From 5d1d86ef4b245ac64e83234a1e88c0ae0d6fb5ca Mon Sep 17 00:00:00 2001 From: rkoster Date: Wed, 16 Oct 2024 16:58:52 +0200 Subject: [PATCH] vendor pgzip --- vendor/github.com/klauspost/compress/LICENSE | 304 ++++ .../klauspost/compress/flate/deflate.go | 1017 +++++++++++++ .../klauspost/compress/flate/dict_decoder.go | 184 +++ .../klauspost/compress/flate/fast_encoder.go | 193 +++ .../compress/flate/huffman_bit_writer.go | 1182 +++++++++++++++ .../klauspost/compress/flate/huffman_code.go | 417 ++++++ .../compress/flate/huffman_sortByFreq.go | 159 ++ .../compress/flate/huffman_sortByLiteral.go | 201 +++ .../klauspost/compress/flate/inflate.go | 865 +++++++++++ .../klauspost/compress/flate/inflate_gen.go | 1283 +++++++++++++++++ .../klauspost/compress/flate/level1.go | 241 ++++ .../klauspost/compress/flate/level2.go | 214 +++ .../klauspost/compress/flate/level3.go | 241 ++++ .../klauspost/compress/flate/level4.go | 221 +++ .../klauspost/compress/flate/level5.go | 708 +++++++++ .../klauspost/compress/flate/level6.go | 325 +++++ .../compress/flate/matchlen_amd64.go | 16 + .../klauspost/compress/flate/matchlen_amd64.s | 66 + .../compress/flate/matchlen_generic.go | 33 + .../klauspost/compress/flate/regmask_amd64.go | 37 + .../klauspost/compress/flate/regmask_other.go | 40 + .../klauspost/compress/flate/stateless.go | 318 ++++ .../klauspost/compress/flate/token.go | 379 +++++ vendor/github.com/klauspost/pgzip/.gitignore | 24 + vendor/github.com/klauspost/pgzip/.travis.yml | 28 + vendor/github.com/klauspost/pgzip/GO_LICENSE | 27 + vendor/github.com/klauspost/pgzip/LICENSE | 22 + vendor/github.com/klauspost/pgzip/README.md | 134 ++ vendor/github.com/klauspost/pgzip/gunzip.go | 597 ++++++++ vendor/github.com/klauspost/pgzip/gzip.go | 519 +++++++ vendor/modules.txt | 6 + 31 files changed, 10001 insertions(+) create mode 100644 vendor/github.com/klauspost/compress/LICENSE create mode 100644 vendor/github.com/klauspost/compress/flate/deflate.go create mode 100644 vendor/github.com/klauspost/compress/flate/dict_decoder.go create mode 100644 vendor/github.com/klauspost/compress/flate/fast_encoder.go create mode 100644 vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go create mode 100644 vendor/github.com/klauspost/compress/flate/huffman_code.go create mode 100644 vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go create mode 100644 vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go create mode 100644 vendor/github.com/klauspost/compress/flate/inflate.go create mode 100644 vendor/github.com/klauspost/compress/flate/inflate_gen.go create mode 100644 vendor/github.com/klauspost/compress/flate/level1.go create mode 100644 vendor/github.com/klauspost/compress/flate/level2.go create mode 100644 vendor/github.com/klauspost/compress/flate/level3.go create mode 100644 vendor/github.com/klauspost/compress/flate/level4.go create mode 100644 vendor/github.com/klauspost/compress/flate/level5.go create mode 100644 vendor/github.com/klauspost/compress/flate/level6.go create mode 100644 vendor/github.com/klauspost/compress/flate/matchlen_amd64.go create mode 100644 vendor/github.com/klauspost/compress/flate/matchlen_amd64.s create mode 100644 vendor/github.com/klauspost/compress/flate/matchlen_generic.go create mode 100644 vendor/github.com/klauspost/compress/flate/regmask_amd64.go create mode 100644 vendor/github.com/klauspost/compress/flate/regmask_other.go create mode 100644 vendor/github.com/klauspost/compress/flate/stateless.go create mode 100644 vendor/github.com/klauspost/compress/flate/token.go create mode 100644 vendor/github.com/klauspost/pgzip/.gitignore create mode 100644 vendor/github.com/klauspost/pgzip/.travis.yml create mode 100644 vendor/github.com/klauspost/pgzip/GO_LICENSE create mode 100644 vendor/github.com/klauspost/pgzip/LICENSE create mode 100644 vendor/github.com/klauspost/pgzip/README.md create mode 100644 vendor/github.com/klauspost/pgzip/gunzip.go create mode 100644 vendor/github.com/klauspost/pgzip/gzip.go diff --git a/vendor/github.com/klauspost/compress/LICENSE b/vendor/github.com/klauspost/compress/LICENSE new file mode 100644 index 000000000..87d557477 --- /dev/null +++ b/vendor/github.com/klauspost/compress/LICENSE @@ -0,0 +1,304 @@ +Copyright (c) 2012 The Go Authors. All rights reserved. +Copyright (c) 2019 Klaus Post. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. 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IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go new file mode 100644 index 000000000..af53fb860 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/deflate.go @@ -0,0 +1,1017 @@ +// 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 ConstantCompression. + 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 new file mode 100644 index 000000000..bb36351a5 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/dict_decoder.go @@ -0,0 +1,184 @@ +// 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 new file mode 100644 index 000000000..c8124b5c4 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/fast_encoder.go @@ -0,0 +1,193 @@ +// 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 new file mode 100644 index 000000000..f70594c34 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go @@ -0,0 +1,1182 @@ +// 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 new file mode 100644 index 000000000..be7b58b47 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/huffman_code.go @@ -0,0 +1,417 @@ +// 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<= 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 new file mode 100644 index 000000000..6c05ba8c1 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go @@ -0,0 +1,159 @@ +// 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 new file mode 100644 index 000000000..93f1aea10 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go @@ -0,0 +1,201 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package flate + +// Sort sorts data. +// It makes one call to data.Len to determine n, and O(n*log(n)) calls to +// data.Less and data.Swap. The sort is not guaranteed to be stable. +func sortByLiteral(data []literalNode) { + n := len(data) + quickSort(data, 0, n, maxDepth(n)) +} + +func quickSort(data []literalNode, a, b, maxDepth int) { + for b-a > 12 { // Use ShellSort for slices <= 12 elements + if maxDepth == 0 { + heapSort(data, a, b) + return + } + maxDepth-- + mlo, mhi := doPivot(data, a, b) + // Avoiding recursion on the larger subproblem guarantees + // a stack depth of at most lg(b-a). + if mlo-a < b-mhi { + quickSort(data, a, mlo, maxDepth) + a = mhi // i.e., quickSort(data, mhi, b) + } else { + quickSort(data, mhi, b, maxDepth) + b = mlo // i.e., quickSort(data, a, mlo) + } + } + if b-a > 1 { + // Do ShellSort pass with gap 6 + // It could be written in this simplified form cause b-a <= 12 + for i := a + 6; i < b; i++ { + if data[i].literal < data[i-6].literal { + data[i], data[i-6] = data[i-6], data[i] + } + } + insertionSort(data, a, b) + } +} +func heapSort(data []literalNode, a, b int) { + first := a + lo := 0 + hi := b - a + + // Build heap with greatest element at top. + for i := (hi - 1) / 2; i >= 0; i-- { + siftDown(data, i, hi, first) + } + + // Pop elements, largest first, into end of data. + for i := hi - 1; i >= 0; i-- { + data[first], data[first+i] = data[first+i], data[first] + siftDown(data, lo, i, first) + } +} + +// siftDown implements the heap property on data[lo, hi). +// first is an offset into the array where the root of the heap lies. +func siftDown(data []literalNode, lo, hi, first int) { + root := lo + for { + child := 2*root + 1 + if child >= hi { + break + } + if child+1 < hi && data[first+child].literal < data[first+child+1].literal { + child++ + } + if data[first+root].literal > data[first+child].literal { + return + } + data[first+root], data[first+child] = data[first+child], data[first+root] + root = child + } +} +func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) { + m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow. + if hi-lo > 40 { + // Tukey's ``Ninther,'' median of three medians of three. + s := (hi - lo) / 8 + medianOfThree(data, lo, lo+s, lo+2*s) + medianOfThree(data, m, m-s, m+s) + medianOfThree(data, hi-1, hi-1-s, hi-1-2*s) + } + medianOfThree(data, lo, m, hi-1) + + // Invariants are: + // data[lo] = pivot (set up by ChoosePivot) + // data[lo < i < a] < pivot + // data[a <= i < b] <= pivot + // data[b <= i < c] unexamined + // data[c <= i < hi-1] > pivot + // data[hi-1] >= pivot + pivot := lo + a, c := lo+1, hi-1 + + for ; a < c && data[a].literal < data[pivot].literal; a++ { + } + b := a + for { + for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot + } + for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot + } + if b >= c { + break + } + // data[b] > pivot; data[c-1] <= pivot + data[b], data[c-1] = data[c-1], data[b] + b++ + c-- + } + // If hi-c<3 then there are duplicates (by property of median of nine). + // Let's be a bit more conservative, and set border to 5. + protect := hi-c < 5 + if !protect && hi-c < (hi-lo)/4 { + // Lets test some points for equality to pivot + dups := 0 + if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot + data[c], data[hi-1] = data[hi-1], data[c] + c++ + dups++ + } + if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot + b-- + dups++ + } + // m-lo = (hi-lo)/2 > 6 + // b-lo > (hi-lo)*3/4-1 > 8 + // ==> m < b ==> data[m] <= pivot + if data[m].literal > data[pivot].literal { // data[m] = pivot + data[m], data[b-1] = data[b-1], data[m] + b-- + dups++ + } + // if at least 2 points are equal to pivot, assume skewed distribution + protect = dups > 1 + } + if protect { + // Protect against a lot of duplicates + // Add invariant: + // data[a <= i < b] unexamined + // data[b <= i < c] = pivot + for { + for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot + } + for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot + } + if a >= b { + break + } + // data[a] == pivot; data[b-1] < pivot + data[a], data[b-1] = data[b-1], data[a] + a++ + b-- + } + } + // Swap pivot into middle + data[pivot], data[b-1] = data[b-1], data[pivot] + return b - 1, c +} + +// Insertion sort +func insertionSort(data []literalNode, a, b int) { + for i := a + 1; i < b; i++ { + for j := i; j > a && data[j].literal < data[j-1].literal; j-- { + data[j], data[j-1] = data[j-1], data[j] + } + } +} + +// maxDepth returns a threshold at which quicksort should switch +// to heapsort. It returns 2*ceil(lg(n+1)). +func maxDepth(n int) int { + var depth int + for i := n; i > 0; i >>= 1 { + depth++ + } + return depth * 2 +} + +// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1]. +func medianOfThree(data []literalNode, m1, m0, m2 int) { + // sort 3 elements + if data[m1].literal < data[m0].literal { + data[m1], data[m0] = data[m0], data[m1] + } + // data[m0] <= data[m1] + if data[m2].literal < data[m1].literal { + data[m2], data[m1] = data[m1], data[m2] + // data[m0] <= data[m2] && data[m1] < data[m2] + if data[m1].literal < data[m0].literal { + data[m1], data[m0] = data[m0], data[m1] + } + } + // now data[m0] <= data[m1] <= data[m2] +} diff --git a/vendor/github.com/klauspost/compress/flate/inflate.go b/vendor/github.com/klauspost/compress/flate/inflate.go new file mode 100644 index 000000000..0d7b437f1 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/inflate.go @@ -0,0 +1,865 @@ +// 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< 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<>= 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 +) + +// flushMode tells decompressor when to return data +type flushMode uint8 + +const ( + syncFlush flushMode = iota // return data after sync flush block + partialFlush // return data after each block +) + +// 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 + + flushMode flushMode +} + +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 { + if f.flushMode == syncFlush { + 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 + } else if f.flushMode == partialFlush && f.dict.availRead() > 0 { + f.toRead = f.dict.readFlush() + } + + 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 +} + +type ReaderOpt func(*decompressor) + +// WithPartialBlock tells decompressor to return after each block, +// so it can read data written with partial flush +func WithPartialBlock() ReaderOpt { + return func(f *decompressor) { + f.flushMode = partialFlush + } +} + +// WithDict initializes the reader with a preset dictionary +func WithDict(dict []byte) ReaderOpt { + return func(f *decompressor) { + f.dict.init(maxMatchOffset, dict) + } +} + +// NewReaderOpts returns new reader with provided options +func NewReaderOpts(r io.Reader, opts ...ReaderOpt) 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) + + for _, opt := range opts { + opt(&f) + } + + return &f +} + +// 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 { + return NewReaderOpts(r) +} + +// 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 { + return NewReaderOpts(r, WithDict(dict)) +} diff --git a/vendor/github.com/klauspost/compress/flate/inflate_gen.go b/vendor/github.com/klauspost/compress/flate/inflate_gen.go new file mode 100644 index 000000000..2b2f993f7 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/inflate_gen.go @@ -0,0 +1,1283 @@ +// 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 & 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 & 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 & 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 & 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 & 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 new file mode 100644 index 000000000..703b9a89a --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level1.go @@ -0,0 +1,241 @@ +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)<= 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 new file mode 100644 index 000000000..876dfbe30 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level2.go @@ -0,0 +1,214 @@ +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 new file mode 100644 index 000000000..7aa2b72a1 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level3.go @@ -0,0 +1,241 @@ +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 new file mode 100644 index 000000000..23c08b325 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level4.go @@ -0,0 +1,221 @@ +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 new file mode 100644 index 000000000..1f61ec182 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level5.go @@ -0,0 +1,708 @@ +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 new file mode 100644 index 000000000..f1e9d98fa --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/level6.go @@ -0,0 +1,325 @@ +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 new file mode 100644 index 000000000..4bd388584 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/matchlen_amd64.go @@ -0,0 +1,16 @@ +//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 new file mode 100644 index 000000000..0782b86e3 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/matchlen_amd64.s @@ -0,0 +1,66 @@ +// Copied from S2 implementation. + +//go:build !appengine && !noasm && gc && !noasm + +#include "textflag.h" + +// func matchLen(a []byte, b []byte) int +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 + JZ matchlen_loop_standalone + +#ifdef GOAMD64_v3 + TZCNTQ BX, BX +#else + BSFQ BX, BX +#endif + SHRL $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 new file mode 100644 index 000000000..ad5cd814b --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/matchlen_generic.go @@ -0,0 +1,33 @@ +//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 new file mode 100644 index 000000000..6ed28061b --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/regmask_amd64.go @@ -0,0 +1,37 @@ +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 new file mode 100644 index 000000000..1b7a2cbd7 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/regmask_other.go @@ -0,0 +1,40 @@ +//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 new file mode 100644 index 000000000..f3d4139ef --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/stateless.go @@ -0,0 +1,318 @@ +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 new file mode 100644 index 000000000..d818790c1 --- /dev/null +++ b/vendor/github.com/klauspost/compress/flate/token.go @@ -0,0 +1,379 @@ +// 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<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<= 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) } + +// 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)] +} diff --git a/vendor/github.com/klauspost/pgzip/.gitignore b/vendor/github.com/klauspost/pgzip/.gitignore new file mode 100644 index 000000000..daf913b1b --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/.gitignore @@ -0,0 +1,24 @@ +# Compiled Object files, Static and Dynamic libs (Shared Objects) +*.o +*.a +*.so + +# Folders +_obj +_test + +# Architecture specific extensions/prefixes +*.[568vq] +[568vq].out + +*.cgo1.go +*.cgo2.c +_cgo_defun.c +_cgo_gotypes.go +_cgo_export.* + +_testmain.go + +*.exe +*.test +*.prof diff --git a/vendor/github.com/klauspost/pgzip/.travis.yml b/vendor/github.com/klauspost/pgzip/.travis.yml new file mode 100644 index 000000000..34704000e --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/.travis.yml @@ -0,0 +1,28 @@ + +arch: + - amd64 + - ppc64le +language: go + +os: + - linux + - osx + +go: + - 1.13.x + - 1.14.x + - 1.15.x + - master + +env: + - GO111MODULE=off + +script: + - diff <(gofmt -d .) <(printf "") + - go test -v -cpu=1,2,4 . + - go test -v -cpu=2 -race -short . + +matrix: + allow_failures: + - go: 'master' + fast_finish: true diff --git a/vendor/github.com/klauspost/pgzip/GO_LICENSE b/vendor/github.com/klauspost/pgzip/GO_LICENSE new file mode 100644 index 000000000..744875676 --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/GO_LICENSE @@ -0,0 +1,27 @@ +Copyright (c) 2012 The Go Authors. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/vendor/github.com/klauspost/pgzip/LICENSE b/vendor/github.com/klauspost/pgzip/LICENSE new file mode 100644 index 000000000..2bdc0d751 --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/LICENSE @@ -0,0 +1,22 @@ +The MIT License (MIT) + +Copyright (c) 2014 Klaus Post + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. + diff --git a/vendor/github.com/klauspost/pgzip/README.md b/vendor/github.com/klauspost/pgzip/README.md new file mode 100644 index 000000000..ecc8726fa --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/README.md @@ -0,0 +1,134 @@ +pgzip +===== + +Go parallel gzip compression/decompression. This is a fully gzip compatible drop in replacement for "compress/gzip". + +This will split compression into blocks that are compressed in parallel. +This can be useful for compressing big amounts of data. The output is a standard gzip file. + +The gzip decompression is modified so it decompresses ahead of the current reader. +This means that reads will be non-blocking if the decompressor can keep ahead of your code reading from it. +CRC calculation also takes place in a separate goroutine. + +You should only use this if you are (de)compressing big amounts of data, +say **more than 1MB** at the time, otherwise you will not see any benefit, +and it will likely be faster to use the internal gzip library +or [this package](https://github.com/klauspost/compress). + +It is important to note that this library creates and reads *standard gzip files*. +You do not have to match the compressor/decompressor to get the described speedups, +and the gzip files are fully compatible with other gzip readers/writers. + +A golang variant of this is [bgzf](https://godoc.org/github.com/biogo/hts/bgzf), +which has the same feature, as well as seeking in the resulting file. +The only drawback is a slightly bigger overhead compared to this and pure gzip. +See a comparison below. + +[![GoDoc][1]][2] [![Build Status][3]][4] + +[1]: https://godoc.org/github.com/klauspost/pgzip?status.svg +[2]: https://godoc.org/github.com/klauspost/pgzip +[3]: https://travis-ci.org/klauspost/pgzip.svg +[4]: https://travis-ci.org/klauspost/pgzip + +Installation +==== +```go get github.com/klauspost/pgzip/...``` + +You might need to get/update the dependencies: + +``` +go get -u github.com/klauspost/compress +``` + +Usage +==== +[Godoc Doumentation](https://godoc.org/github.com/klauspost/pgzip) + +To use as a replacement for gzip, exchange + +```import "compress/gzip"``` +with +```import gzip "github.com/klauspost/pgzip"```. + +# Changes + +* Oct 6, 2016: Fixed an issue if the destination writer returned an error. +* Oct 6, 2016: Better buffer reuse, should now generate less garbage. +* Oct 6, 2016: Output does not change based on write sizes. +* Dec 8, 2015: Decoder now supports the io.WriterTo interface, giving a speedup and less GC pressure. +* Oct 9, 2015: Reduced allocations by ~35 by using sync.Pool. ~15% overall speedup. + +Changes in [github.com/klauspost/compress](https://github.com/klauspost/compress#changelog) are also carried over, so see that for more changes. + +## Compression +The simplest way to use this is to simply do the same as you would when using [compress/gzip](http://golang.org/pkg/compress/gzip). + +To change the block size, use the added (*pgzip.Writer).SetConcurrency(blockSize, blocks int) function. With this you can control the approximate size of your blocks, as well as how many you want to be processing in parallel. Default values for this is SetConcurrency(1MB, runtime.GOMAXPROCS(0)), meaning blocks are split at 1 MB and up to the number of CPU threads blocks can be processing at once before the writer blocks. + + +Example: +``` +var b bytes.Buffer +w := gzip.NewWriter(&b) +w.SetConcurrency(100000, 10) +w.Write([]byte("hello, world\n")) +w.Close() +``` + +To get any performance gains, you should at least be compressing more than 1 megabyte of data at the time. + +You should at least have a block size of 100k and at least a number of blocks that match the number of cores your would like to utilize, but about twice the number of blocks would be the best. + +Another side effect of this is, that it is likely to speed up your other code, since writes to the compressor only blocks if the compressor is already compressing the number of blocks you have specified. This also means you don't have worry about buffering input to the compressor. + +## Decompression + +Decompression works similar to compression. That means that you simply call pgzip the same way as you would call [compress/gzip](http://golang.org/pkg/compress/gzip). + +The only difference is that if you want to specify your own readahead, you have to use `pgzip.NewReaderN(r io.Reader, blockSize, blocks int)` to get a reader with your custom blocksizes. The `blockSize` is the size of each block decoded, and `blocks` is the maximum number of blocks that is decoded ahead. + +See [Example on playground](http://play.golang.org/p/uHv1B5NbDh) + +Performance +==== +## Compression + +See my blog post in [Benchmarks of Golang Gzip](https://blog.klauspost.com/go-gzipdeflate-benchmarks/). + +Compression cost is usually about 0.2% with default settings with a block size of 250k. + +Example with GOMAXPROC set to 32 (16 core CPU) + +Content is [Matt Mahoneys 10GB corpus](http://mattmahoney.net/dc/10gb.html). Compression level 6. + +Compressor | MB/sec | speedup | size | size overhead (lower=better) +------------|----------|---------|------|--------- +[gzip](http://golang.org/pkg/compress/gzip) (golang) | 16.91MB/s (1 thread) | 1.0x | 4781329307 | 0% +[gzip](http://github.com/klauspost/compress/gzip) (klauspost) | 127.10MB/s (1 thread) | 7.52x | 4885366806 | +2.17% +[pgzip](https://github.com/klauspost/pgzip) (klauspost) | 2085.35MB/s| 123.34x | 4886132566 | +2.19% +[pargzip](https://godoc.org/github.com/golang/build/pargzip) (builder) | 334.04MB/s | 19.76x | 4786890417 | +0.12% + +pgzip also contains a [huffman only compression](https://github.com/klauspost/compress#linear-time-compression-huffman-only) mode, that will allow compression at ~450MB per core per second, largely independent of the content. + +See the [complete sheet](https://docs.google.com/spreadsheets/d/1nuNE2nPfuINCZJRMt6wFWhKpToF95I47XjSsc-1rbPQ/edit?usp=sharing) for different content types and compression settings. + +## Decompression + +The decompression speedup is there because it allows you to do other work while the decompression is taking place. + +In the example above, the numbers are as follows on a 4 CPU machine: + +Decompressor | Time | Speedup +-------------|------|-------- +[gzip](http://golang.org/pkg/compress/gzip) (golang) | 1m28.85s | 0% +[pgzip](https://github.com/klauspost/pgzip) (klauspost) | 43.48s | 104% + +But wait, since gzip decompression is inherently singlethreaded (aside from CRC calculation) how can it be more than 100% faster? Because pgzip due to its design also acts as a buffer. When using unbuffered gzip, you are also waiting for io when you are decompressing. If the gzip decoder can keep up, it will always have data ready for your reader, and you will not be waiting for input to the gzip decompressor to complete. + +This is pretty much an optimal situation for pgzip, but it reflects most common usecases for CPU intensive gzip usage. + +I haven't included [bgzf](https://godoc.org/github.com/biogo/hts/bgzf) in this comparison, since it only can decompress files created by a compatible encoder, and therefore cannot be considered a generic gzip decompressor. But if you are able to compress your files with a bgzf compatible program, you can expect it to scale beyond 100%. + +# License +This contains large portions of code from the go repository - see GO_LICENSE for more information. The changes are released under MIT License. See LICENSE for more information. diff --git a/vendor/github.com/klauspost/pgzip/gunzip.go b/vendor/github.com/klauspost/pgzip/gunzip.go new file mode 100644 index 000000000..3c4b32f16 --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/gunzip.go @@ -0,0 +1,597 @@ +// 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 pgzip implements reading and writing of gzip format compressed files, +// as specified in RFC 1952. +// +// This is a drop in replacement for "compress/gzip". +// This will split compression into blocks that are compressed in parallel. +// This can be useful for compressing big amounts of data. +// The gzip decompression has not been modified, but remains in the package, +// so you can use it as a complete replacement for "compress/gzip". +// +// See more at https://github.com/klauspost/pgzip +package pgzip + +import ( + "bufio" + "errors" + "hash" + "hash/crc32" + "io" + "sync" + "time" + + "github.com/klauspost/compress/flate" +) + +const ( + gzipID1 = 0x1f + gzipID2 = 0x8b + gzipDeflate = 8 + flagText = 1 << 0 + flagHdrCrc = 1 << 1 + flagExtra = 1 << 2 + flagName = 1 << 3 + flagComment = 1 << 4 +) + +func makeReader(r io.Reader) flate.Reader { + if rr, ok := r.(flate.Reader); ok { + return rr + } + return bufio.NewReader(r) +} + +var ( + // ErrChecksum is returned when reading GZIP data that has an invalid checksum. + ErrChecksum = errors.New("gzip: invalid checksum") + // ErrHeader is returned when reading GZIP data that has an invalid header. + ErrHeader = errors.New("gzip: invalid header") +) + +// The gzip file stores a header giving metadata about the compressed file. +// That header is exposed as the fields of the Writer and Reader structs. +type Header struct { + Comment string // comment + Extra []byte // "extra data" + ModTime time.Time // modification time + Name string // file name + OS byte // operating system type +} + +// A Reader is an io.Reader that can be read to retrieve +// uncompressed data from a gzip-format compressed file. +// +// In general, a gzip file can be a concatenation of gzip files, +// each with its own header. Reads from the Reader +// return the concatenation of the uncompressed data of each. +// Only the first header is recorded in the Reader fields. +// +// Gzip files store a length and checksum of the uncompressed data. +// The Reader will return a ErrChecksum when Read +// reaches the end of the uncompressed data if it does not +// have the expected length or checksum. Clients should treat data +// returned by Read as tentative until they receive the io.EOF +// marking the end of the data. +type Reader struct { + Header + r flate.Reader + decompressor io.ReadCloser + digest hash.Hash32 + size uint32 + flg byte + buf [512]byte + err error + closeErr chan error + multistream bool + + readAhead chan read + roff int // read offset + current []byte + closeReader chan struct{} + lastBlock bool + blockSize int + blocks int + + activeRA bool // Indication if readahead is active + mu sync.Mutex // Lock for above + + blockPool chan []byte +} + +type read struct { + b []byte + err error +} + +// NewReader creates a new Reader reading the given reader. +// The implementation buffers input and may read more data than necessary from r. +// It is the caller's responsibility to call Close on the Reader when done. +func NewReader(r io.Reader) (*Reader, error) { + z := new(Reader) + z.blocks = defaultBlocks + z.blockSize = defaultBlockSize + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.multistream = true + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + if err := z.readHeader(true); err != nil { + return nil, err + } + return z, nil +} + +// NewReaderN creates a new Reader reading the given reader. +// The implementation buffers input and may read more data than necessary from r. +// It is the caller's responsibility to call Close on the Reader when done. +// +// With this you can control the approximate size of your blocks, +// as well as how many blocks you want to have prefetched. +// +// Default values for this is blockSize = 250000, blocks = 16, +// meaning up to 16 blocks of maximum 250000 bytes will be +// prefetched. +func NewReaderN(r io.Reader, blockSize, blocks int) (*Reader, error) { + z := new(Reader) + z.blocks = blocks + z.blockSize = blockSize + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.multistream = true + + // Account for too small values + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + if err := z.readHeader(true); err != nil { + return nil, err + } + return z, nil +} + +// Reset discards the Reader z's state and makes it equivalent to the +// result of its original state from NewReader, but reading from r instead. +// This permits reusing a Reader rather than allocating a new one. +func (z *Reader) Reset(r io.Reader) error { + z.killReadAhead() + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.size = 0 + z.err = nil + z.multistream = true + + // Account for uninitialized values + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + + if z.blockPool == nil { + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + } + + return z.readHeader(true) +} + +// Multistream controls whether the reader supports multistream files. +// +// If enabled (the default), the Reader expects the input to be a sequence +// of individually gzipped data streams, each with its own header and +// trailer, ending at EOF. The effect is that the concatenation of a sequence +// of gzipped files is treated as equivalent to the gzip of the concatenation +// of the sequence. This is standard behavior for gzip readers. +// +// Calling Multistream(false) disables this behavior; disabling the behavior +// can be useful when reading file formats that distinguish individual gzip +// data streams or mix gzip data streams with other data streams. +// In this mode, when the Reader reaches the end of the data stream, +// Read returns io.EOF. If the underlying reader implements io.ByteReader, +// it will be left positioned just after the gzip stream. +// To start the next stream, call z.Reset(r) followed by z.Multistream(false). +// If there is no next stream, z.Reset(r) will return io.EOF. +func (z *Reader) Multistream(ok bool) { + z.multistream = ok +} + +// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950). +func get4(p []byte) uint32 { + return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24 +} + +func (z *Reader) readString() (string, error) { + var err error + needconv := false + for i := 0; ; i++ { + if i >= len(z.buf) { + return "", ErrHeader + } + z.buf[i], err = z.r.ReadByte() + if err != nil { + return "", err + } + if z.buf[i] > 0x7f { + needconv = true + } + if z.buf[i] == 0 { + // GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1). + if needconv { + s := make([]rune, 0, i) + for _, v := range z.buf[0:i] { + s = append(s, rune(v)) + } + return string(s), nil + } + return string(z.buf[0:i]), nil + } + } +} + +func (z *Reader) read2() (uint32, error) { + _, err := io.ReadFull(z.r, z.buf[0:2]) + if err != nil { + return 0, err + } + return uint32(z.buf[0]) | uint32(z.buf[1])<<8, nil +} + +func (z *Reader) readHeader(save bool) error { + z.killReadAhead() + + _, err := io.ReadFull(z.r, z.buf[0:10]) + if err != nil { + return err + } + if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate { + return ErrHeader + } + z.flg = z.buf[3] + if save { + z.ModTime = time.Unix(int64(get4(z.buf[4:8])), 0) + // z.buf[8] is xfl, ignored + z.OS = z.buf[9] + } + z.digest.Reset() + z.digest.Write(z.buf[0:10]) + + if z.flg&flagExtra != 0 { + n, err := z.read2() + if err != nil { + return err + } + data := make([]byte, n) + if _, err = io.ReadFull(z.r, data); err != nil { + return err + } + if save { + z.Extra = data + } + } + + var s string + if z.flg&flagName != 0 { + if s, err = z.readString(); err != nil { + return err + } + if save { + z.Name = s + } + } + + if z.flg&flagComment != 0 { + if s, err = z.readString(); err != nil { + return err + } + if save { + z.Comment = s + } + } + + if z.flg&flagHdrCrc != 0 { + n, err := z.read2() + if err != nil { + return err + } + sum := z.digest.Sum32() & 0xFFFF + if n != sum { + return ErrHeader + } + } + + z.digest.Reset() + z.decompressor = flate.NewReader(z.r) + z.doReadAhead() + return nil +} + +func (z *Reader) killReadAhead() error { + z.mu.Lock() + defer z.mu.Unlock() + if z.activeRA { + if z.closeReader != nil { + close(z.closeReader) + } + + // Wait for decompressor to be closed and return error, if any. + e, ok := <-z.closeErr + z.activeRA = false + + for blk := range z.readAhead { + if blk.b != nil { + z.blockPool <- blk.b + } + } + if cap(z.current) > 0 { + z.blockPool <- z.current + z.current = nil + } + if !ok { + // Channel is closed, so if there was any error it has already been returned. + return nil + } + return e + } + return nil +} + +// Starts readahead. +// Will return on error (including io.EOF) +// or when z.closeReader is closed. +func (z *Reader) doReadAhead() { + z.mu.Lock() + defer z.mu.Unlock() + z.activeRA = true + + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + ra := make(chan read, z.blocks) + z.readAhead = ra + closeReader := make(chan struct{}, 0) + z.closeReader = closeReader + z.lastBlock = false + closeErr := make(chan error, 1) + z.closeErr = closeErr + z.size = 0 + z.roff = 0 + z.current = nil + decomp := z.decompressor + + go func() { + defer func() { + closeErr <- decomp.Close() + close(closeErr) + close(ra) + }() + + // We hold a local reference to digest, since + // it way be changed by reset. + digest := z.digest + var wg sync.WaitGroup + for { + var buf []byte + select { + case buf = <-z.blockPool: + case <-closeReader: + return + } + buf = buf[0:z.blockSize] + // Try to fill the buffer + n, err := io.ReadFull(decomp, buf) + if err == io.ErrUnexpectedEOF { + if n > 0 { + err = nil + } else { + // If we got zero bytes, we need to establish if + // we reached end of stream or truncated stream. + _, err = decomp.Read([]byte{}) + if err == io.EOF { + err = nil + } + } + } + if n < len(buf) { + buf = buf[0:n] + } + wg.Wait() + wg.Add(1) + go func() { + digest.Write(buf) + wg.Done() + }() + z.size += uint32(n) + + // If we return any error, out digest must be ready + if err != nil { + wg.Wait() + } + select { + case z.readAhead <- read{b: buf, err: err}: + case <-closeReader: + // Sent on close, we don't care about the next results + z.blockPool <- buf + return + } + if err != nil { + return + } + } + }() +} + +func (z *Reader) Read(p []byte) (n int, err error) { + if z.err != nil { + return 0, z.err + } + if len(p) == 0 { + return 0, nil + } + + for { + if len(z.current) == 0 && !z.lastBlock { + read := <-z.readAhead + + if read.err != nil { + // If not nil, the reader will have exited + z.closeReader = nil + + if read.err != io.EOF { + z.err = read.err + return + } + if read.err == io.EOF { + z.lastBlock = true + err = nil + } + } + z.current = read.b + z.roff = 0 + } + avail := z.current[z.roff:] + if len(p) >= len(avail) { + // If len(p) >= len(current), return all content of current + n = copy(p, avail) + z.blockPool <- z.current + z.current = nil + if z.lastBlock { + err = io.EOF + break + } + } else { + // We copy as much as there is space for + n = copy(p, avail) + z.roff += n + } + return + } + + // Finished file; check checksum + size. + if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil { + z.err = err + return 0, err + } + crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8]) + sum := z.digest.Sum32() + if sum != crc32 || isize != z.size { + z.err = ErrChecksum + return 0, z.err + } + + // File is ok; should we attempt reading one more? + if !z.multistream { + return 0, io.EOF + } + + // Is there another? + if err = z.readHeader(false); err != nil { + z.err = err + return + } + + // Yes. Reset and read from it. + return z.Read(p) +} + +func (z *Reader) WriteTo(w io.Writer) (n int64, err error) { + total := int64(0) + avail := z.current[z.roff:] + if len(avail) != 0 { + n, err := w.Write(avail) + if n != len(avail) { + return total, io.ErrShortWrite + } + total += int64(n) + if err != nil { + return total, err + } + z.blockPool <- z.current + z.current = nil + } + for { + if z.err != nil { + return total, z.err + } + // We write both to output and digest. + for { + // Read from input + read := <-z.readAhead + if read.err != nil { + // If not nil, the reader will have exited + z.closeReader = nil + + if read.err != io.EOF { + z.err = read.err + return total, z.err + } + if read.err == io.EOF { + z.lastBlock = true + err = nil + } + } + // Write what we got + n, err := w.Write(read.b) + if n != len(read.b) { + return total, io.ErrShortWrite + } + total += int64(n) + if err != nil { + return total, err + } + // Put block back + z.blockPool <- read.b + if z.lastBlock { + break + } + } + + // Finished file; check checksum + size. + if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil { + z.err = err + return total, err + } + crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8]) + sum := z.digest.Sum32() + if sum != crc32 || isize != z.size { + z.err = ErrChecksum + return total, z.err + } + // File is ok; should we attempt reading one more? + if !z.multistream { + return total, nil + } + + // Is there another? + err = z.readHeader(false) + if err == io.EOF { + return total, nil + } + if err != nil { + z.err = err + return total, err + } + } +} + +// Close closes the Reader. It does not close the underlying io.Reader. +func (z *Reader) Close() error { + return z.killReadAhead() +} diff --git a/vendor/github.com/klauspost/pgzip/gzip.go b/vendor/github.com/klauspost/pgzip/gzip.go new file mode 100644 index 000000000..257c4d299 --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/gzip.go @@ -0,0 +1,519 @@ +// Copyright 2010 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pgzip + +import ( + "bytes" + "errors" + "fmt" + "hash" + "hash/crc32" + "io" + "runtime" + "sync" + "time" + + "github.com/klauspost/compress/flate" +) + +const ( + defaultBlockSize = 1 << 20 + tailSize = 16384 + defaultBlocks = 4 +) + +// These constants are copied from the flate package, so that code that imports +// "compress/gzip" does not also have to import "compress/flate". +const ( + NoCompression = flate.NoCompression + BestSpeed = flate.BestSpeed + BestCompression = flate.BestCompression + DefaultCompression = flate.DefaultCompression + ConstantCompression = flate.ConstantCompression + HuffmanOnly = flate.HuffmanOnly +) + +// A Writer is an io.WriteCloser. +// Writes to a Writer are compressed and written to w. +type Writer struct { + Header + w io.Writer + level int + wroteHeader bool + blockSize int + blocks int + currentBuffer []byte + prevTail []byte + digest hash.Hash32 + size int + closed bool + buf [10]byte + errMu sync.RWMutex + err error + pushedErr chan struct{} + results chan result + dictFlatePool sync.Pool + dstPool sync.Pool + wg sync.WaitGroup +} + +type result struct { + result chan []byte + notifyWritten chan struct{} +} + +// Use SetConcurrency to finetune the concurrency level if needed. +// +// With this you can control the approximate size of your blocks, +// as well as how many you want to be processing in parallel. +// +// Default values for this is SetConcurrency(defaultBlockSize, runtime.GOMAXPROCS(0)), +// meaning blocks are split at 1 MB and up to the number of CPU threads +// can be processing at once before the writer blocks. +func (z *Writer) SetConcurrency(blockSize, blocks int) error { + if blockSize <= tailSize { + return fmt.Errorf("gzip: block size cannot be less than or equal to %d", tailSize) + } + if blocks <= 0 { + return errors.New("gzip: blocks cannot be zero or less") + } + if blockSize == z.blockSize && blocks == z.blocks { + return nil + } + z.blockSize = blockSize + z.results = make(chan result, blocks) + z.blocks = blocks + z.dstPool.New = func() interface{} { return make([]byte, 0, blockSize+(blockSize)>>4) } + return nil +} + +// NewWriter returns a new Writer. +// Writes to the returned writer are compressed and written to w. +// +// It is the caller's responsibility to call Close on the WriteCloser when done. +// Writes may be buffered and not flushed until Close. +// +// Callers that wish to set the fields in Writer.Header must do so before +// the first call to Write or Close. The Comment and Name header fields are +// UTF-8 strings in Go, but the underlying format requires NUL-terminated ISO +// 8859-1 (Latin-1). NUL or non-Latin-1 runes in those strings will lead to an +// error on Write. +func NewWriter(w io.Writer) *Writer { + z, _ := NewWriterLevel(w, DefaultCompression) + return z +} + +// NewWriterLevel is like NewWriter but specifies the compression level instead +// of assuming DefaultCompression. +// +// The compression level can be DefaultCompression, NoCompression, or any +// integer value between BestSpeed and BestCompression inclusive. The error +// returned will be nil if the level is valid. +func NewWriterLevel(w io.Writer, level int) (*Writer, error) { + if level < ConstantCompression || level > BestCompression { + return nil, fmt.Errorf("gzip: invalid compression level: %d", level) + } + z := new(Writer) + z.SetConcurrency(defaultBlockSize, runtime.GOMAXPROCS(0)) + z.init(w, level) + return z, nil +} + +// This function must be used by goroutines to set an +// error condition, since z.err access is restricted +// to the callers goruotine. +func (z *Writer) pushError(err error) { + z.errMu.Lock() + if z.err != nil { + z.errMu.Unlock() + return + } + z.err = err + close(z.pushedErr) + z.errMu.Unlock() +} + +func (z *Writer) init(w io.Writer, level int) { + z.wg.Wait() + digest := z.digest + if digest != nil { + digest.Reset() + } else { + digest = crc32.NewIEEE() + } + z.Header = Header{OS: 255} + z.w = w + z.level = level + z.digest = digest + z.pushedErr = make(chan struct{}, 0) + z.results = make(chan result, z.blocks) + z.err = nil + z.closed = false + z.Comment = "" + z.Extra = nil + z.ModTime = time.Time{} + z.wroteHeader = false + z.currentBuffer = nil + z.buf = [10]byte{} + z.prevTail = nil + z.size = 0 + if z.dictFlatePool.New == nil { + z.dictFlatePool.New = func() interface{} { + f, _ := flate.NewWriterDict(w, level, nil) + return f + } + } +} + +// Reset discards the Writer z's state and makes it equivalent to the +// result of its original state from NewWriter or NewWriterLevel, but +// writing to w instead. This permits reusing a Writer rather than +// allocating a new one. +func (z *Writer) Reset(w io.Writer) { + if z.results != nil && !z.closed { + close(z.results) + } + z.SetConcurrency(defaultBlockSize, runtime.GOMAXPROCS(0)) + z.init(w, z.level) +} + +// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950). +func put2(p []byte, v uint16) { + p[0] = uint8(v >> 0) + p[1] = uint8(v >> 8) +} + +func put4(p []byte, v uint32) { + p[0] = uint8(v >> 0) + p[1] = uint8(v >> 8) + p[2] = uint8(v >> 16) + p[3] = uint8(v >> 24) +} + +// writeBytes writes a length-prefixed byte slice to z.w. +func (z *Writer) writeBytes(b []byte) error { + if len(b) > 0xffff { + return errors.New("gzip.Write: Extra data is too large") + } + put2(z.buf[0:2], uint16(len(b))) + _, err := z.w.Write(z.buf[0:2]) + if err != nil { + return err + } + _, err = z.w.Write(b) + return err +} + +// writeString writes a UTF-8 string s in GZIP's format to z.w. +// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1). +func (z *Writer) writeString(s string) (err error) { + // GZIP stores Latin-1 strings; error if non-Latin-1; convert if non-ASCII. + needconv := false + for _, v := range s { + if v == 0 || v > 0xff { + return errors.New("gzip.Write: non-Latin-1 header string") + } + if v > 0x7f { + needconv = true + } + } + if needconv { + b := make([]byte, 0, len(s)) + for _, v := range s { + b = append(b, byte(v)) + } + _, err = z.w.Write(b) + } else { + _, err = io.WriteString(z.w, s) + } + if err != nil { + return err + } + // GZIP strings are NUL-terminated. + z.buf[0] = 0 + _, err = z.w.Write(z.buf[0:1]) + return err +} + +// compressCurrent will compress the data currently buffered +// This should only be called from the main writer/flush/closer +func (z *Writer) compressCurrent(flush bool) { + c := z.currentBuffer + if len(c) > z.blockSize { + // This can never happen through the public interface. + panic("len(z.currentBuffer) > z.blockSize (most likely due to concurrent Write race)") + } + + r := result{} + r.result = make(chan []byte, 1) + r.notifyWritten = make(chan struct{}, 0) + // Reserve a result slot + select { + case z.results <- r: + case <-z.pushedErr: + return + } + + z.wg.Add(1) + tail := z.prevTail + if len(c) > tailSize { + buf := z.dstPool.Get().([]byte) // Put in .compressBlock + // Copy tail from current buffer before handing the buffer over to the + // compressBlock goroutine. + buf = append(buf[:0], c[len(c)-tailSize:]...) + z.prevTail = buf + } else { + z.prevTail = nil + } + go z.compressBlock(c, tail, r, z.closed) + + z.currentBuffer = z.dstPool.Get().([]byte) // Put in .compressBlock + z.currentBuffer = z.currentBuffer[:0] + + // Wait if flushing + if flush { + <-r.notifyWritten + } +} + +// Returns an error if it has been set. +// Cannot be used by functions that are from internal goroutines. +func (z *Writer) checkError() error { + z.errMu.RLock() + err := z.err + z.errMu.RUnlock() + return err +} + +// Write writes a compressed form of p to the underlying io.Writer. The +// compressed bytes are not necessarily flushed to output until +// the Writer is closed or Flush() is called. +// +// The function will return quickly, if there are unused buffers. +// The sent slice (p) is copied, and the caller is free to re-use the buffer +// when the function returns. +// +// Errors that occur during compression will be reported later, and a nil error +// does not signify that the compression succeeded (since it is most likely still running) +// That means that the call that returns an error may not be the call that caused it. +// Only Flush and Close functions are guaranteed to return any errors up to that point. +func (z *Writer) Write(p []byte) (int, error) { + if err := z.checkError(); err != nil { + return 0, err + } + // Write the GZIP header lazily. + if !z.wroteHeader { + z.wroteHeader = true + z.buf[0] = gzipID1 + z.buf[1] = gzipID2 + z.buf[2] = gzipDeflate + z.buf[3] = 0 + if z.Extra != nil { + z.buf[3] |= 0x04 + } + if z.Name != "" { + z.buf[3] |= 0x08 + } + if z.Comment != "" { + z.buf[3] |= 0x10 + } + put4(z.buf[4:8], uint32(z.ModTime.Unix())) + if z.level == BestCompression { + z.buf[8] = 2 + } else if z.level == BestSpeed { + z.buf[8] = 4 + } else { + z.buf[8] = 0 + } + z.buf[9] = z.OS + var n int + var err error + n, err = z.w.Write(z.buf[0:10]) + if err != nil { + z.pushError(err) + return n, err + } + if z.Extra != nil { + err = z.writeBytes(z.Extra) + if err != nil { + z.pushError(err) + return n, err + } + } + if z.Name != "" { + err = z.writeString(z.Name) + if err != nil { + z.pushError(err) + return n, err + } + } + if z.Comment != "" { + err = z.writeString(z.Comment) + if err != nil { + z.pushError(err) + return n, err + } + } + // Start receiving data from compressors + go func() { + listen := z.results + var failed bool + for { + r, ok := <-listen + // If closed, we are finished. + if !ok { + return + } + if failed { + close(r.notifyWritten) + continue + } + buf := <-r.result + n, err := z.w.Write(buf) + if err != nil { + z.pushError(err) + close(r.notifyWritten) + failed = true + continue + } + if n != len(buf) { + z.pushError(fmt.Errorf("gzip: short write %d should be %d", n, len(buf))) + failed = true + close(r.notifyWritten) + continue + } + z.dstPool.Put(buf) + close(r.notifyWritten) + } + }() + z.currentBuffer = z.dstPool.Get().([]byte) + z.currentBuffer = z.currentBuffer[:0] + } + q := p + for len(q) > 0 { + length := len(q) + if length+len(z.currentBuffer) > z.blockSize { + length = z.blockSize - len(z.currentBuffer) + } + z.digest.Write(q[:length]) + z.currentBuffer = append(z.currentBuffer, q[:length]...) + if len(z.currentBuffer) > z.blockSize { + panic("z.currentBuffer too large (most likely due to concurrent Write race)") + } + if len(z.currentBuffer) == z.blockSize { + z.compressCurrent(false) + if err := z.checkError(); err != nil { + return len(p) - len(q), err + } + } + z.size += length + q = q[length:] + } + return len(p), z.checkError() +} + +// Step 1: compresses buffer to buffer +// Step 2: send writer to channel +// Step 3: Close result channel to indicate we are done +func (z *Writer) compressBlock(p, prevTail []byte, r result, closed bool) { + defer func() { + close(r.result) + z.wg.Done() + }() + buf := z.dstPool.Get().([]byte) // Corresponding Put in .Write's result writer + dest := bytes.NewBuffer(buf[:0]) + + compressor := z.dictFlatePool.Get().(*flate.Writer) // Put below + compressor.ResetDict(dest, prevTail) + compressor.Write(p) + z.dstPool.Put(p) // Corresponding Get in .Write and .compressCurrent + + err := compressor.Flush() + if err != nil { + z.pushError(err) + return + } + if closed { + err = compressor.Close() + if err != nil { + z.pushError(err) + return + } + } + z.dictFlatePool.Put(compressor) // Get above + + if prevTail != nil { + z.dstPool.Put(prevTail) // Get in .compressCurrent + } + + // Read back buffer + buf = dest.Bytes() + r.result <- buf +} + +// Flush flushes any pending compressed data to the underlying writer. +// +// It is useful mainly in compressed network protocols, to ensure that +// a remote reader has enough data to reconstruct a packet. Flush does +// not return until the data has been written. If the underlying +// writer returns an error, Flush returns that error. +// +// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH. +func (z *Writer) Flush() error { + if err := z.checkError(); err != nil { + return err + } + if z.closed { + return nil + } + if !z.wroteHeader { + _, err := z.Write(nil) + if err != nil { + return err + } + } + // We send current block to compression + z.compressCurrent(true) + + return z.checkError() +} + +// UncompressedSize will return the number of bytes written. +// pgzip only, not a function in the official gzip package. +func (z *Writer) UncompressedSize() int { + return z.size +} + +// Close closes the Writer, flushing any unwritten data to the underlying +// io.Writer, but does not close the underlying io.Writer. +func (z *Writer) Close() error { + if err := z.checkError(); err != nil { + return err + } + if z.closed { + return nil + } + + z.closed = true + if !z.wroteHeader { + z.Write(nil) + if err := z.checkError(); err != nil { + return err + } + } + z.compressCurrent(true) + if err := z.checkError(); err != nil { + return err + } + close(z.results) + put4(z.buf[0:4], z.digest.Sum32()) + put4(z.buf[4:8], uint32(z.size)) + _, err := z.w.Write(z.buf[0:8]) + if err != nil { + z.pushError(err) + return err + } + return nil +} diff --git a/vendor/modules.txt b/vendor/modules.txt index 3111f408b..1e62d9e82 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -353,6 +353,12 @@ github.com/jmespath/go-jmespath # github.com/jpillora/backoff v1.0.0 ## explicit; go 1.13 github.com/jpillora/backoff +# github.com/klauspost/compress v1.17.11 +## explicit; go 1.21 +github.com/klauspost/compress/flate +# github.com/klauspost/pgzip v1.2.6 +## explicit +github.com/klauspost/pgzip # github.com/mattn/go-colorable v0.1.13 ## explicit; go 1.15 github.com/mattn/go-colorable