Update dependencies (#2007)

* Update dependencies

1 files changed, 696 insertions, 27 deletions

diff --git a/vendor/github.com/klauspost/compress/s2/encode_better.go b/vendor/github.com/klauspost/compress/s2/encode_better.go
index 943215b8..f46adb41 100644
--- a/vendor/github.com/klauspost/compress/s2/encode_better.go
+++ b/vendor/github.com/klauspost/compress/s2/encode_better.go
@@ -6,6 +6,8 @@
 package s2
 
 import (
+	"bytes"
+	"fmt"
 	"math/bits"
 )
 
@@ -42,8 +44,9 @@ func hash8(u uint64, h uint8) uint32 {
 // been written.
 //
 // It also assumes that:
+//
 //	len(dst) >= MaxEncodedLen(len(src)) &&
-// 	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
+//	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
 func encodeBlockBetterGo(dst, src []byte) (d int) {
 	// 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
@@ -56,7 +59,7 @@ func encodeBlockBetterGo(dst, src []byte) (d int) {
 	// Initialize the hash tables.
 	const (
 		// Long hash matches.
-		lTableBits    = 16
+		lTableBits    = 17
 		maxLTableSize = 1 << lTableBits
 
 		// Short hash matches.
@@ -97,9 +100,26 @@ func encodeBlockBetterGo(dst, src []byte) (d int) {
 			lTable[hashL] = uint32(s)
 			sTable[hashS] = uint32(s)
 
+			valLong := load64(src, candidateL)
+			valShort := load64(src, candidateS)
+
+			// If long matches at least 8 bytes, use that.
+			if cv == valLong {
+				break
+			}
+			if cv == valShort {
+				candidateL = candidateS
+				break
+			}
+
 			// Check repeat at offset checkRep.
 			const checkRep = 1
-			if false && uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
+			// Minimum length of a repeat. Tested with various values.
+			// While 4-5 offers improvements in some, 6 reduces
+			// regressions significantly.
+			const wantRepeatBytes = 6
+			const repeatMask = ((1 << (wantRepeatBytes * 8)) - 1) << (8 * checkRep)
+			if false && repeat > 0 && cv&repeatMask == load64(src, s-repeat)&repeatMask {
 				base := s + checkRep
 				// Extend back
 				for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
@@ -109,8 +129,8 @@ func encodeBlockBetterGo(dst, src []byte) (d int) {
 				d += emitLiteral(dst[d:], src[nextEmit:base])
 
 				// Extend forward
-				candidate := s - repeat + 4 + checkRep
-				s += 4 + checkRep
+				candidate := s - repeat + wantRepeatBytes + checkRep
+				s += wantRepeatBytes + checkRep
 				for s < len(src) {
 					if len(src)-s < 8 {
 						if src[s] == src[candidate] {
@@ -127,28 +147,40 @@ func encodeBlockBetterGo(dst, src []byte) (d int) {
 					s += 8
 					candidate += 8
 				}
-				if nextEmit > 0 {
-					// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
-					d += emitRepeat(dst[d:], repeat, s-base)
-				} else {
-					// First match, cannot be repeat.
-					d += emitCopy(dst[d:], repeat, s-base)
-				}
+				// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
+				d += emitRepeat(dst[d:], repeat, s-base)
 				nextEmit = s
 				if s >= sLimit {
 					goto emitRemainder
 				}
+				// Index in-between
+				index0 := base + 1
+				index1 := s - 2
+
+				cv = load64(src, s)
+				for index0 < index1 {
+					cv0 := load64(src, index0)
+					cv1 := load64(src, index1)
+					lTable[hash7(cv0, lTableBits)] = uint32(index0)
+					sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
+					lTable[hash7(cv1, lTableBits)] = uint32(index1)
+					sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+					index0 += 2
+					index1 -= 2
+				}
 
 				cv = load64(src, s)
 				continue
 			}
 
-			if uint32(cv) == load32(src, candidateL) {
+			// Long likely matches 7, so take that.
+			if uint32(cv) == uint32(valLong) {
 				break
 			}
 
 			// Check our short candidate
-			if uint32(cv) == load32(src, candidateS) {
+			if uint32(cv) == uint32(valShort) {
 				// Try a long candidate at s+1
 				hashL = hash7(cv>>8, lTableBits)
 				candidateL = int(lTable[hashL])
@@ -227,21 +259,29 @@ func encodeBlockBetterGo(dst, src []byte) (d int) {
 			// Do we have space for more, if not bail.
 			return 0
 		}
-		// Index match start+1 (long) and start+2 (short)
+
+		// Index short & long
 		index0 := base + 1
-		// Index match end-2 (long) and end-1 (short)
 		index1 := s - 2
 
 		cv0 := load64(src, index0)
 		cv1 := load64(src, index1)
-		cv = load64(src, s)
 		lTable[hash7(cv0, lTableBits)] = uint32(index0)
-		lTable[hash7(cv0>>8, lTableBits)] = uint32(index0 + 1)
-		lTable[hash7(cv1, lTableBits)] = uint32(index1)
-		lTable[hash7(cv1>>8, lTableBits)] = uint32(index1 + 1)
 		sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
-		sTable[hash4(cv0>>16, sTableBits)] = uint32(index0 + 2)
+
+		lTable[hash7(cv1, lTableBits)] = uint32(index1)
 		sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+		index0 += 1
+		index1 -= 1
+		cv = load64(src, s)
+
+		// index every second long in between.
+		for index0 < index1 {
+			lTable[hash7(load64(src, index0), lTableBits)] = uint32(index0)
+			lTable[hash7(load64(src, index1), lTableBits)] = uint32(index1)
+			index0 += 2
+			index1 -= 2
+		}
 	}
 
 emitRemainder:
@@ -260,8 +300,9 @@ emitRemainder:
 // been written.
 //
 // It also assumes that:
+//
 //	len(dst) >= MaxEncodedLen(len(src)) &&
-// 	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
+//	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
 func encodeBlockBetterSnappyGo(dst, src []byte) (d int) {
 	// 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
@@ -402,21 +443,649 @@ func encodeBlockBetterSnappyGo(dst, src []byte) (d int) {
 			// Do we have space for more, if not bail.
 			return 0
 		}
-		// Index match start+1 (long) and start+2 (short)
+
+		// Index short & long
 		index0 := base + 1
-		// Index match end-2 (long) and end-1 (short)
 		index1 := s - 2
 
 		cv0 := load64(src, index0)
 		cv1 := load64(src, index1)
+		lTable[hash7(cv0, lTableBits)] = uint32(index0)
+		sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
+		lTable[hash7(cv1, lTableBits)] = uint32(index1)
+		sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+		index0 += 1
+		index1 -= 1
 		cv = load64(src, s)
+
+		// index every second long in between.
+		for index0 < index1 {
+			lTable[hash7(load64(src, index0), lTableBits)] = uint32(index0)
+			lTable[hash7(load64(src, index1), lTableBits)] = uint32(index1)
+			index0 += 2
+			index1 -= 2
+		}
+	}
+
+emitRemainder:
+	if nextEmit < len(src) {
+		// Bail if we exceed the maximum size.
+		if d+len(src)-nextEmit > dstLimit {
+			return 0
+		}
+		d += emitLiteral(dst[d:], src[nextEmit:])
+	}
+	return d
+}
+
+// encodeBlockBetterDict encodes a non-empty src to a guaranteed-large-enough dst. It
+// assumes that the varint-encoded length of the decompressed bytes has already
+// been written.
+//
+// It also assumes that:
+//
+//	len(dst) >= MaxEncodedLen(len(src)) &&
+//	minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize
+func encodeBlockBetterDict(dst, src []byte, dict *Dict) (d int) {
+	// 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.
+	// Initialize the hash tables.
+	const (
+		// Long hash matches.
+		lTableBits    = 17
+		maxLTableSize = 1 << lTableBits
+
+		// Short hash matches.
+		sTableBits    = 14
+		maxSTableSize = 1 << sTableBits
+
+		maxAhead = 8 // maximum bytes ahead without checking sLimit
+
+		debug = false
+	)
+
+	sLimit := len(src) - inputMargin
+	if sLimit > MaxDictSrcOffset-maxAhead {
+		sLimit = MaxDictSrcOffset - maxAhead
+	}
+	if len(src) < minNonLiteralBlockSize {
+		return 0
+	}
+
+	dict.initBetter()
+
+	var lTable [maxLTableSize]uint32
+	var sTable [maxSTableSize]uint32
+
+	// Bail if we can't compress to at least this.
+	dstLimit := len(src) - len(src)>>5 - 6
+
+	// nextEmit is where in src the next emitLiteral should start from.
+	nextEmit := 0
+
+	// The encoded form must start with a literal, as there are no previous
+	// bytes to copy, so we start looking for hash matches at s == 1.
+	s := 0
+	cv := load64(src, s)
+
+	// We initialize repeat to 0, so we never match on first attempt
+	repeat := len(dict.dict) - dict.repeat
+
+	// While in dict
+searchDict:
+	for {
+		candidateL := 0
+		nextS := 0
+		for {
+			// Next src position to check
+			nextS = s + (s-nextEmit)>>7 + 1
+			if nextS > sLimit {
+				break searchDict
+			}
+			hashL := hash7(cv, lTableBits)
+			hashS := hash4(cv, sTableBits)
+			candidateL = int(lTable[hashL])
+			candidateS := int(sTable[hashS])
+			dictL := int(dict.betterTableLong[hashL])
+			dictS := int(dict.betterTableShort[hashS])
+			lTable[hashL] = uint32(s)
+			sTable[hashS] = uint32(s)
+
+			valLong := load64(src, candidateL)
+			valShort := load64(src, candidateS)
+
+			// If long matches at least 8 bytes, use that.
+			if s != 0 {
+				if cv == valLong {
+					goto emitMatch
+				}
+				if cv == valShort {
+					candidateL = candidateS
+					goto emitMatch
+				}
+			}
+
+			// Check dict repeat.
+			if repeat >= s+4 {
+				candidate := len(dict.dict) - repeat + s
+				if candidate > 0 && uint32(cv) == load32(dict.dict, candidate) {
+					// Extend back
+					base := s
+					for i := candidate; base > nextEmit && i > 0 && dict.dict[i-1] == src[base-1]; {
+						i--
+						base--
+					}
+					d += emitLiteral(dst[d:], src[nextEmit:base])
+					if debug && nextEmit != base {
+						fmt.Println("emitted ", base-nextEmit, "literals")
+					}
+					s += 4
+					candidate += 4
+					for candidate < len(dict.dict)-8 && s <= len(src)-8 {
+						if diff := load64(src, s) ^ load64(dict.dict, candidate); diff != 0 {
+							s += bits.TrailingZeros64(diff) >> 3
+							break
+						}
+						s += 8
+						candidate += 8
+					}
+					d += emitRepeat(dst[d:], repeat, s-base)
+					if debug {
+						fmt.Println("emitted dict repeat length", s-base, "offset:", repeat, "s:", s)
+					}
+					nextEmit = s
+					if s >= sLimit {
+						break searchDict
+					}
+					cv = load64(src, s)
+					// Index in-between
+					index0 := base + 1
+					index1 := s - 2
+
+					cv = load64(src, s)
+					for index0 < index1 {
+						cv0 := load64(src, index0)
+						cv1 := load64(src, index1)
+						lTable[hash7(cv0, lTableBits)] = uint32(index0)
+						sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
+						lTable[hash7(cv1, lTableBits)] = uint32(index1)
+						sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+						index0 += 2
+						index1 -= 2
+					}
+					continue
+				}
+			}
+			// Don't try to find match at s==0
+			if s == 0 {
+				cv = load64(src, nextS)
+				s = nextS
+				continue
+			}
+
+			// Long likely matches 7, so take that.
+			if uint32(cv) == uint32(valLong) {
+				goto emitMatch
+			}
+
+			// Long dict...
+			if uint32(cv) == load32(dict.dict, dictL) {
+				candidateL = dictL
+				goto emitDict
+			}
+
+			// Check our short candidate
+			if uint32(cv) == uint32(valShort) {
+				// Try a long candidate at s+1
+				hashL = hash7(cv>>8, lTableBits)
+				candidateL = int(lTable[hashL])
+				lTable[hashL] = uint32(s + 1)
+				if uint32(cv>>8) == load32(src, candidateL) {
+					s++
+					goto emitMatch
+				}
+				// Use our short candidate.
+				candidateL = candidateS
+				goto emitMatch
+			}
+			if uint32(cv) == load32(dict.dict, dictS) {
+				// Try a long candidate at s+1
+				hashL = hash7(cv>>8, lTableBits)
+				candidateL = int(lTable[hashL])
+				lTable[hashL] = uint32(s + 1)
+				if uint32(cv>>8) == load32(src, candidateL) {
+					s++
+					goto emitMatch
+				}
+				candidateL = dictS
+				goto emitDict
+			}
+			cv = load64(src, nextS)
+			s = nextS
+		}
+	emitDict:
+		{
+			if debug {
+				if load32(dict.dict, candidateL) != load32(src, s) {
+					panic("dict emit mismatch")
+				}
+			}
+			// Extend backwards.
+			// The top bytes will be rechecked to get the full match.
+			for candidateL > 0 && s > nextEmit && dict.dict[candidateL-1] == src[s-1] {
+				candidateL--
+				s--
+			}
+
+			// Bail if we exceed the maximum size.
+			if d+(s-nextEmit) > dstLimit {
+				return 0
+			}
+
+			// 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.
+
+			d += emitLiteral(dst[d:], src[nextEmit:s])
+			if debug && nextEmit != s {
+				fmt.Println("emitted ", s-nextEmit, "literals")
+			}
+			{
+				// Invariant: we have a 4-byte match at s, and no need to emit any
+				// literal bytes prior to s.
+				base := s
+				offset := s + (len(dict.dict)) - candidateL
+
+				// Extend the 4-byte match as long as possible.
+				s += 4
+				candidateL += 4
+				for s <= len(src)-8 && len(dict.dict)-candidateL >= 8 {
+					if diff := load64(src, s) ^ load64(dict.dict, candidateL); diff != 0 {
+						s += bits.TrailingZeros64(diff) >> 3
+						break
+					}
+					s += 8
+					candidateL += 8
+				}
+
+				if repeat == offset {
+					if debug {
+						fmt.Println("emitted dict repeat, length", s-base, "offset:", offset, "s:", s, "dict offset:", candidateL)
+					}
+					d += emitRepeat(dst[d:], offset, s-base)
+				} else {
+					if debug {
+						fmt.Println("emitted dict copy, length", s-base, "offset:", offset, "s:", s, "dict offset:", candidateL)
+					}
+					// Matches longer than 64 are split.
+					if s <= sLimit || s-base < 8 {
+						d += emitCopy(dst[d:], offset, s-base)
+					} else {
+						// Split to ensure we don't start a copy within next block.
+						d += emitCopy(dst[d:], offset, 4)
+						d += emitRepeat(dst[d:], offset, s-base-4)
+					}
+					repeat = offset
+				}
+				if false {
+					// Validate match.
+					if s <= candidateL {
+						panic("s <= candidate")
+					}
+					a := src[base:s]
+					b := dict.dict[base-repeat : base-repeat+(s-base)]
+					if !bytes.Equal(a, b) {
+						panic("mismatch")
+					}
+				}
+
+				nextEmit = s
+				if s >= sLimit {
+					break searchDict
+				}
+
+				if d > dstLimit {
+					// Do we have space for more, if not bail.
+					return 0
+				}
+
+				// Index short & long
+				index0 := base + 1
+				index1 := s - 2
+
+				cv0 := load64(src, index0)
+				cv1 := load64(src, index1)
+				lTable[hash7(cv0, lTableBits)] = uint32(index0)
+				sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
+				lTable[hash7(cv1, lTableBits)] = uint32(index1)
+				sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+				index0 += 1
+				index1 -= 1
+				cv = load64(src, s)
+
+				// index every second long in between.
+				for index0 < index1 {
+					lTable[hash7(load64(src, index0), lTableBits)] = uint32(index0)
+					lTable[hash7(load64(src, index1), lTableBits)] = uint32(index1)
+					index0 += 2
+					index1 -= 2
+				}
+			}
+			continue
+		}
+	emitMatch:
+
+		// Extend backwards
+		for candidateL > 0 && s > nextEmit && src[candidateL-1] == src[s-1] {
+			candidateL--
+			s--
+		}
+
+		// Bail if we exceed the maximum size.
+		if d+(s-nextEmit) > dstLimit {
+			return 0
+		}
+
+		base := s
+		offset := base - candidateL
+
+		// Extend the 4-byte match as long as possible.
+		s += 4
+		candidateL += 4
+		for s < len(src) {
+			if len(src)-s < 8 {
+				if src[s] == src[candidateL] {
+					s++
+					candidateL++
+					continue
+				}
+				break
+			}
+			if diff := load64(src, s) ^ load64(src, candidateL); diff != 0 {
+				s += bits.TrailingZeros64(diff) >> 3
+				break
+			}
+			s += 8
+			candidateL += 8
+		}
+
+		if offset > 65535 && s-base <= 5 && repeat != offset {
+			// Bail if the match is equal or worse to the encoding.
+			s = nextS + 1
+			if s >= sLimit {
+				goto emitRemainder
+			}
+			cv = load64(src, s)
+			continue
+		}
+
+		d += emitLiteral(dst[d:], src[nextEmit:base])
+		if debug && nextEmit != s {
+			fmt.Println("emitted ", s-nextEmit, "literals")
+		}
+		if repeat == offset {
+			if debug {
+				fmt.Println("emitted match repeat, length", s-base, "offset:", offset, "s:", s)
+			}
+			d += emitRepeat(dst[d:], offset, s-base)
+		} else {
+			if debug {
+				fmt.Println("emitted match copy, length", s-base, "offset:", offset, "s:", s)
+			}
+			d += emitCopy(dst[d:], offset, s-base)
+			repeat = offset
+		}
+
+		nextEmit = s
+		if s >= sLimit {
+			goto emitRemainder
+		}
+
+		if d > dstLimit {
+			// Do we have space for more, if not bail.
+			return 0
+		}
+
+		// Index short & long
+		index0 := base + 1
+		index1 := s - 2
+
+		cv0 := load64(src, index0)
+		cv1 := load64(src, index1)
 		lTable[hash7(cv0, lTableBits)] = uint32(index0)
-		lTable[hash7(cv0>>8, lTableBits)] = uint32(index0 + 1)
+		sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
 		lTable[hash7(cv1, lTableBits)] = uint32(index1)
-		lTable[hash7(cv1>>8, lTableBits)] = uint32(index1 + 1)
+		sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+		index0 += 1
+		index1 -= 1
+		cv = load64(src, s)
+
+		// index every second long in between.
+		for index0 < index1 {
+			lTable[hash7(load64(src, index0), lTableBits)] = uint32(index0)
+			lTable[hash7(load64(src, index1), lTableBits)] = uint32(index1)
+			index0 += 2
+			index1 -= 2
+		}
+	}
+
+	// Search without dict:
+	if repeat > s {
+		repeat = 0
+	}
+
+	// No more dict
+	sLimit = len(src) - inputMargin
+	if s >= sLimit {
+		goto emitRemainder
+	}
+	cv = load64(src, s)
+	if debug {
+		fmt.Println("now", s, "->", sLimit, "out:", d, "left:", len(src)-s, "nextemit:", nextEmit, "dstLimit:", dstLimit, "s:", s)
+	}
+	for {
+		candidateL := 0
+		nextS := 0
+		for {
+			// Next src position to check
+			nextS = s + (s-nextEmit)>>7 + 1
+			if nextS > sLimit {
+				goto emitRemainder
+			}
+			hashL := hash7(cv, lTableBits)
+			hashS := hash4(cv, sTableBits)
+			candidateL = int(lTable[hashL])
+			candidateS := int(sTable[hashS])
+			lTable[hashL] = uint32(s)
+			sTable[hashS] = uint32(s)
+
+			valLong := load64(src, candidateL)
+			valShort := load64(src, candidateS)
+
+			// If long matches at least 8 bytes, use that.
+			if cv == valLong {
+				break
+			}
+			if cv == valShort {
+				candidateL = candidateS
+				break
+			}
+
+			// Check repeat at offset checkRep.
+			const checkRep = 1
+			// Minimum length of a repeat. Tested with various values.
+			// While 4-5 offers improvements in some, 6 reduces
+			// regressions significantly.
+			const wantRepeatBytes = 6
+			const repeatMask = ((1 << (wantRepeatBytes * 8)) - 1) << (8 * checkRep)
+			if false && repeat > 0 && cv&repeatMask == load64(src, s-repeat)&repeatMask {
+				base := s + checkRep
+				// Extend back
+				for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
+					i--
+					base--
+				}
+				d += emitLiteral(dst[d:], src[nextEmit:base])
+
+				// Extend forward
+				candidate := s - repeat + wantRepeatBytes + checkRep
+				s += wantRepeatBytes + checkRep
+				for s < len(src) {
+					if len(src)-s < 8 {
+						if src[s] == src[candidate] {
+							s++
+							candidate++
+							continue
+						}
+						break
+					}
+					if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
+						s += bits.TrailingZeros64(diff) >> 3
+						break
+					}
+					s += 8
+					candidate += 8
+				}
+				// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
+				d += emitRepeat(dst[d:], repeat, s-base)
+				nextEmit = s
+				if s >= sLimit {
+					goto emitRemainder
+				}
+				// Index in-between
+				index0 := base + 1
+				index1 := s - 2
+
+				cv = load64(src, s)
+				for index0 < index1 {
+					cv0 := load64(src, index0)
+					cv1 := load64(src, index1)
+					lTable[hash7(cv0, lTableBits)] = uint32(index0)
+					sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
+
+					lTable[hash7(cv1, lTableBits)] = uint32(index1)
+					sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+					index0 += 2
+					index1 -= 2
+				}
+
+				cv = load64(src, s)
+				continue
+			}
+
+			// Long likely matches 7, so take that.
+			if uint32(cv) == uint32(valLong) {
+				break
+			}
+
+			// Check our short candidate
+			if uint32(cv) == uint32(valShort) {
+				// Try a long candidate at s+1
+				hashL = hash7(cv>>8, lTableBits)
+				candidateL = int(lTable[hashL])
+				lTable[hashL] = uint32(s + 1)
+				if uint32(cv>>8) == load32(src, candidateL) {
+					s++
+					break
+				}
+				// Use our short candidate.
+				candidateL = candidateS
+				break
+			}
+
+			cv = load64(src, nextS)
+			s = nextS
+		}
+
+		// Extend backwards
+		for candidateL > 0 && s > nextEmit && src[candidateL-1] == src[s-1] {
+			candidateL--
+			s--
+		}
+
+		// Bail if we exceed the maximum size.
+		if d+(s-nextEmit) > dstLimit {
+			return 0
+		}
+
+		base := s
+		offset := base - candidateL
+
+		// Extend the 4-byte match as long as possible.
+		s += 4
+		candidateL += 4
+		for s < len(src) {
+			if len(src)-s < 8 {
+				if src[s] == src[candidateL] {
+					s++
+					candidateL++
+					continue
+				}
+				break
+			}
+			if diff := load64(src, s) ^ load64(src, candidateL); diff != 0 {
+				s += bits.TrailingZeros64(diff) >> 3
+				break
+			}
+			s += 8
+			candidateL += 8
+		}
+
+		if offset > 65535 && s-base <= 5 && repeat != offset {
+			// Bail if the match is equal or worse to the encoding.
+			s = nextS + 1
+			if s >= sLimit {
+				goto emitRemainder
+			}
+			cv = load64(src, s)
+			continue
+		}
+
+		d += emitLiteral(dst[d:], src[nextEmit:base])
+		if repeat == offset {
+			d += emitRepeat(dst[d:], offset, s-base)
+		} else {
+			d += emitCopy(dst[d:], offset, s-base)
+			repeat = offset
+		}
+
+		nextEmit = s
+		if s >= sLimit {
+			goto emitRemainder
+		}
+
+		if d > dstLimit {
+			// Do we have space for more, if not bail.
+			return 0
+		}
+
+		// Index short & long
+		index0 := base + 1
+		index1 := s - 2
+
+		cv0 := load64(src, index0)
+		cv1 := load64(src, index1)
+		lTable[hash7(cv0, lTableBits)] = uint32(index0)
 		sTable[hash4(cv0>>8, sTableBits)] = uint32(index0 + 1)
-		sTable[hash4(cv0>>16, sTableBits)] = uint32(index0 + 2)
+
+		lTable[hash7(cv1, lTableBits)] = uint32(index1)
 		sTable[hash4(cv1>>8, sTableBits)] = uint32(index1 + 1)
+		index0 += 1
+		index1 -= 1
+		cv = load64(src, s)
+
+		// index every second long in between.
+		for index0 < index1 {
+			lTable[hash7(load64(src, index0), lTableBits)] = uint32(index0)
+			lTable[hash7(load64(src, index1), lTableBits)] = uint32(index1)
+			index0 += 2
+			index1 -= 2
+		}
 	}
 
 emitRemainder: