Upgrade github.com/klauspost/compress from v1.11.13 to v1.15.9
The package has multiple improvements and bug fixes. Signed-off-by: Kazuyoshi Kato <katokazu@amazon.com>
This commit is contained in:
		
							
								
								
									
										177
									
								
								vendor/github.com/klauspost/compress/zstd/enc_best.go
									
									
									
										generated
									
									
										vendored
									
									
								
							
							
						
						
									
										177
									
								
								vendor/github.com/klauspost/compress/zstd/enc_best.go
									
									
									
										generated
									
									
										vendored
									
									
								
							@@ -5,22 +5,61 @@
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package zstd
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import (
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	"bytes"
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	"fmt"
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	"math/bits"
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	"github.com/klauspost/compress"
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)
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const (
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	bestLongTableBits = 20                     // Bits used in the long match table
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	bestLongTableBits = 22                     // Bits used in the long match table
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	bestLongTableSize = 1 << bestLongTableBits // Size of the table
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	bestLongLen       = 8                      // Bytes used for table hash
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	// Note: Increasing the short table bits or making the hash shorter
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	// can actually lead to compression degradation since it will 'steal' more from the
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	// long match table and match offsets are quite big.
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	// This greatly depends on the type of input.
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	bestShortTableBits = 16                      // Bits used in the short match table
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	bestShortTableBits = 18                      // Bits used in the short match table
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	bestShortTableSize = 1 << bestShortTableBits // Size of the table
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	bestShortLen       = 4                       // Bytes used for table hash
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)
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type match struct {
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	offset int32
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	s      int32
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	length int32
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	rep    int32
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	est    int32
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}
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const highScore = 25000
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// estBits will estimate output bits from predefined tables.
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func (m *match) estBits(bitsPerByte int32) {
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	mlc := mlCode(uint32(m.length - zstdMinMatch))
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	var ofc uint8
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	if m.rep < 0 {
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		ofc = ofCode(uint32(m.s-m.offset) + 3)
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	} else {
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		ofc = ofCode(uint32(m.rep))
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	}
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	// Cost, excluding
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	ofTT, mlTT := fsePredefEnc[tableOffsets].ct.symbolTT[ofc], fsePredefEnc[tableMatchLengths].ct.symbolTT[mlc]
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	// Add cost of match encoding...
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	m.est = int32(ofTT.outBits + mlTT.outBits)
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	m.est += int32(ofTT.deltaNbBits>>16 + mlTT.deltaNbBits>>16)
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	// Subtract savings compared to literal encoding...
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	m.est -= (m.length * bitsPerByte) >> 10
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	if m.est > 0 {
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		// Unlikely gain..
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		m.length = 0
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		m.est = highScore
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	}
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}
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// bestFastEncoder uses 2 tables, one for short matches (5 bytes) and one for long matches.
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// The long match table contains the previous entry with the same hash,
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// effectively making it a "chain" of length 2.
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@@ -109,6 +148,14 @@ func (e *bestFastEncoder) Encode(blk *blockEnc, src []byte) {
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		return
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	}
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	// Use this to estimate literal cost.
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	// Scaled by 10 bits.
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	bitsPerByte := int32((compress.ShannonEntropyBits(src) * 1024) / len(src))
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	// Huffman can never go < 1 bit/byte
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	if bitsPerByte < 1024 {
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		bitsPerByte = 1024
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	}
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	// Override src
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	src = e.hist
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	sLimit := int32(len(src)) - inputMargin
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@@ -132,7 +179,7 @@ func (e *bestFastEncoder) Encode(blk *blockEnc, src []byte) {
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	}
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	_ = addLiterals
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	if debug {
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	if debugEncoder {
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		println("recent offsets:", blk.recentOffsets)
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	}
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@@ -145,51 +192,49 @@ encodeLoop:
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			panic("offset0 was 0")
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		}
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		type match struct {
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			offset int32
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			s      int32
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			length int32
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			rep    int32
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		}
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		matchAt := func(offset int32, s int32, first uint32, rep int32) match {
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			if s-offset >= e.maxMatchOff || load3232(src, offset) != first {
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				return match{offset: offset, s: s}
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			}
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			return match{offset: offset, s: s, length: 4 + e.matchlen(s+4, offset+4, src), rep: rep}
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		}
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		bestOf := func(a, b match) match {
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			aScore := b.s - a.s + a.length
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			bScore := a.s - b.s + b.length
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			if a.rep < 0 {
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				aScore = aScore - int32(bits.Len32(uint32(a.offset)))/8
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			}
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			if b.rep < 0 {
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				bScore = bScore - int32(bits.Len32(uint32(b.offset)))/8
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			}
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			if aScore >= bScore {
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			if a.est+(a.s-b.s)*bitsPerByte>>10 < b.est+(b.s-a.s)*bitsPerByte>>10 {
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				return a
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			}
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			return b
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		}
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		const goodEnough = 100
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		nextHashL := hash8(cv, bestLongTableBits)
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		nextHashS := hash4x64(cv, bestShortTableBits)
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		nextHashL := hashLen(cv, bestLongTableBits, bestLongLen)
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		nextHashS := hashLen(cv, bestShortTableBits, bestShortLen)
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		candidateL := e.longTable[nextHashL]
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		candidateS := e.table[nextHashS]
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		matchAt := func(offset int32, s int32, first uint32, rep int32) match {
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			if s-offset >= e.maxMatchOff || load3232(src, offset) != first {
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				return match{s: s, est: highScore}
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			}
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			if debugAsserts {
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				if !bytes.Equal(src[s:s+4], src[offset:offset+4]) {
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					panic(fmt.Sprintf("first match mismatch: %v != %v, first: %08x", src[s:s+4], src[offset:offset+4], first))
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				}
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			}
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			m := match{offset: offset, s: s, length: 4 + e.matchlen(s+4, offset+4, src), rep: rep}
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			m.estBits(bitsPerByte)
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			return m
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		}
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		best := bestOf(matchAt(candidateL.offset-e.cur, s, uint32(cv), -1), matchAt(candidateL.prev-e.cur, s, uint32(cv), -1))
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		best = bestOf(best, matchAt(candidateS.offset-e.cur, s, uint32(cv), -1))
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		best = bestOf(best, matchAt(candidateS.prev-e.cur, s, uint32(cv), -1))
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		if canRepeat && best.length < goodEnough {
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			best = bestOf(best, matchAt(s-offset1+1, s+1, uint32(cv>>8), 1))
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			best = bestOf(best, matchAt(s-offset2+1, s+1, uint32(cv>>8), 2))
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			best = bestOf(best, matchAt(s-offset3+1, s+1, uint32(cv>>8), 3))
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			cv32 := uint32(cv >> 8)
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			spp := s + 1
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			best = bestOf(best, matchAt(spp-offset1, spp, cv32, 1))
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			best = bestOf(best, matchAt(spp-offset2, spp, cv32, 2))
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			best = bestOf(best, matchAt(spp-offset3, spp, cv32, 3))
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			if best.length > 0 {
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				best = bestOf(best, matchAt(s-offset1+3, s+3, uint32(cv>>24), 1))
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				best = bestOf(best, matchAt(s-offset2+3, s+3, uint32(cv>>24), 2))
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				best = bestOf(best, matchAt(s-offset3+3, s+3, uint32(cv>>24), 3))
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				cv32 = uint32(cv >> 24)
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				spp += 2
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				best = bestOf(best, matchAt(spp-offset1, spp, cv32, 1))
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				best = bestOf(best, matchAt(spp-offset2, spp, cv32, 2))
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				best = bestOf(best, matchAt(spp-offset3, spp, cv32, 3))
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			}
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		}
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		// Load next and check...
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@@ -209,17 +254,43 @@ encodeLoop:
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			}
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			s++
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			candidateS = e.table[hash4x64(cv>>8, bestShortTableBits)]
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			candidateS = e.table[hashLen(cv>>8, bestShortTableBits, bestShortLen)]
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			cv = load6432(src, s)
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			cv2 := load6432(src, s+1)
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			candidateL = e.longTable[hash8(cv, bestLongTableBits)]
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			candidateL2 := e.longTable[hash8(cv2, bestLongTableBits)]
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			candidateL = e.longTable[hashLen(cv, bestLongTableBits, bestLongLen)]
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			candidateL2 := e.longTable[hashLen(cv2, bestLongTableBits, bestLongLen)]
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			// Short at s+1
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			best = bestOf(best, matchAt(candidateS.offset-e.cur, s, uint32(cv), -1))
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			// Long at s+1, s+2
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			best = bestOf(best, matchAt(candidateL.offset-e.cur, s, uint32(cv), -1))
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			best = bestOf(best, matchAt(candidateL.prev-e.cur, s, uint32(cv), -1))
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			best = bestOf(best, matchAt(candidateL2.offset-e.cur, s+1, uint32(cv2), -1))
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			best = bestOf(best, matchAt(candidateL2.prev-e.cur, s+1, uint32(cv2), -1))
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			if false {
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				// Short at s+3.
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				// Too often worse...
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				best = bestOf(best, matchAt(e.table[hashLen(cv2>>8, bestShortTableBits, bestShortLen)].offset-e.cur, s+2, uint32(cv2>>8), -1))
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			}
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			// See if we can find a better match by checking where the current best ends.
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			// Use that offset to see if we can find a better full match.
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			if sAt := best.s + best.length; sAt < sLimit {
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				nextHashL := hashLen(load6432(src, sAt), bestLongTableBits, bestLongLen)
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				candidateEnd := e.longTable[nextHashL]
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				if pos := candidateEnd.offset - e.cur - best.length; pos >= 0 {
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					bestEnd := bestOf(best, matchAt(pos, best.s, load3232(src, best.s), -1))
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					if pos := candidateEnd.prev - e.cur - best.length; pos >= 0 {
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						bestEnd = bestOf(bestEnd, matchAt(pos, best.s, load3232(src, best.s), -1))
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					}
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					best = bestEnd
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				}
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			}
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		}
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		if debugAsserts {
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			if !bytes.Equal(src[best.s:best.s+best.length], src[best.offset:best.offset+best.length]) {
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				panic(fmt.Sprintf("match mismatch: %v != %v", src[best.s:best.s+best.length], src[best.offset:best.offset+best.length]))
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			}
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		}
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		// We have a match, we can store the forward value
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@@ -260,7 +331,7 @@ encodeLoop:
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			nextEmit = s
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			if s >= sLimit {
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				if debug {
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				if debugEncoder {
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					println("repeat ended", s, best.length)
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				}
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@@ -270,8 +341,8 @@ encodeLoop:
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			off := index0 + e.cur
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			for index0 < s-1 {
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				cv0 := load6432(src, index0)
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				h0 := hash8(cv0, bestLongTableBits)
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				h1 := hash4x64(cv0, bestShortTableBits)
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				h0 := hashLen(cv0, bestLongTableBits, bestLongLen)
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				h1 := hashLen(cv0, bestShortTableBits, bestShortLen)
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				e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
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		||||
				e.table[h1] = prevEntry{offset: off, prev: e.table[h1].offset}
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				off++
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@@ -297,7 +368,7 @@ encodeLoop:
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			panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
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		}
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		if debugAsserts && canRepeat && int(offset1) > len(src) {
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		if debugAsserts && int(offset1) > len(src) {
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			panic("invalid offset")
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		}
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@@ -338,8 +409,8 @@ encodeLoop:
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		// every entry
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		for index0 < s-1 {
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			cv0 := load6432(src, index0)
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			h0 := hash8(cv0, bestLongTableBits)
 | 
			
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			h1 := hash4x64(cv0, bestShortTableBits)
 | 
			
		||||
			h0 := hashLen(cv0, bestLongTableBits, bestLongLen)
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		||||
			h1 := hashLen(cv0, bestShortTableBits, bestShortLen)
 | 
			
		||||
			off := index0 + e.cur
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		||||
			e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
 | 
			
		||||
			e.table[h1] = prevEntry{offset: off, prev: e.table[h1].offset}
 | 
			
		||||
@@ -360,8 +431,8 @@ encodeLoop:
 | 
			
		||||
			}
 | 
			
		||||
 | 
			
		||||
			// Store this, since we have it.
 | 
			
		||||
			nextHashS := hash4x64(cv, bestShortTableBits)
 | 
			
		||||
			nextHashL := hash8(cv, bestLongTableBits)
 | 
			
		||||
			nextHashS := hashLen(cv, bestShortTableBits, bestShortLen)
 | 
			
		||||
			nextHashL := hashLen(cv, bestLongTableBits, bestLongLen)
 | 
			
		||||
 | 
			
		||||
			// We have at least 4 byte match.
 | 
			
		||||
			// No need to check backwards. We come straight from a match
 | 
			
		||||
@@ -398,7 +469,7 @@ encodeLoop:
 | 
			
		||||
	blk.recentOffsets[0] = uint32(offset1)
 | 
			
		||||
	blk.recentOffsets[1] = uint32(offset2)
 | 
			
		||||
	blk.recentOffsets[2] = uint32(offset3)
 | 
			
		||||
	if debug {
 | 
			
		||||
	if debugEncoder {
 | 
			
		||||
		println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits)
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
@@ -411,7 +482,7 @@ func (e *bestFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) {
 | 
			
		||||
	e.Encode(blk, src)
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// ResetDict will reset and set a dictionary if not nil
 | 
			
		||||
// Reset will reset and set a dictionary if not nil
 | 
			
		||||
func (e *bestFastEncoder) Reset(d *dict, singleBlock bool) {
 | 
			
		||||
	e.resetBase(d, singleBlock)
 | 
			
		||||
	if d == nil {
 | 
			
		||||
@@ -427,10 +498,10 @@ func (e *bestFastEncoder) Reset(d *dict, singleBlock bool) {
 | 
			
		||||
			const hashLog = bestShortTableBits
 | 
			
		||||
 | 
			
		||||
			cv := load6432(d.content, i-e.maxMatchOff)
 | 
			
		||||
			nextHash := hash4x64(cv, hashLog)      // 0 -> 4
 | 
			
		||||
			nextHash1 := hash4x64(cv>>8, hashLog)  // 1 -> 5
 | 
			
		||||
			nextHash2 := hash4x64(cv>>16, hashLog) // 2 -> 6
 | 
			
		||||
			nextHash3 := hash4x64(cv>>24, hashLog) // 3 -> 7
 | 
			
		||||
			nextHash := hashLen(cv, hashLog, bestShortLen)      // 0 -> 4
 | 
			
		||||
			nextHash1 := hashLen(cv>>8, hashLog, bestShortLen)  // 1 -> 5
 | 
			
		||||
			nextHash2 := hashLen(cv>>16, hashLog, bestShortLen) // 2 -> 6
 | 
			
		||||
			nextHash3 := hashLen(cv>>24, hashLog, bestShortLen) // 3 -> 7
 | 
			
		||||
			e.dictTable[nextHash] = prevEntry{
 | 
			
		||||
				prev:   e.dictTable[nextHash].offset,
 | 
			
		||||
				offset: i,
 | 
			
		||||
@@ -458,7 +529,7 @@ func (e *bestFastEncoder) Reset(d *dict, singleBlock bool) {
 | 
			
		||||
		}
 | 
			
		||||
		if len(d.content) >= 8 {
 | 
			
		||||
			cv := load6432(d.content, 0)
 | 
			
		||||
			h := hash8(cv, bestLongTableBits)
 | 
			
		||||
			h := hashLen(cv, bestLongTableBits, bestLongLen)
 | 
			
		||||
			e.dictLongTable[h] = prevEntry{
 | 
			
		||||
				offset: e.maxMatchOff,
 | 
			
		||||
				prev:   e.dictLongTable[h].offset,
 | 
			
		||||
@@ -468,7 +539,7 @@ func (e *bestFastEncoder) Reset(d *dict, singleBlock bool) {
 | 
			
		||||
			off := 8 // First to read
 | 
			
		||||
			for i := e.maxMatchOff + 1; i < end; i++ {
 | 
			
		||||
				cv = cv>>8 | (uint64(d.content[off]) << 56)
 | 
			
		||||
				h := hash8(cv, bestLongTableBits)
 | 
			
		||||
				h := hashLen(cv, bestLongTableBits, bestLongLen)
 | 
			
		||||
				e.dictLongTable[h] = prevEntry{
 | 
			
		||||
					offset: i,
 | 
			
		||||
					prev:   e.dictLongTable[h].offset,
 | 
			
		||||
 
 | 
			
		||||
		Reference in New Issue
	
	Block a user