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author | OpenShift Merge Robot <openshift-merge-robot@users.noreply.github.com> | 2021-04-12 18:25:00 +0200 |
---|---|---|
committer | GitHub <noreply@github.com> | 2021-04-12 18:25:00 +0200 |
commit | 7203e0a76a82e278b6a41e7a5851463a0b2f571e (patch) | |
tree | 04252a3261ecba007ace7055154fc8d2ce8a9aea /vendor/github.com/klauspost/compress | |
parent | 3803a2630f2bc53f18cbf2b7a825ff1b068a0fb7 (diff) | |
parent | 3627c4b691a357fc531c2761f07ccfecf937dd12 (diff) | |
download | podman-7203e0a76a82e278b6a41e7a5851463a0b2f571e.tar.gz podman-7203e0a76a82e278b6a41e7a5851463a0b2f571e.tar.bz2 podman-7203e0a76a82e278b6a41e7a5851463a0b2f571e.zip |
Merge pull request #9994 from containers/dependabot/go_modules/github.com/containers/image/v5-5.11.0
Bump github.com/containers/image/v5 from 5.10.5 to 5.11.0
Diffstat (limited to 'vendor/github.com/klauspost/compress')
19 files changed, 1535 insertions, 126 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go index 25dbe3e15..3f428d8b5 100644 --- a/vendor/github.com/klauspost/compress/flate/deflate.go +++ b/vendor/github.com/klauspost/compress/flate/deflate.go @@ -645,15 +645,15 @@ func (d *compressor) init(w io.Writer, level int) (err error) { d.fill = (*compressor).fillBlock d.step = (*compressor).store case level == ConstantCompression: - d.w.logNewTablePenalty = 4 - d.window = make([]byte, maxStoreBlockSize) + d.w.logNewTablePenalty = 8 + 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 = 6 + d.w.logNewTablePenalty = 8 d.fast = newFastEnc(level) d.window = make([]byte, maxStoreBlockSize) d.fill = (*compressor).fillBlock diff --git a/vendor/github.com/klauspost/compress/flate/fast_encoder.go b/vendor/github.com/klauspost/compress/flate/fast_encoder.go index 4a73e1bdd..678f08105 100644 --- a/vendor/github.com/klauspost/compress/flate/fast_encoder.go +++ b/vendor/github.com/klauspost/compress/flate/fast_encoder.go @@ -6,6 +6,7 @@ package flate import ( + "encoding/binary" "fmt" "math/bits" ) @@ -65,26 +66,15 @@ func load32(b []byte, i int) uint32 { } func load64(b []byte, i int) uint64 { - // Help the compiler eliminate bounds checks on the read so it can be done in a single read. - b = b[i:] - b = b[:8] - return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | - uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 + return binary.LittleEndian.Uint64(b[i:]) } func load3232(b []byte, i int32) uint32 { - // Help the compiler eliminate bounds checks on the read so it can be done in a single read. - b = b[i:] - b = b[:4] - return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 + return binary.LittleEndian.Uint32(b[i:]) } func load6432(b []byte, i int32) uint64 { - // Help the compiler eliminate bounds checks on the read so it can be done in a single read. - b = b[i:] - b = b[:8] - return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | - uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 + return binary.LittleEndian.Uint64(b[i:]) } func hash(u uint32) uint32 { @@ -225,9 +215,9 @@ func (e *fastGen) Reset() { func matchLen(a, b []byte) int { b = b[:len(a)] var checked int - if len(a) > 4 { + if len(a) >= 4 { // Try 4 bytes first - if diff := load32(a, 0) ^ load32(b, 0); diff != 0 { + if diff := binary.LittleEndian.Uint32(a) ^ binary.LittleEndian.Uint32(b); diff != 0 { return bits.TrailingZeros32(diff) >> 3 } // Switch to 8 byte matching. @@ -236,7 +226,7 @@ func matchLen(a, b []byte) int { b = b[4:] for len(a) >= 8 { b = b[:len(a)] - if diff := load64(a, 0) ^ load64(b, 0); diff != 0 { + if diff := binary.LittleEndian.Uint64(a) ^ binary.LittleEndian.Uint64(b); diff != 0 { return checked + (bits.TrailingZeros64(diff) >> 3) } checked += 8 @@ -247,7 +237,7 @@ func matchLen(a, b []byte) int { b = b[:len(a)] for i := range a { if a[i] != b[i] { - return int(i) + checked + return i + checked } } return len(a) + checked diff --git a/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go b/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go index 208d66711..db54be139 100644 --- a/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go +++ b/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go @@ -5,6 +5,7 @@ package flate import ( + "encoding/binary" "io" ) @@ -206,7 +207,7 @@ func (w *huffmanBitWriter) write(b []byte) { } func (w *huffmanBitWriter) writeBits(b int32, nb uint16) { - w.bits |= uint64(b) << (w.nbits & reg16SizeMask64) + w.bits |= uint64(b) << w.nbits w.nbits += nb if w.nbits >= 48 { w.writeOutBits() @@ -420,13 +421,11 @@ func (w *huffmanBitWriter) writeOutBits() { w.bits >>= 48 w.nbits -= 48 n := w.nbytes - w.bytes[n] = byte(bits) - w.bytes[n+1] = byte(bits >> 8) - w.bytes[n+2] = byte(bits >> 16) - w.bytes[n+3] = byte(bits >> 24) - w.bytes[n+4] = byte(bits >> 32) - w.bytes[n+5] = byte(bits >> 40) + + // We over-write, but faster... + binary.LittleEndian.PutUint64(w.bytes[n:], bits) n += 6 + if n >= bufferFlushSize { if w.err != nil { n = 0 @@ -435,6 +434,7 @@ func (w *huffmanBitWriter) writeOutBits() { w.write(w.bytes[:n]) n = 0 } + w.nbytes = n } @@ -759,7 +759,7 @@ func (w *huffmanBitWriter) writeTokens(tokens []token, leCodes, oeCodes []hcode) } else { // inlined c := lengths[lengthCode&31] - w.bits |= uint64(c.code) << (w.nbits & reg16SizeMask64) + w.bits |= uint64(c.code) << w.nbits w.nbits += c.len if w.nbits >= 48 { w.writeOutBits() @@ -779,7 +779,7 @@ func (w *huffmanBitWriter) writeTokens(tokens []token, leCodes, oeCodes []hcode) } else { // inlined c := offs[offsetCode&31] - w.bits |= uint64(c.code) << (w.nbits & reg16SizeMask64) + w.bits |= uint64(c.code) << w.nbits w.nbits += c.len if w.nbits >= 48 { w.writeOutBits() @@ -830,8 +830,8 @@ func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte, sync bool) { // Assume header is around 70 bytes: // https://stackoverflow.com/a/25454430 const guessHeaderSizeBits = 70 * 8 - estBits, estExtra := histogramSize(input, w.literalFreq[:], !eof && !sync) - estBits += w.lastHeader + 15 + estBits := histogramSize(input, w.literalFreq[:], !eof && !sync) + estBits += w.lastHeader + len(input)/32 if w.lastHeader == 0 { estBits += guessHeaderSizeBits } @@ -845,9 +845,9 @@ func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte, sync bool) { return } + reuseSize := 0 if w.lastHeader > 0 { - reuseSize := w.literalEncoding.bitLength(w.literalFreq[:256]) - estBits += estExtra + reuseSize = w.literalEncoding.bitLength(w.literalFreq[:256]) if estBits < reuseSize { // We owe an EOB @@ -859,6 +859,10 @@ func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte, sync bool) { const numLiterals = endBlockMarker + 1 const numOffsets = 1 if w.lastHeader == 0 { + if !eof && !sync { + // Generate a slightly suboptimal tree that can be used for all. + fillHist(w.literalFreq[:numLiterals]) + } w.literalFreq[endBlockMarker] = 1 w.literalEncoding.generate(w.literalFreq[:numLiterals], 15) @@ -878,19 +882,14 @@ func (w *huffmanBitWriter) writeBlockHuff(eof bool, input []byte, sync bool) { for _, t := range input { // Bitwriting inlined, ~30% speedup c := encoding[t] - w.bits |= uint64(c.code) << ((w.nbits) & reg16SizeMask64) + w.bits |= uint64(c.code) << w.nbits w.nbits += c.len if w.nbits >= 48 { bits := w.bits w.bits >>= 48 w.nbits -= 48 n := w.nbytes - w.bytes[n] = byte(bits) - w.bytes[n+1] = byte(bits >> 8) - w.bytes[n+2] = byte(bits >> 16) - w.bytes[n+3] = byte(bits >> 24) - w.bytes[n+4] = byte(bits >> 32) - w.bytes[n+5] = byte(bits >> 40) + binary.LittleEndian.PutUint64(w.bytes[n:], bits) n += 6 if n >= bufferFlushSize { if w.err != nil { diff --git a/vendor/github.com/klauspost/compress/flate/huffman_code.go b/vendor/github.com/klauspost/compress/flate/huffman_code.go index 4c39a3018..0d3445a1c 100644 --- a/vendor/github.com/klauspost/compress/flate/huffman_code.go +++ b/vendor/github.com/klauspost/compress/flate/huffman_code.go @@ -122,6 +122,16 @@ func (h *huffmanEncoder) bitLength(freq []uint16) int { return total } +func (h *huffmanEncoder) bitLengthRaw(b []byte) int { + var total int + for _, f := range b { + if f != 0 { + total += int(h.codes[f].len) + } + } + return total +} + // Return the number of literals assigned to each bit size in the Huffman encoding // // This method is only called when list.length >= 3 @@ -327,37 +337,40 @@ func atLeastOne(v float32) float32 { return v } +// Unassigned values are assigned '1' in the histogram. +func fillHist(b []uint16) { + for i, v := range b { + if v == 0 { + b[i] = 1 + } + } +} + // histogramSize accumulates a histogram of b in h. // An estimated size in bits is returned. -// Unassigned values are assigned '1' in the histogram. // len(h) must be >= 256, and h's elements must be all zeroes. -func histogramSize(b []byte, h []uint16, fill bool) (int, int) { +func histogramSize(b []byte, h []uint16, fill bool) (bits int) { h = h[:256] for _, t := range b { h[t]++ } - invTotal := 1.0 / float32(len(b)) - shannon := float32(0.0) - var extra float32 + total := len(b) if fill { - oneBits := atLeastOne(-mFastLog2(invTotal)) - for i, v := range h[:] { - if v > 0 { - n := float32(v) - shannon += atLeastOne(-mFastLog2(n*invTotal)) * n - } else { - h[i] = 1 - extra += oneBits + for _, v := range h { + if v == 0 { + total++ } } - } else { - for _, v := range h[:] { - if v > 0 { - n := float32(v) - shannon += atLeastOne(-mFastLog2(n*invTotal)) * n - } + } + + invTotal := 1.0 / float32(total) + shannon := float32(0.0) + for _, v := range h { + if v > 0 { + n := float32(v) + shannon += atLeastOne(-mFastLog2(n*invTotal)) * n } } - return int(shannon + 0.99), int(extra + 0.99) + return int(shannon + 0.99) } diff --git a/vendor/github.com/klauspost/compress/flate/level2.go b/vendor/github.com/klauspost/compress/flate/level2.go index 5b986a194..234c4389a 100644 --- a/vendor/github.com/klauspost/compress/flate/level2.go +++ b/vendor/github.com/klauspost/compress/flate/level2.go @@ -155,7 +155,7 @@ func (e *fastEncL2) Encode(dst *tokens, src []byte) { // Store every second hash in-between, but offset by 1. for i := s - l + 2; i < s-5; i += 7 { - x := load6432(src, int32(i)) + x := load6432(src, i) nextHash := hash4u(uint32(x), bTableBits) e.table[nextHash] = tableEntry{offset: e.cur + i} // Skip one diff --git a/vendor/github.com/klauspost/compress/fse/compress.go b/vendor/github.com/klauspost/compress/fse/compress.go index b69237c9b..0d31f5ebc 100644 --- a/vendor/github.com/klauspost/compress/fse/compress.go +++ b/vendor/github.com/klauspost/compress/fse/compress.go @@ -301,7 +301,7 @@ func (s *Scratch) writeCount() error { out[outP+1] = byte(bitStream >> 8) outP += (bitCount + 7) / 8 - if uint16(charnum) > s.symbolLen { + if charnum > s.symbolLen { return errors.New("internal error: charnum > s.symbolLen") } s.Out = out[:outP] @@ -331,7 +331,7 @@ type cTable struct { func (s *Scratch) allocCtable() { tableSize := 1 << s.actualTableLog // get tableSymbol that is big enough. - if cap(s.ct.tableSymbol) < int(tableSize) { + if cap(s.ct.tableSymbol) < tableSize { s.ct.tableSymbol = make([]byte, tableSize) } s.ct.tableSymbol = s.ct.tableSymbol[:tableSize] @@ -565,8 +565,8 @@ func (s *Scratch) normalizeCount2() error { distributed uint32 total = uint32(s.br.remain()) tableLog = s.actualTableLog - lowThreshold = uint32(total >> tableLog) - lowOne = uint32((total * 3) >> (tableLog + 1)) + lowThreshold = total >> tableLog + lowOne = (total * 3) >> (tableLog + 1) ) for i, cnt := range s.count[:s.symbolLen] { if cnt == 0 { @@ -591,7 +591,7 @@ func (s *Scratch) normalizeCount2() error { if (total / toDistribute) > lowOne { // risk of rounding to zero - lowOne = uint32((total * 3) / (toDistribute * 2)) + lowOne = (total * 3) / (toDistribute * 2) for i, cnt := range s.count[:s.symbolLen] { if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) { s.norm[i] = 1 diff --git a/vendor/github.com/klauspost/compress/fse/decompress.go b/vendor/github.com/klauspost/compress/fse/decompress.go index 413ec3b3c..926f5f153 100644 --- a/vendor/github.com/klauspost/compress/fse/decompress.go +++ b/vendor/github.com/klauspost/compress/fse/decompress.go @@ -172,7 +172,7 @@ type decSymbol struct { // allocDtable will allocate decoding tables if they are not big enough. func (s *Scratch) allocDtable() { tableSize := 1 << s.actualTableLog - if cap(s.decTable) < int(tableSize) { + if cap(s.decTable) < tableSize { s.decTable = make([]decSymbol, tableSize) } s.decTable = s.decTable[:tableSize] @@ -340,7 +340,7 @@ type decoder struct { func (d *decoder) init(in *bitReader, dt []decSymbol, tableLog uint8) { d.dt = dt d.br = in - d.state = uint16(in.getBits(tableLog)) + d.state = in.getBits(tableLog) } // next returns the next symbol and sets the next state. diff --git a/vendor/github.com/klauspost/compress/huff0/compress.go b/vendor/github.com/klauspost/compress/huff0/compress.go index f9ed5f830..dea115b33 100644 --- a/vendor/github.com/klauspost/compress/huff0/compress.go +++ b/vendor/github.com/klauspost/compress/huff0/compress.go @@ -403,7 +403,7 @@ func (s *Scratch) buildCTable() error { var startNode = int16(s.symbolLen) nonNullRank := s.symbolLen - 1 - nodeNb := int16(startNode) + nodeNb := startNode huffNode := s.nodes[1 : huffNodesLen+1] // This overlays the slice above, but allows "-1" index lookups. @@ -580,7 +580,7 @@ func (s *Scratch) setMaxHeight(lastNonNull int) uint8 { // Get pos of last (smallest) symbol per rank { - currentNbBits := uint8(maxNbBits) + currentNbBits := maxNbBits for pos := int(n); pos >= 0; pos-- { if huffNode[pos].nbBits >= currentNbBits { continue diff --git a/vendor/github.com/klauspost/compress/snappy/snappy.go b/vendor/github.com/klauspost/compress/snappy/snappy.go index 74a36689e..ea58ced88 100644 --- a/vendor/github.com/klauspost/compress/snappy/snappy.go +++ b/vendor/github.com/klauspost/compress/snappy/snappy.go @@ -94,5 +94,5 @@ var crcTable = crc32.MakeTable(crc32.Castagnoli) // https://github.com/google/snappy/blob/master/framing_format.txt func crc(b []byte) uint32 { c := crc32.Update(0, crcTable, b) - return uint32(c>>15|c<<17) + 0xa282ead8 + return c>>15 | c<<17 + 0xa282ead8 } diff --git a/vendor/github.com/klauspost/compress/zstd/blockenc.go b/vendor/github.com/klauspost/compress/zstd/blockenc.go index c85c40255..9647c64e5 100644 --- a/vendor/github.com/klauspost/compress/zstd/blockenc.go +++ b/vendor/github.com/klauspost/compress/zstd/blockenc.go @@ -22,28 +22,44 @@ type blockEnc struct { dictLitEnc *huff0.Scratch wr bitWriter - extraLits int - last bool - + extraLits int output []byte recentOffsets [3]uint32 prevRecentOffsets [3]uint32 + + last bool + lowMem bool } // init should be used once the block has been created. // If called more than once, the effect is the same as calling reset. func (b *blockEnc) init() { - if cap(b.literals) < maxCompressedLiteralSize { - b.literals = make([]byte, 0, maxCompressedLiteralSize) - } - const defSeqs = 200 - b.literals = b.literals[:0] - if cap(b.sequences) < defSeqs { - b.sequences = make([]seq, 0, defSeqs) - } - if cap(b.output) < maxCompressedBlockSize { - b.output = make([]byte, 0, maxCompressedBlockSize) + if b.lowMem { + // 1K literals + if cap(b.literals) < 1<<10 { + b.literals = make([]byte, 0, 1<<10) + } + const defSeqs = 20 + if cap(b.sequences) < defSeqs { + b.sequences = make([]seq, 0, defSeqs) + } + // 1K + if cap(b.output) < 1<<10 { + b.output = make([]byte, 0, 1<<10) + } + } else { + if cap(b.literals) < maxCompressedBlockSize { + b.literals = make([]byte, 0, maxCompressedBlockSize) + } + const defSeqs = 200 + if cap(b.sequences) < defSeqs { + b.sequences = make([]seq, 0, defSeqs) + } + if cap(b.output) < maxCompressedBlockSize { + b.output = make([]byte, 0, maxCompressedBlockSize) + } } + if b.coders.mlEnc == nil { b.coders.mlEnc = &fseEncoder{} b.coders.mlPrev = &fseEncoder{} diff --git a/vendor/github.com/klauspost/compress/zstd/enc_base.go b/vendor/github.com/klauspost/compress/zstd/enc_base.go index b1b7c6e6a..2d4d893eb 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_base.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_base.go @@ -7,6 +7,10 @@ import ( "github.com/klauspost/compress/zstd/internal/xxhash" ) +const ( + dictShardBits = 6 +) + type fastBase struct { // cur is the offset at the start of hist cur int32 @@ -17,6 +21,7 @@ type fastBase struct { tmp [8]byte blk *blockEnc lastDictID uint32 + lowMem bool } // CRC returns the underlying CRC writer. @@ -57,15 +62,10 @@ func (e *fastBase) addBlock(src []byte) int32 { // check if we have space already if len(e.hist)+len(src) > cap(e.hist) { if cap(e.hist) == 0 { - l := e.maxMatchOff * 2 - // Make it at least 1MB. - if l < 1<<20 { - l = 1 << 20 - } - e.hist = make([]byte, 0, l) + e.ensureHist(len(src)) } else { - if cap(e.hist) < int(e.maxMatchOff*2) { - panic("unexpected buffer size") + if cap(e.hist) < int(e.maxMatchOff+maxCompressedBlockSize) { + panic(fmt.Errorf("unexpected buffer cap %d, want at least %d with window %d", cap(e.hist), e.maxMatchOff+maxCompressedBlockSize, e.maxMatchOff)) } // Move down offset := int32(len(e.hist)) - e.maxMatchOff @@ -79,6 +79,28 @@ func (e *fastBase) addBlock(src []byte) int32 { return s } +// ensureHist will ensure that history can keep at least this many bytes. +func (e *fastBase) ensureHist(n int) { + if cap(e.hist) >= n { + return + } + l := e.maxMatchOff + if (e.lowMem && e.maxMatchOff > maxCompressedBlockSize) || e.maxMatchOff <= maxCompressedBlockSize { + l += maxCompressedBlockSize + } else { + l += e.maxMatchOff + } + // Make it at least 1MB. + if l < 1<<20 && !e.lowMem { + l = 1 << 20 + } + // Make it at least the requested size. + if l < int32(n) { + l = int32(n) + } + e.hist = make([]byte, 0, l) +} + // useBlock will replace the block with the provided one, // but transfer recent offsets from the previous. func (e *fastBase) UseBlock(enc *blockEnc) { @@ -117,7 +139,7 @@ func (e *fastBase) matchlen(s, t int32, src []byte) int32 { // Reset the encoding table. func (e *fastBase) resetBase(d *dict, singleBlock bool) { if e.blk == nil { - e.blk = &blockEnc{} + e.blk = &blockEnc{lowMem: e.lowMem} e.blk.init() } else { e.blk.reset(nil) diff --git a/vendor/github.com/klauspost/compress/zstd/enc_best.go b/vendor/github.com/klauspost/compress/zstd/enc_best.go index bb71d1eea..fe3625c5f 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_best.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_best.go @@ -407,6 +407,7 @@ encodeLoop: // Most notable difference is that src will not be copied for history and // we do not need to check for max match length. func (e *bestFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) { + e.ensureHist(len(src)) e.Encode(blk, src) } diff --git a/vendor/github.com/klauspost/compress/zstd/enc_better.go b/vendor/github.com/klauspost/compress/zstd/enc_better.go index 94a5343d0..c2ce4a2ba 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_better.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_better.go @@ -16,6 +16,12 @@ const ( // This greatly depends on the type of input. betterShortTableBits = 13 // Bits used in the short match table betterShortTableSize = 1 << betterShortTableBits // Size of the table + + betterLongTableShardCnt = 1 << (betterLongTableBits - dictShardBits) // Number of shards in the table + betterLongTableShardSize = betterLongTableSize / betterLongTableShardCnt // Size of an individual shard + + betterShortTableShardCnt = 1 << (betterShortTableBits - dictShardBits) // Number of shards in the table + betterShortTableShardSize = betterShortTableSize / betterShortTableShardCnt // Size of an individual shard ) type prevEntry struct { @@ -31,10 +37,17 @@ type prevEntry struct { // and that it is longer (lazy matching). type betterFastEncoder struct { fastBase - table [betterShortTableSize]tableEntry - longTable [betterLongTableSize]prevEntry - dictTable []tableEntry - dictLongTable []prevEntry + table [betterShortTableSize]tableEntry + longTable [betterLongTableSize]prevEntry +} + +type betterFastEncoderDict struct { + betterFastEncoder + dictTable []tableEntry + dictLongTable []prevEntry + shortTableShardDirty [betterShortTableShardCnt]bool + longTableShardDirty [betterLongTableShardCnt]bool + allDirty bool } // Encode improves compression... @@ -516,12 +529,512 @@ encodeLoop: // Most notable difference is that src will not be copied for history and // we do not need to check for max match length. func (e *betterFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) { + e.ensureHist(len(src)) e.Encode(blk, src) } +// Encode improves compression... +func (e *betterFastEncoderDict) Encode(blk *blockEnc, src []byte) { + const ( + // Input margin is the number of bytes we read (8) + // and the maximum we will read ahead (2) + inputMargin = 8 + 2 + minNonLiteralBlockSize = 16 + ) + + // 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.longTable[:] { + e.longTable[i] = prevEntry{} + } + e.cur = e.maxMatchOff + e.allDirty = true + break + } + // Shift down everything in the table that isn't already too far away. + minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff + for i := range e.table[:] { + v := e.table[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.table[i].offset = v + } + for i := range e.longTable[:] { + v := e.longTable[i].offset + v2 := e.longTable[i].prev + if v < minOff { + v = 0 + v2 = 0 + } else { + v = v - e.cur + e.maxMatchOff + if v2 < minOff { + v2 = 0 + } else { + v2 = v2 - e.cur + e.maxMatchOff + } + } + e.longTable[i] = prevEntry{ + offset: v, + prev: v2, + } + } + e.allDirty = true + e.cur = e.maxMatchOff + break + } + + s := e.addBlock(src) + blk.size = len(src) + if len(src) < minNonLiteralBlockSize { + blk.extraLits = len(src) + blk.literals = blk.literals[:len(src)] + copy(blk.literals, src) + return + } + + // Override src + src = e.hist + sLimit := int32(len(src)) - inputMargin + // stepSize is the number of bytes to skip on every main loop iteration. + // It should be >= 1. + const stepSize = 1 + + const kSearchStrength = 9 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := s + cv := load6432(src, s) + + // Relative offsets + offset1 := int32(blk.recentOffsets[0]) + offset2 := int32(blk.recentOffsets[1]) + + addLiterals := func(s *seq, until int32) { + if until == nextEmit { + return + } + blk.literals = append(blk.literals, src[nextEmit:until]...) + s.litLen = uint32(until - nextEmit) + } + if debug { + println("recent offsets:", blk.recentOffsets) + } + +encodeLoop: + for { + var t int32 + // We allow the encoder to optionally turn off repeat offsets across blocks + canRepeat := len(blk.sequences) > 2 + var matched int32 + + for { + if debugAsserts && canRepeat && offset1 == 0 { + panic("offset0 was 0") + } + + nextHashS := hash5(cv, betterShortTableBits) + nextHashL := hash8(cv, betterLongTableBits) + candidateL := e.longTable[nextHashL] + candidateS := e.table[nextHashS] + + const repOff = 1 + repIndex := s - offset1 + repOff + off := s + e.cur + e.longTable[nextHashL] = prevEntry{offset: off, prev: candidateL.offset} + e.markLongShardDirty(nextHashL) + e.table[nextHashS] = tableEntry{offset: off, val: uint32(cv)} + e.markShortShardDirty(nextHashS) + + if canRepeat { + if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) { + // Consider history as well. + var seq seq + lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + repOff + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 0 + seq.offset = 1 + if debugSequences { + println("repeat sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Index match start+1 (long) -> s - 1 + index0 := s + repOff + s += lenght + repOff + + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + // Index skipped... + for index0 < s-1 { + cv0 := load6432(src, index0) + cv1 := cv0 >> 8 + h0 := hash8(cv0, betterLongTableBits) + off := index0 + e.cur + e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset} + e.markLongShardDirty(h0) + h1 := hash5(cv1, betterShortTableBits) + e.table[h1] = tableEntry{offset: off + 1, val: uint32(cv1)} + e.markShortShardDirty(h1) + index0 += 2 + } + cv = load6432(src, s) + continue + } + const repOff2 = 1 + + // We deviate from the reference encoder and also check offset 2. + // Still slower and not much better, so disabled. + // repIndex = s - offset2 + repOff2 + if false && repIndex >= 0 && load6432(src, repIndex) == load6432(src, s+repOff) { + // Consider history as well. + var seq seq + lenght := 8 + e.matchlen(s+8+repOff2, repIndex+8, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + repOff2 + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 2 + seq.offset = 2 + if debugSequences { + println("repeat sequence 2", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + index0 := s + repOff2 + s += lenght + repOff2 + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + + // Index skipped... + for index0 < s-1 { + cv0 := load6432(src, index0) + cv1 := cv0 >> 8 + h0 := hash8(cv0, betterLongTableBits) + off := index0 + e.cur + e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset} + e.markLongShardDirty(h0) + h1 := hash5(cv1, betterShortTableBits) + e.table[h1] = tableEntry{offset: off + 1, val: uint32(cv1)} + e.markShortShardDirty(h1) + index0 += 2 + } + cv = load6432(src, s) + // Swap offsets + offset1, offset2 = offset2, offset1 + continue + } + } + // Find the offsets of our two matches. + coffsetL := candidateL.offset - e.cur + coffsetLP := candidateL.prev - e.cur + + // Check if we have a long match. + if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) { + // Found a long match, at least 8 bytes. + matched = e.matchlen(s+8, coffsetL+8, src) + 8 + t = coffsetL + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugMatches { + println("long match") + } + + if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) { + // Found a long match, at least 8 bytes. + prevMatch := e.matchlen(s+8, coffsetLP+8, src) + 8 + if prevMatch > matched { + matched = prevMatch + t = coffsetLP + } + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugMatches { + println("long match") + } + } + break + } + + // Check if we have a long match on prev. + if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) { + // Found a long match, at least 8 bytes. + matched = e.matchlen(s+8, coffsetLP+8, src) + 8 + t = coffsetLP + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugMatches { + println("long match") + } + break + } + + coffsetS := candidateS.offset - e.cur + + // Check if we have a short match. + if s-coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { + // found a regular match + matched = e.matchlen(s+4, coffsetS+4, src) + 4 + + // See if we can find a long match at s+1 + const checkAt = 1 + cv := load6432(src, s+checkAt) + nextHashL = hash8(cv, betterLongTableBits) + candidateL = e.longTable[nextHashL] + coffsetL = candidateL.offset - e.cur + + // We can store it, since we have at least a 4 byte match. + e.longTable[nextHashL] = prevEntry{offset: s + checkAt + e.cur, prev: candidateL.offset} + e.markLongShardDirty(nextHashL) + if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) { + // Found a long match, at least 8 bytes. + matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8 + if matchedNext > matched { + t = coffsetL + s += checkAt + matched = matchedNext + if debugMatches { + println("long match (after short)") + } + break + } + } + + // Check prev long... + coffsetL = candidateL.prev - e.cur + if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) { + // Found a long match, at least 8 bytes. + matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8 + if matchedNext > matched { + t = coffsetL + s += checkAt + matched = matchedNext + if debugMatches { + println("prev long match (after short)") + } + break + } + } + t = coffsetS + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugAsserts && t < 0 { + panic("t<0") + } + if debugMatches { + println("short match") + } + break + } + + // No match found, move forward in input. + s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + } + + // A 4-byte match has been found. Update recent offsets. + // We'll later see if more than 4 bytes. + offset2 = offset1 + offset1 = s - t + + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + + if debugAsserts && canRepeat && int(offset1) > len(src) { + panic("invalid offset") + } + + // Extend the n-byte match as long as possible. + l := matched + + // Extend backwards + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { + s-- + t-- + l++ + } + + // Write our sequence + var seq seq + seq.litLen = uint32(s - nextEmit) + seq.matchLen = uint32(l - zstdMinMatch) + if seq.litLen > 0 { + blk.literals = append(blk.literals, src[nextEmit:s]...) + } + seq.offset = uint32(s-t) + 3 + s += l + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + nextEmit = s + if s >= sLimit { + break encodeLoop + } + + // Index match start+1 (long) -> s - 1 + index0 := s - l + 1 + for index0 < s-1 { + cv0 := load6432(src, index0) + cv1 := cv0 >> 8 + h0 := hash8(cv0, betterLongTableBits) + off := index0 + e.cur + e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset} + e.markLongShardDirty(h0) + h1 := hash5(cv1, betterShortTableBits) + e.table[h1] = tableEntry{offset: off + 1, val: uint32(cv1)} + e.markShortShardDirty(h1) + index0 += 2 + } + + cv = load6432(src, s) + if !canRepeat { + continue + } + + // Check offset 2 + for { + o2 := s - offset2 + if load3232(src, o2) != uint32(cv) { + // Do regular search + break + } + + // Store this, since we have it. + nextHashS := hash5(cv, betterShortTableBits) + nextHashL := hash8(cv, betterLongTableBits) + + // We have at least 4 byte match. + // No need to check backwards. We come straight from a match + l := 4 + e.matchlen(s+4, o2+4, src) + + e.longTable[nextHashL] = prevEntry{offset: s + e.cur, prev: e.longTable[nextHashL].offset} + e.markLongShardDirty(nextHashL) + e.table[nextHashS] = tableEntry{offset: s + e.cur, val: uint32(cv)} + e.markShortShardDirty(nextHashS) + seq.matchLen = uint32(l) - zstdMinMatch + seq.litLen = 0 + + // Since litlen is always 0, this is offset 1. + seq.offset = 1 + s += l + nextEmit = s + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Swap offset 1 and 2. + offset1, offset2 = offset2, offset1 + if s >= sLimit { + // Finished + break encodeLoop + } + cv = load6432(src, s) + } + } + + if int(nextEmit) < len(src) { + blk.literals = append(blk.literals, src[nextEmit:]...) + blk.extraLits = len(src) - int(nextEmit) + } + blk.recentOffsets[0] = uint32(offset1) + blk.recentOffsets[1] = uint32(offset2) + if debug { + println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) + } +} + // ResetDict will reset and set a dictionary if not nil func (e *betterFastEncoder) Reset(d *dict, singleBlock bool) { e.resetBase(d, singleBlock) + if d != nil { + panic("betterFastEncoder: Reset with dict") + } +} + +// ResetDict will reset and set a dictionary if not nil +func (e *betterFastEncoderDict) Reset(d *dict, singleBlock bool) { + e.resetBase(d, singleBlock) if d == nil { return } @@ -557,6 +1070,7 @@ func (e *betterFastEncoder) Reset(d *dict, singleBlock bool) { } } e.lastDictID = d.id + e.allDirty = true } // Init or copy dict table @@ -585,11 +1099,72 @@ func (e *betterFastEncoder) Reset(d *dict, singleBlock bool) { } } e.lastDictID = d.id + e.allDirty = true } + // Reset table to initial state - copy(e.longTable[:], e.dictLongTable) + { + dirtyShardCnt := 0 + if !e.allDirty { + for i := range e.shortTableShardDirty { + if e.shortTableShardDirty[i] { + dirtyShardCnt++ + } + } + } + const shardCnt = betterShortTableShardCnt + const shardSize = betterShortTableShardSize + if e.allDirty || dirtyShardCnt > shardCnt*4/6 { + copy(e.table[:], e.dictTable) + for i := range e.shortTableShardDirty { + e.shortTableShardDirty[i] = false + } + } else { + for i := range e.shortTableShardDirty { + if !e.shortTableShardDirty[i] { + continue + } + copy(e.table[i*shardSize:(i+1)*shardSize], e.dictTable[i*shardSize:(i+1)*shardSize]) + e.shortTableShardDirty[i] = false + } + } + } + { + dirtyShardCnt := 0 + if !e.allDirty { + for i := range e.shortTableShardDirty { + if e.shortTableShardDirty[i] { + dirtyShardCnt++ + } + } + } + const shardCnt = betterLongTableShardCnt + const shardSize = betterLongTableShardSize + if e.allDirty || dirtyShardCnt > shardCnt*4/6 { + copy(e.longTable[:], e.dictLongTable) + for i := range e.longTableShardDirty { + e.longTableShardDirty[i] = false + } + } else { + for i := range e.longTableShardDirty { + if !e.longTableShardDirty[i] { + continue + } + + copy(e.longTable[i*shardSize:(i+1)*shardSize], e.dictLongTable[i*shardSize:(i+1)*shardSize]) + e.longTableShardDirty[i] = false + } + } + } e.cur = e.maxMatchOff - // Reset table to initial state - copy(e.table[:], e.dictTable) + e.allDirty = false +} + +func (e *betterFastEncoderDict) markLongShardDirty(entryNum uint32) { + e.longTableShardDirty[entryNum/betterLongTableShardSize] = true +} + +func (e *betterFastEncoderDict) markShortShardDirty(entryNum uint32) { + e.shortTableShardDirty[entryNum/betterShortTableShardSize] = true } diff --git a/vendor/github.com/klauspost/compress/zstd/enc_dfast.go b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go index 19eebf66e..8629d43d8 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_dfast.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go @@ -11,6 +11,9 @@ const ( dFastLongTableSize = 1 << dFastLongTableBits // Size of the table dFastLongTableMask = dFastLongTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. + dLongTableShardCnt = 1 << (dFastLongTableBits - dictShardBits) // Number of shards in the table + dLongTableShardSize = dFastLongTableSize / tableShardCnt // Size of an individual shard + dFastShortTableBits = tableBits // Bits used in the short match table dFastShortTableSize = 1 << dFastShortTableBits // Size of the table dFastShortTableMask = dFastShortTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. @@ -18,8 +21,14 @@ const ( type doubleFastEncoder struct { fastEncoder - longTable [dFastLongTableSize]tableEntry - dictLongTable []tableEntry + longTable [dFastLongTableSize]tableEntry +} + +type doubleFastEncoderDict struct { + fastEncoderDict + longTable [dFastLongTableSize]tableEntry + dictLongTable []tableEntry + longTableShardDirty [dLongTableShardCnt]bool } // Encode mimmics functionality in zstd_dfast.c @@ -678,9 +687,379 @@ encodeLoop: } } +// Encode will encode the content, with a dictionary if initialized for it. +func (e *doubleFastEncoderDict) Encode(blk *blockEnc, src []byte) { + const ( + // Input margin is the number of bytes we read (8) + // and the maximum we will read ahead (2) + inputMargin = 8 + 2 + minNonLiteralBlockSize = 16 + ) + + // 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.longTable[:] { + e.longTable[i] = tableEntry{} + } + e.markAllShardsDirty() + e.cur = e.maxMatchOff + break + } + // Shift down everything in the table that isn't already too far away. + minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff + for i := range e.table[:] { + v := e.table[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.table[i].offset = v + } + for i := range e.longTable[:] { + v := e.longTable[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.longTable[i].offset = v + } + e.markAllShardsDirty() + e.cur = e.maxMatchOff + break + } + + s := e.addBlock(src) + blk.size = len(src) + if len(src) < minNonLiteralBlockSize { + blk.extraLits = len(src) + blk.literals = blk.literals[:len(src)] + copy(blk.literals, src) + return + } + + // Override src + src = e.hist + sLimit := int32(len(src)) - inputMargin + // stepSize is the number of bytes to skip on every main loop iteration. + // It should be >= 1. + const stepSize = 1 + + const kSearchStrength = 8 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := s + cv := load6432(src, s) + + // Relative offsets + offset1 := int32(blk.recentOffsets[0]) + offset2 := int32(blk.recentOffsets[1]) + + addLiterals := func(s *seq, until int32) { + if until == nextEmit { + return + } + blk.literals = append(blk.literals, src[nextEmit:until]...) + s.litLen = uint32(until - nextEmit) + } + if debug { + println("recent offsets:", blk.recentOffsets) + } + +encodeLoop: + for { + var t int32 + // We allow the encoder to optionally turn off repeat offsets across blocks + canRepeat := len(blk.sequences) > 2 + + for { + if debugAsserts && canRepeat && offset1 == 0 { + panic("offset0 was 0") + } + + nextHashS := hash5(cv, dFastShortTableBits) + nextHashL := hash8(cv, dFastLongTableBits) + candidateL := e.longTable[nextHashL] + candidateS := e.table[nextHashS] + + const repOff = 1 + repIndex := s - offset1 + repOff + entry := tableEntry{offset: s + e.cur, val: uint32(cv)} + e.longTable[nextHashL] = entry + e.markLongShardDirty(nextHashL) + e.table[nextHashS] = entry + e.markShardDirty(nextHashS) + + if canRepeat { + if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) { + // Consider history as well. + var seq seq + lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + repOff + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 0 + seq.offset = 1 + if debugSequences { + println("repeat sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + s += lenght + repOff + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + cv = load6432(src, s) + continue + } + } + // Find the offsets of our two matches. + coffsetL := s - (candidateL.offset - e.cur) + coffsetS := s - (candidateS.offset - e.cur) + + // Check if we have a long match. + if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { + // Found a long match, likely at least 8 bytes. + // Reference encoder checks all 8 bytes, we only check 4, + // but the likelihood of both the first 4 bytes and the hash matching should be enough. + t = candidateL.offset - e.cur + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugMatches { + println("long match") + } + break + } + + // Check if we have a short match. + if coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { + // found a regular match + // See if we can find a long match at s+1 + const checkAt = 1 + cv := load6432(src, s+checkAt) + nextHashL = hash8(cv, dFastLongTableBits) + candidateL = e.longTable[nextHashL] + coffsetL = s - (candidateL.offset - e.cur) + checkAt + + // We can store it, since we have at least a 4 byte match. + e.longTable[nextHashL] = tableEntry{offset: s + checkAt + e.cur, val: uint32(cv)} + e.markLongShardDirty(nextHashL) + if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { + // Found a long match, likely at least 8 bytes. + // Reference encoder checks all 8 bytes, we only check 4, + // but the likelihood of both the first 4 bytes and the hash matching should be enough. + t = candidateL.offset - e.cur + s += checkAt + if debugMatches { + println("long match (after short)") + } + break + } + + t = candidateS.offset - e.cur + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugAsserts && t < 0 { + panic("t<0") + } + if debugMatches { + println("short match") + } + break + } + + // No match found, move forward in input. + s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + } + + // A 4-byte match has been found. Update recent offsets. + // We'll later see if more than 4 bytes. + offset2 = offset1 + offset1 = s - t + + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + + if debugAsserts && canRepeat && int(offset1) > len(src) { + panic("invalid offset") + } + + // Extend the 4-byte match as long as possible. + l := e.matchlen(s+4, t+4, src) + 4 + + // Extend backwards + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { + s-- + t-- + l++ + } + + // Write our sequence + var seq seq + seq.litLen = uint32(s - nextEmit) + seq.matchLen = uint32(l - zstdMinMatch) + if seq.litLen > 0 { + blk.literals = append(blk.literals, src[nextEmit:s]...) + } + seq.offset = uint32(s-t) + 3 + s += l + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + nextEmit = s + if s >= sLimit { + break encodeLoop + } + + // Index match start+1 (long) and start+2 (short) + index0 := s - l + 1 + // Index match end-2 (long) and end-1 (short) + index1 := s - 2 + + cv0 := load6432(src, index0) + cv1 := load6432(src, index1) + te0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)} + te1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)} + longHash1 := hash8(cv0, dFastLongTableBits) + longHash2 := hash8(cv0, dFastLongTableBits) + e.longTable[longHash1] = te0 + e.longTable[longHash2] = te1 + e.markLongShardDirty(longHash1) + e.markLongShardDirty(longHash2) + cv0 >>= 8 + cv1 >>= 8 + te0.offset++ + te1.offset++ + te0.val = uint32(cv0) + te1.val = uint32(cv1) + hashVal1 := hash5(cv0, dFastShortTableBits) + hashVal2 := hash5(cv1, dFastShortTableBits) + e.table[hashVal1] = te0 + e.markShardDirty(hashVal1) + e.table[hashVal2] = te1 + e.markShardDirty(hashVal2) + + cv = load6432(src, s) + + if !canRepeat { + continue + } + + // Check offset 2 + for { + o2 := s - offset2 + if load3232(src, o2) != uint32(cv) { + // Do regular search + break + } + + // Store this, since we have it. + nextHashS := hash5(cv, dFastShortTableBits) + nextHashL := hash8(cv, dFastLongTableBits) + + // We have at least 4 byte match. + // No need to check backwards. We come straight from a match + l := 4 + e.matchlen(s+4, o2+4, src) + + entry := tableEntry{offset: s + e.cur, val: uint32(cv)} + e.longTable[nextHashL] = entry + e.markLongShardDirty(nextHashL) + e.table[nextHashS] = entry + e.markShardDirty(nextHashS) + seq.matchLen = uint32(l) - zstdMinMatch + seq.litLen = 0 + + // Since litlen is always 0, this is offset 1. + seq.offset = 1 + s += l + nextEmit = s + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Swap offset 1 and 2. + offset1, offset2 = offset2, offset1 + if s >= sLimit { + // Finished + break encodeLoop + } + cv = load6432(src, s) + } + } + + if int(nextEmit) < len(src) { + blk.literals = append(blk.literals, src[nextEmit:]...) + blk.extraLits = len(src) - int(nextEmit) + } + blk.recentOffsets[0] = uint32(offset1) + blk.recentOffsets[1] = uint32(offset2) + if debug { + println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) + } + // If we encoded more than 64K mark all dirty. + if len(src) > 64<<10 { + e.markAllShardsDirty() + } +} + // ResetDict will reset and set a dictionary if not nil func (e *doubleFastEncoder) Reset(d *dict, singleBlock bool) { e.fastEncoder.Reset(d, singleBlock) + if d != nil { + panic("doubleFastEncoder: Reset with dict not supported") + } +} + +// ResetDict will reset and set a dictionary if not nil +func (e *doubleFastEncoderDict) Reset(d *dict, singleBlock bool) { + allDirty := e.allDirty + e.fastEncoderDict.Reset(d, singleBlock) if d == nil { return } @@ -706,8 +1085,37 @@ func (e *doubleFastEncoder) Reset(d *dict, singleBlock bool) { } } e.lastDictID = d.id + e.allDirty = true } // Reset table to initial state e.cur = e.maxMatchOff - copy(e.longTable[:], e.dictLongTable) + + dirtyShardCnt := 0 + if !allDirty { + for i := range e.longTableShardDirty { + if e.longTableShardDirty[i] { + dirtyShardCnt++ + } + } + } + + if allDirty || dirtyShardCnt > dLongTableShardCnt/2 { + copy(e.longTable[:], e.dictLongTable) + for i := range e.longTableShardDirty { + e.longTableShardDirty[i] = false + } + return + } + for i := range e.longTableShardDirty { + if !e.longTableShardDirty[i] { + continue + } + + copy(e.longTable[i*dLongTableShardSize:(i+1)*dLongTableShardSize], e.dictLongTable[i*dLongTableShardSize:(i+1)*dLongTableShardSize]) + e.longTableShardDirty[i] = false + } +} + +func (e *doubleFastEncoderDict) markLongShardDirty(entryNum uint32) { + e.longTableShardDirty[entryNum/dLongTableShardSize] = true } diff --git a/vendor/github.com/klauspost/compress/zstd/enc_fast.go b/vendor/github.com/klauspost/compress/zstd/enc_fast.go index 0045016d9..ba4a17e10 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_fast.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_fast.go @@ -11,9 +11,11 @@ import ( ) const ( - tableBits = 15 // Bits used in the table - tableSize = 1 << tableBits // Size of the table - tableMask = tableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. + tableBits = 15 // Bits used in the table + tableSize = 1 << tableBits // Size of the table + tableShardCnt = 1 << (tableBits - dictShardBits) // Number of shards in the table + tableShardSize = tableSize / tableShardCnt // Size of an individual shard + tableMask = tableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. maxMatchLength = 131074 ) @@ -24,8 +26,14 @@ type tableEntry struct { type fastEncoder struct { fastBase - table [tableSize]tableEntry - dictTable []tableEntry + table [tableSize]tableEntry +} + +type fastEncoderDict struct { + fastEncoder + dictTable []tableEntry + tableShardDirty [tableShardCnt]bool + allDirty bool } // Encode mimmics functionality in zstd_fast.c @@ -617,9 +625,323 @@ encodeLoop: } } +// Encode will encode the content, with a dictionary if initialized for it. +func (e *fastEncoderDict) Encode(blk *blockEnc, src []byte) { + const ( + inputMargin = 8 + minNonLiteralBlockSize = 1 + 1 + inputMargin + ) + if e.allDirty || len(src) > 32<<10 { + e.fastEncoder.Encode(blk, src) + e.allDirty = true + return + } + // 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 = e.maxMatchOff + break + } + // Shift down everything in the table that isn't already too far away. + minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff + for i := range e.table[:] { + v := e.table[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.table[i].offset = v + } + e.cur = e.maxMatchOff + break + } + + s := e.addBlock(src) + blk.size = len(src) + if len(src) < minNonLiteralBlockSize { + blk.extraLits = len(src) + blk.literals = blk.literals[:len(src)] + copy(blk.literals, src) + return + } + + // Override src + src = e.hist + sLimit := int32(len(src)) - inputMargin + // stepSize is the number of bytes to skip on every main loop iteration. + // It should be >= 2. + const stepSize = 2 + + // TEMPLATE + const hashLog = tableBits + // seems global, but would be nice to tweak. + const kSearchStrength = 7 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := s + cv := load6432(src, s) + + // Relative offsets + offset1 := int32(blk.recentOffsets[0]) + offset2 := int32(blk.recentOffsets[1]) + + addLiterals := func(s *seq, until int32) { + if until == nextEmit { + return + } + blk.literals = append(blk.literals, src[nextEmit:until]...) + s.litLen = uint32(until - nextEmit) + } + if debug { + println("recent offsets:", blk.recentOffsets) + } + +encodeLoop: + for { + // t will contain the match offset when we find one. + // When existing the search loop, we have already checked 4 bytes. + var t int32 + + // We will not use repeat offsets across blocks. + // By not using them for the first 3 matches + canRepeat := len(blk.sequences) > 2 + + for { + if debugAsserts && canRepeat && offset1 == 0 { + panic("offset0 was 0") + } + + nextHash := hash6(cv, hashLog) + nextHash2 := hash6(cv>>8, hashLog) + candidate := e.table[nextHash] + candidate2 := e.table[nextHash2] + repIndex := s - offset1 + 2 + + e.table[nextHash] = tableEntry{offset: s + e.cur, val: uint32(cv)} + e.markShardDirty(nextHash) + e.table[nextHash2] = tableEntry{offset: s + e.cur + 1, val: uint32(cv >> 8)} + e.markShardDirty(nextHash2) + + if canRepeat && repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>16) { + // Consider history as well. + var seq seq + var length int32 + // length = 4 + e.matchlen(s+6, repIndex+4, src) + { + a := src[s+6:] + b := src[repIndex+4:] + endI := len(a) & (math.MaxInt32 - 7) + length = int32(endI) + 4 + for i := 0; i < endI; i += 8 { + if diff := load64(a, i) ^ load64(b, i); diff != 0 { + length = int32(i+bits.TrailingZeros64(diff)>>3) + 4 + break + } + } + } + + seq.matchLen = uint32(length - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + 2 + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + sMin := s - e.maxMatchOff + if sMin < 0 { + sMin = 0 + } + for repIndex > sMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 0 + seq.offset = 1 + if debugSequences { + println("repeat sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + s += length + 2 + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, length) + + } + break encodeLoop + } + cv = load6432(src, s) + continue + } + coffset0 := s - (candidate.offset - e.cur) + coffset1 := s - (candidate2.offset - e.cur) + 1 + if coffset0 < e.maxMatchOff && uint32(cv) == candidate.val { + // found a regular match + t = candidate.offset - e.cur + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + break + } + + if coffset1 < e.maxMatchOff && uint32(cv>>8) == candidate2.val { + // found a regular match + t = candidate2.offset - e.cur + s++ + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + if debugAsserts && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debugAsserts && t < 0 { + panic("t<0") + } + break + } + s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + } + // A 4-byte match has been found. We'll later see if more than 4 bytes. + offset2 = offset1 + offset1 = s - t + + if debugAsserts && s <= t { + panic(fmt.Sprintf("s (%d) <= t (%d)", s, t)) + } + + if debugAsserts && canRepeat && int(offset1) > len(src) { + panic("invalid offset") + } + + // Extend the 4-byte match as long as possible. + //l := e.matchlen(s+4, t+4, src) + 4 + var l int32 + { + a := src[s+4:] + b := src[t+4:] + endI := len(a) & (math.MaxInt32 - 7) + l = int32(endI) + 4 + for i := 0; i < endI; i += 8 { + if diff := load64(a, i) ^ load64(b, i); diff != 0 { + l = int32(i+bits.TrailingZeros64(diff)>>3) + 4 + break + } + } + } + + // Extend backwards + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { + s-- + t-- + l++ + } + + // Write our sequence. + var seq seq + seq.litLen = uint32(s - nextEmit) + seq.matchLen = uint32(l - zstdMinMatch) + if seq.litLen > 0 { + blk.literals = append(blk.literals, src[nextEmit:s]...) + } + // Don't use repeat offsets + seq.offset = uint32(s-t) + 3 + s += l + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + nextEmit = s + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + + // Check offset 2 + if o2 := s - offset2; canRepeat && load3232(src, o2) == uint32(cv) { + // We have at least 4 byte match. + // No need to check backwards. We come straight from a match + //l := 4 + e.matchlen(s+4, o2+4, src) + var l int32 + { + a := src[s+4:] + b := src[o2+4:] + endI := len(a) & (math.MaxInt32 - 7) + l = int32(endI) + 4 + for i := 0; i < endI; i += 8 { + if diff := load64(a, i) ^ load64(b, i); diff != 0 { + l = int32(i+bits.TrailingZeros64(diff)>>3) + 4 + break + } + } + } + + // Store this, since we have it. + nextHash := hash6(cv, hashLog) + e.table[nextHash] = tableEntry{offset: s + e.cur, val: uint32(cv)} + e.markShardDirty(nextHash) + seq.matchLen = uint32(l) - zstdMinMatch + seq.litLen = 0 + // Since litlen is always 0, this is offset 1. + seq.offset = 1 + s += l + nextEmit = s + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Swap offset 1 and 2. + offset1, offset2 = offset2, offset1 + if s >= sLimit { + break encodeLoop + } + // Prepare next loop. + cv = load6432(src, s) + } + } + + if int(nextEmit) < len(src) { + blk.literals = append(blk.literals, src[nextEmit:]...) + blk.extraLits = len(src) - int(nextEmit) + } + blk.recentOffsets[0] = uint32(offset1) + blk.recentOffsets[1] = uint32(offset2) + if debug { + println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) + } +} + // ResetDict will reset and set a dictionary if not nil func (e *fastEncoder) Reset(d *dict, singleBlock bool) { e.resetBase(d, singleBlock) + if d != nil { + panic("fastEncoder: Reset with dict") + } +} + +// ResetDict will reset and set a dictionary if not nil +func (e *fastEncoderDict) Reset(d *dict, singleBlock bool) { + e.resetBase(d, singleBlock) if d == nil { return } @@ -653,9 +975,44 @@ func (e *fastEncoder) Reset(d *dict, singleBlock bool) { } } e.lastDictID = d.id + e.allDirty = true } e.cur = e.maxMatchOff - // Reset table to initial state - copy(e.table[:], e.dictTable) + dirtyShardCnt := 0 + if !e.allDirty { + for i := range e.tableShardDirty { + if e.tableShardDirty[i] { + dirtyShardCnt++ + } + } + } + + const shardCnt = tableShardCnt + const shardSize = tableShardSize + if e.allDirty || dirtyShardCnt > shardCnt*4/6 { + copy(e.table[:], e.dictTable) + for i := range e.tableShardDirty { + e.tableShardDirty[i] = false + } + e.allDirty = false + return + } + for i := range e.tableShardDirty { + if !e.tableShardDirty[i] { + continue + } + + copy(e.table[i*shardSize:(i+1)*shardSize], e.dictTable[i*shardSize:(i+1)*shardSize]) + e.tableShardDirty[i] = false + } + e.allDirty = false +} + +func (e *fastEncoderDict) markAllShardsDirty() { + e.allDirty = true +} + +func (e *fastEncoderDict) markShardDirty(entryNum uint32) { + e.tableShardDirty[entryNum/tableShardSize] = true } diff --git a/vendor/github.com/klauspost/compress/zstd/encoder.go b/vendor/github.com/klauspost/compress/zstd/encoder.go index f5759211d..6f0265099 100644 --- a/vendor/github.com/klauspost/compress/zstd/encoder.go +++ b/vendor/github.com/klauspost/compress/zstd/encoder.go @@ -106,7 +106,7 @@ func (e *Encoder) Reset(w io.Writer) { s.encoder = e.o.encoder() } if s.writing == nil { - s.writing = &blockEnc{} + s.writing = &blockEnc{lowMem: e.o.lowMem} s.writing.init() } s.writing.initNewEncode() @@ -176,6 +176,12 @@ func (e *Encoder) nextBlock(final bool) error { } if !s.headerWritten { // If we have a single block encode, do a sync compression. + if final && len(s.filling) == 0 && !e.o.fullZero { + s.headerWritten = true + s.fullFrameWritten = true + s.eofWritten = true + return nil + } if final && len(s.filling) > 0 { s.current = e.EncodeAll(s.filling, s.current[:0]) var n2 int @@ -471,7 +477,7 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte { } // If less than 1MB, allocate a buffer up front. - if len(dst) == 0 && cap(dst) == 0 && len(src) < 1<<20 { + if len(dst) == 0 && cap(dst) == 0 && len(src) < 1<<20 && !e.o.lowMem { dst = make([]byte, 0, len(src)) } dst, err := fh.appendTo(dst) diff --git a/vendor/github.com/klauspost/compress/zstd/encoder_options.go b/vendor/github.com/klauspost/compress/zstd/encoder_options.go index a7312f42a..18a47eb03 100644 --- a/vendor/github.com/klauspost/compress/zstd/encoder_options.go +++ b/vendor/github.com/klauspost/compress/zstd/encoder_options.go @@ -24,12 +24,12 @@ type encoderOptions struct { allLitEntropy bool customWindow bool customALEntropy bool + lowMem bool dict *dict } func (o *encoderOptions) setDefault() { *o = encoderOptions{ - // use less ram: true for now, but may change. concurrent: runtime.GOMAXPROCS(0), crc: true, single: nil, @@ -37,20 +37,31 @@ func (o *encoderOptions) setDefault() { windowSize: 8 << 20, level: SpeedDefault, allLitEntropy: true, + lowMem: false, } } // encoder returns an encoder with the selected options. func (o encoderOptions) encoder() encoder { switch o.level { + case SpeedFastest: + if o.dict != nil { + return &fastEncoderDict{fastEncoder: fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}}} + } + return &fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}} + case SpeedDefault: - return &doubleFastEncoder{fastEncoder: fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}}} + if o.dict != nil { + return &doubleFastEncoderDict{fastEncoderDict: fastEncoderDict{fastEncoder: fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}}}} + } + return &doubleFastEncoder{fastEncoder: fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}}} case SpeedBetterCompression: - return &betterFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}} + if o.dict != nil { + return &betterFastEncoderDict{betterFastEncoder: betterFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}}} + } + return &betterFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}} case SpeedBestCompression: - return &bestFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}} - case SpeedFastest: - return &fastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize)}} + return &bestFastEncoder{fastBase: fastBase{maxMatchOff: int32(o.windowSize), lowMem: o.lowMem}} } panic("unknown compression level") } @@ -276,6 +287,17 @@ func WithSingleSegment(b bool) EOption { } } +// WithLowerEncoderMem will trade in some memory cases trade less memory usage for +// slower encoding speed. +// This will not change the window size which is the primary function for reducing +// memory usage. See WithWindowSize. +func WithLowerEncoderMem(b bool) EOption { + return func(o *encoderOptions) error { + o.lowMem = b + return nil + } +} + // WithEncoderDict allows to register a dictionary that will be used for the encode. // The encoder *may* choose to use no dictionary instead for certain payloads. func WithEncoderDict(dict []byte) EOption { diff --git a/vendor/github.com/klauspost/compress/zstd/fse_encoder.go b/vendor/github.com/klauspost/compress/zstd/fse_encoder.go index aa9eba88b..b80709d5e 100644 --- a/vendor/github.com/klauspost/compress/zstd/fse_encoder.go +++ b/vendor/github.com/klauspost/compress/zstd/fse_encoder.go @@ -97,7 +97,7 @@ func (s *fseEncoder) prepare() (*fseEncoder, error) { func (s *fseEncoder) allocCtable() { tableSize := 1 << s.actualTableLog // get tableSymbol that is big enough. - if cap(s.ct.tableSymbol) < int(tableSize) { + if cap(s.ct.tableSymbol) < tableSize { s.ct.tableSymbol = make([]byte, tableSize) } s.ct.tableSymbol = s.ct.tableSymbol[:tableSize] @@ -202,13 +202,13 @@ func (s *fseEncoder) buildCTable() error { case 0: case -1, 1: symbolTT[i].deltaNbBits = tl - symbolTT[i].deltaFindState = int16(total - 1) + symbolTT[i].deltaFindState = total - 1 total++ default: maxBitsOut := uint32(tableLog) - highBit(uint32(v-1)) minStatePlus := uint32(v) << maxBitsOut symbolTT[i].deltaNbBits = (maxBitsOut << 16) - minStatePlus - symbolTT[i].deltaFindState = int16(total - v) + symbolTT[i].deltaFindState = total - v total += v } } @@ -353,8 +353,8 @@ func (s *fseEncoder) normalizeCount2(length int) error { distributed uint32 total = uint32(length) tableLog = s.actualTableLog - lowThreshold = uint32(total >> tableLog) - lowOne = uint32((total * 3) >> (tableLog + 1)) + lowThreshold = total >> tableLog + lowOne = (total * 3) >> (tableLog + 1) ) for i, cnt := range s.count[:s.symbolLen] { if cnt == 0 { @@ -379,7 +379,7 @@ func (s *fseEncoder) normalizeCount2(length int) error { if (total / toDistribute) > lowOne { // risk of rounding to zero - lowOne = uint32((total * 3) / (toDistribute * 2)) + lowOne = (total * 3) / (toDistribute * 2) for i, cnt := range s.count[:s.symbolLen] { if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) { s.norm[i] = 1 diff --git a/vendor/github.com/klauspost/compress/zstd/snappy.go b/vendor/github.com/klauspost/compress/zstd/snappy.go index 841fd95ac..c95fe5111 100644 --- a/vendor/github.com/klauspost/compress/zstd/snappy.go +++ b/vendor/github.com/klauspost/compress/zstd/snappy.go @@ -417,7 +417,7 @@ var crcTable = crc32.MakeTable(crc32.Castagnoli) // https://github.com/google/snappy/blob/master/framing_format.txt func snappyCRC(b []byte) uint32 { c := crc32.Update(0, crcTable, b) - return uint32(c>>15|c<<17) + 0xa282ead8 + return c>>15 | c<<17 + 0xa282ead8 } // snappyDecodedLen returns the length of the decoded block and the number of bytes |