+s)
|
||||
medianOfThree(data, hi-1, hi-1-s, hi-1-2*s)
|
||||
}
|
||||
medianOfThree(data, lo, m, hi-1)
|
||||
|
||||
// Invariants are:
|
||||
// data[lo] = pivot (set up by ChoosePivot)
|
||||
// data[lo < i < a] < pivot
|
||||
// data[a <= i < b] <= pivot
|
||||
// data[b <= i < c] unexamined
|
||||
// data[c <= i < hi-1] > pivot
|
||||
// data[hi-1] >= pivot
|
||||
pivot := lo
|
||||
a, c := lo+1, hi-1
|
||||
|
||||
for ; a < c && data[a].literal < data[pivot].literal; a++ {
|
||||
}
|
||||
b := a
|
||||
for {
|
||||
for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot
|
||||
}
|
||||
for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot
|
||||
}
|
||||
if b >= c {
|
||||
break
|
||||
}
|
||||
// data[b] > pivot; data[c-1] <= pivot
|
||||
data[b], data[c-1] = data[c-1], data[b]
|
||||
b++
|
||||
c--
|
||||
}
|
||||
// If hi-c<3 then there are duplicates (by property of median of nine).
|
||||
// Let's be a bit more conservative, and set border to 5.
|
||||
protect := hi-c < 5
|
||||
if !protect && hi-c < (hi-lo)/4 {
|
||||
// Lets test some points for equality to pivot
|
||||
dups := 0
|
||||
if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot
|
||||
data[c], data[hi-1] = data[hi-1], data[c]
|
||||
c++
|
||||
dups++
|
||||
}
|
||||
if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot
|
||||
b--
|
||||
dups++
|
||||
}
|
||||
// m-lo = (hi-lo)/2 > 6
|
||||
// b-lo > (hi-lo)*3/4-1 > 8
|
||||
// ==> m < b ==> data[m] <= pivot
|
||||
if data[m].literal > data[pivot].literal { // data[m] = pivot
|
||||
data[m], data[b-1] = data[b-1], data[m]
|
||||
b--
|
||||
dups++
|
||||
}
|
||||
// if at least 2 points are equal to pivot, assume skewed distribution
|
||||
protect = dups > 1
|
||||
}
|
||||
if protect {
|
||||
// Protect against a lot of duplicates
|
||||
// Add invariant:
|
||||
// data[a <= i < b] unexamined
|
||||
// data[b <= i < c] = pivot
|
||||
for {
|
||||
for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot
|
||||
}
|
||||
for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot
|
||||
}
|
||||
if a >= b {
|
||||
break
|
||||
}
|
||||
// data[a] == pivot; data[b-1] < pivot
|
||||
data[a], data[b-1] = data[b-1], data[a]
|
||||
a++
|
||||
b--
|
||||
}
|
||||
}
|
||||
// Swap pivot into middle
|
||||
data[pivot], data[b-1] = data[b-1], data[pivot]
|
||||
return b - 1, c
|
||||
}
|
||||
|
||||
// Insertion sort
|
||||
func insertionSort(data []literalNode, a, b int) {
|
||||
for i := a + 1; i < b; i++ {
|
||||
for j := i; j > a && data[j].literal < data[j-1].literal; j-- {
|
||||
data[j], data[j-1] = data[j-1], data[j]
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// maxDepth returns a threshold at which quicksort should switch
|
||||
// to heapsort. It returns 2*ceil(lg(n+1)).
|
||||
func maxDepth(n int) int {
|
||||
var depth int
|
||||
for i := n; i > 0; i >>= 1 {
|
||||
depth++
|
||||
}
|
||||
return depth * 2
|
||||
}
|
||||
|
||||
// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
|
||||
func medianOfThree(data []literalNode, m1, m0, m2 int) {
|
||||
// sort 3 elements
|
||||
if data[m1].literal < data[m0].literal {
|
||||
data[m1], data[m0] = data[m0], data[m1]
|
||||
}
|
||||
// data[m0] <= data[m1]
|
||||
if data[m2].literal < data[m1].literal {
|
||||
data[m2], data[m1] = data[m1], data[m2]
|
||||
// data[m0] <= data[m2] && data[m1] < data[m2]
|
||||
if data[m1].literal < data[m0].literal {
|
||||
data[m1], data[m0] = data[m0], data[m1]
|
||||
}
|
||||
}
|
||||
// now data[m0] <= data[m1] <= data[m2]
|
||||
}
|
@ -0,0 +1,922 @@
|
||||
// Code generated by go generate gen_inflate.go. DO NOT EDIT.
|
||||
|
||||
package flate
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"bytes"
|
||||
"fmt"
|
||||
"math/bits"
|
||||
"strings"
|
||||
)
|
||||
|
||||
// Decode a single Huffman block from f.
|
||||
// hl and hd are the Huffman states for the lit/length values
|
||||
// and the distance values, respectively. If hd == nil, using the
|
||||
// fixed distance encoding associated with fixed Huffman blocks.
|
||||
func (f *decompressor) huffmanBytesBuffer() {
|
||||
const (
|
||||
stateInit = iota // Zero value must be stateInit
|
||||
stateDict
|
||||
)
|
||||
fr := f.r.(*bytes.Buffer)
|
||||
moreBits := func() error {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
return noEOF(err)
|
||||
}
|
||||
f.roffset++
|
||||
f.b |= uint32(c) << f.nb
|
||||
f.nb += 8
|
||||
return nil
|
||||
}
|
||||
|
||||
switch f.stepState {
|
||||
case stateInit:
|
||||
goto readLiteral
|
||||
case stateDict:
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
readLiteral:
|
||||
// Read literal and/or (length, distance) according to RFC section 3.2.3.
|
||||
{
|
||||
var v int
|
||||
{
|
||||
// Inlined v, err := f.huffSym(f.hl)
|
||||
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
|
||||
// with single element, huffSym must error on these two edge cases. In both
|
||||
// cases, the chunks slice will be 0 for the invalid sequence, leading it
|
||||
// satisfy the n == 0 check below.
|
||||
n := uint(f.hl.maxRead)
|
||||
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
|
||||
// but is smart enough to keep local variables in registers, so use nb and b,
|
||||
// inline call to moreBits and reassign b,nb back to f on return.
|
||||
nb, b := f.nb, f.b
|
||||
for {
|
||||
for nb < n {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
f.err = noEOF(err)
|
||||
return
|
||||
}
|
||||
f.roffset++
|
||||
b |= uint32(c) << (nb & 31)
|
||||
nb += 8
|
||||
}
|
||||
chunk := f.hl.chunks[b&(huffmanNumChunks-1)]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
if n > huffmanChunkBits {
|
||||
chunk = f.hl.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&f.hl.linkMask]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
}
|
||||
if n <= nb {
|
||||
if n == 0 {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
if debugDecode {
|
||||
fmt.Println("huffsym: n==0")
|
||||
}
|
||||
f.err = CorruptInputError(f.roffset)
|
||||
return
|
||||
}
|
||||
f.b = b >> (n & 31)
|
||||
f.nb = nb - n
|
||||
v = int(chunk >> huffmanValueShift)
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
var n uint // number of bits extra
|
||||
var length int
|
||||
var err error
|
||||
switch {
|
||||
case v < 256:
|
||||
f.dict.writeByte(byte(v))
|
||||
if f.dict.availWrite() == 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBytesBuffer
|
||||
f.stepState = stateInit
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
case v == 256:
|
||||
f.finishBlock()
|
||||
return
|
||||
// otherwise, reference to older data
|
||||
case v < 265:
|
||||
length = v - (257 - 3)
|
||||
n = 0
|
||||
case v < 269:
|
||||
length = v*2 - (265*2 - 11)
|
||||
n = 1
|
||||
case v < 273:
|
||||
length = v*4 - (269*4 - 19)
|
||||
n = 2
|
||||
case v < 277:
|
||||
length = v*8 - (273*8 - 35)
|
||||
n = 3
|
||||
case v < 281:
|
||||
length = v*16 - (277*16 - 67)
|
||||
n = 4
|
||||
case v < 285:
|
||||
length = v*32 - (281*32 - 131)
|
||||
n = 5
|
||||
case v < maxNumLit:
|
||||
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 = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits n>0:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
length += int(f.b & uint32(1<<n-1))
|
||||
f.b >>= n
|
||||
f.nb -= n
|
||||
}
|
||||
|
||||
var dist int
|
||||
if f.hd == nil {
|
||||
for f.nb < 5 {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<5:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
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
|
||||
}
|
||||
}
|
||||
|
||||
switch {
|
||||
case dist < 4:
|
||||
dist++
|
||||
case dist < maxNumDist:
|
||||
nb := uint(dist-2) >> 1
|
||||
// have 1 bit in bottom of dist, need nb more.
|
||||
extra := (dist & 1) << nb
|
||||
for f.nb < nb {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<nb:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
extra |= int(f.b & uint32(1<<nb-1))
|
||||
f.b >>= nb
|
||||
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
|
||||
}
|
||||
|
||||
f.copyLen, f.copyDist = length, dist
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
copyHistory:
|
||||
// Perform a backwards copy according to RFC section 3.2.3.
|
||||
{
|
||||
cnt := f.dict.tryWriteCopy(f.copyDist, f.copyLen)
|
||||
if cnt == 0 {
|
||||
cnt = f.dict.writeCopy(f.copyDist, f.copyLen)
|
||||
}
|
||||
f.copyLen -= cnt
|
||||
|
||||
if f.dict.availWrite() == 0 || f.copyLen > 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBytesBuffer // We need to continue this work
|
||||
f.stepState = stateDict
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
}
|
||||
}
|
||||
|
||||
// Decode a single Huffman block from f.
|
||||
// hl and hd are the Huffman states for the lit/length values
|
||||
// and the distance values, respectively. If hd == nil, using the
|
||||
// fixed distance encoding associated with fixed Huffman blocks.
|
||||
func (f *decompressor) huffmanBytesReader() {
|
||||
const (
|
||||
stateInit = iota // Zero value must be stateInit
|
||||
stateDict
|
||||
)
|
||||
fr := f.r.(*bytes.Reader)
|
||||
moreBits := func() error {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
return noEOF(err)
|
||||
}
|
||||
f.roffset++
|
||||
f.b |= uint32(c) << f.nb
|
||||
f.nb += 8
|
||||
return nil
|
||||
}
|
||||
|
||||
switch f.stepState {
|
||||
case stateInit:
|
||||
goto readLiteral
|
||||
case stateDict:
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
readLiteral:
|
||||
// Read literal and/or (length, distance) according to RFC section 3.2.3.
|
||||
{
|
||||
var v int
|
||||
{
|
||||
// Inlined v, err := f.huffSym(f.hl)
|
||||
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
|
||||
// with single element, huffSym must error on these two edge cases. In both
|
||||
// cases, the chunks slice will be 0 for the invalid sequence, leading it
|
||||
// satisfy the n == 0 check below.
|
||||
n := uint(f.hl.maxRead)
|
||||
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
|
||||
// but is smart enough to keep local variables in registers, so use nb and b,
|
||||
// inline call to moreBits and reassign b,nb back to f on return.
|
||||
nb, b := f.nb, f.b
|
||||
for {
|
||||
for nb < n {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
f.err = noEOF(err)
|
||||
return
|
||||
}
|
||||
f.roffset++
|
||||
b |= uint32(c) << (nb & 31)
|
||||
nb += 8
|
||||
}
|
||||
chunk := f.hl.chunks[b&(huffmanNumChunks-1)]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
if n > huffmanChunkBits {
|
||||
chunk = f.hl.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&f.hl.linkMask]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
}
|
||||
if n <= nb {
|
||||
if n == 0 {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
if debugDecode {
|
||||
fmt.Println("huffsym: n==0")
|
||||
}
|
||||
f.err = CorruptInputError(f.roffset)
|
||||
return
|
||||
}
|
||||
f.b = b >> (n & 31)
|
||||
f.nb = nb - n
|
||||
v = int(chunk >> huffmanValueShift)
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
var n uint // number of bits extra
|
||||
var length int
|
||||
var err error
|
||||
switch {
|
||||
case v < 256:
|
||||
f.dict.writeByte(byte(v))
|
||||
if f.dict.availWrite() == 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBytesReader
|
||||
f.stepState = stateInit
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
case v == 256:
|
||||
f.finishBlock()
|
||||
return
|
||||
// otherwise, reference to older data
|
||||
case v < 265:
|
||||
length = v - (257 - 3)
|
||||
n = 0
|
||||
case v < 269:
|
||||
length = v*2 - (265*2 - 11)
|
||||
n = 1
|
||||
case v < 273:
|
||||
length = v*4 - (269*4 - 19)
|
||||
n = 2
|
||||
case v < 277:
|
||||
length = v*8 - (273*8 - 35)
|
||||
n = 3
|
||||
case v < 281:
|
||||
length = v*16 - (277*16 - 67)
|
||||
n = 4
|
||||
case v < 285:
|
||||
length = v*32 - (281*32 - 131)
|
||||
n = 5
|
||||
case v < maxNumLit:
|
||||
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 = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits n>0:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
length += int(f.b & uint32(1<<n-1))
|
||||
f.b >>= n
|
||||
f.nb -= n
|
||||
}
|
||||
|
||||
var dist int
|
||||
if f.hd == nil {
|
||||
for f.nb < 5 {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<5:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
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
|
||||
}
|
||||
}
|
||||
|
||||
switch {
|
||||
case dist < 4:
|
||||
dist++
|
||||
case dist < maxNumDist:
|
||||
nb := uint(dist-2) >> 1
|
||||
// have 1 bit in bottom of dist, need nb more.
|
||||
extra := (dist & 1) << nb
|
||||
for f.nb < nb {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<nb:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
extra |= int(f.b & uint32(1<<nb-1))
|
||||
f.b >>= nb
|
||||
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
|
||||
}
|
||||
|
||||
f.copyLen, f.copyDist = length, dist
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
copyHistory:
|
||||
// Perform a backwards copy according to RFC section 3.2.3.
|
||||
{
|
||||
cnt := f.dict.tryWriteCopy(f.copyDist, f.copyLen)
|
||||
if cnt == 0 {
|
||||
cnt = f.dict.writeCopy(f.copyDist, f.copyLen)
|
||||
}
|
||||
f.copyLen -= cnt
|
||||
|
||||
if f.dict.availWrite() == 0 || f.copyLen > 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBytesReader // We need to continue this work
|
||||
f.stepState = stateDict
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
}
|
||||
}
|
||||
|
||||
// Decode a single Huffman block from f.
|
||||
// hl and hd are the Huffman states for the lit/length values
|
||||
// and the distance values, respectively. If hd == nil, using the
|
||||
// fixed distance encoding associated with fixed Huffman blocks.
|
||||
func (f *decompressor) huffmanBufioReader() {
|
||||
const (
|
||||
stateInit = iota // Zero value must be stateInit
|
||||
stateDict
|
||||
)
|
||||
fr := f.r.(*bufio.Reader)
|
||||
moreBits := func() error {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
return noEOF(err)
|
||||
}
|
||||
f.roffset++
|
||||
f.b |= uint32(c) << f.nb
|
||||
f.nb += 8
|
||||
return nil
|
||||
}
|
||||
|
||||
switch f.stepState {
|
||||
case stateInit:
|
||||
goto readLiteral
|
||||
case stateDict:
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
readLiteral:
|
||||
// Read literal and/or (length, distance) according to RFC section 3.2.3.
|
||||
{
|
||||
var v int
|
||||
{
|
||||
// Inlined v, err := f.huffSym(f.hl)
|
||||
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
|
||||
// with single element, huffSym must error on these two edge cases. In both
|
||||
// cases, the chunks slice will be 0 for the invalid sequence, leading it
|
||||
// satisfy the n == 0 check below.
|
||||
n := uint(f.hl.maxRead)
|
||||
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
|
||||
// but is smart enough to keep local variables in registers, so use nb and b,
|
||||
// inline call to moreBits and reassign b,nb back to f on return.
|
||||
nb, b := f.nb, f.b
|
||||
for {
|
||||
for nb < n {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
f.err = noEOF(err)
|
||||
return
|
||||
}
|
||||
f.roffset++
|
||||
b |= uint32(c) << (nb & 31)
|
||||
nb += 8
|
||||
}
|
||||
chunk := f.hl.chunks[b&(huffmanNumChunks-1)]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
if n > huffmanChunkBits {
|
||||
chunk = f.hl.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&f.hl.linkMask]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
}
|
||||
if n <= nb {
|
||||
if n == 0 {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
if debugDecode {
|
||||
fmt.Println("huffsym: n==0")
|
||||
}
|
||||
f.err = CorruptInputError(f.roffset)
|
||||
return
|
||||
}
|
||||
f.b = b >> (n & 31)
|
||||
f.nb = nb - n
|
||||
v = int(chunk >> huffmanValueShift)
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
var n uint // number of bits extra
|
||||
var length int
|
||||
var err error
|
||||
switch {
|
||||
case v < 256:
|
||||
f.dict.writeByte(byte(v))
|
||||
if f.dict.availWrite() == 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBufioReader
|
||||
f.stepState = stateInit
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
case v == 256:
|
||||
f.finishBlock()
|
||||
return
|
||||
// otherwise, reference to older data
|
||||
case v < 265:
|
||||
length = v - (257 - 3)
|
||||
n = 0
|
||||
case v < 269:
|
||||
length = v*2 - (265*2 - 11)
|
||||
n = 1
|
||||
case v < 273:
|
||||
length = v*4 - (269*4 - 19)
|
||||
n = 2
|
||||
case v < 277:
|
||||
length = v*8 - (273*8 - 35)
|
||||
n = 3
|
||||
case v < 281:
|
||||
length = v*16 - (277*16 - 67)
|
||||
n = 4
|
||||
case v < 285:
|
||||
length = v*32 - (281*32 - 131)
|
||||
n = 5
|
||||
case v < maxNumLit:
|
||||
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 = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits n>0:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
length += int(f.b & uint32(1<<n-1))
|
||||
f.b >>= n
|
||||
f.nb -= n
|
||||
}
|
||||
|
||||
var dist int
|
||||
if f.hd == nil {
|
||||
for f.nb < 5 {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<5:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
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
|
||||
}
|
||||
}
|
||||
|
||||
switch {
|
||||
case dist < 4:
|
||||
dist++
|
||||
case dist < maxNumDist:
|
||||
nb := uint(dist-2) >> 1
|
||||
// have 1 bit in bottom of dist, need nb more.
|
||||
extra := (dist & 1) << nb
|
||||
for f.nb < nb {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<nb:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
extra |= int(f.b & uint32(1<<nb-1))
|
||||
f.b >>= nb
|
||||
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
|
||||
}
|
||||
|
||||
f.copyLen, f.copyDist = length, dist
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
copyHistory:
|
||||
// Perform a backwards copy according to RFC section 3.2.3.
|
||||
{
|
||||
cnt := f.dict.tryWriteCopy(f.copyDist, f.copyLen)
|
||||
if cnt == 0 {
|
||||
cnt = f.dict.writeCopy(f.copyDist, f.copyLen)
|
||||
}
|
||||
f.copyLen -= cnt
|
||||
|
||||
if f.dict.availWrite() == 0 || f.copyLen > 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanBufioReader // We need to continue this work
|
||||
f.stepState = stateDict
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
}
|
||||
}
|
||||
|
||||
// Decode a single Huffman block from f.
|
||||
// hl and hd are the Huffman states for the lit/length values
|
||||
// and the distance values, respectively. If hd == nil, using the
|
||||
// fixed distance encoding associated with fixed Huffman blocks.
|
||||
func (f *decompressor) huffmanStringsReader() {
|
||||
const (
|
||||
stateInit = iota // Zero value must be stateInit
|
||||
stateDict
|
||||
)
|
||||
fr := f.r.(*strings.Reader)
|
||||
moreBits := func() error {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
return noEOF(err)
|
||||
}
|
||||
f.roffset++
|
||||
f.b |= uint32(c) << f.nb
|
||||
f.nb += 8
|
||||
return nil
|
||||
}
|
||||
|
||||
switch f.stepState {
|
||||
case stateInit:
|
||||
goto readLiteral
|
||||
case stateDict:
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
readLiteral:
|
||||
// Read literal and/or (length, distance) according to RFC section 3.2.3.
|
||||
{
|
||||
var v int
|
||||
{
|
||||
// Inlined v, err := f.huffSym(f.hl)
|
||||
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
|
||||
// with single element, huffSym must error on these two edge cases. In both
|
||||
// cases, the chunks slice will be 0 for the invalid sequence, leading it
|
||||
// satisfy the n == 0 check below.
|
||||
n := uint(f.hl.maxRead)
|
||||
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
|
||||
// but is smart enough to keep local variables in registers, so use nb and b,
|
||||
// inline call to moreBits and reassign b,nb back to f on return.
|
||||
nb, b := f.nb, f.b
|
||||
for {
|
||||
for nb < n {
|
||||
c, err := fr.ReadByte()
|
||||
if err != nil {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
f.err = noEOF(err)
|
||||
return
|
||||
}
|
||||
f.roffset++
|
||||
b |= uint32(c) << (nb & 31)
|
||||
nb += 8
|
||||
}
|
||||
chunk := f.hl.chunks[b&(huffmanNumChunks-1)]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
if n > huffmanChunkBits {
|
||||
chunk = f.hl.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&f.hl.linkMask]
|
||||
n = uint(chunk & huffmanCountMask)
|
||||
}
|
||||
if n <= nb {
|
||||
if n == 0 {
|
||||
f.b = b
|
||||
f.nb = nb
|
||||
if debugDecode {
|
||||
fmt.Println("huffsym: n==0")
|
||||
}
|
||||
f.err = CorruptInputError(f.roffset)
|
||||
return
|
||||
}
|
||||
f.b = b >> (n & 31)
|
||||
f.nb = nb - n
|
||||
v = int(chunk >> huffmanValueShift)
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
var n uint // number of bits extra
|
||||
var length int
|
||||
var err error
|
||||
switch {
|
||||
case v < 256:
|
||||
f.dict.writeByte(byte(v))
|
||||
if f.dict.availWrite() == 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanStringsReader
|
||||
f.stepState = stateInit
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
case v == 256:
|
||||
f.finishBlock()
|
||||
return
|
||||
// otherwise, reference to older data
|
||||
case v < 265:
|
||||
length = v - (257 - 3)
|
||||
n = 0
|
||||
case v < 269:
|
||||
length = v*2 - (265*2 - 11)
|
||||
n = 1
|
||||
case v < 273:
|
||||
length = v*4 - (269*4 - 19)
|
||||
n = 2
|
||||
case v < 277:
|
||||
length = v*8 - (273*8 - 35)
|
||||
n = 3
|
||||
case v < 281:
|
||||
length = v*16 - (277*16 - 67)
|
||||
n = 4
|
||||
case v < 285:
|
||||
length = v*32 - (281*32 - 131)
|
||||
n = 5
|
||||
case v < maxNumLit:
|
||||
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 = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits n>0:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
length += int(f.b & uint32(1<<n-1))
|
||||
f.b >>= n
|
||||
f.nb -= n
|
||||
}
|
||||
|
||||
var dist int
|
||||
if f.hd == nil {
|
||||
for f.nb < 5 {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<5:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
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
|
||||
}
|
||||
}
|
||||
|
||||
switch {
|
||||
case dist < 4:
|
||||
dist++
|
||||
case dist < maxNumDist:
|
||||
nb := uint(dist-2) >> 1
|
||||
// have 1 bit in bottom of dist, need nb more.
|
||||
extra := (dist & 1) << nb
|
||||
for f.nb < nb {
|
||||
if err = moreBits(); err != nil {
|
||||
if debugDecode {
|
||||
fmt.Println("morebits f.nb<nb:", err)
|
||||
}
|
||||
f.err = err
|
||||
return
|
||||
}
|
||||
}
|
||||
extra |= int(f.b & uint32(1<<nb-1))
|
||||
f.b >>= nb
|
||||
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
|
||||
}
|
||||
|
||||
f.copyLen, f.copyDist = length, dist
|
||||
goto copyHistory
|
||||
}
|
||||
|
||||
copyHistory:
|
||||
// Perform a backwards copy according to RFC section 3.2.3.
|
||||
{
|
||||
cnt := f.dict.tryWriteCopy(f.copyDist, f.copyLen)
|
||||
if cnt == 0 {
|
||||
cnt = f.dict.writeCopy(f.copyDist, f.copyLen)
|
||||
}
|
||||
f.copyLen -= cnt
|
||||
|
||||
if f.dict.availWrite() == 0 || f.copyLen > 0 {
|
||||
f.toRead = f.dict.readFlush()
|
||||
f.step = (*decompressor).huffmanStringsReader // We need to continue this work
|
||||
f.stepState = stateDict
|
||||
return
|
||||
}
|
||||
goto readLiteral
|
||||
}
|
||||
}
|
||||
|
||||
func (f *decompressor) huffmanBlockDecoder() func() {
|
||||
switch f.r.(type) {
|
||||
case *bytes.Buffer:
|
||||
return f.huffmanBytesBuffer
|
||||
case *bytes.Reader:
|
||||
return f.huffmanBytesReader
|
||||
case *bufio.Reader:
|
||||
return f.huffmanBufioReader
|
||||
case *strings.Reader:
|
||||
return f.huffmanStringsReader
|
||||
default:
|
||||
return f.huffmanBlockGeneric
|
||||
}
|
||||
}
|
Loading…
Reference in new issue