vendor: github.com/klauspost/compress v1.17.4

newer versions continue to include performance improvements, so it's good
to stay up-to-date.

full diff: https://github.com/klauspost/compress/compare/v1.16.5...v1.17.4

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/klauspost/compress/huff0/bitwriter.go

@@ -13,14 +13,6 @@ type bitWriter struct {
 	out          []byte
 }
 
-// bitMask16 is bitmasks. Has extra to avoid bounds check.
-var bitMask16 = [32]uint16{
-	0, 1, 3, 7, 0xF, 0x1F,
-	0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF,
-	0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF,
-	0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
-	0xFFFF, 0xFFFF} /* up to 16 bits */
-
 // addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
 // It will not check if there is space for them, so the caller must ensure that it has flushed recently.
 func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
@@ -102,10 +94,9 @@ func (b *bitWriter) flushAlign() {
 
 // close will write the alignment bit and write the final byte(s)
 // to the output.
-func (b *bitWriter) close() error {
+func (b *bitWriter) close() {
 	// End mark
 	b.addBits16Clean(1, 1)
 	// flush until next byte.
 	b.flushAlign()
-	return nil
 }

vendor/github.com/klauspost/compress/huff0/bytereader.go

@@ -1,44 +0,0 @@
-// Copyright 2018 Klaus Post. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
-
-package huff0
-
-// byteReader provides a byte reader that reads
-// little endian values from a byte stream.
-// The input stream is manually advanced.
-// The reader performs no bounds checks.
-type byteReader struct {
-	b   []byte
-	off int
-}
-
-// init will initialize the reader and set the input.
-func (b *byteReader) init(in []byte) {
-	b.b = in
-	b.off = 0
-}
-
-// Int32 returns a little endian int32 starting at current offset.
-func (b byteReader) Int32() int32 {
-	v3 := int32(b.b[b.off+3])
-	v2 := int32(b.b[b.off+2])
-	v1 := int32(b.b[b.off+1])
-	v0 := int32(b.b[b.off])
-	return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0
-}
-
-// Uint32 returns a little endian uint32 starting at current offset.
-func (b byteReader) Uint32() uint32 {
-	v3 := uint32(b.b[b.off+3])
-	v2 := uint32(b.b[b.off+2])
-	v1 := uint32(b.b[b.off+1])
-	v0 := uint32(b.b[b.off])
-	return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0
-}
-
-// remain will return the number of bytes remaining.
-func (b byteReader) remain() int {
-	return len(b.b) - b.off
-}

vendor/github.com/klauspost/compress/huff0/compress.go

@@ -227,10 +227,10 @@ func EstimateSizes(in []byte, s *Scratch) (tableSz, dataSz, reuseSz int, err err
 }
 
 func (s *Scratch) compress1X(src []byte) ([]byte, error) {
-	return s.compress1xDo(s.Out, src)
+	return s.compress1xDo(s.Out, src), nil
 }
 
-func (s *Scratch) compress1xDo(dst, src []byte) ([]byte, error) {
+func (s *Scratch) compress1xDo(dst, src []byte) []byte {
 	var bw = bitWriter{out: dst}
 
 	// N is length divisible by 4.
@@ -260,8 +260,8 @@ func (s *Scratch) compress1xDo(dst, src []byte) ([]byte, error) {
 			bw.encTwoSymbols(cTable, tmp[1], tmp[0])
 		}
 	}
-	err := bw.close()
-	return bw.out, err
+	bw.close()
+	return bw.out
 }
 
 var sixZeros [6]byte
@@ -283,12 +283,8 @@ func (s *Scratch) compress4X(src []byte) ([]byte, error) {
 		}
 		src = src[len(toDo):]
 
-		var err error
 		idx := len(s.Out)
-		s.Out, err = s.compress1xDo(s.Out, toDo)
-		if err != nil {
-			return nil, err
-		}
+		s.Out = s.compress1xDo(s.Out, toDo)
 		if len(s.Out)-idx > math.MaxUint16 {
 			// We cannot store the size in the jump table
 			return nil, ErrIncompressible
@@ -315,7 +311,6 @@ func (s *Scratch) compress4Xp(src []byte) ([]byte, error) {
 
 	segmentSize := (len(src) + 3) / 4
 	var wg sync.WaitGroup
-	var errs [4]error
 	wg.Add(4)
 	for i := 0; i < 4; i++ {
 		toDo := src
@@ -326,15 +321,12 @@ func (s *Scratch) compress4Xp(src []byte) ([]byte, error) {
 
 		// Separate goroutine for each block.
 		go func(i int) {
-			s.tmpOut[i], errs[i] = s.compress1xDo(s.tmpOut[i][:0], toDo)
+			s.tmpOut[i] = s.compress1xDo(s.tmpOut[i][:0], toDo)
 			wg.Done()
 		}(i)
 	}
 	wg.Wait()
 	for i := 0; i < 4; i++ {
-		if errs[i] != nil {
-			return nil, errs[i]
-		}
 		o := s.tmpOut[i]
 		if len(o) > math.MaxUint16 {
 			// We cannot store the size in the jump table
@@ -358,6 +350,7 @@ func (s *Scratch) compress4Xp(src []byte) ([]byte, error) {
 // Does not update s.clearCount.
 func (s *Scratch) countSimple(in []byte) (max int, reuse bool) {
 	reuse = true
+	_ = s.count // Assert that s != nil to speed up the following loop.
 	for _, v := range in {
 		s.count[v]++
 	}
@@ -423,7 +416,7 @@ func (s *Scratch) validateTable(c cTable) bool {
 
 // minTableLog provides the minimum logSize to safely represent a distribution.
 func (s *Scratch) minTableLog() uint8 {
-	minBitsSrc := highBit32(uint32(s.br.remain())) + 1
+	minBitsSrc := highBit32(uint32(s.srcLen)) + 1
 	minBitsSymbols := highBit32(uint32(s.symbolLen-1)) + 2
 	if minBitsSrc < minBitsSymbols {
 		return uint8(minBitsSrc)
@@ -435,7 +428,7 @@ func (s *Scratch) minTableLog() uint8 {
 func (s *Scratch) optimalTableLog() {
 	tableLog := s.TableLog
 	minBits := s.minTableLog()
-	maxBitsSrc := uint8(highBit32(uint32(s.br.remain()-1))) - 1
+	maxBitsSrc := uint8(highBit32(uint32(s.srcLen-1))) - 1
 	if maxBitsSrc < tableLog {
 		// Accuracy can be reduced
 		tableLog = maxBitsSrc

vendor/github.com/klauspost/compress/huff0/decompress.go

@@ -253,7 +253,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
 
 	switch d.actualTableLog {
 	case 8:
-		const shift = 8 - 8
+		const shift = 0
 		for br.off >= 4 {
 			br.fillFast()
 			v := dt[uint8(br.value>>(56+shift))]

vendor/github.com/klauspost/compress/huff0/huff0.go

@@ -88,7 +88,7 @@ type Scratch struct {
 	// Decoders will return ErrMaxDecodedSizeExceeded is this limit is exceeded.
 	MaxDecodedSize int
 
-	br byteReader
+	srcLen int
 
 	// MaxSymbolValue will override the maximum symbol value of the next block.
 	MaxSymbolValue uint8
@@ -170,7 +170,7 @@ func (s *Scratch) prepare(in []byte) (*Scratch, error) {
 	if s.fse == nil {
 		s.fse = &fse.Scratch{}
 	}
-	s.br.init(in)
+	s.srcLen = len(in)
 
 	return s, nil
 }