diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/flate')
22 files changed, 0 insertions, 8306 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go deleted file mode 100644 index 66d1657d2..000000000 --- a/vendor/github.com/klauspost/compress/flate/deflate.go +++ /dev/null @@ -1,1017 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Copyright (c) 2015 Klaus Post -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -import ( - "encoding/binary" - "errors" - "fmt" - "io" - "math" -) - -const ( - NoCompression = 0 - BestSpeed = 1 - BestCompression = 9 - DefaultCompression = -1 - - // HuffmanOnly disables Lempel-Ziv match searching and only performs Huffman - // entropy encoding. This mode is useful in compressing data that has - // already been compressed with an LZ style algorithm (e.g. Snappy or LZ4) - // that lacks an entropy encoder. Compression gains are achieved when - // certain bytes in the input stream occur more frequently than others. - // - // Note that HuffmanOnly produces a compressed output that is - // RFC 1951 compliant. That is, any valid DEFLATE decompressor will - // continue to be able to decompress this output. - HuffmanOnly = -2 - ConstantCompression = HuffmanOnly // compatibility alias. - - logWindowSize = 15 - windowSize = 1 << logWindowSize - windowMask = windowSize - 1 - logMaxOffsetSize = 15 // Standard DEFLATE - minMatchLength = 4 // The smallest match that the compressor looks for - maxMatchLength = 258 // The longest match for the compressor - minOffsetSize = 1 // The shortest offset that makes any sense - - // The maximum number of tokens we will encode at the time. - // Smaller sizes usually creates less optimal blocks. - // Bigger can make context switching slow. - // We use this for levels 7-9, so we make it big. - maxFlateBlockTokens = 1 << 15 - maxStoreBlockSize = 65535 - hashBits = 17 // After 17 performance degrades - hashSize = 1 << hashBits - hashMask = (1 << hashBits) - 1 - hashShift = (hashBits + minMatchLength - 1) / minMatchLength - maxHashOffset = 1 << 28 - - skipNever = math.MaxInt32 - - debugDeflate = false -) - -type compressionLevel struct { - good, lazy, nice, chain, fastSkipHashing, level int -} - -// Compression levels have been rebalanced from zlib deflate defaults -// to give a bigger spread in speed and compression. -// See https://blog.klauspost.com/rebalancing-deflate-compression-levels/ -var levels = []compressionLevel{ - {}, // 0 - // Level 1-6 uses specialized algorithm - values not used - {0, 0, 0, 0, 0, 1}, - {0, 0, 0, 0, 0, 2}, - {0, 0, 0, 0, 0, 3}, - {0, 0, 0, 0, 0, 4}, - {0, 0, 0, 0, 0, 5}, - {0, 0, 0, 0, 0, 6}, - // Levels 7-9 use increasingly more lazy matching - // and increasingly stringent conditions for "good enough". - {8, 12, 16, 24, skipNever, 7}, - {16, 30, 40, 64, skipNever, 8}, - {32, 258, 258, 1024, skipNever, 9}, -} - -// advancedState contains state for the advanced levels, with bigger hash tables, etc. -type advancedState struct { - // deflate state - length int - offset int - maxInsertIndex int - chainHead int - hashOffset int - - ii uint16 // position of last match, intended to overflow to reset. - - // input window: unprocessed data is window[index:windowEnd] - index int - hashMatch [maxMatchLength + minMatchLength]uint32 - - // Input hash chains - // hashHead[hashValue] contains the largest inputIndex with the specified hash value - // If hashHead[hashValue] is within the current window, then - // hashPrev[hashHead[hashValue] & windowMask] contains the previous index - // with the same hash value. - hashHead [hashSize]uint32 - hashPrev [windowSize]uint32 -} - -type compressor struct { - compressionLevel - - h *huffmanEncoder - w *huffmanBitWriter - - // compression algorithm - fill func(*compressor, []byte) int // copy data to window - step func(*compressor) // process window - - window []byte - windowEnd int - blockStart int // window index where current tokens start - err error - - // queued output tokens - tokens tokens - fast fastEnc - state *advancedState - - sync bool // requesting flush - byteAvailable bool // if true, still need to process window[index-1]. -} - -func (d *compressor) fillDeflate(b []byte) int { - s := d.state - if s.index >= 2*windowSize-(minMatchLength+maxMatchLength) { - // shift the window by windowSize - //copy(d.window[:], d.window[windowSize:2*windowSize]) - *(*[windowSize]byte)(d.window) = *(*[windowSize]byte)(d.window[windowSize:]) - s.index -= windowSize - d.windowEnd -= windowSize - if d.blockStart >= windowSize { - d.blockStart -= windowSize - } else { - d.blockStart = math.MaxInt32 - } - s.hashOffset += windowSize - if s.hashOffset > maxHashOffset { - delta := s.hashOffset - 1 - s.hashOffset -= delta - s.chainHead -= delta - // Iterate over slices instead of arrays to avoid copying - // the entire table onto the stack (Issue #18625). - for i, v := range s.hashPrev[:] { - if int(v) > delta { - s.hashPrev[i] = uint32(int(v) - delta) - } else { - s.hashPrev[i] = 0 - } - } - for i, v := range s.hashHead[:] { - if int(v) > delta { - s.hashHead[i] = uint32(int(v) - delta) - } else { - s.hashHead[i] = 0 - } - } - } - } - n := copy(d.window[d.windowEnd:], b) - d.windowEnd += n - return n -} - -func (d *compressor) writeBlock(tok *tokens, index int, eof bool) error { - if index > 0 || eof { - var window []byte - if d.blockStart <= index { - window = d.window[d.blockStart:index] - } - d.blockStart = index - //d.w.writeBlock(tok, eof, window) - d.w.writeBlockDynamic(tok, eof, window, d.sync) - return d.w.err - } - return nil -} - -// writeBlockSkip writes the current block and uses the number of tokens -// to determine if the block should be stored on no matches, or -// only huffman encoded. -func (d *compressor) writeBlockSkip(tok *tokens, index int, eof bool) error { - if index > 0 || eof { - if d.blockStart <= index { - window := d.window[d.blockStart:index] - // If we removed less than a 64th of all literals - // we huffman compress the block. - if int(tok.n) > len(window)-int(tok.n>>6) { - d.w.writeBlockHuff(eof, window, d.sync) - } else { - // Write a dynamic huffman block. - d.w.writeBlockDynamic(tok, eof, window, d.sync) - } - } else { - d.w.writeBlock(tok, eof, nil) - } - d.blockStart = index - return d.w.err - } - return nil -} - -// fillWindow will fill the current window with the supplied -// dictionary and calculate all hashes. -// This is much faster than doing a full encode. -// Should only be used after a start/reset. -func (d *compressor) fillWindow(b []byte) { - // Do not fill window if we are in store-only or huffman mode. - if d.level <= 0 && d.level > -MinCustomWindowSize { - return - } - if d.fast != nil { - // encode the last data, but discard the result - if len(b) > maxMatchOffset { - b = b[len(b)-maxMatchOffset:] - } - d.fast.Encode(&d.tokens, b) - d.tokens.Reset() - return - } - s := d.state - // If we are given too much, cut it. - if len(b) > windowSize { - b = b[len(b)-windowSize:] - } - // Add all to window. - n := copy(d.window[d.windowEnd:], b) - - // Calculate 256 hashes at the time (more L1 cache hits) - loops := (n + 256 - minMatchLength) / 256 - for j := 0; j < loops; j++ { - startindex := j * 256 - end := startindex + 256 + minMatchLength - 1 - if end > n { - end = n - } - tocheck := d.window[startindex:end] - dstSize := len(tocheck) - minMatchLength + 1 - - if dstSize <= 0 { - continue - } - - dst := s.hashMatch[:dstSize] - bulkHash4(tocheck, dst) - var newH uint32 - for i, val := range dst { - di := i + startindex - newH = val & hashMask - // Get previous value with the same hash. - // Our chain should point to the previous value. - s.hashPrev[di&windowMask] = s.hashHead[newH] - // Set the head of the hash chain to us. - s.hashHead[newH] = uint32(di + s.hashOffset) - } - } - // Update window information. - d.windowEnd += n - s.index = n -} - -// Try to find a match starting at index whose length is greater than prevSize. -// We only look at chainCount possibilities before giving up. -// pos = s.index, prevHead = s.chainHead-s.hashOffset, prevLength=minMatchLength-1, lookahead -func (d *compressor) findMatch(pos int, prevHead int, lookahead int) (length, offset int, ok bool) { - minMatchLook := maxMatchLength - if lookahead < minMatchLook { - minMatchLook = lookahead - } - - win := d.window[0 : pos+minMatchLook] - - // We quit when we get a match that's at least nice long - nice := len(win) - pos - if d.nice < nice { - nice = d.nice - } - - // If we've got a match that's good enough, only look in 1/4 the chain. - tries := d.chain - length = minMatchLength - 1 - - wEnd := win[pos+length] - wPos := win[pos:] - minIndex := pos - windowSize - if minIndex < 0 { - minIndex = 0 - } - offset = 0 - - if d.chain < 100 { - for i := prevHead; tries > 0; tries-- { - if wEnd == win[i+length] { - n := matchLen(win[i:i+minMatchLook], wPos) - if n > length { - length = n - offset = pos - i - ok = true - if n >= nice { - // The match is good enough that we don't try to find a better one. - break - } - wEnd = win[pos+n] - } - } - if i <= minIndex { - // hashPrev[i & windowMask] has already been overwritten, so stop now. - break - } - i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset - if i < minIndex { - break - } - } - return - } - - // Minimum gain to accept a match. - cGain := 4 - - // Some like it higher (CSV), some like it lower (JSON) - const baseCost = 3 - // Base is 4 bytes at with an additional cost. - // Matches must be better than this. - - for i := prevHead; tries > 0; tries-- { - if wEnd == win[i+length] { - n := matchLen(win[i:i+minMatchLook], wPos) - if n > length { - // Calculate gain. Estimate - newGain := d.h.bitLengthRaw(wPos[:n]) - int(offsetExtraBits[offsetCode(uint32(pos-i))]) - baseCost - int(lengthExtraBits[lengthCodes[(n-3)&255]]) - - //fmt.Println("gain:", newGain, "prev:", cGain, "raw:", d.h.bitLengthRaw(wPos[:n]), "this-len:", n, "prev-len:", length) - if newGain > cGain { - length = n - offset = pos - i - cGain = newGain - ok = true - if n >= nice { - // The match is good enough that we don't try to find a better one. - break - } - wEnd = win[pos+n] - } - } - } - if i <= minIndex { - // hashPrev[i & windowMask] has already been overwritten, so stop now. - break - } - i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset - if i < minIndex { - break - } - } - return -} - -func (d *compressor) writeStoredBlock(buf []byte) error { - if d.w.writeStoredHeader(len(buf), false); d.w.err != nil { - return d.w.err - } - d.w.writeBytes(buf) - return d.w.err -} - -// hash4 returns a hash representation of the first 4 bytes -// of the supplied slice. -// The caller must ensure that len(b) >= 4. -func hash4(b []byte) uint32 { - return hash4u(binary.LittleEndian.Uint32(b), hashBits) -} - -// 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) -} - -// bulkHash4 will compute hashes using the same -// algorithm as hash4 -func bulkHash4(b []byte, dst []uint32) { - if len(b) < 4 { - return - } - hb := binary.LittleEndian.Uint32(b) - - dst[0] = hash4u(hb, hashBits) - end := len(b) - 4 + 1 - for i := 1; i < end; i++ { - hb = (hb >> 8) | uint32(b[i+3])<<24 - dst[i] = hash4u(hb, hashBits) - } -} - -func (d *compressor) initDeflate() { - d.window = make([]byte, 2*windowSize) - d.byteAvailable = false - d.err = nil - if d.state == nil { - return - } - s := d.state - s.index = 0 - s.hashOffset = 1 - s.length = minMatchLength - 1 - s.offset = 0 - s.chainHead = -1 -} - -// deflateLazy is the same as deflate, but with d.fastSkipHashing == skipNever, -// meaning it always has lazy matching on. -func (d *compressor) deflateLazy() { - s := d.state - // Sanity enables additional runtime tests. - // It's intended to be used during development - // to supplement the currently ad-hoc unit tests. - const sanity = debugDeflate - - if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync { - return - } - if d.windowEnd != s.index && d.chain > 100 { - // Get literal huffman coder. - if d.h == nil { - d.h = newHuffmanEncoder(maxFlateBlockTokens) - } - var tmp [256]uint16 - for _, v := range d.window[s.index:d.windowEnd] { - tmp[v]++ - } - d.h.generate(tmp[:], 15) - } - - s.maxInsertIndex = d.windowEnd - (minMatchLength - 1) - - for { - if sanity && s.index > d.windowEnd { - panic("index > windowEnd") - } - lookahead := d.windowEnd - s.index - if lookahead < minMatchLength+maxMatchLength { - if !d.sync { - return - } - if sanity && s.index > d.windowEnd { - panic("index > windowEnd") - } - if lookahead == 0 { - // Flush current output block if any. - if d.byteAvailable { - // There is still one pending token that needs to be flushed - d.tokens.AddLiteral(d.window[s.index-1]) - d.byteAvailable = false - } - if d.tokens.n > 0 { - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - return - } - } - if s.index < s.maxInsertIndex { - // Update the hash - hash := hash4(d.window[s.index:]) - ch := s.hashHead[hash] - s.chainHead = int(ch) - s.hashPrev[s.index&windowMask] = ch - s.hashHead[hash] = uint32(s.index + s.hashOffset) - } - prevLength := s.length - prevOffset := s.offset - s.length = minMatchLength - 1 - s.offset = 0 - minIndex := s.index - windowSize - if minIndex < 0 { - minIndex = 0 - } - - if s.chainHead-s.hashOffset >= minIndex && lookahead > prevLength && prevLength < d.lazy { - if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead); ok { - s.length = newLength - s.offset = newOffset - } - } - - if prevLength >= minMatchLength && s.length <= prevLength { - // No better match, but check for better match at end... - // - // Skip forward a number of bytes. - // Offset of 2 seems to yield best results. 3 is sometimes better. - const checkOff = 2 - - // Check all, except full length - if prevLength < maxMatchLength-checkOff { - prevIndex := s.index - 1 - if prevIndex+prevLength < s.maxInsertIndex { - end := lookahead - if lookahead > maxMatchLength+checkOff { - end = maxMatchLength + checkOff - } - end += prevIndex - - // Hash at match end. - h := hash4(d.window[prevIndex+prevLength:]) - ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength - if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff { - length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:]) - // It seems like a pure length metric is best. - if length > prevLength { - prevLength = length - prevOffset = prevIndex - ch2 - - // Extend back... - for i := checkOff - 1; i >= 0; i-- { - if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i] { - // Emit tokens we "owe" - for j := 0; j <= i; j++ { - d.tokens.AddLiteral(d.window[prevIndex+j]) - if d.tokens.n == maxFlateBlockTokens { - // The block includes the current character - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - s.index++ - if s.index < s.maxInsertIndex { - h := hash4(d.window[s.index:]) - ch := s.hashHead[h] - s.chainHead = int(ch) - s.hashPrev[s.index&windowMask] = ch - s.hashHead[h] = uint32(s.index + s.hashOffset) - } - } - break - } else { - prevLength++ - } - } - } else if false { - // Check one further ahead. - // Only rarely better, disabled for now. - prevIndex++ - h := hash4(d.window[prevIndex+prevLength:]) - ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength - if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff { - length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:]) - // It seems like a pure length metric is best. - if length > prevLength+checkOff { - prevLength = length - prevOffset = prevIndex - ch2 - prevIndex-- - - // Extend back... - for i := checkOff; i >= 0; i-- { - if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i-1] { - // Emit tokens we "owe" - for j := 0; j <= i; j++ { - d.tokens.AddLiteral(d.window[prevIndex+j]) - if d.tokens.n == maxFlateBlockTokens { - // The block includes the current character - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - s.index++ - if s.index < s.maxInsertIndex { - h := hash4(d.window[s.index:]) - ch := s.hashHead[h] - s.chainHead = int(ch) - s.hashPrev[s.index&windowMask] = ch - s.hashHead[h] = uint32(s.index + s.hashOffset) - } - } - break - } else { - prevLength++ - } - } - } - } - } - } - } - } - // There was a match at the previous step, and the current match is - // not better. Output the previous match. - d.tokens.AddMatch(uint32(prevLength-3), uint32(prevOffset-minOffsetSize)) - - // Insert in the hash table all strings up to the end of the match. - // index and index-1 are already inserted. If there is not enough - // lookahead, the last two strings are not inserted into the hash - // table. - newIndex := s.index + prevLength - 1 - // Calculate missing hashes - end := newIndex - if end > s.maxInsertIndex { - end = s.maxInsertIndex - } - end += minMatchLength - 1 - startindex := s.index + 1 - if startindex > s.maxInsertIndex { - startindex = s.maxInsertIndex - } - tocheck := d.window[startindex:end] - dstSize := len(tocheck) - minMatchLength + 1 - if dstSize > 0 { - dst := s.hashMatch[:dstSize] - bulkHash4(tocheck, dst) - var newH uint32 - for i, val := range dst { - di := i + startindex - newH = val & hashMask - // Get previous value with the same hash. - // Our chain should point to the previous value. - s.hashPrev[di&windowMask] = s.hashHead[newH] - // Set the head of the hash chain to us. - s.hashHead[newH] = uint32(di + s.hashOffset) - } - } - - s.index = newIndex - d.byteAvailable = false - s.length = minMatchLength - 1 - if d.tokens.n == maxFlateBlockTokens { - // The block includes the current character - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - s.ii = 0 - } else { - // Reset, if we got a match this run. - if s.length >= minMatchLength { - s.ii = 0 - } - // We have a byte waiting. Emit it. - if d.byteAvailable { - s.ii++ - d.tokens.AddLiteral(d.window[s.index-1]) - if d.tokens.n == maxFlateBlockTokens { - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - s.index++ - - // If we have a long run of no matches, skip additional bytes - // Resets when s.ii overflows after 64KB. - if n := int(s.ii) - d.chain; n > 0 { - n = 1 + int(n>>6) - for j := 0; j < n; j++ { - if s.index >= d.windowEnd-1 { - break - } - d.tokens.AddLiteral(d.window[s.index-1]) - if d.tokens.n == maxFlateBlockTokens { - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - // Index... - if s.index < s.maxInsertIndex { - h := hash4(d.window[s.index:]) - ch := s.hashHead[h] - s.chainHead = int(ch) - s.hashPrev[s.index&windowMask] = ch - s.hashHead[h] = uint32(s.index + s.hashOffset) - } - s.index++ - } - // Flush last byte - d.tokens.AddLiteral(d.window[s.index-1]) - d.byteAvailable = false - // s.length = minMatchLength - 1 // not needed, since s.ii is reset above, so it should never be > minMatchLength - if d.tokens.n == maxFlateBlockTokens { - if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil { - return - } - d.tokens.Reset() - } - } - } else { - s.index++ - d.byteAvailable = true - } - } - } -} - -func (d *compressor) store() { - if d.windowEnd > 0 && (d.windowEnd == maxStoreBlockSize || d.sync) { - d.err = d.writeStoredBlock(d.window[:d.windowEnd]) - d.windowEnd = 0 - } -} - -// fillWindow will fill the buffer with data for huffman-only compression. -// The number of bytes copied is returned. -func (d *compressor) fillBlock(b []byte) int { - n := copy(d.window[d.windowEnd:], b) - d.windowEnd += n - return n -} - -// storeHuff will compress and store the currently added data, -// if enough has been accumulated or we at the end of the stream. -// Any error that occurred will be in d.err -func (d *compressor) storeHuff() { - if d.windowEnd < len(d.window) && !d.sync || d.windowEnd == 0 { - return - } - d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync) - d.err = d.w.err - d.windowEnd = 0 -} - -// storeFast will compress and store the currently added data, -// if enough has been accumulated or we at the end of the stream. -// Any error that occurred will be in d.err -func (d *compressor) storeFast() { - // We only compress if we have maxStoreBlockSize. - if d.windowEnd < len(d.window) { - if !d.sync { - return - } - // Handle extremely small sizes. - if d.windowEnd < 128 { - if d.windowEnd == 0 { - return - } - if d.windowEnd <= 32 { - d.err = d.writeStoredBlock(d.window[:d.windowEnd]) - } else { - d.w.writeBlockHuff(false, d.window[:d.windowEnd], true) - d.err = d.w.err - } - d.tokens.Reset() - d.windowEnd = 0 - d.fast.Reset() - return - } - } - - d.fast.Encode(&d.tokens, d.window[:d.windowEnd]) - // If we made zero matches, store the block as is. - if d.tokens.n == 0 { - d.err = d.writeStoredBlock(d.window[:d.windowEnd]) - // If we removed less than 1/16th, huffman compress the block. - } else if int(d.tokens.n) > d.windowEnd-(d.windowEnd>>4) { - d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync) - d.err = d.w.err - } else { - d.w.writeBlockDynamic(&d.tokens, false, d.window[:d.windowEnd], d.sync) - d.err = d.w.err - } - d.tokens.Reset() - d.windowEnd = 0 -} - -// write will add input byte to the stream. -// Unless an error occurs all bytes will be consumed. -func (d *compressor) write(b []byte) (n int, err error) { - if d.err != nil { - return 0, d.err - } - n = len(b) - for len(b) > 0 { - if d.windowEnd == len(d.window) || d.sync { - d.step(d) - } - b = b[d.fill(d, b):] - if d.err != nil { - return 0, d.err - } - } - return n, d.err -} - -func (d *compressor) syncFlush() error { - d.sync = true - if d.err != nil { - return d.err - } - d.step(d) - if d.err == nil { - d.w.writeStoredHeader(0, false) - d.w.flush() - d.err = d.w.err - } - d.sync = false - return d.err -} - -func (d *compressor) init(w io.Writer, level int) (err error) { - d.w = newHuffmanBitWriter(w) - - switch { - case level == NoCompression: - d.window = make([]byte, maxStoreBlockSize) - d.fill = (*compressor).fillBlock - d.step = (*compressor).store - case level == ConstantCompression: - d.w.logNewTablePenalty = 10 - d.window = make([]byte, 32<<10) - d.fill = (*compressor).fillBlock - d.step = (*compressor).storeHuff - case level == DefaultCompression: - level = 5 - fallthrough - case level >= 1 && level <= 6: - d.w.logNewTablePenalty = 7 - d.fast = newFastEnc(level) - d.window = make([]byte, maxStoreBlockSize) - d.fill = (*compressor).fillBlock - d.step = (*compressor).storeFast - case 7 <= level && level <= 9: - d.w.logNewTablePenalty = 8 - d.state = &advancedState{} - d.compressionLevel = levels[level] - d.initDeflate() - d.fill = (*compressor).fillDeflate - d.step = (*compressor).deflateLazy - case -level >= MinCustomWindowSize && -level <= MaxCustomWindowSize: - d.w.logNewTablePenalty = 7 - d.fast = &fastEncL5Window{maxOffset: int32(-level), cur: maxStoreBlockSize} - d.window = make([]byte, maxStoreBlockSize) - d.fill = (*compressor).fillBlock - d.step = (*compressor).storeFast - default: - return fmt.Errorf("flate: invalid compression level %d: want value in range [-2, 9]", level) - } - d.level = level - return nil -} - -// reset the state of the compressor. -func (d *compressor) reset(w io.Writer) { - d.w.reset(w) - d.sync = false - d.err = nil - // We only need to reset a few things for Snappy. - if d.fast != nil { - d.fast.Reset() - d.windowEnd = 0 - d.tokens.Reset() - return - } - switch d.compressionLevel.chain { - case 0: - // level was NoCompression or ConstantCompresssion. - d.windowEnd = 0 - default: - s := d.state - s.chainHead = -1 - for i := range s.hashHead { - s.hashHead[i] = 0 - } - for i := range s.hashPrev { - s.hashPrev[i] = 0 - } - s.hashOffset = 1 - s.index, d.windowEnd = 0, 0 - d.blockStart, d.byteAvailable = 0, false - d.tokens.Reset() - s.length = minMatchLength - 1 - s.offset = 0 - s.ii = 0 - s.maxInsertIndex = 0 - } -} - -func (d *compressor) close() error { - if d.err != nil { - return d.err - } - d.sync = true - d.step(d) - if d.err != nil { - return d.err - } - if d.w.writeStoredHeader(0, true); d.w.err != nil { - return d.w.err - } - d.w.flush() - d.w.reset(nil) - return d.w.err -} - -// NewWriter returns a new Writer compressing data at the given level. -// Following zlib, levels range from 1 (BestSpeed) to 9 (BestCompression); -// higher levels typically run slower but compress more. -// Level 0 (NoCompression) does not attempt any compression; it only adds the -// necessary DEFLATE framing. -// Level -1 (DefaultCompression) uses the default compression level. -// Level -2 (ConstantCompression) will use Huffman compression only, giving -// a very fast compression for all types of input, but sacrificing considerable -// compression efficiency. -// -// If level is in the range [-2, 9] then the error returned will be nil. -// Otherwise the error returned will be non-nil. -func NewWriter(w io.Writer, level int) (*Writer, error) { - var dw Writer - if err := dw.d.init(w, level); err != nil { - return nil, err - } - return &dw, nil -} - -// NewWriterDict is like NewWriter but initializes the new -// Writer with a preset dictionary. The returned Writer behaves -// as if the dictionary had been written to it without producing -// any compressed output. The compressed data written to w -// can only be decompressed by a Reader initialized with the -// same dictionary. -func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) { - zw, err := NewWriter(w, level) - if err != nil { - return nil, err - } - zw.d.fillWindow(dict) - zw.dict = append(zw.dict, dict...) // duplicate dictionary for Reset method. - return zw, err -} - -// MinCustomWindowSize is the minimum window size that can be sent to NewWriterWindow. -const MinCustomWindowSize = 32 - -// MaxCustomWindowSize is the maximum custom window that can be sent to NewWriterWindow. -const MaxCustomWindowSize = windowSize - -// NewWriterWindow returns a new Writer compressing data with a custom window size. -// windowSize must be from MinCustomWindowSize to MaxCustomWindowSize. -func NewWriterWindow(w io.Writer, windowSize int) (*Writer, error) { - if windowSize < MinCustomWindowSize { - return nil, errors.New("flate: requested window size less than MinWindowSize") - } - if windowSize > MaxCustomWindowSize { - return nil, errors.New("flate: requested window size bigger than MaxCustomWindowSize") - } - var dw Writer - if err := dw.d.init(w, -windowSize); err != nil { - return nil, err - } - return &dw, nil -} - -// A Writer takes data written to it and writes the compressed -// form of that data to an underlying writer (see NewWriter). -type Writer struct { - d compressor - dict []byte -} - -// Write writes data to w, which will eventually write the -// compressed form of data to its underlying writer. -func (w *Writer) Write(data []byte) (n int, err error) { - return w.d.write(data) -} - -// Flush flushes any pending data to the underlying writer. -// It is useful mainly in compressed network protocols, to ensure that -// a remote reader has enough data to reconstruct a packet. -// Flush does not return until the data has been written. -// Calling Flush when there is no pending data still causes the Writer -// to emit a sync marker of at least 4 bytes. -// If the underlying writer returns an error, Flush returns that error. -// -// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH. -func (w *Writer) Flush() error { - // For more about flushing: - // http://www.bolet.org/~pornin/deflate-flush.html - return w.d.syncFlush() -} - -// Close flushes and closes the writer. -func (w *Writer) Close() error { - return w.d.close() -} - -// Reset discards the writer's state and makes it equivalent to -// the result of NewWriter or NewWriterDict called with dst -// and w's level and dictionary. -func (w *Writer) Reset(dst io.Writer) { - if len(w.dict) > 0 { - // w was created with NewWriterDict - w.d.reset(dst) - if dst != nil { - w.d.fillWindow(w.dict) - } - } else { - // w was created with NewWriter - w.d.reset(dst) - } -} - -// ResetDict discards the writer's state and makes it equivalent to -// the result of NewWriter or NewWriterDict called with dst -// and w's level, but sets a specific dictionary. -func (w *Writer) ResetDict(dst io.Writer, dict []byte) { - w.dict = dict - w.d.reset(dst) - w.d.fillWindow(w.dict) -} diff --git a/vendor/github.com/klauspost/compress/flate/dict_decoder.go b/vendor/github.com/klauspost/compress/flate/dict_decoder.go deleted file mode 100644 index bb36351a5..000000000 --- a/vendor/github.com/klauspost/compress/flate/dict_decoder.go +++ /dev/null @@ -1,184 +0,0 @@ -// Copyright 2016 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -// dictDecoder implements the LZ77 sliding dictionary as used in decompression. -// LZ77 decompresses data through sequences of two forms of commands: -// -// - Literal insertions: Runs of one or more symbols are inserted into the data -// stream as is. This is accomplished through the writeByte method for a -// single symbol, or combinations of writeSlice/writeMark for multiple symbols. -// Any valid stream must start with a literal insertion if no preset dictionary -// is used. -// -// - Backward copies: Runs of one or more symbols are copied from previously -// emitted data. Backward copies come as the tuple (dist, length) where dist -// determines how far back in the stream to copy from and length determines how -// many bytes to copy. Note that it is valid for the length to be greater than -// the distance. Since LZ77 uses forward copies, that situation is used to -// perform a form of run-length encoding on repeated runs of symbols. -// The writeCopy and tryWriteCopy are used to implement this command. -// -// For performance reasons, this implementation performs little to no sanity -// checks about the arguments. As such, the invariants documented for each -// method call must be respected. -type dictDecoder struct { - hist []byte // Sliding window history - - // Invariant: 0 <= rdPos <= wrPos <= len(hist) - wrPos int // Current output position in buffer - rdPos int // Have emitted hist[:rdPos] already - full bool // Has a full window length been written yet? -} - -// init initializes dictDecoder to have a sliding window dictionary of the given -// size. If a preset dict is provided, it will initialize the dictionary with -// the contents of dict. -func (dd *dictDecoder) init(size int, dict []byte) { - *dd = dictDecoder{hist: dd.hist} - - if cap(dd.hist) < size { - dd.hist = make([]byte, size) - } - dd.hist = dd.hist[:size] - - if len(dict) > len(dd.hist) { - dict = dict[len(dict)-len(dd.hist):] - } - dd.wrPos = copy(dd.hist, dict) - if dd.wrPos == len(dd.hist) { - dd.wrPos = 0 - dd.full = true - } - dd.rdPos = dd.wrPos -} - -// histSize reports the total amount of historical data in the dictionary. -func (dd *dictDecoder) histSize() int { - if dd.full { - return len(dd.hist) - } - return dd.wrPos -} - -// availRead reports the number of bytes that can be flushed by readFlush. -func (dd *dictDecoder) availRead() int { - return dd.wrPos - dd.rdPos -} - -// availWrite reports the available amount of output buffer space. -func (dd *dictDecoder) availWrite() int { - return len(dd.hist) - dd.wrPos -} - -// writeSlice returns a slice of the available buffer to write data to. -// -// This invariant will be kept: len(s) <= availWrite() -func (dd *dictDecoder) writeSlice() []byte { - return dd.hist[dd.wrPos:] -} - -// writeMark advances the writer pointer by cnt. -// -// This invariant must be kept: 0 <= cnt <= availWrite() -func (dd *dictDecoder) writeMark(cnt int) { - dd.wrPos += cnt -} - -// writeByte writes a single byte to the dictionary. -// -// This invariant must be kept: 0 < availWrite() -func (dd *dictDecoder) writeByte(c byte) { - dd.hist[dd.wrPos] = c - dd.wrPos++ -} - -// writeCopy copies a string at a given (dist, length) to the output. -// This returns the number of bytes copied and may be less than the requested -// length if the available space in the output buffer is too small. -// -// This invariant must be kept: 0 < dist <= histSize() -func (dd *dictDecoder) writeCopy(dist, length int) int { - dstBase := dd.wrPos - dstPos := dstBase - srcPos := dstPos - dist - endPos := dstPos + length - if endPos > len(dd.hist) { - endPos = len(dd.hist) - } - - // Copy non-overlapping section after destination position. - // - // This section is non-overlapping in that the copy length for this section - // is always less than or equal to the backwards distance. This can occur - // if a distance refers to data that wraps-around in the buffer. - // Thus, a backwards copy is performed here; that is, the exact bytes in - // the source prior to the copy is placed in the destination. - if srcPos < 0 { - srcPos += len(dd.hist) - dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:]) - srcPos = 0 - } - - // Copy possibly overlapping section before destination position. - // - // This section can overlap if the copy length for this section is larger - // than the backwards distance. This is allowed by LZ77 so that repeated - // strings can be succinctly represented using (dist, length) pairs. - // Thus, a forwards copy is performed here; that is, the bytes copied is - // possibly dependent on the resulting bytes in the destination as the copy - // progresses along. This is functionally equivalent to the following: - // - // for i := 0; i < endPos-dstPos; i++ { - // dd.hist[dstPos+i] = dd.hist[srcPos+i] - // } - // dstPos = endPos - // - for dstPos < endPos { - dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos]) - } - - dd.wrPos = dstPos - return dstPos - dstBase -} - -// tryWriteCopy tries to copy a string at a given (distance, length) to the -// output. This specialized version is optimized for short distances. -// -// This method is designed to be inlined for performance reasons. -// -// This invariant must be kept: 0 < dist <= histSize() -func (dd *dictDecoder) tryWriteCopy(dist, length int) int { - dstPos := dd.wrPos - endPos := dstPos + length - if dstPos < dist || endPos > len(dd.hist) { - return 0 - } - dstBase := dstPos - srcPos := dstPos - dist - - // Copy possibly overlapping section before destination position. -loop: - dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos]) - if dstPos < endPos { - goto loop // Avoid for-loop so that this function can be inlined - } - - dd.wrPos = dstPos - return dstPos - dstBase -} - -// readFlush returns a slice of the historical buffer that is ready to be -// emitted to the user. The data returned by readFlush must be fully consumed -// before calling any other dictDecoder methods. -func (dd *dictDecoder) readFlush() []byte { - toRead := dd.hist[dd.rdPos:dd.wrPos] - dd.rdPos = dd.wrPos - if dd.wrPos == len(dd.hist) { - dd.wrPos, dd.rdPos = 0, 0 - dd.full = true - } - return toRead -} diff --git a/vendor/github.com/klauspost/compress/flate/fast_encoder.go b/vendor/github.com/klauspost/compress/flate/fast_encoder.go deleted file mode 100644 index c8124b5c4..000000000 --- a/vendor/github.com/klauspost/compress/flate/fast_encoder.go +++ /dev/null @@ -1,193 +0,0 @@ -// Copyright 2011 The Snappy-Go Authors. All rights reserved. -// Modified for deflate by Klaus Post (c) 2015. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -import ( - "encoding/binary" - "fmt" -) - -type fastEnc interface { - Encode(dst *tokens, src []byte) - Reset() -} - -func newFastEnc(level int) fastEnc { - switch level { - case 1: - return &fastEncL1{fastGen: fastGen{cur: maxStoreBlockSize}} - case 2: - return &fastEncL2{fastGen: fastGen{cur: maxStoreBlockSize}} - case 3: - return &fastEncL3{fastGen: fastGen{cur: maxStoreBlockSize}} - case 4: - return &fastEncL4{fastGen: fastGen{cur: maxStoreBlockSize}} - case 5: - return &fastEncL5{fastGen: fastGen{cur: maxStoreBlockSize}} - case 6: - return &fastEncL6{fastGen: fastGen{cur: maxStoreBlockSize}} - default: - panic("invalid level specified") - } -} - -const ( - tableBits = 15 // Bits used in the table - tableSize = 1 << tableBits // Size of the table - tableShift = 32 - tableBits // Right-shift to get the tableBits most significant bits of a uint32. - baseMatchOffset = 1 // The smallest match offset - baseMatchLength = 3 // The smallest match length per the RFC section 3.2.5 - maxMatchOffset = 1 << 15 // The largest match offset - - bTableBits = 17 // Bits used in the big tables - bTableSize = 1 << bTableBits // Size of the table - allocHistory = maxStoreBlockSize * 5 // Size to preallocate for history. - bufferReset = (1 << 31) - allocHistory - maxStoreBlockSize - 1 // Reset the buffer offset when reaching this. -) - -const ( - prime3bytes = 506832829 - prime4bytes = 2654435761 - prime5bytes = 889523592379 - prime6bytes = 227718039650203 - prime7bytes = 58295818150454627 - prime8bytes = 0xcf1bbcdcb7a56463 -) - -func load3232(b []byte, i int32) uint32 { - return binary.LittleEndian.Uint32(b[i:]) -} - -func load6432(b []byte, i int32) uint64 { - return binary.LittleEndian.Uint64(b[i:]) -} - -type tableEntry struct { - offset int32 -} - -// fastGen maintains the table for matches, -// and the previous byte block for level 2. -// This is the generic implementation. -type fastGen struct { - hist []byte - cur int32 -} - -func (e *fastGen) addBlock(src []byte) int32 { - // check if we have space already - if len(e.hist)+len(src) > cap(e.hist) { - if cap(e.hist) == 0 { - e.hist = make([]byte, 0, allocHistory) - } else { - if cap(e.hist) < maxMatchOffset*2 { - panic("unexpected buffer size") - } - // Move down - offset := int32(len(e.hist)) - maxMatchOffset - // copy(e.hist[0:maxMatchOffset], e.hist[offset:]) - *(*[maxMatchOffset]byte)(e.hist) = *(*[maxMatchOffset]byte)(e.hist[offset:]) - e.cur += offset - e.hist = e.hist[:maxMatchOffset] - } - } - s := int32(len(e.hist)) - e.hist = append(e.hist, src...) - return s -} - -type tableEntryPrev struct { - Cur tableEntry - Prev tableEntry -} - -// hash7 returns the hash of the lowest 7 bytes of u to fit in a hash table with h bits. -// Preferably h should be a constant and should always be <64. -func hash7(u uint64, h uint8) uint32 { - return uint32(((u << (64 - 56)) * prime7bytes) >> ((64 - h) & reg8SizeMask64)) -} - -// hashLen returns a hash of the lowest mls bytes of with length output bits. -// mls must be >=3 and <=8. Any other value will return hash for 4 bytes. -// length should always be < 32. -// Preferably length and mls should be a constant for inlining. -func hashLen(u uint64, length, mls uint8) uint32 { - switch mls { - case 3: - return (uint32(u<<8) * prime3bytes) >> (32 - length) - case 5: - return uint32(((u << (64 - 40)) * prime5bytes) >> (64 - length)) - case 6: - return uint32(((u << (64 - 48)) * prime6bytes) >> (64 - length)) - case 7: - return uint32(((u << (64 - 56)) * prime7bytes) >> (64 - length)) - case 8: - return uint32((u * prime8bytes) >> (64 - length)) - default: - return (uint32(u) * prime4bytes) >> (32 - length) - } -} - -// matchlen will return the match length between offsets and t in src. -// The maximum length returned is maxMatchLength - 4. -// It is assumed that s > t, that t >=0 and s < len(src). -func (e *fastGen) matchlen(s, t int32, src []byte) int32 { - if debugDecode { - if t >= s { - panic(fmt.Sprint("t >=s:", t, s)) - } - if int(s) >= len(src) { - panic(fmt.Sprint("s >= len(src):", s, len(src))) - } - if t < 0 { - panic(fmt.Sprint("t < 0:", t)) - } - if s-t > maxMatchOffset { - panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")")) - } - } - s1 := int(s) + maxMatchLength - 4 - if s1 > len(src) { - s1 = len(src) - } - - // Extend the match to be as long as possible. - return int32(matchLen(src[s:s1], src[t:])) -} - -// matchlenLong will return the match length between offsets and t in src. -// It is assumed that s > t, that t >=0 and s < len(src). -func (e *fastGen) matchlenLong(s, t int32, src []byte) int32 { - if debugDeflate { - if t >= s { - panic(fmt.Sprint("t >=s:", t, s)) - } - if int(s) >= len(src) { - panic(fmt.Sprint("s >= len(src):", s, len(src))) - } - if t < 0 { - panic(fmt.Sprint("t < 0:", t)) - } - if s-t > maxMatchOffset { - panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")")) - } - } - // Extend the match to be as long as possible. - return int32(matchLen(src[s:], src[t:])) -} - -// Reset the encoding table. -func (e *fastGen) Reset() { - if cap(e.hist) < allocHistory { - e.hist = make([]byte, 0, allocHistory) - } - // We offset current position so everything will be out of reach. - // If we are above the buffer reset it will be cleared anyway since len(hist) == 0. - if e.cur <= bufferReset { - e.cur += maxMatchOffset + int32(len(e.hist)) - } - e.hist = e.hist[:0] -} diff --git a/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go b/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go deleted file mode 100644 index f70594c34..000000000 --- a/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go +++ /dev/null @@ -1,1182 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -import ( - "encoding/binary" - "fmt" - "io" - "math" -) - -const ( - // The largest offset code. - offsetCodeCount = 30 - - // The special code used to mark the end of a block. - endBlockMarker = 256 - - // The first length code. - lengthCodesStart = 257 - - // The number of codegen codes. - codegenCodeCount = 19 - badCode = 255 - - // maxPredefinedTokens is the maximum number of tokens - // where we check if fixed size is smaller. - maxPredefinedTokens = 250 - - // bufferFlushSize indicates the buffer size - // after which bytes are flushed to the writer. - // Should preferably be a multiple of 6, since - // we accumulate 6 bytes between writes to the buffer. - bufferFlushSize = 246 -) - -// Minimum length code that emits bits. -const lengthExtraBitsMinCode = 8 - -// The number of extra bits needed by length code X - LENGTH_CODES_START. -var lengthExtraBits = [32]uint8{ - /* 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, - /* 280 */ 4, 5, 5, 5, 5, 0, -} - -// The length indicated by length code X - LENGTH_CODES_START. -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, -} - -// Minimum offset code that emits bits. -const offsetExtraBitsMinCode = 4 - -// offset code word extra bits. -var offsetExtraBits = [32]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, - /* extended window */ - 14, 14, -} - -var offsetCombined = [32]uint32{} - -func init() { - var offsetBase = [32]uint32{ - /* normal deflate */ - 0x000000, 0x000001, 0x000002, 0x000003, 0x000004, - 0x000006, 0x000008, 0x00000c, 0x000010, 0x000018, - 0x000020, 0x000030, 0x000040, 0x000060, 0x000080, - 0x0000c0, 0x000100, 0x000180, 0x000200, 0x000300, - 0x000400, 0x000600, 0x000800, 0x000c00, 0x001000, - 0x001800, 0x002000, 0x003000, 0x004000, 0x006000, - - /* extended window */ - 0x008000, 0x00c000, - } - - for i := range offsetCombined[:] { - // Don't use extended window values... - if offsetExtraBits[i] == 0 || offsetBase[i] > 0x006000 { - continue - } - offsetCombined[i] = uint32(offsetExtraBits[i]) | (offsetBase[i] << 8) - } -} - -// The odd order in which the codegen code sizes are written. -var codegenOrder = []uint32{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15} - -type huffmanBitWriter struct { - // writer is the underlying writer. - // Do not use it directly; use the write method, which ensures - // that Write errors are sticky. - writer io.Writer - - // Data waiting to be written is bytes[0:nbytes] - // and then the low nbits of bits. - bits uint64 - nbits uint8 - nbytes uint8 - lastHuffMan bool - literalEncoding *huffmanEncoder - tmpLitEncoding *huffmanEncoder - offsetEncoding *huffmanEncoder - codegenEncoding *huffmanEncoder - err error - lastHeader int - // Set between 0 (reused block can be up to 2x the size) - logNewTablePenalty uint - bytes [256 + 8]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 'logNewTablePenalty'. -// 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, - literalEncoding: newHuffmanEncoder(literalCount), - tmpLitEncoding: newHuffmanEncoder(literalCount), - codegenEncoding: newHuffmanEncoder(codegenCodeCount), - offsetEncoding: newHuffmanEncoder(offsetCodeCount), - } -} - -func (w *huffmanBitWriter) reset(writer io.Writer) { - w.writer = writer - w.bits, w.nbits, w.nbytes, w.err = 0, 0, 0, nil - w.lastHeader = 0 - w.lastHuffMan = false -} - -func (w *huffmanBitWriter) canReuse(t *tokens) (ok bool) { - a := t.offHist[:offsetCodeCount] - b := w.offsetEncoding.codes - b = b[:len(a)] - for i, v := range a { - if v != 0 && b[i].zero() { - return false - } - } - - a = t.extraHist[:literalCount-256] - b = w.literalEncoding.codes[256:literalCount] - b = b[:len(a)] - for i, v := range a { - if v != 0 && b[i].zero() { - return false - } - } - - a = t.litHist[:256] - b = w.literalEncoding.codes[:len(a)] - for i, v := range a { - if v != 0 && b[i].zero() { - return false - } - } - return true -} - -func (w *huffmanBitWriter) flush() { - if w.err != nil { - w.nbits = 0 - return - } - if w.lastHeader > 0 { - // We owe an EOB - w.writeCode(w.literalEncoding.codes[endBlockMarker]) - w.lastHeader = 0 - } - n := w.nbytes - for w.nbits != 0 { - w.bytes[n] = byte(w.bits) - w.bits >>= 8 - if w.nbits > 8 { // Avoid underflow - w.nbits -= 8 - } else { - w.nbits = 0 - } - n++ - } - w.bits = 0 - w.write(w.bytes[:n]) - w.nbytes = 0 -} - -func (w *huffmanBitWriter) write(b []byte) { - if w.err != nil { - return - } - _, w.err = w.writer.Write(b) -} - -func (w *huffmanBitWriter) writeBits(b int32, nb uint8) { - w.bits |= uint64(b) << (w.nbits & 63) - w.nbits += nb - if w.nbits >= 48 { - w.writeOutBits() - } -} - -func (w *huffmanBitWriter) writeBytes(bytes []byte) { - if w.err != nil { - return - } - n := w.nbytes - if w.nbits&7 != 0 { - w.err = InternalError("writeBytes with unfinished bits") - return - } - for w.nbits != 0 { - w.bytes[n] = byte(w.bits) - w.bits >>= 8 - w.nbits -= 8 - n++ - } - if n != 0 { - w.write(w.bytes[:n]) - } - w.nbytes = 0 - w.write(bytes) -} - -// RFC 1951 3.2.7 specifies a special run-length encoding for specifying -// the literal and offset lengths arrays (which are concatenated into a single -// array). This method generates that run-length encoding. -// -// The result is written into the codegen array, and the frequencies -// of each code is written into the codegenFreq array. -// Codes 0-15 are single byte codes. Codes 16-18 are followed by additional -// information. Code badCode is an end marker -// -// numLiterals The number of literals in literalEncoding -// numOffsets The number of offsets in offsetEncoding -// litenc, offenc The literal and offset encoder to use -func (w *huffmanBitWriter) generateCodegen(numLiterals int, numOffsets int, litEnc, offEnc *huffmanEncoder) { - for i := range w.codegenFreq { - w.codegenFreq[i] = 0 - } - // Note that we are using codegen both as a temporary variable for holding - // 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 - // Copy the concatenated code sizes to codegen. Put a marker at the end. - cgnl := codegen[:numLiterals] - for i := range cgnl { - cgnl[i] = litEnc.codes[i].len() - } - - cgnl = codegen[numLiterals : numLiterals+numOffsets] - for i := range cgnl { - cgnl[i] = offEnc.codes[i].len() - } - codegen[numLiterals+numOffsets] = badCode - - size := codegen[0] - count := 1 - outIndex := 0 - for inIndex := 1; size != badCode; inIndex++ { - // INVARIANT: We have seen "count" copies of size that have not yet - // had output generated for them. - nextSize := codegen[inIndex] - if nextSize == size { - count++ - continue - } - // We need to generate codegen indicating "count" of size. - if size != 0 { - codegen[outIndex] = size - outIndex++ - w.codegenFreq[size]++ - count-- - for count >= 3 { - n := 6 - if n > count { - n = count - } - codegen[outIndex] = 16 - outIndex++ - codegen[outIndex] = uint8(n - 3) - outIndex++ - w.codegenFreq[16]++ - count -= n - } - } else { - for count >= 11 { - n := 138 - if n > count { - n = count - } - codegen[outIndex] = 18 - outIndex++ - codegen[outIndex] = uint8(n - 11) - outIndex++ - w.codegenFreq[18]++ - count -= n - } - if count >= 3 { - // count >= 3 && count <= 10 - codegen[outIndex] = 17 - outIndex++ - codegen[outIndex] = uint8(count - 3) - outIndex++ - w.codegenFreq[17]++ - count = 0 - } - } - count-- - for ; count >= 0; count-- { - codegen[outIndex] = size - outIndex++ - w.codegenFreq[size]++ - } - // Set up invariant for next time through the loop. - size = nextSize - count = 1 - } - // Marker indicating the end of the codegen. - codegen[outIndex] = badCode -} - -func (w *huffmanBitWriter) codegens() 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-- - } - 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, numCodegens -} - -// dynamicSize returns the size of dynamically encoded data in bits. -func (w *huffmanBitWriter) dynamicReuseSize(litEnc, offEnc *huffmanEncoder) (size int) { - size = litEnc.bitLength(w.literalFreq[:]) + - offEnc.bitLength(w.offsetFreq[:]) - return size -} - -// 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[:]) + - fixedOffsetEncoding.bitLength(w.offsetFreq[:]) + - extraBits -} - -// storedSize calculates the stored size, including header. -// The function returns the size in bits and whether the block -// fits inside a single block. -func (w *huffmanBitWriter) storedSize(in []byte) (int, bool) { - if in == nil { - return 0, false - } - if len(in) <= maxStoreBlockSize { - return (len(in) + 5) * 8, true - } - return 0, false -} - -func (w *huffmanBitWriter) writeCode(c hcode) { - // The function does not get inlined if we "& 63" the shift. - w.bits |= c.code64() << (w.nbits & 63) - 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 - - // We over-write, but faster... - binary.LittleEndian.PutUint64(w.bytes[n:], bits) - 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. -// -// numLiterals The number of literals specified in codegen -// numOffsets The number of offsets specified in codegen -// numCodegens The number of codegens used in codegen -func (w *huffmanBitWriter) writeDynamicHeader(numLiterals int, numOffsets int, numCodegens int, isEof bool) { - if w.err != nil { - return - } - var firstBits int32 = 4 - if isEof { - firstBits = 5 - } - w.writeBits(firstBits, 3) - w.writeBits(int32(numLiterals-257), 5) - w.writeBits(int32(numOffsets-1), 5) - w.writeBits(int32(numCodegens-4), 4) - - for i := 0; i < numCodegens; i++ { - value := uint(w.codegenEncoding.codes[codegenOrder[i]].len()) - w.writeBits(int32(value), 3) - } - - i := 0 - for { - var codeWord = uint32(w.codegen[i]) - i++ - if codeWord == badCode { - break - } - w.writeCode(w.codegenEncoding.codes[codeWord]) - - switch codeWord { - case 16: - w.writeBits(int32(w.codegen[i]), 2) - i++ - case 17: - w.writeBits(int32(w.codegen[i]), 3) - i++ - case 18: - w.writeBits(int32(w.codegen[i]), 7) - i++ - } - } -} - -// writeStoredHeader will write a stored header. -// If the stored block is only used for EOF, -// it is replaced with a fixed huffman block. -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 - } - - // To write EOF, use a fixed encoding block. 10 bits instead of 5 bytes. - if length == 0 && isEof { - w.writeFixedHeader(isEof) - // EOB: 7 bits, value: 0 - w.writeBits(0, 7) - w.flush() - return - } - - var flag int32 - if isEof { - flag = 1 - } - w.writeBits(flag, 3) - w.flush() - w.writeBits(int32(length), 16) - w.writeBits(int32(^uint16(length)), 16) -} - -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 { - value = 3 - } - w.writeBits(value, 3) -} - -// writeBlock will write a block of tokens with the smallest encoding. -// The original input can be supplied, and if the huffman encoded data -// 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 *tokens, eof bool, input []byte) { - if w.err != nil { - return - } - - tokens.AddEOB() - 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() - var extraBits int - storedSize, storable := w.storedSize(input) - if storable { - extraBits = w.extraBitSize() - } - - // Figure out smallest code. - // Fixed Huffman baseline. - var literalEncoding = fixedLiteralEncoding - var offsetEncoding = fixedOffsetEncoding - var size = math.MaxInt32 - if tokens.n < maxPredefinedTokens { - size = w.fixedSize(extraBits) - } - - // Dynamic Huffman? - var numCodegens int - - // 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) - dynamicSize, numCodegens := w.dynamicSize(w.literalEncoding, w.offsetEncoding, extraBits) - - if dynamicSize < size { - size = dynamicSize - literalEncoding = w.literalEncoding - offsetEncoding = w.offsetEncoding - } - - // Stored bytes? - if storable && storedSize <= size { - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - - // Huffman. - if literalEncoding == fixedLiteralEncoding { - w.writeFixedHeader(eof) - } else { - w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof) - } - - // Write the tokens. - w.writeTokens(tokens.Slice(), literalEncoding.codes, offsetEncoding.codes) -} - -// writeBlockDynamic encodes a block using a dynamic Huffman table. -// This should be used if the symbols used have a disproportionate -// 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 *tokens, eof bool, input []byte, sync bool) { - if w.err != nil { - return - } - - sync = sync || eof - if sync { - tokens.AddEOB() - } - - // We cannot reuse pure huffman table, and must mark as EOF. - if (w.lastHuffMan || eof) && w.lastHeader > 0 { - // We will not try to reuse. - w.writeCode(w.literalEncoding.codes[endBlockMarker]) - w.lastHeader = 0 - w.lastHuffMan = false - } - - // fillReuse enables filling of empty values. - // This will make encodings always reusable without testing. - // However, this does not appear to benefit on most cases. - const fillReuse = false - - // Check if we can reuse... - if !fillReuse && w.lastHeader > 0 && !w.canReuse(tokens) { - w.writeCode(w.literalEncoding.codes[endBlockMarker]) - w.lastHeader = 0 - } - - numLiterals, numOffsets := w.indexTokens(tokens, !sync) - extraBits := 0 - ssize, storable := w.storedSize(input) - - const usePrefs = true - if storable || w.lastHeader > 0 { - extraBits = w.extraBitSize() - } - - var size int - - // Check if we should reuse. - if w.lastHeader > 0 { - // Estimate size for using a new table. - // Use the previous header size as the best estimate. - newSize := w.lastHeader + tokens.EstimatedBits() - newSize += int(w.literalEncoding.codes[endBlockMarker].len()) + newSize>>w.logNewTablePenalty - - // The estimated size is calculated as an optimal table. - // We add a penalty to make it more realistic and re-use a bit more. - reuseSize := w.dynamicReuseSize(w.literalEncoding, w.offsetEncoding) + extraBits - - // 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 - } - - if tokens.n < maxPredefinedTokens { - if preSize := w.fixedSize(extraBits) + 7; usePrefs && preSize < size { - // Check if we get a reasonable size decrease. - if storable && ssize <= size { - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - w.writeFixedHeader(eof) - if !sync { - tokens.AddEOB() - } - w.writeTokens(tokens.Slice(), fixedLiteralEncoding.codes, fixedOffsetEncoding.codes) - return - } - } - // Check if we get a reasonable size decrease. - if storable && ssize <= size { - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - } - - // We want a new block/table - if w.lastHeader == 0 { - if fillReuse && !sync { - w.fillTokens() - numLiterals, numOffsets = maxNumLit, maxNumDist - } else { - w.literalFreq[endBlockMarker] = 1 - } - - w.generate() - // 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) - - var numCodegens int - if fillReuse && !sync { - // Reindex for accurate size... - w.indexTokens(tokens, true) - } - size, numCodegens = w.dynamicSize(w.literalEncoding, w.offsetEncoding, extraBits) - - // Store predefined, if we don't get a reasonable improvement. - if tokens.n < maxPredefinedTokens { - if preSize := w.fixedSize(extraBits); usePrefs && preSize <= size { - // Store bytes, if we don't get an improvement. - if storable && ssize <= preSize { - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - w.writeFixedHeader(eof) - if !sync { - tokens.AddEOB() - } - w.writeTokens(tokens.Slice(), fixedLiteralEncoding.codes, fixedOffsetEncoding.codes) - return - } - } - - if storable && ssize <= size { - // Store bytes, if we don't get an improvement. - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - - // Write Huffman table. - w.writeDynamicHeader(numLiterals, numOffsets, numCodegens, eof) - if !sync { - w.lastHeader, _ = w.headerSize() - } - w.lastHuffMan = false - } - - if sync { - w.lastHeader = 0 - } - // Write the tokens. - w.writeTokens(tokens.Slice(), w.literalEncoding.codes, w.offsetEncoding.codes) -} - -func (w *huffmanBitWriter) fillTokens() { - for i, v := range w.literalFreq[:literalCount] { - if v == 0 { - w.literalFreq[i] = 1 - } - } - for i, v := range w.offsetFreq[:offsetCodeCount] { - if v == 0 { - w.offsetFreq[i] = 1 - } - } -} - -// 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(t *tokens, filled bool) (numLiterals, numOffsets int) { - //copy(w.literalFreq[:], t.litHist[:]) - *(*[256]uint16)(w.literalFreq[:]) = t.litHist - //copy(w.literalFreq[256:], t.extraHist[:]) - *(*[32]uint16)(w.literalFreq[256:]) = t.extraHist - w.offsetFreq = t.offHist - - if t.n == 0 { - return - } - if filled { - return maxNumLit, maxNumDist - } - // get the number of literals - numLiterals = len(w.literalFreq) - for w.literalFreq[numLiterals-1] == 0 { - numLiterals-- - } - // get the number of offsets - numOffsets = len(w.offsetFreq) - for numOffsets > 0 && w.offsetFreq[numOffsets-1] == 0 { - numOffsets-- - } - if numOffsets == 0 { - // We haven't found a single match. If we want to go with the dynamic encoding, - // we should count at least one offset to be sure that the offset huffman tree could be encoded. - w.offsetFreq[0] = 1 - numOffsets = 1 - } - return -} - -func (w *huffmanBitWriter) generate() { - 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] - - // Go 1.16 LOVES having these on stack. - bits, nbits, nbytes := w.bits, w.nbits, w.nbytes - - for _, t := range tokens { - if t < 256 { - //w.writeCode(lits[t.literal()]) - c := lits[t] - bits |= c.code64() << (nbits & 63) - nbits += c.len() - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - continue - } - - // Write the length - length := t.length() - lengthCode := lengthCode(length) & 31 - if false { - w.writeCode(lengths[lengthCode]) - } else { - // inlined - c := lengths[lengthCode] - bits |= c.code64() << (nbits & 63) - nbits += c.len() - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - } - - if lengthCode >= lengthExtraBitsMinCode { - extraLengthBits := lengthExtraBits[lengthCode] - //w.writeBits(extraLength, extraLengthBits) - extraLength := int32(length - lengthBase[lengthCode]) - bits |= uint64(extraLength) << (nbits & 63) - nbits += extraLengthBits - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - } - // Write the offset - offset := t.offset() - offsetCode := (offset >> 16) & 31 - if false { - w.writeCode(offs[offsetCode]) - } else { - // inlined - c := offs[offsetCode] - bits |= c.code64() << (nbits & 63) - nbits += c.len() - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - } - - if offsetCode >= offsetExtraBitsMinCode { - offsetComb := offsetCombined[offsetCode] - //w.writeBits(extraOffset, extraOffsetBits) - bits |= uint64((offset-(offsetComb>>8))&matchOffsetOnlyMask) << (nbits & 63) - nbits += uint8(offsetComb) - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - } - } - // Restore... - w.bits, w.nbits, w.nbytes = bits, nbits, nbytes - - if deferEOB { - w.writeCode(leCodes[endBlockMarker]) - } -} - -// huffOffset is a static offset encoder used for huffman only encoding. -// It can be reused since we will not be encoding offset values. -var huffOffset *huffmanEncoder - -func init() { - w := newHuffmanBitWriter(nil) - w.offsetFreq[0] = 1 - huffOffset = newHuffmanEncoder(offsetCodeCount) - 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, sync bool) { - if w.err != nil { - return - } - - // Clear histogram - for i := range w.literalFreq[:] { - w.literalFreq[i] = 0 - } - if !w.lastHuffMan { - for i := range w.offsetFreq[:] { - w.offsetFreq[i] = 0 - } - } - - const numLiterals = endBlockMarker + 1 - const numOffsets = 1 - - // Add everything as literals - // We have to estimate the header size. - // Assume header is around 70 bytes: - // https://stackoverflow.com/a/25454430 - const guessHeaderSizeBits = 70 * 8 - histogram(input, w.literalFreq[:numLiterals]) - ssize, storable := w.storedSize(input) - if storable && len(input) > 1024 { - // Quick check for incompressible content. - abs := float64(0) - avg := float64(len(input)) / 256 - max := float64(len(input) * 2) - for _, v := range w.literalFreq[:256] { - diff := float64(v) - avg - abs += diff * diff - if abs > max { - break - } - } - if abs < max { - if debugDeflate { - fmt.Println("stored", abs, "<", max) - } - // No chance we can compress this... - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - } - w.literalFreq[endBlockMarker] = 1 - w.tmpLitEncoding.generate(w.literalFreq[:numLiterals], 15) - estBits := w.tmpLitEncoding.canReuseBits(w.literalFreq[:numLiterals]) - if estBits < math.MaxInt32 { - estBits += w.lastHeader - if w.lastHeader == 0 { - estBits += guessHeaderSizeBits - } - estBits += estBits >> w.logNewTablePenalty - } - - // Store bytes, if we don't get a reasonable improvement. - if storable && ssize <= estBits { - if debugDeflate { - fmt.Println("stored,", ssize, "<=", estBits) - } - w.writeStoredHeader(len(input), eof) - w.writeBytes(input) - return - } - - if w.lastHeader > 0 { - reuseSize := w.literalEncoding.canReuseBits(w.literalFreq[:256]) - - if estBits < reuseSize { - if debugDeflate { - fmt.Println("NOT reusing, reuse:", reuseSize/8, "> new:", estBits/8, "header est:", w.lastHeader/8, "bytes") - } - // We owe an EOB - w.writeCode(w.literalEncoding.codes[endBlockMarker]) - w.lastHeader = 0 - } else if debugDeflate { - fmt.Println("reusing, reuse:", reuseSize/8, "> new:", estBits/8, "- header est:", w.lastHeader/8) - } - } - - count := 0 - if w.lastHeader == 0 { - // Use the temp encoding, so swap. - w.literalEncoding, w.tmpLitEncoding = w.tmpLitEncoding, w.literalEncoding - // 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() - if debugDeflate { - count += w.lastHeader - fmt.Println("header:", count/8) - } - } - - encoding := w.literalEncoding.codes[:256] - // Go 1.16 LOVES having these on stack. At least 1.5x the speed. - bits, nbits, nbytes := w.bits, w.nbits, w.nbytes - - if debugDeflate { - count -= int(nbytes)*8 + int(nbits) - } - // Unroll, write 3 codes/loop. - // Fastest number of unrolls. - for len(input) > 3 { - // We must have at least 48 bits free. - if nbits >= 8 { - n := nbits >> 3 - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - bits >>= (n * 8) & 63 - nbits -= n * 8 - nbytes += n - } - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - if debugDeflate { - count += int(nbytes) * 8 - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - a, b := encoding[input[0]], encoding[input[1]] - bits |= a.code64() << (nbits & 63) - bits |= b.code64() << ((nbits + a.len()) & 63) - c := encoding[input[2]] - nbits += b.len() + a.len() - bits |= c.code64() << (nbits & 63) - nbits += c.len() - input = input[3:] - } - - // Remaining... - for _, t := range input { - if nbits >= 48 { - binary.LittleEndian.PutUint64(w.bytes[nbytes:], bits) - //*(*uint64)(unsafe.Pointer(&w.bytes[nbytes])) = bits - bits >>= 48 - nbits -= 48 - nbytes += 6 - if nbytes >= bufferFlushSize { - if w.err != nil { - nbytes = 0 - return - } - if debugDeflate { - count += int(nbytes) * 8 - } - _, w.err = w.writer.Write(w.bytes[:nbytes]) - nbytes = 0 - } - } - // Bitwriting inlined, ~30% speedup - c := encoding[t] - bits |= c.code64() << (nbits & 63) - - nbits += c.len() - if debugDeflate { - count += int(c.len()) - } - } - // Restore... - w.bits, w.nbits, w.nbytes = bits, nbits, nbytes - - if debugDeflate { - nb := count + int(nbytes)*8 + int(nbits) - fmt.Println("wrote", nb, "bits,", nb/8, "bytes.") - } - // Flush if needed to have space. - if w.nbits >= 48 { - w.writeOutBits() - } - - if eof || sync { - w.writeCode(w.literalEncoding.codes[endBlockMarker]) - w.lastHeader = 0 - w.lastHuffMan = false - } -} diff --git a/vendor/github.com/klauspost/compress/flate/huffman_code.go b/vendor/github.com/klauspost/compress/flate/huffman_code.go deleted file mode 100644 index be7b58b47..000000000 --- a/vendor/github.com/klauspost/compress/flate/huffman_code.go +++ /dev/null @@ -1,417 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -import ( - "math" - "math/bits" -) - -const ( - maxBitsLimit = 16 - // number of valid literals - literalCount = 286 -) - -// hcode is a huffman code with a bit code and bit length. -type hcode uint32 - -func (h hcode) len() uint8 { - return uint8(h) -} - -func (h hcode) code64() uint64 { - return uint64(h >> 8) -} - -func (h hcode) zero() bool { - return h == 0 -} - -type huffmanEncoder struct { - codes []hcode - bitCount [17]int32 - - // Allocate a reusable buffer with the longest possible frequency table. - // Possible lengths are codegenCodeCount, offsetCodeCount and literalCount. - // The largest of these is literalCount, so we allocate for that case. - freqcache [literalCount + 1]literalNode -} - -type literalNode struct { - literal uint16 - freq uint16 -} - -// A levelInfo describes the state of the constructed tree for a given depth. -type levelInfo struct { - // Our level. for better printing - level int32 - - // The frequency of the last node at this level - lastFreq int32 - - // The frequency of the next character to add to this level - nextCharFreq int32 - - // The frequency of the next pair (from level below) to add to this level. - // Only valid if the "needed" value of the next lower level is 0. - nextPairFreq int32 - - // The number of chains remaining to generate for this level before moving - // up to the next level - needed int32 -} - -// set sets the code and length of an hcode. -func (h *hcode) set(code uint16, length uint8) { - *h = hcode(length) | (hcode(code) << 8) -} - -func newhcode(code uint16, length uint8) hcode { - return hcode(length) | (hcode(code) << 8) -} - -func reverseBits(number uint16, bitLength byte) uint16 { - return bits.Reverse16(number << ((16 - bitLength) & 15)) -} - -func maxNode() literalNode { return literalNode{math.MaxUint16, math.MaxUint16} } - -func newHuffmanEncoder(size int) *huffmanEncoder { - // Make capacity to next power of two. - c := uint(bits.Len32(uint32(size - 1))) - return &huffmanEncoder{codes: make([]hcode, size, 1<<c)} -} - -// Generates a HuffmanCode corresponding to the fixed literal table -func generateFixedLiteralEncoding() *huffmanEncoder { - h := newHuffmanEncoder(literalCount) - codes := h.codes - var ch uint16 - for ch = 0; ch < literalCount; ch++ { - var bits uint16 - var size uint8 - switch { - case ch < 144: - // size 8, 000110000 .. 10111111 - bits = ch + 48 - size = 8 - case ch < 256: - // size 9, 110010000 .. 111111111 - bits = ch + 400 - 144 - size = 9 - case ch < 280: - // size 7, 0000000 .. 0010111 - bits = ch - 256 - size = 7 - default: - // size 8, 11000000 .. 11000111 - bits = ch + 192 - 280 - size = 8 - } - codes[ch] = newhcode(reverseBits(bits, size), size) - } - return h -} - -func generateFixedOffsetEncoding() *huffmanEncoder { - h := newHuffmanEncoder(30) - codes := h.codes - for ch := range codes { - codes[ch] = newhcode(reverseBits(uint16(ch), 5), 5) - } - return h -} - -var fixedLiteralEncoding = generateFixedLiteralEncoding() -var fixedOffsetEncoding = generateFixedOffsetEncoding() - -func (h *huffmanEncoder) bitLength(freq []uint16) int { - var total int - for i, f := range freq { - if f != 0 { - total += int(f) * int(h.codes[i].len()) - } - } - return total -} - -func (h *huffmanEncoder) bitLengthRaw(b []byte) int { - var total int - for _, f := range b { - total += int(h.codes[f].len()) - } - return total -} - -// canReuseBits returns the number of bits or math.MaxInt32 if the encoder cannot be reused. -func (h *huffmanEncoder) canReuseBits(freq []uint16) int { - var total int - for i, f := range freq { - if f != 0 { - code := h.codes[i] - if code.zero() { - return math.MaxInt32 - } - total += int(f) * int(code.len()) - } - } - return total -} - -// Return the number of literals assigned to each bit size in the Huffman encoding -// -// This method is only called when list.length >= 3 -// The cases of 0, 1, and 2 literals are handled by special case code. -// -// list An array of the literals with non-zero frequencies -// -// and their associated frequencies. The array is in order of increasing -// frequency, and has as its last element a special element with frequency -// MaxInt32 -// -// maxBits The maximum number of bits that should be used to encode any literal. -// -// Must be less than 16. -// -// return An integer array in which array[i] indicates the number of literals -// -// that should be encoded in i bits. -func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 { - if maxBits >= maxBitsLimit { - panic("flate: maxBits too large") - } - n := int32(len(list)) - list = list[0 : n+1] - list[n] = maxNode() - - // The tree can't have greater depth than n - 1, no matter what. This - // saves a little bit of work in some small cases - if maxBits > n-1 { - maxBits = n - 1 - } - - // Create information about each of the levels. - // A bogus "Level 0" whose sole purpose is so that - // level1.prev.needed==0. This makes level1.nextPairFreq - // be a legitimate value that never gets chosen. - var levels [maxBitsLimit]levelInfo - // leafCounts[i] counts the number of literals at the left - // of ancestors of the rightmost node at level i. - // leafCounts[i][j] is the number of literals at the left - // of the level j ancestor. - var leafCounts [maxBitsLimit][maxBitsLimit]int32 - - // Descending to only have 1 bounds check. - l2f := int32(list[2].freq) - l1f := int32(list[1].freq) - l0f := int32(list[0].freq) + int32(list[1].freq) - - for level := int32(1); level <= maxBits; level++ { - // For every level, the first two items are the first two characters. - // We initialize the levels as if we had already figured this out. - levels[level] = levelInfo{ - level: level, - lastFreq: l1f, - nextCharFreq: l2f, - nextPairFreq: l0f, - } - leafCounts[level][level] = 2 - if level == 1 { - levels[level].nextPairFreq = math.MaxInt32 - } - } - - // We need a total of 2*n - 2 items at top level and have already generated 2. - levels[maxBits].needed = 2*n - 4 - - level := uint32(maxBits) - for level < 16 { - l := &levels[level] - if l.nextPairFreq == math.MaxInt32 && l.nextCharFreq == math.MaxInt32 { - // We've run out of both leafs and pairs. - // End all calculations for this level. - // To make sure we never come back to this level or any lower level, - // set nextPairFreq impossibly large. - l.needed = 0 - levels[level+1].nextPairFreq = math.MaxInt32 - level++ - continue - } - - prevFreq := l.lastFreq - if l.nextCharFreq < l.nextPairFreq { - // The next item on this row is a leaf node. - n := leafCounts[level][level] + 1 - l.lastFreq = l.nextCharFreq - // Lower leafCounts are the same of the previous node. - leafCounts[level][level] = n - e := list[n] - if e.literal < math.MaxUint16 { - l.nextCharFreq = int32(e.freq) - } else { - l.nextCharFreq = math.MaxInt32 - } - } else { - // The next item on this row is a pair from the previous row. - // nextPairFreq isn't valid until we generate two - // more values in the level below - l.lastFreq = l.nextPairFreq - // Take leaf counts from the lower level, except counts[level] remains the same. - if true { - save := leafCounts[level][level] - leafCounts[level] = leafCounts[level-1] - leafCounts[level][level] = save - } else { - copy(leafCounts[level][:level], leafCounts[level-1][:level]) - } - levels[l.level-1].needed = 2 - } - - if l.needed--; l.needed == 0 { - // We've done everything we need to do for this level. - // Continue calculating one level up. Fill in nextPairFreq - // of that level with the sum of the two nodes we've just calculated on - // this level. - if l.level == maxBits { - // All done! - break - } - levels[l.level+1].nextPairFreq = prevFreq + l.lastFreq - level++ - } else { - // If we stole from below, move down temporarily to replenish it. - for levels[level-1].needed > 0 { - level-- - } - } - } - - // Somethings is wrong if at the end, the top level is null or hasn't used - // all of the leaves. - if leafCounts[maxBits][maxBits] != n { - panic("leafCounts[maxBits][maxBits] != n") - } - - bitCount := h.bitCount[:maxBits+1] - bits := 1 - counts := &leafCounts[maxBits] - for level := maxBits; level > 0; level-- { - // chain.leafCount gives the number of literals requiring at least "bits" - // bits to encode. - bitCount[bits] = counts[level] - counts[level-1] - bits++ - } - return bitCount -} - -// Look at the leaves and assign them a bit count and an encoding as specified -// in RFC 1951 3.2.2 -func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalNode) { - code := uint16(0) - for n, bits := range bitCount { - code <<= 1 - if n == 0 || bits == 0 { - continue - } - // The literals list[len(list)-bits] .. list[len(list)-bits] - // are encoded using "bits" bits, and get the values - // code, code + 1, .... The code values are - // assigned in literal order (not frequency order). - chunk := list[len(list)-int(bits):] - - sortByLiteral(chunk) - for _, node := range chunk { - h.codes[node.literal] = newhcode(reverseBits(code, uint8(n)), uint8(n)) - code++ - } - list = list[0 : len(list)-int(bits)] - } -} - -// Update this Huffman Code object to be the minimum code for the specified frequency count. -// -// freq An array of frequencies, in which frequency[i] gives the frequency of literal i. -// maxBits The maximum number of bits to use for any literal. -func (h *huffmanEncoder) generate(freq []uint16, maxBits int32) { - list := h.freqcache[:len(freq)+1] - codes := h.codes[:len(freq)] - // Number of non-zero literals - count := 0 - // Set list to be the set of all non-zero literals and their frequencies - for i, f := range freq { - if f != 0 { - list[count] = literalNode{uint16(i), f} - count++ - } else { - codes[i] = 0 - } - } - list[count] = literalNode{} - - list = list[:count] - if count <= 2 { - // Handle the small cases here, because they are awkward for the general case code. With - // two or fewer literals, everything has bit length 1. - for i, node := range list { - // "list" is in order of increasing literal value. - h.codes[node.literal].set(uint16(i), 1) - } - return - } - sortByFreq(list) - - // Get the number of literals for each bit count - bitCount := h.bitCounts(list, maxBits) - // And do the assignment - h.assignEncodingAndSize(bitCount, list) -} - -// atLeastOne clamps the result between 1 and 15. -func atLeastOne(v float32) float32 { - if v < 1 { - return 1 - } - if v > 15 { - return 15 - } - return v -} - -func histogram(b []byte, h []uint16) { - if true && len(b) >= 8<<10 { - // Split for bigger inputs - histogramSplit(b, h) - } else { - h = h[:256] - for _, t := range b { - h[t]++ - } - } -} - -func histogramSplit(b []byte, h []uint16) { - // Tested, and slightly faster than 2-way. - // Writing to separate arrays and combining is also slightly slower. - h = h[:256] - for len(b)&3 != 0 { - h[b[0]]++ - b = b[1:] - } - n := len(b) / 4 - x, y, z, w := b[:n], b[n:], b[n+n:], b[n+n+n:] - y, z, w = y[:len(x)], z[:len(x)], w[:len(x)] - for i, t := range x { - v0 := &h[t] - v1 := &h[y[i]] - v3 := &h[w[i]] - v2 := &h[z[i]] - *v0++ - *v1++ - *v2++ - *v3++ - } -} diff --git a/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go b/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go deleted file mode 100644 index 6c05ba8c1..000000000 --- a/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go +++ /dev/null @@ -1,159 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -// Sort sorts data. -// It makes one call to data.Len to determine n, and O(n*log(n)) calls to -// data.Less and data.Swap. The sort is not guaranteed to be stable. -func sortByFreq(data []literalNode) { - n := len(data) - quickSortByFreq(data, 0, n, maxDepth(n)) -} - -func quickSortByFreq(data []literalNode, a, b, maxDepth int) { - for b-a > 12 { // Use ShellSort for slices <= 12 elements - if maxDepth == 0 { - heapSort(data, a, b) - return - } - maxDepth-- - mlo, mhi := doPivotByFreq(data, a, b) - // Avoiding recursion on the larger subproblem guarantees - // a stack depth of at most lg(b-a). - if mlo-a < b-mhi { - quickSortByFreq(data, a, mlo, maxDepth) - a = mhi // i.e., quickSortByFreq(data, mhi, b) - } else { - quickSortByFreq(data, mhi, b, maxDepth) - b = mlo // i.e., quickSortByFreq(data, a, mlo) - } - } - if b-a > 1 { - // Do ShellSort pass with gap 6 - // It could be written in this simplified form cause b-a <= 12 - for i := a + 6; i < b; i++ { - if data[i].freq == data[i-6].freq && data[i].literal < data[i-6].literal || data[i].freq < data[i-6].freq { - data[i], data[i-6] = data[i-6], data[i] - } - } - insertionSortByFreq(data, a, b) - } -} - -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] -} diff --git a/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go b/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go deleted file mode 100644 index 93f1aea10..000000000 --- a/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go +++ /dev/null @@ -1,201 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -// Sort sorts data. -// It makes one call to data.Len to determine n, and O(n*log(n)) calls to -// data.Less and data.Swap. The sort is not guaranteed to be stable. -func sortByLiteral(data []literalNode) { - n := len(data) - quickSort(data, 0, n, maxDepth(n)) -} - -func quickSort(data []literalNode, a, b, maxDepth int) { - for b-a > 12 { // Use ShellSort for slices <= 12 elements - if maxDepth == 0 { - heapSort(data, a, b) - return - } - maxDepth-- - mlo, mhi := doPivot(data, a, b) - // Avoiding recursion on the larger subproblem guarantees - // a stack depth of at most lg(b-a). - if mlo-a < b-mhi { - quickSort(data, a, mlo, maxDepth) - a = mhi // i.e., quickSort(data, mhi, b) - } else { - quickSort(data, mhi, b, maxDepth) - b = mlo // i.e., quickSort(data, a, mlo) - } - } - if b-a > 1 { - // Do ShellSort pass with gap 6 - // It could be written in this simplified form cause b-a <= 12 - for i := a + 6; i < b; i++ { - if data[i].literal < data[i-6].literal { - data[i], data[i-6] = data[i-6], data[i] - } - } - insertionSort(data, a, b) - } -} -func heapSort(data []literalNode, a, b int) { - first := a - lo := 0 - hi := b - a - - // Build heap with greatest element at top. - for i := (hi - 1) / 2; i >= 0; i-- { - siftDown(data, i, hi, first) - } - - // Pop elements, largest first, into end of data. - for i := hi - 1; i >= 0; i-- { - data[first], data[first+i] = data[first+i], data[first] - siftDown(data, lo, i, first) - } -} - -// siftDown implements the heap property on data[lo, hi). -// first is an offset into the array where the root of the heap lies. -func siftDown(data []literalNode, lo, hi, first int) { - root := lo - for { - child := 2*root + 1 - if child >= hi { - break - } - if child+1 < hi && data[first+child].literal < data[first+child+1].literal { - child++ - } - if data[first+root].literal > data[first+child].literal { - return - } - data[first+root], data[first+child] = data[first+child], data[first+root] - root = child - } -} -func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) { - m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow. - if hi-lo > 40 { - // Tukey's ``Ninther,'' median of three medians of three. - s := (hi - lo) / 8 - medianOfThree(data, lo, lo+s, lo+2*s) - medianOfThree(data, m, m-s, m+s) - medianOfThree(data, hi-1, hi-1-s, hi-1-2*s) - } - medianOfThree(data, lo, m, hi-1) - - // Invariants are: - // data[lo] = pivot (set up by ChoosePivot) - // data[lo < i < a] < pivot - // data[a <= i < b] <= pivot - // data[b <= i < c] unexamined - // data[c <= i < hi-1] > pivot - // data[hi-1] >= pivot - pivot := lo - a, c := lo+1, hi-1 - - for ; a < c && data[a].literal < data[pivot].literal; a++ { - } - b := a - for { - for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot - } - for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot - } - if b >= c { - break - } - // data[b] > pivot; data[c-1] <= pivot - data[b], data[c-1] = data[c-1], data[b] - b++ - c-- - } - // If hi-c<3 then there are duplicates (by property of median of nine). - // Let's be a bit more conservative, and set border to 5. - protect := hi-c < 5 - if !protect && hi-c < (hi-lo)/4 { - // Lets test some points for equality to pivot - dups := 0 - if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot - data[c], data[hi-1] = data[hi-1], data[c] - c++ - dups++ - } - if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot - b-- - dups++ - } - // m-lo = (hi-lo)/2 > 6 - // b-lo > (hi-lo)*3/4-1 > 8 - // ==> m < b ==> data[m] <= pivot - if data[m].literal > data[pivot].literal { // data[m] = pivot - data[m], data[b-1] = data[b-1], data[m] - b-- - dups++ - } - // if at least 2 points are equal to pivot, assume skewed distribution - protect = dups > 1 - } - if protect { - // Protect against a lot of duplicates - // Add invariant: - // data[a <= i < b] unexamined - // data[b <= i < c] = pivot - for { - for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot - } - for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot - } - if a >= b { - break - } - // data[a] == pivot; data[b-1] < pivot - data[a], data[b-1] = data[b-1], data[a] - a++ - b-- - } - } - // Swap pivot into middle - data[pivot], data[b-1] = data[b-1], data[pivot] - return b - 1, c -} - -// Insertion sort -func insertionSort(data []literalNode, a, b int) { - for i := a + 1; i < b; i++ { - for j := i; j > a && data[j].literal < data[j-1].literal; j-- { - data[j], data[j-1] = data[j-1], data[j] - } - } -} - -// maxDepth returns a threshold at which quicksort should switch -// to heapsort. It returns 2*ceil(lg(n+1)). -func maxDepth(n int) int { - var depth int - for i := n; i > 0; i >>= 1 { - depth++ - } - return depth * 2 -} - -// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1]. -func medianOfThree(data []literalNode, m1, m0, m2 int) { - // sort 3 elements - if data[m1].literal < data[m0].literal { - data[m1], data[m0] = data[m0], data[m1] - } - // data[m0] <= data[m1] - if data[m2].literal < data[m1].literal { - data[m2], data[m1] = data[m1], data[m2] - // data[m0] <= data[m2] && data[m1] < data[m2] - if data[m1].literal < data[m0].literal { - data[m1], data[m0] = data[m0], data[m1] - } - } - // now data[m0] <= data[m1] <= data[m2] -} diff --git a/vendor/github.com/klauspost/compress/flate/inflate.go b/vendor/github.com/klauspost/compress/flate/inflate.go deleted file mode 100644 index 2f410d64f..000000000 --- a/vendor/github.com/klauspost/compress/flate/inflate.go +++ /dev/null @@ -1,829 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package flate implements the DEFLATE compressed data format, described in -// RFC 1951. The gzip and zlib packages implement access to DEFLATE-based file -// formats. -package flate - -import ( - "bufio" - "compress/flate" - "fmt" - "io" - "math/bits" - "sync" -) - -const ( - maxCodeLen = 16 // max length of Huffman code - maxCodeLenMask = 15 // mask for max length of Huffman code - // The next three numbers come from the RFC section 3.2.7, with the - // additional proviso in section 3.2.5 which implies that distance codes - // 30 and 31 should never occur in compressed data. - maxNumLit = 286 - maxNumDist = 30 - numCodes = 19 // number of codes in Huffman meta-code - - debugDecode = false -) - -// Value of length - 3 and extra bits. -type lengthExtra struct { - length, extra uint8 -} - -var decCodeToLen = [32]lengthExtra{{length: 0x0, extra: 0x0}, {length: 0x1, extra: 0x0}, {length: 0x2, extra: 0x0}, {length: 0x3, extra: 0x0}, {length: 0x4, extra: 0x0}, {length: 0x5, extra: 0x0}, {length: 0x6, extra: 0x0}, {length: 0x7, extra: 0x0}, {length: 0x8, extra: 0x1}, {length: 0xa, extra: 0x1}, {length: 0xc, extra: 0x1}, {length: 0xe, extra: 0x1}, {length: 0x10, extra: 0x2}, {length: 0x14, extra: 0x2}, {length: 0x18, extra: 0x2}, {length: 0x1c, extra: 0x2}, {length: 0x20, extra: 0x3}, {length: 0x28, extra: 0x3}, {length: 0x30, extra: 0x3}, {length: 0x38, extra: 0x3}, {length: 0x40, extra: 0x4}, {length: 0x50, extra: 0x4}, {length: 0x60, extra: 0x4}, {length: 0x70, extra: 0x4}, {length: 0x80, extra: 0x5}, {length: 0xa0, extra: 0x5}, {length: 0xc0, extra: 0x5}, {length: 0xe0, extra: 0x5}, {length: 0xff, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}} - -var bitMask32 = [32]uint32{ - 0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, - 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, - 0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF, - 0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF, -} // up to 32 bits - -// Initialize the fixedHuffmanDecoder only once upon first use. -var fixedOnce sync.Once -var fixedHuffmanDecoder huffmanDecoder - -// A CorruptInputError reports the presence of corrupt input at a given offset. -type CorruptInputError = flate.CorruptInputError - -// An InternalError reports an error in the flate code itself. -type InternalError string - -func (e InternalError) Error() string { return "flate: internal error: " + string(e) } - -// A ReadError reports an error encountered while reading input. -// -// Deprecated: No longer returned. -type ReadError = flate.ReadError - -// A WriteError reports an error encountered while writing output. -// -// Deprecated: No longer returned. -type WriteError = flate.WriteError - -// Resetter resets a ReadCloser returned by NewReader or NewReaderDict to -// to switch to a new underlying Reader. This permits reusing a ReadCloser -// instead of allocating a new one. -type Resetter interface { - // Reset discards any buffered data and resets the Resetter as if it was - // newly initialized with the given reader. - Reset(r io.Reader, dict []byte) error -} - -// The data structure for decoding Huffman tables is based on that of -// zlib. There is a lookup table of a fixed bit width (huffmanChunkBits), -// For codes smaller than the table width, there are multiple entries -// (each combination of trailing bits has the same value). For codes -// larger than the table width, the table contains a link to an overflow -// table. The width of each entry in the link table is the maximum code -// size minus the chunk width. -// -// Note that you can do a lookup in the table even without all bits -// filled. Since the extra bits are zero, and the DEFLATE Huffman codes -// have the property that shorter codes come before longer ones, the -// bit length estimate in the result is a lower bound on the actual -// number of bits. -// -// See the following: -// http://www.gzip.org/algorithm.txt - -// chunk & 15 is number of bits -// chunk >> 4 is value, including table link - -const ( - huffmanChunkBits = 9 - huffmanNumChunks = 1 << huffmanChunkBits - huffmanCountMask = 15 - huffmanValueShift = 4 -) - -type huffmanDecoder struct { - maxRead int // the maximum number of bits we can read and not overread - chunks *[huffmanNumChunks]uint16 // chunks as described above - links [][]uint16 // overflow links - linkMask uint32 // mask the width of the link table -} - -// Initialize Huffman decoding tables from array of code lengths. -// Following this function, h is guaranteed to be initialized into a complete -// tree (i.e., neither over-subscribed nor under-subscribed). The exception is a -// degenerate case where the tree has only a single symbol with length 1. Empty -// trees are permitted. -func (h *huffmanDecoder) init(lengths []int) bool { - // Sanity enables additional runtime tests during Huffman - // table construction. It's intended to be used during - // development to supplement the currently ad-hoc unit tests. - const sanity = false - - if h.chunks == nil { - h.chunks = new([huffmanNumChunks]uint16) - } - - if h.maxRead != 0 { - *h = huffmanDecoder{chunks: h.chunks, links: h.links} - } - - // Count number of codes of each length, - // compute maxRead and max length. - var count [maxCodeLen]int - var min, max int - for _, n := range lengths { - if n == 0 { - continue - } - if min == 0 || n < min { - min = n - } - if n > max { - max = n - } - count[n&maxCodeLenMask]++ - } - - // Empty tree. The decompressor.huffSym function will fail later if the tree - // is used. Technically, an empty tree is only valid for the HDIST tree and - // not the HCLEN and HLIT tree. However, a stream with an empty HCLEN tree - // is guaranteed to fail since it will attempt to use the tree to decode the - // codes for the HLIT and HDIST trees. Similarly, an empty HLIT tree is - // guaranteed to fail later since the compressed data section must be - // composed of at least one symbol (the end-of-block marker). - if max == 0 { - return true - } - - code := 0 - var nextcode [maxCodeLen]int - for i := min; i <= max; i++ { - code <<= 1 - nextcode[i&maxCodeLenMask] = code - code += count[i&maxCodeLenMask] - } - - // Check that the coding is complete (i.e., that we've - // assigned all 2-to-the-max possible bit sequences). - // Exception: To be compatible with zlib, we also need to - // accept degenerate single-code codings. See also - // TestDegenerateHuffmanCoding. - if code != 1<<uint(max) && !(code == 1 && max == 1) { - if debugDecode { - fmt.Println("coding failed, code, max:", code, max, code == 1<<uint(max), code == 1 && max == 1, "(one should be true)") - } - return false - } - - h.maxRead = min - - chunks := h.chunks[:] - for i := range chunks { - chunks[i] = 0 - } - - if max > huffmanChunkBits { - numLinks := 1 << (uint(max) - huffmanChunkBits) - h.linkMask = uint32(numLinks - 1) - - // create link tables - link := nextcode[huffmanChunkBits+1] >> 1 - if cap(h.links) < huffmanNumChunks-link { - h.links = make([][]uint16, huffmanNumChunks-link) - } else { - h.links = h.links[:huffmanNumChunks-link] - } - for j := uint(link); j < huffmanNumChunks; j++ { - reverse := int(bits.Reverse16(uint16(j))) - reverse >>= uint(16 - huffmanChunkBits) - off := j - uint(link) - if sanity && h.chunks[reverse] != 0 { - panic("impossible: overwriting existing chunk") - } - h.chunks[reverse] = uint16(off<<huffmanValueShift | (huffmanChunkBits + 1)) - if cap(h.links[off]) < numLinks { - h.links[off] = make([]uint16, numLinks) - } else { - h.links[off] = h.links[off][:numLinks] - } - } - } else { - h.links = h.links[:0] - } - - for i, n := range lengths { - if n == 0 { - continue - } - code := nextcode[n] - nextcode[n]++ - chunk := uint16(i<<huffmanValueShift | n) - reverse := int(bits.Reverse16(uint16(code))) - reverse >>= uint(16 - n) - if n <= huffmanChunkBits { - for off := reverse; off < len(h.chunks); off += 1 << uint(n) { - // We should never need to overwrite - // an existing chunk. Also, 0 is - // never a valid chunk, because the - // lower 4 "count" bits should be - // between 1 and 15. - if sanity && h.chunks[off] != 0 { - panic("impossible: overwriting existing chunk") - } - h.chunks[off] = chunk - } - } else { - j := reverse & (huffmanNumChunks - 1) - if sanity && h.chunks[j]&huffmanCountMask != huffmanChunkBits+1 { - // Longer codes should have been - // associated with a link table above. - panic("impossible: not an indirect chunk") - } - value := h.chunks[j] >> huffmanValueShift - linktab := h.links[value] - reverse >>= huffmanChunkBits - for off := reverse; off < len(linktab); off += 1 << uint(n-huffmanChunkBits) { - if sanity && linktab[off] != 0 { - panic("impossible: overwriting existing chunk") - } - linktab[off] = chunk - } - } - } - - if sanity { - // Above we've sanity checked that we never overwrote - // an existing entry. Here we additionally check that - // we filled the tables completely. - for i, chunk := range h.chunks { - if chunk == 0 { - // As an exception, in the degenerate - // single-code case, we allow odd - // chunks to be missing. - if code == 1 && i%2 == 1 { - continue - } - panic("impossible: missing chunk") - } - } - for _, linktab := range h.links { - for _, chunk := range linktab { - if chunk == 0 { - panic("impossible: missing chunk") - } - } - } - } - - return true -} - -// Reader is the actual read interface needed by NewReader. -// If the passed in io.Reader does not also have ReadByte, -// the NewReader will introduce its own buffering. -type Reader interface { - io.Reader - io.ByteReader -} - -type step uint8 - -const ( - copyData step = iota + 1 - nextBlock - huffmanBytesBuffer - huffmanBytesReader - huffmanBufioReader - huffmanStringsReader - huffmanGenericReader -) - -// Decompress state. -type decompressor struct { - // Input source. - r Reader - roffset int64 - - // Huffman decoders for literal/length, distance. - h1, h2 huffmanDecoder - - // Length arrays used to define Huffman codes. - bits *[maxNumLit + maxNumDist]int - codebits *[numCodes]int - - // Output history, buffer. - dict dictDecoder - - // Next step in the decompression, - // and decompression state. - step step - stepState int - err error - toRead []byte - hl, hd *huffmanDecoder - copyLen int - copyDist int - - // Temporary buffer (avoids repeated allocation). - buf [4]byte - - // Input bits, in top of b. - b uint32 - - nb uint - final bool -} - -func (f *decompressor) nextBlock() { - for f.nb < 1+2 { - if f.err = f.moreBits(); f.err != nil { - return - } - } - f.final = f.b&1 == 1 - f.b >>= 1 - typ := f.b & 3 - f.b >>= 2 - f.nb -= 1 + 2 - switch typ { - case 0: - f.dataBlock() - if debugDecode { - fmt.Println("stored block") - } - case 1: - // compressed, fixed Huffman tables - f.hl = &fixedHuffmanDecoder - f.hd = nil - f.huffmanBlockDecoder() - if debugDecode { - fmt.Println("predefinied huffman block") - } - case 2: - // compressed, dynamic Huffman tables - if f.err = f.readHuffman(); f.err != nil { - break - } - f.hl = &f.h1 - f.hd = &f.h2 - f.huffmanBlockDecoder() - if debugDecode { - fmt.Println("dynamic huffman block") - } - default: - // 3 is reserved. - if debugDecode { - fmt.Println("reserved data block encountered") - } - f.err = CorruptInputError(f.roffset) - } -} - -func (f *decompressor) Read(b []byte) (int, error) { - for { - if len(f.toRead) > 0 { - n := copy(b, f.toRead) - f.toRead = f.toRead[n:] - if len(f.toRead) == 0 { - return n, f.err - } - return n, nil - } - if f.err != nil { - return 0, f.err - } - - f.doStep() - - if f.err != nil && len(f.toRead) == 0 { - f.toRead = f.dict.readFlush() // Flush what's left in case of error - } - } -} - -// WriteTo implements the io.WriteTo interface for io.Copy and friends. -func (f *decompressor) WriteTo(w io.Writer) (int64, error) { - total := int64(0) - flushed := false - for { - if len(f.toRead) > 0 { - n, err := w.Write(f.toRead) - total += int64(n) - if err != nil { - f.err = err - return total, err - } - if n != len(f.toRead) { - return total, io.ErrShortWrite - } - f.toRead = f.toRead[:0] - } - if f.err != nil && flushed { - if f.err == io.EOF { - return total, nil - } - return total, f.err - } - if f.err == nil { - f.doStep() - } - if len(f.toRead) == 0 && f.err != nil && !flushed { - f.toRead = f.dict.readFlush() // Flush what's left in case of error - flushed = true - } - } -} - -func (f *decompressor) Close() error { - if f.err == io.EOF { - return nil - } - return f.err -} - -// RFC 1951 section 3.2.7. -// Compression with dynamic Huffman codes - -var codeOrder = [...]int{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15} - -func (f *decompressor) readHuffman() error { - // HLIT[5], HDIST[5], HCLEN[4]. - for f.nb < 5+5+4 { - if err := f.moreBits(); err != nil { - return err - } - } - nlit := int(f.b&0x1F) + 257 - if nlit > maxNumLit { - if debugDecode { - fmt.Println("nlit > maxNumLit", nlit) - } - return CorruptInputError(f.roffset) - } - f.b >>= 5 - ndist := int(f.b&0x1F) + 1 - if ndist > maxNumDist { - if debugDecode { - fmt.Println("ndist > maxNumDist", ndist) - } - return CorruptInputError(f.roffset) - } - f.b >>= 5 - nclen := int(f.b&0xF) + 4 - // numCodes is 19, so nclen is always valid. - f.b >>= 4 - f.nb -= 5 + 5 + 4 - - // (HCLEN+4)*3 bits: code lengths in the magic codeOrder order. - for i := 0; i < nclen; i++ { - for f.nb < 3 { - if err := f.moreBits(); err != nil { - return err - } - } - f.codebits[codeOrder[i]] = int(f.b & 0x7) - f.b >>= 3 - f.nb -= 3 - } - for i := nclen; i < len(codeOrder); i++ { - f.codebits[codeOrder[i]] = 0 - } - if !f.h1.init(f.codebits[0:]) { - if debugDecode { - fmt.Println("init codebits failed") - } - return CorruptInputError(f.roffset) - } - - // HLIT + 257 code lengths, HDIST + 1 code lengths, - // using the code length Huffman code. - for i, n := 0, nlit+ndist; i < n; { - x, err := f.huffSym(&f.h1) - if err != nil { - return err - } - if x < 16 { - // Actual length. - f.bits[i] = x - i++ - continue - } - // Repeat previous length or zero. - var rep int - var nb uint - var b int - switch x { - default: - return InternalError("unexpected length code") - case 16: - rep = 3 - nb = 2 - if i == 0 { - if debugDecode { - fmt.Println("i==0") - } - return CorruptInputError(f.roffset) - } - b = f.bits[i-1] - case 17: - rep = 3 - nb = 3 - b = 0 - case 18: - rep = 11 - nb = 7 - b = 0 - } - for f.nb < nb { - if err := f.moreBits(); err != nil { - if debugDecode { - fmt.Println("morebits:", err) - } - return err - } - } - rep += int(f.b & uint32(1<<(nb®SizeMaskUint32)-1)) - f.b >>= nb & regSizeMaskUint32 - f.nb -= nb - if i+rep > n { - if debugDecode { - fmt.Println("i+rep > n", i, rep, n) - } - return CorruptInputError(f.roffset) - } - for j := 0; j < rep; j++ { - f.bits[i] = b - i++ - } - } - - if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) { - if debugDecode { - fmt.Println("init2 failed") - } - return CorruptInputError(f.roffset) - } - - // As an optimization, we can initialize the maxRead bits to read at a time - // for the HLIT tree to the length of the EOB marker since we know that - // every block must terminate with one. This preserves the property that - // we never read any extra bytes after the end of the DEFLATE stream. - if f.h1.maxRead < f.bits[endBlockMarker] { - f.h1.maxRead = f.bits[endBlockMarker] - } - if !f.final { - // If not the final block, the smallest block possible is - // a predefined table, BTYPE=01, with a single EOB marker. - // This will take up 3 + 7 bits. - f.h1.maxRead += 10 - } - - return nil -} - -// Copy a single uncompressed data block from input to output. -func (f *decompressor) dataBlock() { - // Uncompressed. - // Discard current half-byte. - left := (f.nb) & 7 - f.nb -= left - f.b >>= left - - offBytes := f.nb >> 3 - // Unfilled values will be overwritten. - f.buf[0] = uint8(f.b) - f.buf[1] = uint8(f.b >> 8) - f.buf[2] = uint8(f.b >> 16) - f.buf[3] = uint8(f.b >> 24) - - f.roffset += int64(offBytes) - f.nb, f.b = 0, 0 - - // Length then ones-complement of length. - nr, err := io.ReadFull(f.r, f.buf[offBytes:4]) - f.roffset += int64(nr) - if err != nil { - f.err = noEOF(err) - return - } - n := uint16(f.buf[0]) | uint16(f.buf[1])<<8 - nn := uint16(f.buf[2]) | uint16(f.buf[3])<<8 - if nn != ^n { - if debugDecode { - ncomp := ^n - fmt.Println("uint16(nn) != uint16(^n)", nn, ncomp) - } - f.err = CorruptInputError(f.roffset) - return - } - - if n == 0 { - f.toRead = f.dict.readFlush() - f.finishBlock() - return - } - - f.copyLen = int(n) - f.copyData() -} - -// copyData copies f.copyLen bytes from the underlying reader into f.hist. -// It pauses for reads when f.hist is full. -func (f *decompressor) copyData() { - buf := f.dict.writeSlice() - if len(buf) > f.copyLen { - buf = buf[:f.copyLen] - } - - cnt, err := io.ReadFull(f.r, buf) - f.roffset += int64(cnt) - f.copyLen -= cnt - f.dict.writeMark(cnt) - if err != nil { - f.err = noEOF(err) - return - } - - if f.dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = f.dict.readFlush() - f.step = copyData - return - } - f.finishBlock() -} - -func (f *decompressor) finishBlock() { - if f.final { - if f.dict.availRead() > 0 { - f.toRead = f.dict.readFlush() - } - f.err = io.EOF - } - f.step = nextBlock -} - -func (f *decompressor) doStep() { - switch f.step { - case copyData: - f.copyData() - case nextBlock: - f.nextBlock() - case huffmanBytesBuffer: - f.huffmanBytesBuffer() - case huffmanBytesReader: - f.huffmanBytesReader() - case huffmanBufioReader: - f.huffmanBufioReader() - case huffmanStringsReader: - f.huffmanStringsReader() - case huffmanGenericReader: - f.huffmanGenericReader() - default: - panic("BUG: unexpected step state") - } -} - -// noEOF returns err, unless err == io.EOF, in which case it returns io.ErrUnexpectedEOF. -func noEOF(e error) error { - if e == io.EOF { - return io.ErrUnexpectedEOF - } - return e -} - -func (f *decompressor) moreBits() error { - c, err := f.r.ReadByte() - if err != nil { - return noEOF(err) - } - f.roffset++ - f.b |= uint32(c) << (f.nb & regSizeMaskUint32) - f.nb += 8 - return nil -} - -// Read the next Huffman-encoded symbol from f according to h. -func (f *decompressor) huffSym(h *huffmanDecoder) (int, error) { - // Since a huffmanDecoder can be empty or be composed of a degenerate tree - // with single element, huffSym must error on these two edge cases. In both - // cases, the chunks slice will be 0 for the invalid sequence, leading it - // satisfy the n == 0 check below. - n := uint(h.maxRead) - // Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers, - // but is smart enough to keep local variables in registers, so use nb and b, - // inline call to moreBits and reassign b,nb back to f on return. - nb, b := f.nb, f.b - for { - for nb < n { - c, err := f.r.ReadByte() - if err != nil { - f.b = b - f.nb = nb - return 0, noEOF(err) - } - f.roffset++ - b |= uint32(c) << (nb & regSizeMaskUint32) - nb += 8 - } - chunk := h.chunks[b&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = h.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&h.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= nb { - if n == 0 { - f.b = b - f.nb = nb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return 0, f.err - } - f.b = b >> (n & regSizeMaskUint32) - f.nb = nb - n - return int(chunk >> huffmanValueShift), nil - } - } -} - -func makeReader(r io.Reader) Reader { - if rr, ok := r.(Reader); ok { - return rr - } - return bufio.NewReader(r) -} - -func fixedHuffmanDecoderInit() { - fixedOnce.Do(func() { - // These come from the RFC section 3.2.6. - var bits [288]int - for i := 0; i < 144; i++ { - bits[i] = 8 - } - for i := 144; i < 256; i++ { - bits[i] = 9 - } - for i := 256; i < 280; i++ { - bits[i] = 7 - } - for i := 280; i < 288; i++ { - bits[i] = 8 - } - fixedHuffmanDecoder.init(bits[:]) - }) -} - -func (f *decompressor) Reset(r io.Reader, dict []byte) error { - *f = decompressor{ - r: makeReader(r), - bits: f.bits, - codebits: f.codebits, - h1: f.h1, - h2: f.h2, - dict: f.dict, - step: nextBlock, - } - f.dict.init(maxMatchOffset, dict) - return nil -} - -// NewReader returns a new ReadCloser that can be used -// to read the uncompressed version of r. -// If r does not also implement io.ByteReader, -// the decompressor may read more data than necessary from r. -// It is the caller's responsibility to call Close on the ReadCloser -// when finished reading. -// -// The ReadCloser returned by NewReader also implements Resetter. -func NewReader(r io.Reader) io.ReadCloser { - fixedHuffmanDecoderInit() - - var f decompressor - f.r = makeReader(r) - f.bits = new([maxNumLit + maxNumDist]int) - f.codebits = new([numCodes]int) - f.step = nextBlock - f.dict.init(maxMatchOffset, nil) - return &f -} - -// NewReaderDict is like NewReader but initializes the reader -// with a preset dictionary. The returned Reader behaves as if -// the uncompressed data stream started with the given dictionary, -// which has already been read. NewReaderDict is typically used -// to read data compressed by NewWriterDict. -// -// The ReadCloser returned by NewReader also implements Resetter. -func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser { - fixedHuffmanDecoderInit() - - var f decompressor - f.r = makeReader(r) - f.bits = new([maxNumLit + maxNumDist]int) - f.codebits = new([numCodes]int) - f.step = nextBlock - f.dict.init(maxMatchOffset, dict) - return &f -} diff --git a/vendor/github.com/klauspost/compress/flate/inflate_gen.go b/vendor/github.com/klauspost/compress/flate/inflate_gen.go deleted file mode 100644 index 2b2f993f7..000000000 --- a/vendor/github.com/klauspost/compress/flate/inflate_gen.go +++ /dev/null @@ -1,1283 +0,0 @@ -// 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) - - // 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. - fnb, fb, dict := f.nb, f.b, &f.dict - - 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) - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hl.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hl.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hl.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - v = int(chunk >> huffmanValueShift) - break - } - } - } - - var length int - switch { - case v < 256: - dict.writeByte(byte(v)) - if dict.availWrite() == 0 { - f.toRead = dict.readFlush() - f.step = huffmanBytesBuffer - f.stepState = stateInit - f.b, f.nb = fb, fnb - return - } - goto readLiteral - case v == 256: - f.b, f.nb = fb, fnb - f.finishBlock() - return - // otherwise, reference to older data - case v < 265: - length = v - (257 - 3) - case v < maxNumLit: - val := decCodeToLen[(v - 257)] - length = int(val.length) + 3 - n := uint(val.extra) - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits n>0:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - length += int(fb & bitMask32[n]) - fb >>= n & regSizeMaskUint32 - fnb -= n - default: - if debugDecode { - fmt.Println(v, ">= maxNumLit") - } - f.err = CorruptInputError(f.roffset) - f.b, f.nb = fb, fnb - return - } - - var dist uint32 - if f.hd == nil { - for fnb < 5 { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<5:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - dist = uint32(bits.Reverse8(uint8(fb & 0x1F << 3))) - fb >>= 5 - fnb -= 5 - } else { - // 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.hd.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. - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hd.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hd.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hd.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - dist = uint32(chunk >> huffmanValueShift) - break - } - } - } - - 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 & regSizeMaskUint32) - for fnb < nb { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<nb:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - extra |= fb & bitMask32[nb] - fb >>= nb & regSizeMaskUint32 - fnb -= nb - dist = 1<<((nb+1)®SizeMaskUint32) + 1 + extra - // slower: dist = bitMask32[nb+1] + 2 + extra - default: - f.b, f.nb = fb, fnb - 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 > uint32(dict.histSize()) { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("dist > dict.histSize():", dist, dict.histSize()) - } - f.err = CorruptInputError(f.roffset) - return - } - - f.copyLen, f.copyDist = length, int(dist) - goto copyHistory - } - -copyHistory: - // Perform a backwards copy according to RFC section 3.2.3. - { - cnt := dict.tryWriteCopy(f.copyDist, f.copyLen) - if cnt == 0 { - cnt = dict.writeCopy(f.copyDist, f.copyLen) - } - f.copyLen -= cnt - - if dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = dict.readFlush() - f.step = huffmanBytesBuffer // We need to continue this work - f.stepState = stateDict - f.b, f.nb = fb, fnb - return - } - goto readLiteral - } - // Not reached -} - -// 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) - - // 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. - fnb, fb, dict := f.nb, f.b, &f.dict - - 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) - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hl.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hl.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hl.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - v = int(chunk >> huffmanValueShift) - break - } - } - } - - var length int - switch { - case v < 256: - dict.writeByte(byte(v)) - if dict.availWrite() == 0 { - f.toRead = dict.readFlush() - f.step = huffmanBytesReader - f.stepState = stateInit - f.b, f.nb = fb, fnb - return - } - goto readLiteral - case v == 256: - f.b, f.nb = fb, fnb - f.finishBlock() - return - // otherwise, reference to older data - case v < 265: - length = v - (257 - 3) - case v < maxNumLit: - val := decCodeToLen[(v - 257)] - length = int(val.length) + 3 - n := uint(val.extra) - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits n>0:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - length += int(fb & bitMask32[n]) - fb >>= n & regSizeMaskUint32 - fnb -= n - default: - if debugDecode { - fmt.Println(v, ">= maxNumLit") - } - f.err = CorruptInputError(f.roffset) - f.b, f.nb = fb, fnb - return - } - - var dist uint32 - if f.hd == nil { - for fnb < 5 { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<5:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - dist = uint32(bits.Reverse8(uint8(fb & 0x1F << 3))) - fb >>= 5 - fnb -= 5 - } else { - // 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.hd.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. - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hd.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hd.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hd.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - dist = uint32(chunk >> huffmanValueShift) - break - } - } - } - - 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 & regSizeMaskUint32) - for fnb < nb { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<nb:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - extra |= fb & bitMask32[nb] - fb >>= nb & regSizeMaskUint32 - fnb -= nb - dist = 1<<((nb+1)®SizeMaskUint32) + 1 + extra - // slower: dist = bitMask32[nb+1] + 2 + extra - default: - f.b, f.nb = fb, fnb - 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 > uint32(dict.histSize()) { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("dist > dict.histSize():", dist, dict.histSize()) - } - f.err = CorruptInputError(f.roffset) - return - } - - f.copyLen, f.copyDist = length, int(dist) - goto copyHistory - } - -copyHistory: - // Perform a backwards copy according to RFC section 3.2.3. - { - cnt := dict.tryWriteCopy(f.copyDist, f.copyLen) - if cnt == 0 { - cnt = dict.writeCopy(f.copyDist, f.copyLen) - } - f.copyLen -= cnt - - if dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = dict.readFlush() - f.step = huffmanBytesReader // We need to continue this work - f.stepState = stateDict - f.b, f.nb = fb, fnb - return - } - goto readLiteral - } - // Not reached -} - -// 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) - - // 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. - fnb, fb, dict := f.nb, f.b, &f.dict - - 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) - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hl.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hl.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hl.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - v = int(chunk >> huffmanValueShift) - break - } - } - } - - var length int - switch { - case v < 256: - dict.writeByte(byte(v)) - if dict.availWrite() == 0 { - f.toRead = dict.readFlush() - f.step = huffmanBufioReader - f.stepState = stateInit - f.b, f.nb = fb, fnb - return - } - goto readLiteral - case v == 256: - f.b, f.nb = fb, fnb - f.finishBlock() - return - // otherwise, reference to older data - case v < 265: - length = v - (257 - 3) - case v < maxNumLit: - val := decCodeToLen[(v - 257)] - length = int(val.length) + 3 - n := uint(val.extra) - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits n>0:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - length += int(fb & bitMask32[n]) - fb >>= n & regSizeMaskUint32 - fnb -= n - default: - if debugDecode { - fmt.Println(v, ">= maxNumLit") - } - f.err = CorruptInputError(f.roffset) - f.b, f.nb = fb, fnb - return - } - - var dist uint32 - if f.hd == nil { - for fnb < 5 { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<5:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - dist = uint32(bits.Reverse8(uint8(fb & 0x1F << 3))) - fb >>= 5 - fnb -= 5 - } else { - // 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.hd.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. - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hd.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hd.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hd.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - dist = uint32(chunk >> huffmanValueShift) - break - } - } - } - - 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 & regSizeMaskUint32) - for fnb < nb { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<nb:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - extra |= fb & bitMask32[nb] - fb >>= nb & regSizeMaskUint32 - fnb -= nb - dist = 1<<((nb+1)®SizeMaskUint32) + 1 + extra - // slower: dist = bitMask32[nb+1] + 2 + extra - default: - f.b, f.nb = fb, fnb - 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 > uint32(dict.histSize()) { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("dist > dict.histSize():", dist, dict.histSize()) - } - f.err = CorruptInputError(f.roffset) - return - } - - f.copyLen, f.copyDist = length, int(dist) - goto copyHistory - } - -copyHistory: - // Perform a backwards copy according to RFC section 3.2.3. - { - cnt := dict.tryWriteCopy(f.copyDist, f.copyLen) - if cnt == 0 { - cnt = dict.writeCopy(f.copyDist, f.copyLen) - } - f.copyLen -= cnt - - if dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = dict.readFlush() - f.step = huffmanBufioReader // We need to continue this work - f.stepState = stateDict - f.b, f.nb = fb, fnb - return - } - goto readLiteral - } - // Not reached -} - -// 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) - - // 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. - fnb, fb, dict := f.nb, f.b, &f.dict - - 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) - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hl.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hl.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hl.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - v = int(chunk >> huffmanValueShift) - break - } - } - } - - var length int - switch { - case v < 256: - dict.writeByte(byte(v)) - if dict.availWrite() == 0 { - f.toRead = dict.readFlush() - f.step = huffmanStringsReader - f.stepState = stateInit - f.b, f.nb = fb, fnb - return - } - goto readLiteral - case v == 256: - f.b, f.nb = fb, fnb - f.finishBlock() - return - // otherwise, reference to older data - case v < 265: - length = v - (257 - 3) - case v < maxNumLit: - val := decCodeToLen[(v - 257)] - length = int(val.length) + 3 - n := uint(val.extra) - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits n>0:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - length += int(fb & bitMask32[n]) - fb >>= n & regSizeMaskUint32 - fnb -= n - default: - if debugDecode { - fmt.Println(v, ">= maxNumLit") - } - f.err = CorruptInputError(f.roffset) - f.b, f.nb = fb, fnb - return - } - - var dist uint32 - if f.hd == nil { - for fnb < 5 { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<5:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - dist = uint32(bits.Reverse8(uint8(fb & 0x1F << 3))) - fb >>= 5 - fnb -= 5 - } else { - // 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.hd.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. - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hd.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hd.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hd.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - dist = uint32(chunk >> huffmanValueShift) - break - } - } - } - - 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 & regSizeMaskUint32) - for fnb < nb { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<nb:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - extra |= fb & bitMask32[nb] - fb >>= nb & regSizeMaskUint32 - fnb -= nb - dist = 1<<((nb+1)®SizeMaskUint32) + 1 + extra - // slower: dist = bitMask32[nb+1] + 2 + extra - default: - f.b, f.nb = fb, fnb - 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 > uint32(dict.histSize()) { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("dist > dict.histSize():", dist, dict.histSize()) - } - f.err = CorruptInputError(f.roffset) - return - } - - f.copyLen, f.copyDist = length, int(dist) - goto copyHistory - } - -copyHistory: - // Perform a backwards copy according to RFC section 3.2.3. - { - cnt := dict.tryWriteCopy(f.copyDist, f.copyLen) - if cnt == 0 { - cnt = dict.writeCopy(f.copyDist, f.copyLen) - } - f.copyLen -= cnt - - if dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = dict.readFlush() - f.step = huffmanStringsReader // We need to continue this work - f.stepState = stateDict - f.b, f.nb = fb, fnb - return - } - goto readLiteral - } - // Not reached -} - -// 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) huffmanGenericReader() { - const ( - stateInit = iota // Zero value must be stateInit - stateDict - ) - fr := f.r.(Reader) - - // 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. - fnb, fb, dict := f.nb, f.b, &f.dict - - 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) - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hl.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hl.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hl.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - v = int(chunk >> huffmanValueShift) - break - } - } - } - - var length int - switch { - case v < 256: - dict.writeByte(byte(v)) - if dict.availWrite() == 0 { - f.toRead = dict.readFlush() - f.step = huffmanGenericReader - f.stepState = stateInit - f.b, f.nb = fb, fnb - return - } - goto readLiteral - case v == 256: - f.b, f.nb = fb, fnb - f.finishBlock() - return - // otherwise, reference to older data - case v < 265: - length = v - (257 - 3) - case v < maxNumLit: - val := decCodeToLen[(v - 257)] - length = int(val.length) + 3 - n := uint(val.extra) - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits n>0:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - length += int(fb & bitMask32[n]) - fb >>= n & regSizeMaskUint32 - fnb -= n - default: - if debugDecode { - fmt.Println(v, ">= maxNumLit") - } - f.err = CorruptInputError(f.roffset) - f.b, f.nb = fb, fnb - return - } - - var dist uint32 - if f.hd == nil { - for fnb < 5 { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<5:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - dist = uint32(bits.Reverse8(uint8(fb & 0x1F << 3))) - fb >>= 5 - fnb -= 5 - } else { - // 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.hd.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. - for { - for fnb < n { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - f.err = noEOF(err) - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - chunk := f.hd.chunks[fb&(huffmanNumChunks-1)] - n = uint(chunk & huffmanCountMask) - if n > huffmanChunkBits { - chunk = f.hd.links[chunk>>huffmanValueShift][(fb>>huffmanChunkBits)&f.hd.linkMask] - n = uint(chunk & huffmanCountMask) - } - if n <= fnb { - if n == 0 { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("huffsym: n==0") - } - f.err = CorruptInputError(f.roffset) - return - } - fb = fb >> (n & regSizeMaskUint32) - fnb = fnb - n - dist = uint32(chunk >> huffmanValueShift) - break - } - } - } - - 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 & regSizeMaskUint32) - for fnb < nb { - c, err := fr.ReadByte() - if err != nil { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("morebits f.nb<nb:", err) - } - f.err = err - return - } - f.roffset++ - fb |= uint32(c) << (fnb & regSizeMaskUint32) - fnb += 8 - } - extra |= fb & bitMask32[nb] - fb >>= nb & regSizeMaskUint32 - fnb -= nb - dist = 1<<((nb+1)®SizeMaskUint32) + 1 + extra - // slower: dist = bitMask32[nb+1] + 2 + extra - default: - f.b, f.nb = fb, fnb - 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 > uint32(dict.histSize()) { - f.b, f.nb = fb, fnb - if debugDecode { - fmt.Println("dist > dict.histSize():", dist, dict.histSize()) - } - f.err = CorruptInputError(f.roffset) - return - } - - f.copyLen, f.copyDist = length, int(dist) - goto copyHistory - } - -copyHistory: - // Perform a backwards copy according to RFC section 3.2.3. - { - cnt := dict.tryWriteCopy(f.copyDist, f.copyLen) - if cnt == 0 { - cnt = dict.writeCopy(f.copyDist, f.copyLen) - } - f.copyLen -= cnt - - if dict.availWrite() == 0 || f.copyLen > 0 { - f.toRead = dict.readFlush() - f.step = huffmanGenericReader // We need to continue this work - f.stepState = stateDict - f.b, f.nb = fb, fnb - return - } - goto readLiteral - } - // Not reached -} - -func (f *decompressor) huffmanBlockDecoder() { - switch f.r.(type) { - case *bytes.Buffer: - f.huffmanBytesBuffer() - case *bytes.Reader: - f.huffmanBytesReader() - case *bufio.Reader: - f.huffmanBufioReader() - case *strings.Reader: - f.huffmanStringsReader() - case Reader: - f.huffmanGenericReader() - default: - f.huffmanGenericReader() - } -} diff --git a/vendor/github.com/klauspost/compress/flate/level1.go b/vendor/github.com/klauspost/compress/flate/level1.go deleted file mode 100644 index 703b9a89a..000000000 --- a/vendor/github.com/klauspost/compress/flate/level1.go +++ /dev/null @@ -1,241 +0,0 @@ -package flate - -import ( - "encoding/binary" - "fmt" - "math/bits" -) - -// fastGen maintains the table for matches, -// and the previous byte block for level 2. -// This is the generic implementation. -type fastEncL1 struct { - fastGen - table [tableSize]tableEntry -} - -// EncodeL1 uses a similar algorithm to level 1 -func (e *fastEncL1) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashBytes = 5 - ) - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - - for { - const skipLog = 5 - const doEvery = 2 - - nextS := s - var candidate tableEntry - for { - nextHash := hashLen(cv, tableBits, hashBytes) - candidate = e.table[nextHash] - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - - now := load6432(src, nextS) - e.table[nextHash] = tableEntry{offset: s + e.cur} - nextHash = hashLen(now, tableBits, hashBytes) - - offset := s - (candidate.offset - e.cur) - if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - e.table[nextHash] = tableEntry{offset: nextS + e.cur} - break - } - - // Do one right away... - cv = now - s = nextS - nextS++ - candidate = e.table[nextHash] - now >>= 8 - e.table[nextHash] = tableEntry{offset: s + e.cur} - - offset = s - (candidate.offset - e.cur) - if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - e.table[nextHash] = tableEntry{offset: nextS + e.cur} - break - } - cv = now - s = nextS - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - for { - // Invariant: we have a 4-byte match at s, and no need to emit any - // literal bytes prior to s. - - // Extend the 4-byte match as long as possible. - t := candidate.offset - e.cur - var l = int32(4) - if false { - l = e.matchlenLong(s+4, t+4, src) + 4 - } else { - // inlined: - a := src[s+4:] - b := src[t+4:] - for len(a) >= 8 { - if diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b); diff != 0 { - l += int32(bits.TrailingZeros64(diff) >> 3) - break - } - l += 8 - a = a[8:] - b = b[8:] - } - if len(a) < 8 { - b = b[:len(a)] - for i := range a { - if a[i] != b[i] { - break - } - l++ - } - } - } - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - - // Save the match found - if false { - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - } else { - // Inlined... - xoffset := uint32(s - t - baseMatchOffset) - xlength := l - oc := offsetCode(xoffset) - xoffset |= oc << 16 - for xlength > 0 { - xl := xlength - if xl > 258 { - if xl > 258+baseMatchLength { - xl = 258 - } else { - xl = 258 - baseMatchLength - } - } - xlength -= xl - xl -= baseMatchLength - dst.extraHist[lengthCodes1[uint8(xl)]]++ - dst.offHist[oc]++ - dst.tokens[dst.n] = token(matchType | uint32(xl)<<lengthShift | xoffset) - dst.n++ - } - } - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - if s >= sLimit { - // Index first pair after match end. - if int(s+l+8) < len(src) { - cv := load6432(src, s) - e.table[hashLen(cv, tableBits, hashBytes)] = tableEntry{offset: s + e.cur} - } - goto emitRemainder - } - - // We could immediately start working at s now, but to improve - // compression we first update the hash table at s-2 and at s. If - // another emitCopy is not our next move, also calculate nextHash - // at s+1. At least on GOARCH=amd64, these three hash calculations - // are faster as one load64 call (with some shifts) instead of - // three load32 calls. - x := load6432(src, s-2) - o := e.cur + s - 2 - prevHash := hashLen(x, tableBits, hashBytes) - e.table[prevHash] = tableEntry{offset: o} - x >>= 16 - currHash := hashLen(x, tableBits, hashBytes) - candidate = e.table[currHash] - e.table[currHash] = tableEntry{offset: o + 2} - - offset := s - (candidate.offset - e.cur) - if offset > maxMatchOffset || uint32(x) != load3232(src, candidate.offset-e.cur) { - cv = 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:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/level2.go b/vendor/github.com/klauspost/compress/flate/level2.go deleted file mode 100644 index 876dfbe30..000000000 --- a/vendor/github.com/klauspost/compress/flate/level2.go +++ /dev/null @@ -1,214 +0,0 @@ -package flate - -import "fmt" - -// fastGen maintains the table for matches, -// and the previous byte block for level 2. -// This is the generic implementation. -type fastEncL2 struct { - fastGen - table [bTableSize]tableEntry -} - -// EncodeL2 uses a similar algorithm to level 1, but is capable -// of matching across blocks giving better compression at a small slowdown. -func (e *fastEncL2) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashBytes = 5 - ) - - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(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 := hashLen(cv, bTableBits, hashBytes) - s = nextS - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - candidate = e.table[nextHash] - now := load6432(src, nextS) - e.table[nextHash] = tableEntry{offset: s + e.cur} - nextHash = hashLen(now, bTableBits, hashBytes) - - offset := s - (candidate.offset - e.cur) - if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - e.table[nextHash] = tableEntry{offset: nextS + e.cur} - break - } - - // Do one right away... - cv = now - s = nextS - nextS++ - candidate = e.table[nextHash] - now >>= 8 - e.table[nextHash] = tableEntry{offset: s + e.cur} - - offset = s - (candidate.offset - e.cur) - if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - 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. - - // Call emitCopy, and then see if another emitCopy could be our next - // move. Repeat until we find no match for the input immediately after - // what was consumed by the last emitCopy call. - // - // If we exit this loop normally then we need to call emitLiteral next, - // though we don't yet know how big the literal will be. We handle that - // by proceeding to the next iteration of the main loop. We also can - // exit this loop via goto if we get close to exhausting the input. - for { - // Invariant: we have a 4-byte match at s, and no need to emit any - // literal bytes prior to s. - - // Extend the 4-byte match as long as possible. - t := candidate.offset - e.cur - l := e.matchlenLong(s+4, t+4, src) + 4 - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - // Index first pair after match end. - if int(s+l+8) < len(src) { - cv := load6432(src, s) - e.table[hashLen(cv, bTableBits, hashBytes)] = tableEntry{offset: s + e.cur} - } - goto emitRemainder - } - - // Store every second hash in-between, but offset by 1. - for i := s - l + 2; i < s-5; i += 7 { - x := load6432(src, i) - nextHash := hashLen(x, bTableBits, hashBytes) - e.table[nextHash] = tableEntry{offset: e.cur + i} - // Skip one - x >>= 16 - nextHash = hashLen(x, bTableBits, hashBytes) - e.table[nextHash] = tableEntry{offset: e.cur + i + 2} - // Skip one - x >>= 16 - nextHash = hashLen(x, bTableBits, hashBytes) - e.table[nextHash] = tableEntry{offset: e.cur + i + 4} - } - - // We could immediately start working at s now, but to improve - // compression we first update the hash table at s-2 to s. If - // another emitCopy is not our next move, also calculate nextHash - // at s+1. At least on GOARCH=amd64, these three hash calculations - // are faster as one load64 call (with some shifts) instead of - // three load32 calls. - x := load6432(src, s-2) - o := e.cur + s - 2 - prevHash := hashLen(x, bTableBits, hashBytes) - prevHash2 := hashLen(x>>8, bTableBits, hashBytes) - e.table[prevHash] = tableEntry{offset: o} - e.table[prevHash2] = tableEntry{offset: o + 1} - currHash := hashLen(x>>16, bTableBits, hashBytes) - candidate = e.table[currHash] - e.table[currHash] = tableEntry{offset: o + 2} - - offset := s - (candidate.offset - e.cur) - if offset > maxMatchOffset || uint32(x>>16) != load3232(src, candidate.offset-e.cur) { - cv = 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:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/level3.go b/vendor/github.com/klauspost/compress/flate/level3.go deleted file mode 100644 index 7aa2b72a1..000000000 --- a/vendor/github.com/klauspost/compress/flate/level3.go +++ /dev/null @@ -1,241 +0,0 @@ -package flate - -import "fmt" - -// fastEncL3 -type fastEncL3 struct { - fastGen - table [1 << 16]tableEntryPrev -} - -// Encode uses a similar algorithm to level 2, will check up to two candidates. -func (e *fastEncL3) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - tableBits = 16 - tableSize = 1 << tableBits - hashBytes = 5 - ) - - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntryPrev{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i] - if v.Cur.offset <= minOff { - v.Cur.offset = 0 - } else { - v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset - } - if v.Prev.offset <= minOff { - v.Prev.offset = 0 - } else { - v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset - } - e.table[i] = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // Skip if too small. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - for { - const skipLog = 7 - nextS := s - var candidate tableEntry - for { - nextHash := hashLen(cv, tableBits, hashBytes) - s = nextS - nextS = s + 1 + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - candidates := e.table[nextHash] - now := load6432(src, nextS) - - // Safe offset distance until s + 4... - minOffset := e.cur + s - (maxMatchOffset - 4) - e.table[nextHash] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur}} - - // Check both candidates - candidate = candidates.Cur - if candidate.offset < minOffset { - cv = now - // Previous will also be invalid, we have nothing. - continue - } - - if uint32(cv) == load3232(src, candidate.offset-e.cur) { - if candidates.Prev.offset < minOffset || uint32(cv) != load3232(src, candidates.Prev.offset-e.cur) { - break - } - // Both match and are valid, pick longest. - offset := s - (candidate.offset - e.cur) - o2 := s - (candidates.Prev.offset - e.cur) - l1, l2 := matchLen(src[s+4:], src[s-offset+4:]), matchLen(src[s+4:], src[s-o2+4:]) - if l2 > l1 { - candidate = candidates.Prev - } - break - } else { - // We only check if value mismatches. - // Offset will always be invalid in other cases. - candidate = candidates.Prev - if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - break - } - } - cv = now - } - - // Call emitCopy, and then see if another emitCopy could be our next - // move. Repeat until we find no match for the input immediately after - // what was consumed by the last emitCopy call. - // - // If we exit this loop normally then we need to call emitLiteral next, - // though we don't yet know how big the literal will be. We handle that - // by proceeding to the next iteration of the main loop. We also can - // exit this loop via goto if we get close to exhausting the input. - for { - // Invariant: we have a 4-byte match at s, and no need to emit any - // literal bytes prior to s. - - // Extend the 4-byte match as long as possible. - // - t := candidate.offset - e.cur - l := e.matchlenLong(s+4, t+4, src) + 4 - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - t += l - // Index first pair after match end. - if int(t+8) < len(src) && t > 0 { - cv = load6432(src, t) - nextHash := hashLen(cv, tableBits, hashBytes) - e.table[nextHash] = tableEntryPrev{ - Prev: e.table[nextHash].Cur, - Cur: tableEntry{offset: e.cur + t}, - } - } - goto emitRemainder - } - - // Store every 5th hash in-between. - for i := s - l + 2; i < s-5; i += 6 { - nextHash := hashLen(load6432(src, i), tableBits, hashBytes) - e.table[nextHash] = tableEntryPrev{ - Prev: e.table[nextHash].Cur, - Cur: tableEntry{offset: e.cur + i}} - } - // We could immediately start working at s now, but to improve - // compression we first update the hash table at s-2 to s. - x := load6432(src, s-2) - prevHash := hashLen(x, tableBits, hashBytes) - - e.table[prevHash] = tableEntryPrev{ - Prev: e.table[prevHash].Cur, - Cur: tableEntry{offset: e.cur + s - 2}, - } - x >>= 8 - prevHash = hashLen(x, tableBits, hashBytes) - - e.table[prevHash] = tableEntryPrev{ - Prev: e.table[prevHash].Cur, - Cur: tableEntry{offset: e.cur + s - 1}, - } - x >>= 8 - currHash := hashLen(x, tableBits, hashBytes) - candidates := e.table[currHash] - cv = x - e.table[currHash] = tableEntryPrev{ - Prev: candidates.Cur, - Cur: tableEntry{offset: s + e.cur}, - } - - // Check both candidates - candidate = candidates.Cur - minOffset := e.cur + s - (maxMatchOffset - 4) - - if candidate.offset > minOffset { - if uint32(cv) == load3232(src, candidate.offset-e.cur) { - // Found a match... - continue - } - candidate = candidates.Prev - if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { - // Match at prev... - continue - } - } - cv = 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:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/level4.go b/vendor/github.com/klauspost/compress/flate/level4.go deleted file mode 100644 index 23c08b325..000000000 --- a/vendor/github.com/klauspost/compress/flate/level4.go +++ /dev/null @@ -1,221 +0,0 @@ -package flate - -import "fmt" - -type fastEncL4 struct { - fastGen - table [tableSize]tableEntry - bTable [tableSize]tableEntry -} - -func (e *fastEncL4) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashShortBytes = 4 - ) - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - for i := range e.bTable[:] { - e.bTable[i] = tableEntry{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - for i := range e.bTable[:] { - v := e.bTable[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.bTable[i].offset = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - for { - const skipLog = 6 - const doEvery = 1 - - nextS := s - var t int32 - for { - nextHashS := hashLen(cv, tableBits, hashShortBytes) - nextHashL := hash7(cv, tableBits) - - s = nextS - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - // Fetch a short+long candidate - sCandidate := e.table[nextHashS] - lCandidate := e.bTable[nextHashL] - next := load6432(src, nextS) - entry := tableEntry{offset: s + e.cur} - e.table[nextHashS] = entry - e.bTable[nextHashL] = entry - - t = lCandidate.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.offset-e.cur) { - // We got a long match. Use that. - break - } - - t = sCandidate.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) { - // Found a 4 match... - lCandidate = e.bTable[hash7(next, tableBits)] - - // If the next long is a candidate, check if we should use that instead... - lOff := nextS - (lCandidate.offset - e.cur) - if lOff < maxMatchOffset && load3232(src, lCandidate.offset-e.cur) == uint32(next) { - l1, l2 := matchLen(src[s+4:], src[t+4:]), matchLen(src[nextS+4:], src[nextS-lOff+4:]) - if l2 > l1 { - s = nextS - t = lCandidate.offset - e.cur - } - } - break - } - cv = next - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - - // Extend the 4-byte match as long as possible. - l := e.matchlenLong(s+4, t+4, src) + 4 - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - if debugDeflate { - if t >= s { - panic("s-t") - } - if (s - t) > maxMatchOffset { - panic(fmt.Sprintln("mmo", t)) - } - if l < baseMatchLength { - panic("bml") - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - // Index first pair after match end. - if int(s+8) < len(src) { - cv := load6432(src, s) - e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: s + e.cur} - e.bTable[hash7(cv, tableBits)] = tableEntry{offset: s + e.cur} - } - goto emitRemainder - } - - // Store every 3rd hash in-between - if true { - i := nextS - if i < s-1 { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - t2 := tableEntry{offset: t.offset + 1} - e.bTable[hash7(cv, tableBits)] = t - e.bTable[hash7(cv>>8, tableBits)] = t2 - e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2 - - i += 3 - for ; i < s-1; i += 3 { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - t2 := tableEntry{offset: t.offset + 1} - e.bTable[hash7(cv, tableBits)] = t - e.bTable[hash7(cv>>8, tableBits)] = t2 - e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = 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 := hashLen(x, tableBits, hashShortBytes) - prevHashL := hash7(x, tableBits) - e.table[prevHashS] = tableEntry{offset: o} - e.bTable[prevHashL] = tableEntry{offset: o} - cv = x >> 8 - } - -emitRemainder: - if int(nextEmit) < len(src) { - // If nothing was added, don't encode literals. - if dst.n == 0 { - return - } - - emitLiteral(dst, src[nextEmit:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/level5.go b/vendor/github.com/klauspost/compress/flate/level5.go deleted file mode 100644 index 1f61ec182..000000000 --- a/vendor/github.com/klauspost/compress/flate/level5.go +++ /dev/null @@ -1,708 +0,0 @@ -package flate - -import "fmt" - -type fastEncL5 struct { - fastGen - table [tableSize]tableEntry - bTable [tableSize]tableEntryPrev -} - -func (e *fastEncL5) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashShortBytes = 4 - ) - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - for i := range e.bTable[:] { - e.bTable[i] = tableEntryPrev{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - for i := range e.bTable[:] { - v := e.bTable[i] - if v.Cur.offset <= minOff { - v.Cur.offset = 0 - v.Prev.offset = 0 - } else { - v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset - if v.Prev.offset <= minOff { - v.Prev.offset = 0 - } else { - v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset - } - } - e.bTable[i] = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - for { - const skipLog = 6 - const doEvery = 1 - - nextS := s - var l int32 - var t int32 - for { - nextHashS := hashLen(cv, tableBits, hashShortBytes) - nextHashL := hash7(cv, tableBits) - - s = nextS - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - // Fetch a short+long candidate - sCandidate := e.table[nextHashS] - lCandidate := e.bTable[nextHashL] - next := load6432(src, nextS) - entry := tableEntry{offset: s + e.cur} - e.table[nextHashS] = entry - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = entry, eLong.Cur - - nextHashS = hashLen(next, tableBits, hashShortBytes) - nextHashL = hash7(next, tableBits) - - t = lCandidate.Cur.offset - e.cur - if s-t < maxMatchOffset { - if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) { - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - t2 := lCandidate.Prev.offset - e.cur - if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - l = e.matchlen(s+4, t+4, src) + 4 - ml1 := e.matchlen(s+4, t2+4, src) + 4 - if ml1 > l { - t = t2 - l = ml1 - break - } - } - break - } - t = lCandidate.Prev.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - break - } - } - - t = sCandidate.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) { - // Found a 4 match... - l = e.matchlen(s+4, t+4, src) + 4 - lCandidate = e.bTable[nextHashL] - // Store the next match - - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - // If the next long is a candidate, use that... - t2 := lCandidate.Cur.offset - e.cur - if nextS-t2 < maxMatchOffset { - if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - break - } - } - // If the previous long is a candidate, use that... - t2 = lCandidate.Prev.offset - e.cur - if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - break - } - } - } - break - } - cv = next - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - - if l == 0 { - // Extend the 4-byte match as long as possible. - l = e.matchlenLong(s+4, t+4, src) + 4 - } else if l == maxMatchLength { - l += e.matchlenLong(s+l, t+l, src) - } - - // Try to locate a better match by checking the end of best match... - if sAt := s + l; l < 30 && sAt < sLimit { - // Allow some bytes at the beginning to mismatch. - // Sweet spot is 2/3 bytes depending on input. - // 3 is only a little better when it is but sometimes a lot worse. - // The skipped bytes are tested in Extend backwards, - // and still picked up as part of the match if they do. - const skipBeginning = 2 - eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset - t2 := eLong - e.cur - l + skipBeginning - s2 := s + skipBeginning - off := s2 - t2 - if t2 >= 0 && off < maxMatchOffset && off > 0 { - if l2 := e.matchlenLong(s2, t2, src); l2 > l { - t = t2 - l = l2 - s = s2 - } - } - } - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - if debugDeflate { - if t >= s { - panic(fmt.Sprintln("s-t", s, t)) - } - if (s - t) > maxMatchOffset { - panic(fmt.Sprintln("mmo", s-t)) - } - if l < baseMatchLength { - panic("bml") - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - goto emitRemainder - } - - // Store every 3rd hash in-between. - if true { - const hashEvery = 3 - i := s - l + 1 - if i < s-1 { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - e.table[hashLen(cv, tableBits, hashShortBytes)] = t - eLong := &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - - // Do an long at i+1 - cv >>= 8 - t = tableEntry{offset: t.offset + 1} - eLong = &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - - // We only have enough bits for a short entry at i+2 - cv >>= 8 - t = tableEntry{offset: t.offset + 1} - e.table[hashLen(cv, tableBits, hashShortBytes)] = t - - // Skip one - otherwise we risk hitting 's' - i += 4 - for ; i < s-1; i += hashEvery { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - t2 := tableEntry{offset: t.offset + 1} - eLong := &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = 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 := hashLen(x, tableBits, hashShortBytes) - prevHashL := hash7(x, tableBits) - e.table[prevHashS] = tableEntry{offset: o} - eLong := &e.bTable[prevHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur - cv = x >> 8 - } - -emitRemainder: - if int(nextEmit) < len(src) { - // If nothing was added, don't encode literals. - if dst.n == 0 { - return - } - - emitLiteral(dst, src[nextEmit:]) - } -} - -// fastEncL5Window is a level 5 encoder, -// but with a custom window size. -type fastEncL5Window struct { - hist []byte - cur int32 - maxOffset int32 - table [tableSize]tableEntry - bTable [tableSize]tableEntryPrev -} - -func (e *fastEncL5Window) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashShortBytes = 4 - ) - maxMatchOffset := e.maxOffset - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - for i := range e.bTable[:] { - e.bTable[i] = tableEntryPrev{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - for i := range e.bTable[:] { - v := e.bTable[i] - if v.Cur.offset <= minOff { - v.Cur.offset = 0 - v.Prev.offset = 0 - } else { - v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset - if v.Prev.offset <= minOff { - v.Prev.offset = 0 - } else { - v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset - } - } - e.bTable[i] = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - for { - const skipLog = 6 - const doEvery = 1 - - nextS := s - var l int32 - var t int32 - for { - nextHashS := hashLen(cv, tableBits, hashShortBytes) - nextHashL := hash7(cv, tableBits) - - s = nextS - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - // Fetch a short+long candidate - sCandidate := e.table[nextHashS] - lCandidate := e.bTable[nextHashL] - next := load6432(src, nextS) - entry := tableEntry{offset: s + e.cur} - e.table[nextHashS] = entry - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = entry, eLong.Cur - - nextHashS = hashLen(next, tableBits, hashShortBytes) - nextHashL = hash7(next, tableBits) - - t = lCandidate.Cur.offset - e.cur - if s-t < maxMatchOffset { - if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) { - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - t2 := lCandidate.Prev.offset - e.cur - if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - l = e.matchlen(s+4, t+4, src) + 4 - ml1 := e.matchlen(s+4, t2+4, src) + 4 - if ml1 > l { - t = t2 - l = ml1 - break - } - } - break - } - t = lCandidate.Prev.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - break - } - } - - t = sCandidate.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) { - // Found a 4 match... - l = e.matchlen(s+4, t+4, src) + 4 - lCandidate = e.bTable[nextHashL] - // Store the next match - - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - // If the next long is a candidate, use that... - t2 := lCandidate.Cur.offset - e.cur - if nextS-t2 < maxMatchOffset { - if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - break - } - } - // If the previous long is a candidate, use that... - t2 = lCandidate.Prev.offset - e.cur - if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - break - } - } - } - break - } - cv = next - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - - if l == 0 { - // Extend the 4-byte match as long as possible. - l = e.matchlenLong(s+4, t+4, src) + 4 - } else if l == maxMatchLength { - l += e.matchlenLong(s+l, t+l, src) - } - - // Try to locate a better match by checking the end of best match... - if sAt := s + l; l < 30 && sAt < sLimit { - // Allow some bytes at the beginning to mismatch. - // Sweet spot is 2/3 bytes depending on input. - // 3 is only a little better when it is but sometimes a lot worse. - // The skipped bytes are tested in Extend backwards, - // and still picked up as part of the match if they do. - const skipBeginning = 2 - eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset - t2 := eLong - e.cur - l + skipBeginning - s2 := s + skipBeginning - off := s2 - t2 - if t2 >= 0 && off < maxMatchOffset && off > 0 { - if l2 := e.matchlenLong(s2, t2, src); l2 > l { - t = t2 - l = l2 - s = s2 - } - } - } - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - if debugDeflate { - if t >= s { - panic(fmt.Sprintln("s-t", s, t)) - } - if (s - t) > maxMatchOffset { - panic(fmt.Sprintln("mmo", s-t)) - } - if l < baseMatchLength { - panic("bml") - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - goto emitRemainder - } - - // Store every 3rd hash in-between. - if true { - const hashEvery = 3 - i := s - l + 1 - if i < s-1 { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - e.table[hashLen(cv, tableBits, hashShortBytes)] = t - eLong := &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - - // Do an long at i+1 - cv >>= 8 - t = tableEntry{offset: t.offset + 1} - eLong = &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - - // We only have enough bits for a short entry at i+2 - cv >>= 8 - t = tableEntry{offset: t.offset + 1} - e.table[hashLen(cv, tableBits, hashShortBytes)] = t - - // Skip one - otherwise we risk hitting 's' - i += 4 - for ; i < s-1; i += hashEvery { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - t2 := tableEntry{offset: t.offset + 1} - eLong := &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = t, eLong.Cur - e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = 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 := hashLen(x, tableBits, hashShortBytes) - prevHashL := hash7(x, tableBits) - e.table[prevHashS] = tableEntry{offset: o} - eLong := &e.bTable[prevHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur - cv = x >> 8 - } - -emitRemainder: - if int(nextEmit) < len(src) { - // If nothing was added, don't encode literals. - if dst.n == 0 { - return - } - - emitLiteral(dst, src[nextEmit:]) - } -} - -// Reset the encoding table. -func (e *fastEncL5Window) Reset() { - // We keep the same allocs, since we are compressing the same block sizes. - if cap(e.hist) < allocHistory { - e.hist = make([]byte, 0, allocHistory) - } - - // We offset current position so everything will be out of reach. - // If we are above the buffer reset it will be cleared anyway since len(hist) == 0. - if e.cur <= int32(bufferReset) { - e.cur += e.maxOffset + int32(len(e.hist)) - } - e.hist = e.hist[:0] -} - -func (e *fastEncL5Window) addBlock(src []byte) int32 { - // check if we have space already - maxMatchOffset := e.maxOffset - - 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) < int(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 -} - -// 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 *fastEncL5Window) 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 > e.maxOffset { - 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 *fastEncL5Window) matchlenLong(s, t int32, src []byte) int32 { - if debugDeflate { - if t >= s { - panic(fmt.Sprint("t >=s:", t, s)) - } - if int(s) >= len(src) { - panic(fmt.Sprint("s >= len(src):", s, len(src))) - } - if t < 0 { - panic(fmt.Sprint("t < 0:", t)) - } - if s-t > e.maxOffset { - 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:])) -} diff --git a/vendor/github.com/klauspost/compress/flate/level6.go b/vendor/github.com/klauspost/compress/flate/level6.go deleted file mode 100644 index f1e9d98fa..000000000 --- a/vendor/github.com/klauspost/compress/flate/level6.go +++ /dev/null @@ -1,325 +0,0 @@ -package flate - -import "fmt" - -type fastEncL6 struct { - fastGen - table [tableSize]tableEntry - bTable [tableSize]tableEntryPrev -} - -func (e *fastEncL6) Encode(dst *tokens, src []byte) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - hashShortBytes = 4 - ) - if debugDeflate && e.cur < 0 { - panic(fmt.Sprint("e.cur < 0: ", e.cur)) - } - - // Protect against e.cur wraparound. - for e.cur >= bufferReset { - if len(e.hist) == 0 { - for i := range e.table[:] { - e.table[i] = tableEntry{} - } - for i := range e.bTable[:] { - e.bTable[i] = tableEntryPrev{} - } - e.cur = maxMatchOffset - break - } - // Shift down everything in the table that isn't already too far away. - minOff := e.cur + int32(len(e.hist)) - maxMatchOffset - for i := range e.table[:] { - v := e.table[i].offset - if v <= minOff { - v = 0 - } else { - v = v - e.cur + maxMatchOffset - } - e.table[i].offset = v - } - for i := range e.bTable[:] { - v := e.bTable[i] - if v.Cur.offset <= minOff { - v.Cur.offset = 0 - v.Prev.offset = 0 - } else { - v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset - if v.Prev.offset <= minOff { - v.Prev.offset = 0 - } else { - v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset - } - } - e.bTable[i] = v - } - e.cur = maxMatchOffset - } - - s := e.addBlock(src) - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = uint16(len(src)) - return - } - - // Override src - src = e.hist - nextEmit := s - - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int32(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load6432(src, s) - // Repeat MUST be > 1 and within range - repeat := int32(1) - for { - const skipLog = 7 - const doEvery = 1 - - nextS := s - var l int32 - var t int32 - for { - nextHashS := hashLen(cv, tableBits, hashShortBytes) - nextHashL := hash7(cv, tableBits) - s = nextS - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit { - goto emitRemainder - } - // Fetch a short+long candidate - sCandidate := e.table[nextHashS] - lCandidate := e.bTable[nextHashL] - next := load6432(src, nextS) - entry := tableEntry{offset: s + e.cur} - e.table[nextHashS] = entry - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = entry, eLong.Cur - - // Calculate hashes of 'next' - nextHashS = hashLen(next, tableBits, hashShortBytes) - nextHashL = hash7(next, tableBits) - - t = lCandidate.Cur.offset - e.cur - if s-t < maxMatchOffset { - if uint32(cv) == load3232(src, lCandidate.Cur.offset-e.cur) { - // Long candidate matches at least 4 bytes. - - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - // Check the previous long candidate as well. - t2 := lCandidate.Prev.offset - e.cur - if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - l = e.matchlen(s+4, t+4, src) + 4 - ml1 := e.matchlen(s+4, t2+4, src) + 4 - if ml1 > l { - t = t2 - l = ml1 - break - } - } - break - } - // Current value did not match, but check if previous long value does. - t = lCandidate.Prev.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, lCandidate.Prev.offset-e.cur) { - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - break - } - } - - t = sCandidate.offset - e.cur - if s-t < maxMatchOffset && uint32(cv) == load3232(src, sCandidate.offset-e.cur) { - // Found a 4 match... - l = e.matchlen(s+4, t+4, src) + 4 - - // Look up next long candidate (at nextS) - lCandidate = e.bTable[nextHashL] - - // Store the next match - e.table[nextHashS] = tableEntry{offset: nextS + e.cur} - eLong := &e.bTable[nextHashL] - eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur - - // Check repeat at s + repOff - const repOff = 1 - t2 := s - repeat + repOff - if load3232(src, t2) == uint32(cv>>(8*repOff)) { - ml := e.matchlen(s+4+repOff, t2+4, src) + 4 - if ml > l { - t = t2 - l = ml - s += repOff - // Not worth checking more. - break - } - } - - // If the next long is a candidate, use that... - t2 = lCandidate.Cur.offset - e.cur - if nextS-t2 < maxMatchOffset { - if load3232(src, lCandidate.Cur.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - // This is ok, but check previous as well. - } - } - // If the previous long is a candidate, use that... - t2 = lCandidate.Prev.offset - e.cur - if nextS-t2 < maxMatchOffset && load3232(src, lCandidate.Prev.offset-e.cur) == uint32(next) { - ml := e.matchlen(nextS+4, t2+4, src) + 4 - if ml > l { - t = t2 - s = nextS - l = ml - break - } - } - } - break - } - cv = next - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - - // Extend the 4-byte match as long as possible. - if l == 0 { - l = e.matchlenLong(s+4, t+4, src) + 4 - } else if l == maxMatchLength { - l += e.matchlenLong(s+l, t+l, src) - } - - // Try to locate a better match by checking the end-of-match... - if sAt := s + l; sAt < sLimit { - // Allow some bytes at the beginning to mismatch. - // Sweet spot is 2/3 bytes depending on input. - // 3 is only a little better when it is but sometimes a lot worse. - // The skipped bytes are tested in Extend backwards, - // and still picked up as part of the match if they do. - const skipBeginning = 2 - eLong := &e.bTable[hash7(load6432(src, sAt), tableBits)] - // Test current - t2 := eLong.Cur.offset - e.cur - l + skipBeginning - s2 := s + skipBeginning - off := s2 - t2 - if off < maxMatchOffset { - if off > 0 && t2 >= 0 { - if l2 := e.matchlenLong(s2, t2, src); l2 > l { - t = t2 - l = l2 - s = s2 - } - } - // Test next: - t2 = eLong.Prev.offset - e.cur - l + skipBeginning - off := s2 - t2 - if off > 0 && off < maxMatchOffset && t2 >= 0 { - if l2 := e.matchlenLong(s2, t2, src); l2 > l { - t = t2 - l = l2 - s = s2 - } - } - } - } - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - if false { - if t >= s { - panic(fmt.Sprintln("s-t", s, t)) - } - if (s - t) > maxMatchOffset { - panic(fmt.Sprintln("mmo", s-t)) - } - if l < baseMatchLength { - panic("bml") - } - } - - dst.AddMatchLong(l, uint32(s-t-baseMatchOffset)) - repeat = s - t - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - - if s >= sLimit { - // Index after match end. - for i := nextS + 1; i < int32(len(src))-8; i += 2 { - cv := load6432(src, i) - e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: i + e.cur} - eLong := &e.bTable[hash7(cv, tableBits)] - eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur}, eLong.Cur - } - goto emitRemainder - } - - // Store every long hash in-between and every second short. - if true { - for i := nextS + 1; i < s-1; i += 2 { - cv := load6432(src, i) - t := tableEntry{offset: i + e.cur} - t2 := tableEntry{offset: t.offset + 1} - eLong := &e.bTable[hash7(cv, tableBits)] - eLong2 := &e.bTable[hash7(cv>>8, tableBits)] - e.table[hashLen(cv, tableBits, hashShortBytes)] = 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:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/matchlen_amd64.go b/vendor/github.com/klauspost/compress/flate/matchlen_amd64.go deleted file mode 100644 index 4bd388584..000000000 --- a/vendor/github.com/klauspost/compress/flate/matchlen_amd64.go +++ /dev/null @@ -1,16 +0,0 @@ -//go:build amd64 && !appengine && !noasm && gc -// +build amd64,!appengine,!noasm,gc - -// Copyright 2019+ Klaus Post. All rights reserved. -// License information can be found in the LICENSE file. - -package flate - -// matchLen returns how many bytes match in a and b -// -// It assumes that: -// -// len(a) <= len(b) and len(a) > 0 -// -//go:noescape -func matchLen(a []byte, b []byte) int diff --git a/vendor/github.com/klauspost/compress/flate/matchlen_amd64.s b/vendor/github.com/klauspost/compress/flate/matchlen_amd64.s deleted file mode 100644 index 9a7655c0f..000000000 --- a/vendor/github.com/klauspost/compress/flate/matchlen_amd64.s +++ /dev/null @@ -1,68 +0,0 @@ -// Copied from S2 implementation. - -//go:build !appengine && !noasm && gc && !noasm - -#include "textflag.h" - -// func matchLen(a []byte, b []byte) int -// Requires: BMI -TEXT ·matchLen(SB), NOSPLIT, $0-56 - MOVQ a_base+0(FP), AX - MOVQ b_base+24(FP), CX - MOVQ a_len+8(FP), DX - - // matchLen - XORL SI, SI - CMPL DX, $0x08 - JB matchlen_match4_standalone - -matchlen_loopback_standalone: - MOVQ (AX)(SI*1), BX - XORQ (CX)(SI*1), BX - TESTQ BX, BX - JZ matchlen_loop_standalone - -#ifdef GOAMD64_v3 - TZCNTQ BX, BX -#else - BSFQ BX, BX -#endif - SARQ $0x03, BX - LEAL (SI)(BX*1), SI - JMP gen_match_len_end - -matchlen_loop_standalone: - LEAL -8(DX), DX - LEAL 8(SI), SI - CMPL DX, $0x08 - JAE matchlen_loopback_standalone - -matchlen_match4_standalone: - CMPL DX, $0x04 - JB matchlen_match2_standalone - MOVL (AX)(SI*1), BX - CMPL (CX)(SI*1), BX - JNE matchlen_match2_standalone - LEAL -4(DX), DX - LEAL 4(SI), SI - -matchlen_match2_standalone: - CMPL DX, $0x02 - JB matchlen_match1_standalone - MOVW (AX)(SI*1), BX - CMPW (CX)(SI*1), BX - JNE matchlen_match1_standalone - LEAL -2(DX), DX - LEAL 2(SI), SI - -matchlen_match1_standalone: - CMPL DX, $0x01 - JB gen_match_len_end - MOVB (AX)(SI*1), BL - CMPB (CX)(SI*1), BL - JNE gen_match_len_end - INCL SI - -gen_match_len_end: - MOVQ SI, ret+48(FP) - RET diff --git a/vendor/github.com/klauspost/compress/flate/matchlen_generic.go b/vendor/github.com/klauspost/compress/flate/matchlen_generic.go deleted file mode 100644 index ad5cd814b..000000000 --- a/vendor/github.com/klauspost/compress/flate/matchlen_generic.go +++ /dev/null @@ -1,33 +0,0 @@ -//go:build !amd64 || appengine || !gc || noasm -// +build !amd64 appengine !gc noasm - -// Copyright 2019+ Klaus Post. All rights reserved. -// License information can be found in the LICENSE file. - -package flate - -import ( - "encoding/binary" - "math/bits" -) - -// matchLen returns the maximum common prefix length of a and b. -// a must be the shortest of the two. -func matchLen(a, b []byte) (n int) { - for ; len(a) >= 8 && len(b) >= 8; a, b = a[8:], b[8:] { - diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b) - if diff != 0 { - return n + bits.TrailingZeros64(diff)>>3 - } - n += 8 - } - - for i := range a { - if a[i] != b[i] { - break - } - n++ - } - return n - -} diff --git a/vendor/github.com/klauspost/compress/flate/regmask_amd64.go b/vendor/github.com/klauspost/compress/flate/regmask_amd64.go deleted file mode 100644 index 6ed28061b..000000000 --- a/vendor/github.com/klauspost/compress/flate/regmask_amd64.go +++ /dev/null @@ -1,37 +0,0 @@ -package flate - -const ( - // Masks for shifts with register sizes of the shift value. - // This can be used to work around the x86 design of shifting by mod register size. - // It can be used when a variable shift is always smaller than the register size. - - // reg8SizeMaskX - shift value is 8 bits, shifted is X - reg8SizeMask8 = 7 - reg8SizeMask16 = 15 - reg8SizeMask32 = 31 - reg8SizeMask64 = 63 - - // reg16SizeMaskX - shift value is 16 bits, shifted is X - reg16SizeMask8 = reg8SizeMask8 - reg16SizeMask16 = reg8SizeMask16 - reg16SizeMask32 = reg8SizeMask32 - reg16SizeMask64 = reg8SizeMask64 - - // reg32SizeMaskX - shift value is 32 bits, shifted is X - reg32SizeMask8 = reg8SizeMask8 - reg32SizeMask16 = reg8SizeMask16 - reg32SizeMask32 = reg8SizeMask32 - reg32SizeMask64 = reg8SizeMask64 - - // reg64SizeMaskX - shift value is 64 bits, shifted is X - reg64SizeMask8 = reg8SizeMask8 - reg64SizeMask16 = reg8SizeMask16 - reg64SizeMask32 = reg8SizeMask32 - reg64SizeMask64 = reg8SizeMask64 - - // regSizeMaskUintX - shift value is uint, shifted is X - regSizeMaskUint8 = reg8SizeMask8 - regSizeMaskUint16 = reg8SizeMask16 - regSizeMaskUint32 = reg8SizeMask32 - regSizeMaskUint64 = reg8SizeMask64 -) diff --git a/vendor/github.com/klauspost/compress/flate/regmask_other.go b/vendor/github.com/klauspost/compress/flate/regmask_other.go deleted file mode 100644 index 1b7a2cbd7..000000000 --- a/vendor/github.com/klauspost/compress/flate/regmask_other.go +++ /dev/null @@ -1,40 +0,0 @@ -//go:build !amd64 -// +build !amd64 - -package flate - -const ( - // Masks for shifts with register sizes of the shift value. - // This can be used to work around the x86 design of shifting by mod register size. - // It can be used when a variable shift is always smaller than the register size. - - // reg8SizeMaskX - shift value is 8 bits, shifted is X - reg8SizeMask8 = 0xff - reg8SizeMask16 = 0xff - reg8SizeMask32 = 0xff - reg8SizeMask64 = 0xff - - // reg16SizeMaskX - shift value is 16 bits, shifted is X - reg16SizeMask8 = 0xffff - reg16SizeMask16 = 0xffff - reg16SizeMask32 = 0xffff - reg16SizeMask64 = 0xffff - - // reg32SizeMaskX - shift value is 32 bits, shifted is X - reg32SizeMask8 = 0xffffffff - reg32SizeMask16 = 0xffffffff - reg32SizeMask32 = 0xffffffff - reg32SizeMask64 = 0xffffffff - - // reg64SizeMaskX - shift value is 64 bits, shifted is X - reg64SizeMask8 = 0xffffffffffffffff - reg64SizeMask16 = 0xffffffffffffffff - reg64SizeMask32 = 0xffffffffffffffff - reg64SizeMask64 = 0xffffffffffffffff - - // regSizeMaskUintX - shift value is uint, shifted is X - regSizeMaskUint8 = ^uint(0) - regSizeMaskUint16 = ^uint(0) - regSizeMaskUint32 = ^uint(0) - regSizeMaskUint64 = ^uint(0) -) diff --git a/vendor/github.com/klauspost/compress/flate/stateless.go b/vendor/github.com/klauspost/compress/flate/stateless.go deleted file mode 100644 index f3d4139ef..000000000 --- a/vendor/github.com/klauspost/compress/flate/stateless.go +++ /dev/null @@ -1,318 +0,0 @@ -package flate - -import ( - "io" - "math" - "sync" -) - -const ( - maxStatelessBlock = math.MaxInt16 - // dictionary will be taken from maxStatelessBlock, so limit it. - maxStatelessDict = 8 << 10 - - slTableBits = 13 - slTableSize = 1 << slTableBits - slTableShift = 32 - slTableBits -) - -type statelessWriter struct { - dst io.Writer - closed bool -} - -func (s *statelessWriter) Close() error { - if s.closed { - return nil - } - s.closed = true - // Emit EOF block - return StatelessDeflate(s.dst, nil, true, nil) -} - -func (s *statelessWriter) Write(p []byte) (n int, err error) { - err = StatelessDeflate(s.dst, p, false, nil) - if err != nil { - return 0, err - } - return len(p), nil -} - -func (s *statelessWriter) Reset(w io.Writer) { - s.dst = w - s.closed = false -} - -// NewStatelessWriter will do compression but without maintaining any state -// between Write calls. -// There will be no memory kept between Write calls, -// but compression and speed will be suboptimal. -// Because of this, the size of actual Write calls will affect output size. -func NewStatelessWriter(dst io.Writer) io.WriteCloser { - return &statelessWriter{dst: dst} -} - -// bitWriterPool contains bit writers that can be reused. -var bitWriterPool = sync.Pool{ - New: func() interface{} { - return newHuffmanBitWriter(nil) - }, -} - -// StatelessDeflate allows compressing directly to a Writer without retaining state. -// When returning everything will be flushed. -// Up to 8KB of an optional dictionary can be given which is presumed to precede the block. -// Longer dictionaries will be truncated and will still produce valid output. -// Sending nil dictionary is perfectly fine. -func StatelessDeflate(out io.Writer, in []byte, eof bool, dict []byte) error { - var dst tokens - bw := bitWriterPool.Get().(*huffmanBitWriter) - bw.reset(out) - defer func() { - // don't keep a reference to our output - bw.reset(nil) - bitWriterPool.Put(bw) - }() - if eof && len(in) == 0 { - // Just write an EOF block. - // Could be faster... - bw.writeStoredHeader(0, true) - bw.flush() - return bw.err - } - - // Truncate dict - if len(dict) > maxStatelessDict { - dict = dict[len(dict)-maxStatelessDict:] - } - - // For subsequent loops, keep shallow dict reference to avoid alloc+copy. - var inDict []byte - - for len(in) > 0 { - todo := in - if len(inDict) > 0 { - if len(todo) > maxStatelessBlock-maxStatelessDict { - todo = todo[:maxStatelessBlock-maxStatelessDict] - } - } else if len(todo) > maxStatelessBlock-len(dict) { - todo = todo[:maxStatelessBlock-len(dict)] - } - inOrg := in - in = in[len(todo):] - uncompressed := todo - if len(dict) > 0 { - // combine dict and source - bufLen := len(todo) + len(dict) - combined := make([]byte, bufLen) - copy(combined, dict) - copy(combined[len(dict):], todo) - todo = combined - } - // Compress - if len(inDict) == 0 { - statelessEnc(&dst, todo, int16(len(dict))) - } else { - statelessEnc(&dst, inDict[:maxStatelessDict+len(todo)], maxStatelessDict) - } - isEof := eof && len(in) == 0 - - if dst.n == 0 { - bw.writeStoredHeader(len(uncompressed), isEof) - if bw.err != nil { - return bw.err - } - bw.writeBytes(uncompressed) - } else if int(dst.n) > len(uncompressed)-len(uncompressed)>>4 { - // If we removed less than 1/16th, huffman compress the block. - bw.writeBlockHuff(isEof, uncompressed, len(in) == 0) - } else { - bw.writeBlockDynamic(&dst, isEof, uncompressed, len(in) == 0) - } - if len(in) > 0 { - // Retain a dict if we have more - inDict = inOrg[len(uncompressed)-maxStatelessDict:] - dict = nil - dst.Reset() - } - if bw.err != nil { - return bw.err - } - } - if !eof { - // Align, only a stored block can do that. - bw.writeStoredHeader(0, false) - } - bw.flush() - return bw.err -} - -func hashSL(u uint32) uint32 { - return (u * 0x1e35a7bd) >> slTableShift -} - -func load3216(b []byte, i int16) uint32 { - // Help the compiler eliminate bounds checks on the read so it can be done in a single read. - b = b[i:] - b = b[:4] - return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 -} - -func load6416(b []byte, i int16) uint64 { - // Help the compiler eliminate bounds checks on the read so it can be done in a single read. - b = b[i:] - b = b[:8] - return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | - uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 -} - -func statelessEnc(dst *tokens, src []byte, startAt int16) { - const ( - inputMargin = 12 - 1 - minNonLiteralBlockSize = 1 + 1 + inputMargin - ) - - type tableEntry struct { - offset int16 - } - - var table [slTableSize]tableEntry - - // This check isn't in the Snappy implementation, but there, the caller - // instead of the callee handles this case. - if len(src)-int(startAt) < minNonLiteralBlockSize { - // We do not fill the token table. - // This will be picked up by caller. - dst.n = 0 - return - } - // Index until startAt - if startAt > 0 { - cv := load3232(src, 0) - for i := int16(0); i < startAt; i++ { - table[hashSL(cv)] = tableEntry{offset: i} - cv = (cv >> 8) | (uint32(src[i+4]) << 24) - } - } - - s := startAt + 1 - nextEmit := startAt - // sLimit is when to stop looking for offset/length copies. The inputMargin - // lets us use a fast path for emitLiteral in the main loop, while we are - // looking for copies. - sLimit := int16(len(src) - inputMargin) - - // nextEmit is where in src the next emitLiteral should start from. - cv := load3216(src, s) - - for { - const skipLog = 5 - const doEvery = 2 - - nextS := s - var candidate tableEntry - for { - nextHash := hashSL(cv) - candidate = table[nextHash] - nextS = s + doEvery + (s-nextEmit)>>skipLog - if nextS > sLimit || nextS <= 0 { - goto emitRemainder - } - - now := load6416(src, nextS) - table[nextHash] = tableEntry{offset: s} - nextHash = hashSL(uint32(now)) - - if cv == load3216(src, candidate.offset) { - table[nextHash] = tableEntry{offset: nextS} - break - } - - // Do one right away... - cv = uint32(now) - s = nextS - nextS++ - candidate = table[nextHash] - now >>= 8 - table[nextHash] = tableEntry{offset: s} - - if cv == load3216(src, candidate.offset) { - table[nextHash] = tableEntry{offset: nextS} - break - } - cv = uint32(now) - s = nextS - } - - // A 4-byte match has been found. We'll later see if more than 4 bytes - // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit - // them as literal bytes. - for { - // Invariant: we have a 4-byte match at s, and no need to emit any - // literal bytes prior to s. - - // Extend the 4-byte match as long as possible. - t := candidate.offset - l := int16(matchLen(src[s+4:], src[t+4:]) + 4) - - // Extend backwards - for t > 0 && s > nextEmit && src[t-1] == src[s-1] { - s-- - t-- - l++ - } - if nextEmit < s { - if false { - emitLiteral(dst, src[nextEmit:s]) - } else { - for _, v := range src[nextEmit:s] { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } - } - } - - // Save the match found - dst.AddMatchLong(int32(l), uint32(s-t-baseMatchOffset)) - s += l - nextEmit = s - if nextS >= s { - s = nextS + 1 - } - if s >= sLimit { - goto emitRemainder - } - - // We could immediately start working at s now, but to improve - // compression we first update the hash table at s-2 and at s. If - // another emitCopy is not our next move, also calculate nextHash - // at s+1. At least on GOARCH=amd64, these three hash calculations - // are faster as one load64 call (with some shifts) instead of - // three load32 calls. - x := load6416(src, s-2) - o := s - 2 - prevHash := hashSL(uint32(x)) - table[prevHash] = tableEntry{offset: o} - x >>= 16 - currHash := hashSL(uint32(x)) - candidate = table[currHash] - table[currHash] = tableEntry{offset: o + 2} - - if uint32(x) != load3216(src, candidate.offset) { - cv = uint32(x >> 8) - s++ - break - } - } - } - -emitRemainder: - if int(nextEmit) < len(src) { - // If nothing was added, don't encode literals. - if dst.n == 0 { - return - } - emitLiteral(dst, src[nextEmit:]) - } -} diff --git a/vendor/github.com/klauspost/compress/flate/token.go b/vendor/github.com/klauspost/compress/flate/token.go deleted file mode 100644 index d818790c1..000000000 --- a/vendor/github.com/klauspost/compress/flate/token.go +++ /dev/null @@ -1,379 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package flate - -import ( - "bytes" - "encoding/binary" - "fmt" - "io" - "math" -) - -const ( - // bits 0-16 xoffset = offset - MIN_OFFSET_SIZE, or literal - 16 bits - // bits 16-22 offsetcode - 5 bits - // bits 22-30 xlength = length - MIN_MATCH_LENGTH - 8 bits - // bits 30-32 type 0 = literal 1=EOF 2=Match 3=Unused - 2 bits - lengthShift = 22 - offsetMask = 1<<lengthShift - 1 - typeMask = 3 << 30 - literalType = 0 << 30 - matchType = 1 << 30 - matchOffsetOnlyMask = 0xffff -) - -// The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH) -// is lengthCodes[length - MIN_MATCH_LENGTH] -var lengthCodes = [256]uint8{ - 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, - 9, 9, 10, 10, 11, 11, 12, 12, 12, 12, - 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, - 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, - 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, - 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, - 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, - 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, - 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, - 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, - 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, - 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, - 23, 23, 23, 23, 23, 23, 23, 23, 24, 24, - 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, - 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, - 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 25, 25, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 28, -} - -// lengthCodes1 is length codes, but starting at 1. -var lengthCodes1 = [256]uint8{ - 1, 2, 3, 4, 5, 6, 7, 8, 9, 9, - 10, 10, 11, 11, 12, 12, 13, 13, 13, 13, - 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, - 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, - 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, - 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, - 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, - 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, - 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, - 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, - 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, - 23, 23, 24, 24, 24, 24, 24, 24, 24, 24, - 24, 24, 24, 24, 24, 24, 24, 24, 25, 25, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 29, -} - -var offsetCodes = [256]uint32{ - 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, - 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, - 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, - 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, - 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, - 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, - 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, - 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, - 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, - 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, - 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, - 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, - 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, - 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, - 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, - 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, -} - -// offsetCodes14 are offsetCodes, but with 14 added. -var offsetCodes14 = [256]uint32{ - 14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, - 22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, - 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, - 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, - 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, - 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, - 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, - 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, -} - -type token uint32 - -type tokens struct { - extraHist [32]uint16 // codes 256->maxnumlit - offHist [32]uint16 // offset codes - litHist [256]uint16 // codes 0->255 - nFilled int - n uint16 // Must be able to contain maxStoreBlockSize - tokens [maxStoreBlockSize + 1]token -} - -func (t *tokens) Reset() { - if t.n == 0 { - return - } - t.n = 0 - t.nFilled = 0 - for i := range t.litHist[:] { - t.litHist[i] = 0 - } - for i := range t.extraHist[:] { - t.extraHist[i] = 0 - } - for i := range t.offHist[:] { - t.offHist[i] = 0 - } -} - -func (t *tokens) Fill() { - if t.n == 0 { - return - } - for i, v := range t.litHist[:] { - if v == 0 { - t.litHist[i] = 1 - t.nFilled++ - } - } - for i, v := range t.extraHist[:literalCount-256] { - if v == 0 { - t.nFilled++ - t.extraHist[i] = 1 - } - } - for i, v := range t.offHist[:offsetCodeCount] { - if v == 0 { - t.offHist[i] = 1 - } - } -} - -func indexTokens(in []token) tokens { - var t tokens - t.indexTokens(in) - return t -} - -func (t *tokens) indexTokens(in []token) { - t.Reset() - for _, tok := range in { - if tok < matchType { - t.AddLiteral(tok.literal()) - continue - } - t.AddMatch(uint32(tok.length()), tok.offset()&matchOffsetOnlyMask) - } -} - -// emitLiteral writes a literal chunk and returns the number of bytes written. -func emitLiteral(dst *tokens, lit []byte) { - for _, v := range lit { - dst.tokens[dst.n] = token(v) - dst.litHist[v]++ - dst.n++ - } -} - -func (t *tokens) AddLiteral(lit byte) { - t.tokens[t.n] = token(lit) - t.litHist[lit]++ - t.n++ -} - -// from https://stackoverflow.com/a/28730362 -func mFastLog2(val float32) float32 { - ux := int32(math.Float32bits(val)) - log2 := (float32)(((ux >> 23) & 255) - 128) - ux &= -0x7f800001 - ux += 127 << 23 - uval := math.Float32frombits(uint32(ux)) - log2 += ((-0.34484843)*uval+2.02466578)*uval - 0.67487759 - return log2 -} - -// EstimatedBits will return an minimum size estimated by an *optimal* -// compression of the block. -// The size of the block -func (t *tokens) EstimatedBits() int { - shannon := float32(0) - bits := int(0) - nMatches := 0 - total := int(t.n) + t.nFilled - if total > 0 { - invTotal := 1.0 / float32(total) - for _, v := range t.litHist[:] { - if v > 0 { - n := float32(v) - shannon += atLeastOne(-mFastLog2(n*invTotal)) * n - } - } - // Just add 15 for EOB - shannon += 15 - for i, v := range t.extraHist[1 : literalCount-256] { - if v > 0 { - n := float32(v) - shannon += atLeastOne(-mFastLog2(n*invTotal)) * n - bits += int(lengthExtraBits[i&31]) * int(v) - nMatches += int(v) - } - } - } - if nMatches > 0 { - invTotal := 1.0 / float32(nMatches) - for i, v := range t.offHist[:offsetCodeCount] { - if v > 0 { - n := float32(v) - shannon += atLeastOne(-mFastLog2(n*invTotal)) * n - bits += int(offsetExtraBits[i&31]) * int(v) - } - } - } - return int(shannon) + bits -} - -// AddMatch adds a match to the tokens. -// This function is very sensitive to inlining and right on the border. -func (t *tokens) AddMatch(xlength uint32, xoffset uint32) { - if debugDeflate { - if xlength >= maxMatchLength+baseMatchLength { - panic(fmt.Errorf("invalid length: %v", xlength)) - } - if xoffset >= maxMatchOffset+baseMatchOffset { - panic(fmt.Errorf("invalid offset: %v", xoffset)) - } - } - oCode := offsetCode(xoffset) - xoffset |= oCode << 16 - - t.extraHist[lengthCodes1[uint8(xlength)]]++ - t.offHist[oCode&31]++ - t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset) - t.n++ -} - -// AddMatchLong adds a match to the tokens, potentially longer than max match length. -// Length should NOT have the base subtracted, only offset should. -func (t *tokens) AddMatchLong(xlength int32, xoffset uint32) { - if debugDeflate { - if xoffset >= maxMatchOffset+baseMatchOffset { - panic(fmt.Errorf("invalid offset: %v", xoffset)) - } - } - oc := offsetCode(xoffset) - xoffset |= oc << 16 - for xlength > 0 { - xl := xlength - if xl > 258 { - // We need to have at least baseMatchLength left over for next loop. - if xl > 258+baseMatchLength { - xl = 258 - } else { - xl = 258 - baseMatchLength - } - } - xlength -= xl - xl -= baseMatchLength - t.extraHist[lengthCodes1[uint8(xl)]]++ - t.offHist[oc&31]++ - t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset) - t.n++ - } -} - -func (t *tokens) AddEOB() { - t.tokens[t.n] = token(endBlockMarker) - t.extraHist[0]++ - t.n++ -} - -func (t *tokens) Slice() []token { - return t.tokens[:t.n] -} - -// VarInt returns the tokens as varint encoded bytes. -func (t *tokens) VarInt() []byte { - var b = make([]byte, binary.MaxVarintLen32*int(t.n)) - var off int - for _, v := range t.tokens[:t.n] { - off += binary.PutUvarint(b[off:], uint64(v)) - } - return b[:off] -} - -// FromVarInt restores t to the varint encoded tokens provided. -// Any data in t is removed. -func (t *tokens) FromVarInt(b []byte) error { - var buf = bytes.NewReader(b) - var toks []token - for { - r, err := binary.ReadUvarint(buf) - if err == io.EOF { - break - } - if err != nil { - return err - } - toks = append(toks, token(r)) - } - t.indexTokens(toks) - return nil -} - -// Returns the type of a token -func (t token) typ() uint32 { return uint32(t) & typeMask } - -// Returns the literal of a literal token -func (t token) literal() uint8 { return uint8(t) } - -// Returns the extra offset of a match token -func (t token) offset() uint32 { return uint32(t) & offsetMask } - -func (t token) length() uint8 { return uint8(t >> lengthShift) } - -// Convert length to code. -func lengthCode(len uint8) uint8 { return lengthCodes[len] } - -// Returns the offset code corresponding to a specific offset -func offsetCode(off uint32) uint32 { - if false { - if off < uint32(len(offsetCodes)) { - return offsetCodes[off&255] - } else if off>>7 < uint32(len(offsetCodes)) { - return offsetCodes[(off>>7)&255] + 14 - } else { - return offsetCodes[(off>>14)&255] + 28 - } - } - if off < uint32(len(offsetCodes)) { - return offsetCodes[uint8(off)] - } - return offsetCodes14[uint8(off>>7)] -} |