vendor github.com/containers/image/v5@v5.5.1

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/klauspost/compress/zstd/bitreader.go

@@ -5,6 +5,7 @@
 package zstd
 
 import (
+	"encoding/binary"
 	"errors"
 	"io"
 	"math/bits"
@@ -34,8 +35,12 @@ func (b *bitReader) init(in []byte) error {
 	}
 	b.bitsRead = 64
 	b.value = 0
-	b.fill()
-	b.fill()
+	if len(in) >= 8 {
+		b.fillFastStart()
+	} else {
+		b.fill()
+		b.fill()
+	}
 	b.bitsRead += 8 - uint8(highBits(uint32(v)))
 	return nil
 }
@@ -63,21 +68,31 @@ func (b *bitReader) fillFast() {
 	if b.bitsRead < 32 {
 		return
 	}
-	// Do single re-slice to avoid bounds checks.
-	v := b.in[b.off-4 : b.off]
+	// 2 bounds checks.
+	v := b.in[b.off-4:]
+	v = v[:4]
 	low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 	b.value = (b.value << 32) | uint64(low)
 	b.bitsRead -= 32
 	b.off -= 4
 }
 
+// fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read.
+func (b *bitReader) fillFastStart() {
+	// Do single re-slice to avoid bounds checks.
+	b.value = binary.LittleEndian.Uint64(b.in[b.off-8:])
+	b.bitsRead = 0
+	b.off -= 8
+}
+
 // fill() will make sure at least 32 bits are available.
 func (b *bitReader) fill() {
 	if b.bitsRead < 32 {
 		return
 	}
 	if b.off >= 4 {
-		v := b.in[b.off-4 : b.off]
+		v := b.in[b.off-4:]
+		v = v[:4]
 		low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
 		b.value = (b.value << 32) | uint64(low)
 		b.bitsRead -= 32

vendor/github.com/klauspost/compress/zstd/blockdec.go

@@ -83,6 +83,10 @@ type blockDec struct {
 	err         error
 	decWG       sync.WaitGroup
 
+	// Frame to use for singlethreaded decoding.
+	// Should not be used by the decoder itself since parent may be another frame.
+	localFrame *frameDec
+
 	// Block is RLE, this is the size.
 	RLESize uint32
 	tmp     [4]byte

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

@@ -4,8 +4,6 @@
 
 package zstd
 
-import "encoding/binary"
-
 // byteReader provides a byte reader that reads
 // little endian values from a byte stream.
 // The input stream is manually advanced.
@@ -33,7 +31,8 @@ func (b *byteReader) overread() bool {
 
 // Int32 returns a little endian int32 starting at current offset.
 func (b byteReader) Int32() int32 {
-	b2 := b.b[b.off : b.off+4 : b.off+4]
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
 	v3 := int32(b2[3])
 	v2 := int32(b2[2])
 	v1 := int32(b2[1])
@@ -57,7 +56,25 @@ func (b byteReader) Uint32() uint32 {
 		}
 		return v
 	}
-	return binary.LittleEndian.Uint32(b.b[b.off : b.off+4])
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
+	v3 := uint32(b2[3])
+	v2 := uint32(b2[2])
+	v1 := uint32(b2[1])
+	v0 := uint32(b2[0])
+	return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
+}
+
+// Uint32NC returns a little endian uint32 starting at current offset.
+// The caller must be sure if there are at least 4 bytes left.
+func (b byteReader) Uint32NC() uint32 {
+	b2 := b.b[b.off:]
+	b2 = b2[:4]
+	v3 := uint32(b2[3])
+	v2 := uint32(b2[2])
+	v1 := uint32(b2[1])
+	v0 := uint32(b2[0])
+	return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24)
 }
 
 // unread returns the unread portion of the input.

vendor/github.com/klauspost/compress/zstd/decoder.go

@@ -23,9 +23,6 @@ type Decoder struct {
 	// Unreferenced decoders, ready for use.
 	decoders chan *blockDec
 
-	// Unreferenced decoders, ready for use.
-	frames chan *frameDec
-
 	// Streams ready to be decoded.
 	stream chan decodeStream
 
@@ -90,10 +87,10 @@ func NewReader(r io.Reader, opts ...DOption) (*Decoder, error) {
 
 	// Create decoders
 	d.decoders = make(chan *blockDec, d.o.concurrent)
-	d.frames = make(chan *frameDec, d.o.concurrent)
 	for i := 0; i < d.o.concurrent; i++ {
-		d.frames <- newFrameDec(d.o)
-		d.decoders <- newBlockDec(d.o.lowMem)
+		dec := newBlockDec(d.o.lowMem)
+		dec.localFrame = newFrameDec(d.o)
+		d.decoders <- dec
 	}
 
 	if r == nil {
@@ -283,15 +280,15 @@ func (d *Decoder) DecodeAll(input, dst []byte) ([]byte, error) {
 	}
 
 	// Grab a block decoder and frame decoder.
-	block, frame := <-d.decoders, <-d.frames
+	block := <-d.decoders
+	frame := block.localFrame
 	defer func() {
 		if debug {
 			printf("re-adding decoder: %p", block)
 		}
-		d.decoders <- block
 		frame.rawInput = nil
 		frame.bBuf = nil
-		d.frames <- frame
+		d.decoders <- block
 	}()
 	frame.bBuf = input
 

vendor/github.com/klauspost/compress/zstd/fse_decoder.go

@@ -55,7 +55,7 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 	if b.remain() < 4 {
 		return errors.New("input too small")
 	}
-	bitStream := b.Uint32()
+	bitStream := b.Uint32NC()
 	nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog
 	if nbBits > tablelogAbsoluteMax {
 		println("Invalid tablelog:", nbBits)
@@ -79,7 +79,8 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 				n0 += 24
 				if r := b.remain(); r > 5 {
 					b.advance(2)
-					bitStream = b.Uint32() >> bitCount
+					// The check above should make sure we can read 32 bits
+					bitStream = b.Uint32NC() >> bitCount
 				} else {
 					// end of bit stream
 					bitStream >>= 16
@@ -104,10 +105,11 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 				charnum++
 			}
 
-			if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 {
+			if r := b.remain(); r >= 7 || r-int(bitCount>>3) >= 4 {
 				b.advance(bitCount >> 3)
 				bitCount &= 7
-				bitStream = b.Uint32() >> bitCount
+				// The check above should make sure we can read 32 bits
+				bitStream = b.Uint32NC() >> bitCount
 			} else {
 				bitStream >>= 2
 			}
@@ -148,17 +150,16 @@ func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error {
 			threshold >>= 1
 		}
 
-		//println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "remain:", b.remain())
-		if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 {
+		if r := b.remain(); r >= 7 || r-int(bitCount>>3) >= 4 {
 			b.advance(bitCount >> 3)
 			bitCount &= 7
+			// The check above should make sure we can read 32 bits
+			bitStream = b.Uint32NC() >> (bitCount & 31)
 		} else {
 			bitCount -= (uint)(8 * (len(b.b) - 4 - b.off))
 			b.off = len(b.b) - 4
-			//println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "iend", iend)
+			bitStream = b.Uint32() >> (bitCount & 31)
 		}
-		bitStream = b.Uint32() >> (bitCount & 31)
-		//printf("bitstream is now: 0b%b", bitStream)
 	}
 	s.symbolLen = charnum
 	if s.symbolLen <= 1 {