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path: root/vendor/github.com/klauspost/compress/zstd/blockdec.go
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-rw-r--r--vendor/github.com/klauspost/compress/zstd/blockdec.go422
1 files changed, 191 insertions, 231 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/blockdec.go b/vendor/github.com/klauspost/compress/zstd/blockdec.go
index dc587b2c9..607b62ee3 100644
--- a/vendor/github.com/klauspost/compress/zstd/blockdec.go
+++ b/vendor/github.com/klauspost/compress/zstd/blockdec.go
@@ -76,16 +76,25 @@ type blockDec struct {
// Window size of the block.
WindowSize uint64
- history chan *history
- input chan struct{}
- result chan decodeOutput
- err error
- decWG sync.WaitGroup
+ err error
+
+ // Check against this crc
+ checkCRC []byte
// Frame to use for singlethreaded decoding.
// Should not be used by the decoder itself since parent may be another frame.
localFrame *frameDec
+ sequence []seqVals
+
+ async struct {
+ newHist *history
+ literals []byte
+ seqData []byte
+ seqSize int // Size of uncompressed sequences
+ fcs uint64
+ }
+
// Block is RLE, this is the size.
RLESize uint32
tmp [4]byte
@@ -108,13 +117,8 @@ func (b *blockDec) String() string {
func newBlockDec(lowMem bool) *blockDec {
b := blockDec{
- lowMem: lowMem,
- result: make(chan decodeOutput, 1),
- input: make(chan struct{}, 1),
- history: make(chan *history, 1),
+ lowMem: lowMem,
}
- b.decWG.Add(1)
- go b.startDecoder()
return &b
}
@@ -137,6 +141,12 @@ func (b *blockDec) reset(br byteBuffer, windowSize uint64) error {
case blockTypeReserved:
return ErrReservedBlockType
case blockTypeRLE:
+ if cSize > maxCompressedBlockSize || cSize > int(b.WindowSize) {
+ if debugDecoder {
+ printf("rle block too big: csize:%d block: %+v\n", uint64(cSize), b)
+ }
+ return ErrWindowSizeExceeded
+ }
b.RLESize = uint32(cSize)
if b.lowMem {
maxSize = cSize
@@ -158,6 +168,13 @@ func (b *blockDec) reset(br byteBuffer, windowSize uint64) error {
return ErrCompressedSizeTooBig
}
case blockTypeRaw:
+ if cSize > maxCompressedBlockSize || cSize > int(b.WindowSize) {
+ if debugDecoder {
+ printf("rle block too big: csize:%d block: %+v\n", uint64(cSize), b)
+ }
+ return ErrWindowSizeExceeded
+ }
+
b.RLESize = 0
// We do not need a destination for raw blocks.
maxSize = -1
@@ -192,85 +209,14 @@ func (b *blockDec) sendErr(err error) {
b.Last = true
b.Type = blockTypeReserved
b.err = err
- b.input <- struct{}{}
}
// Close will release resources.
// Closed blockDec cannot be reset.
func (b *blockDec) Close() {
- close(b.input)
- close(b.history)
- close(b.result)
- b.decWG.Wait()
-}
-
-// decodeAsync will prepare decoding the block when it receives input.
-// This will separate output and history.
-func (b *blockDec) startDecoder() {
- defer b.decWG.Done()
- for range b.input {
- //println("blockDec: Got block input")
- switch b.Type {
- case blockTypeRLE:
- if cap(b.dst) < int(b.RLESize) {
- if b.lowMem {
- b.dst = make([]byte, b.RLESize)
- } else {
- b.dst = make([]byte, maxBlockSize)
- }
- }
- o := decodeOutput{
- d: b,
- b: b.dst[:b.RLESize],
- err: nil,
- }
- v := b.data[0]
- for i := range o.b {
- o.b[i] = v
- }
- hist := <-b.history
- hist.append(o.b)
- b.result <- o
- case blockTypeRaw:
- o := decodeOutput{
- d: b,
- b: b.data,
- err: nil,
- }
- hist := <-b.history
- hist.append(o.b)
- b.result <- o
- case blockTypeCompressed:
- b.dst = b.dst[:0]
- err := b.decodeCompressed(nil)
- o := decodeOutput{
- d: b,
- b: b.dst,
- err: err,
- }
- if debugDecoder {
- println("Decompressed to", len(b.dst), "bytes, error:", err)
- }
- b.result <- o
- case blockTypeReserved:
- // Used for returning errors.
- <-b.history
- b.result <- decodeOutput{
- d: b,
- b: nil,
- err: b.err,
- }
- default:
- panic("Invalid block type")
- }
- if debugDecoder {
- println("blockDec: Finished block")
- }
- }
}
-// decodeAsync will prepare decoding the block when it receives the history.
-// If history is provided, it will not fetch it from the channel.
+// decodeBuf
func (b *blockDec) decodeBuf(hist *history) error {
switch b.Type {
case blockTypeRLE:
@@ -293,14 +239,23 @@ func (b *blockDec) decodeBuf(hist *history) error {
return nil
case blockTypeCompressed:
saved := b.dst
- b.dst = hist.b
- hist.b = nil
+ // Append directly to history
+ if hist.ignoreBuffer == 0 {
+ b.dst = hist.b
+ hist.b = nil
+ } else {
+ b.dst = b.dst[:0]
+ }
err := b.decodeCompressed(hist)
if debugDecoder {
println("Decompressed to total", len(b.dst), "bytes, hash:", xxhash.Sum64(b.dst), "error:", err)
}
- hist.b = b.dst
- b.dst = saved
+ if hist.ignoreBuffer == 0 {
+ hist.b = b.dst
+ b.dst = saved
+ } else {
+ hist.appendKeep(b.dst)
+ }
return err
case blockTypeReserved:
// Used for returning errors.
@@ -310,30 +265,18 @@ func (b *blockDec) decodeBuf(hist *history) error {
}
}
-// decodeCompressed will start decompressing a block.
-// If no history is supplied the decoder will decodeAsync as much as possible
-// before fetching from blockDec.history
-func (b *blockDec) decodeCompressed(hist *history) error {
- in := b.data
- delayedHistory := hist == nil
-
- if delayedHistory {
- // We must always grab history.
- defer func() {
- if hist == nil {
- <-b.history
- }
- }()
- }
+func (b *blockDec) decodeLiterals(in []byte, hist *history) (remain []byte, err error) {
// There must be at least one byte for Literals_Block_Type and one for Sequences_Section_Header
if len(in) < 2 {
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
+
litType := literalsBlockType(in[0] & 3)
var litRegenSize int
var litCompSize int
sizeFormat := (in[0] >> 2) & 3
var fourStreams bool
+ var literals []byte
switch litType {
case literalsBlockRaw, literalsBlockRLE:
switch sizeFormat {
@@ -349,7 +292,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
// Regenerated_Size uses 20 bits (0-1048575). Literals_Section_Header uses 3 bytes.
if len(in) < 3 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
litRegenSize = int(in[0]>>4) + (int(in[1]) << 4) + (int(in[2]) << 12)
in = in[3:]
@@ -360,7 +303,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
// Both Regenerated_Size and Compressed_Size use 10 bits (0-1023).
if len(in) < 3 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12)
litRegenSize = int(n & 1023)
@@ -371,7 +314,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
fourStreams = true
if len(in) < 4 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20)
litRegenSize = int(n & 16383)
@@ -381,7 +324,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
fourStreams = true
if len(in) < 5 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in))
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20) + (uint64(in[4]) << 28)
litRegenSize = int(n & 262143)
@@ -392,13 +335,15 @@ func (b *blockDec) decodeCompressed(hist *history) error {
if debugDecoder {
println("literals type:", litType, "litRegenSize:", litRegenSize, "litCompSize:", litCompSize, "sizeFormat:", sizeFormat, "4X:", fourStreams)
}
- var literals []byte
- var huff *huff0.Scratch
+ if litRegenSize > int(b.WindowSize) || litRegenSize > maxCompressedBlockSize {
+ return in, ErrWindowSizeExceeded
+ }
+
switch litType {
case literalsBlockRaw:
if len(in) < litRegenSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litRegenSize)
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
literals = in[:litRegenSize]
in = in[litRegenSize:]
@@ -406,7 +351,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
case literalsBlockRLE:
if len(in) < 1 {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", 1)
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
if cap(b.literalBuf) < litRegenSize {
if b.lowMem {
@@ -417,7 +362,6 @@ func (b *blockDec) decodeCompressed(hist *history) error {
b.literalBuf = make([]byte, litRegenSize)
} else {
b.literalBuf = make([]byte, litRegenSize, maxCompressedLiteralSize)
-
}
}
}
@@ -433,7 +377,7 @@ func (b *blockDec) decodeCompressed(hist *history) error {
case literalsBlockTreeless:
if len(in) < litCompSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize)
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
// Store compressed literals, so we defer decoding until we get history.
literals = in[:litCompSize]
@@ -441,31 +385,65 @@ func (b *blockDec) decodeCompressed(hist *history) error {
if debugDecoder {
printf("Found %d compressed literals\n", litCompSize)
}
+ huff := hist.huffTree
+ if huff == nil {
+ return in, errors.New("literal block was treeless, but no history was defined")
+ }
+ // Ensure we have space to store it.
+ if cap(b.literalBuf) < litRegenSize {
+ if b.lowMem {
+ b.literalBuf = make([]byte, 0, litRegenSize)
+ } else {
+ b.literalBuf = make([]byte, 0, maxCompressedLiteralSize)
+ }
+ }
+ var err error
+ // Use our out buffer.
+ huff.MaxDecodedSize = maxCompressedBlockSize
+ if fourStreams {
+ literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
+ } else {
+ literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
+ }
+ // Make sure we don't leak our literals buffer
+ if err != nil {
+ println("decompressing literals:", err)
+ return in, err
+ }
+ if len(literals) != litRegenSize {
+ return in, fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
+ }
+
case literalsBlockCompressed:
if len(in) < litCompSize {
println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize)
- return ErrBlockTooSmall
+ return in, ErrBlockTooSmall
}
literals = in[:litCompSize]
in = in[litCompSize:]
- huff = huffDecoderPool.Get().(*huff0.Scratch)
- var err error
// Ensure we have space to store it.
if cap(b.literalBuf) < litRegenSize {
if b.lowMem {
b.literalBuf = make([]byte, 0, litRegenSize)
} else {
- b.literalBuf = make([]byte, 0, maxCompressedLiteralSize)
+ b.literalBuf = make([]byte, 0, maxCompressedBlockSize)
}
}
- if huff == nil {
- huff = &huff0.Scratch{}
+ huff := hist.huffTree
+ if huff == nil || (hist.dict != nil && huff == hist.dict.litEnc) {
+ huff = huffDecoderPool.Get().(*huff0.Scratch)
+ if huff == nil {
+ huff = &huff0.Scratch{}
+ }
}
+ var err error
huff, literals, err = huff0.ReadTable(literals, huff)
if err != nil {
println("reading huffman table:", err)
- return err
+ return in, err
}
+ hist.huffTree = huff
+ huff.MaxDecodedSize = maxCompressedBlockSize
// Use our out buffer.
if fourStreams {
literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
@@ -474,24 +452,52 @@ func (b *blockDec) decodeCompressed(hist *history) error {
}
if err != nil {
println("decoding compressed literals:", err)
- return err
+ return in, err
}
// Make sure we don't leak our literals buffer
if len(literals) != litRegenSize {
- return fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
+ return in, fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
}
if debugDecoder {
printf("Decompressed %d literals into %d bytes\n", litCompSize, litRegenSize)
}
}
+ hist.decoders.literals = literals
+ return in, nil
+}
+
+// decodeCompressed will start decompressing a block.
+func (b *blockDec) decodeCompressed(hist *history) error {
+ in := b.data
+ in, err := b.decodeLiterals(in, hist)
+ if err != nil {
+ return err
+ }
+ err = b.prepareSequences(in, hist)
+ if err != nil {
+ return err
+ }
+ if hist.decoders.nSeqs == 0 {
+ b.dst = append(b.dst, hist.decoders.literals...)
+ return nil
+ }
+ err = hist.decoders.decodeSync(hist)
+ if err != nil {
+ return err
+ }
+ b.dst = hist.decoders.out
+ hist.recentOffsets = hist.decoders.prevOffset
+ return nil
+}
+func (b *blockDec) prepareSequences(in []byte, hist *history) (err error) {
// Decode Sequences
// https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#sequences-section
if len(in) < 1 {
return ErrBlockTooSmall
}
+ var nSeqs int
seqHeader := in[0]
- nSeqs := 0
switch {
case seqHeader == 0:
in = in[1:]
@@ -512,7 +518,8 @@ func (b *blockDec) decodeCompressed(hist *history) error {
in = in[3:]
}
- var seqs = &sequenceDecs{}
+ var seqs = &hist.decoders
+ seqs.nSeqs = nSeqs
if nSeqs > 0 {
if len(in) < 1 {
return ErrBlockTooSmall
@@ -541,6 +548,9 @@ func (b *blockDec) decodeCompressed(hist *history) error {
}
switch mode {
case compModePredefined:
+ if seq.fse != nil && !seq.fse.preDefined {
+ fseDecoderPool.Put(seq.fse)
+ }
seq.fse = &fsePredef[i]
case compModeRLE:
if br.remain() < 1 {
@@ -548,34 +558,36 @@ func (b *blockDec) decodeCompressed(hist *history) error {
}
v := br.Uint8()
br.advance(1)
- dec := fseDecoderPool.Get().(*fseDecoder)
+ if seq.fse == nil || seq.fse.preDefined {
+ seq.fse = fseDecoderPool.Get().(*fseDecoder)
+ }
symb, err := decSymbolValue(v, symbolTableX[i])
if err != nil {
printf("RLE Transform table (%v) error: %v", tableIndex(i), err)
return err
}
- dec.setRLE(symb)
- seq.fse = dec
+ seq.fse.setRLE(symb)
if debugDecoder {
printf("RLE set to %+v, code: %v", symb, v)
}
case compModeFSE:
println("Reading table for", tableIndex(i))
- dec := fseDecoderPool.Get().(*fseDecoder)
- err := dec.readNCount(&br, uint16(maxTableSymbol[i]))
+ if seq.fse == nil || seq.fse.preDefined {
+ seq.fse = fseDecoderPool.Get().(*fseDecoder)
+ }
+ err := seq.fse.readNCount(&br, uint16(maxTableSymbol[i]))
if err != nil {
println("Read table error:", err)
return err
}
- err = dec.transform(symbolTableX[i])
+ err = seq.fse.transform(symbolTableX[i])
if err != nil {
println("Transform table error:", err)
return err
}
if debugDecoder {
- println("Read table ok", "symbolLen:", dec.symbolLen)
+ println("Read table ok", "symbolLen:", seq.fse.symbolLen)
}
- seq.fse = dec
case compModeRepeat:
seq.repeat = true
}
@@ -585,140 +597,88 @@ func (b *blockDec) decodeCompressed(hist *history) error {
}
in = br.unread()
}
-
- // Wait for history.
- // All time spent after this is critical since it is strictly sequential.
- if hist == nil {
- hist = <-b.history
- if hist.error {
- return ErrDecoderClosed
- }
- }
-
- // Decode treeless literal block.
- if litType == literalsBlockTreeless {
- // TODO: We could send the history early WITHOUT the stream history.
- // This would allow decoding treeless literals before the byte history is available.
- // Silencia stats: Treeless 4393, with: 32775, total: 37168, 11% treeless.
- // So not much obvious gain here.
-
- if hist.huffTree == nil {
- return errors.New("literal block was treeless, but no history was defined")
- }
- // Ensure we have space to store it.
- if cap(b.literalBuf) < litRegenSize {
- if b.lowMem {
- b.literalBuf = make([]byte, 0, litRegenSize)
- } else {
- b.literalBuf = make([]byte, 0, maxCompressedLiteralSize)
- }
- }
- var err error
- // Use our out buffer.
- huff = hist.huffTree
- if fourStreams {
- literals, err = huff.Decoder().Decompress4X(b.literalBuf[:0:litRegenSize], literals)
- } else {
- literals, err = huff.Decoder().Decompress1X(b.literalBuf[:0:litRegenSize], literals)
- }
- // Make sure we don't leak our literals buffer
- if err != nil {
- println("decompressing literals:", err)
- return err
- }
- if len(literals) != litRegenSize {
- return fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals))
- }
- } else {
- if hist.huffTree != nil && huff != nil {
- if hist.dict == nil || hist.dict.litEnc != hist.huffTree {
- huffDecoderPool.Put(hist.huffTree)
- }
- hist.huffTree = nil
- }
- }
- if huff != nil {
- hist.huffTree = huff
- }
if debugDecoder {
- println("Final literals:", len(literals), "hash:", xxhash.Sum64(literals), "and", nSeqs, "sequences.")
+ println("Literals:", len(seqs.literals), "hash:", xxhash.Sum64(seqs.literals), "and", seqs.nSeqs, "sequences.")
}
if nSeqs == 0 {
- // Decompressed content is defined entirely as Literals Section content.
- b.dst = append(b.dst, literals...)
- if delayedHistory {
- hist.append(literals)
+ if len(b.sequence) > 0 {
+ b.sequence = b.sequence[:0]
}
return nil
}
-
- seqs, err := seqs.mergeHistory(&hist.decoders)
- if err != nil {
- return err
+ br := seqs.br
+ if br == nil {
+ br = &bitReader{}
}
- if debugDecoder {
- println("History merged ok")
- }
- br := &bitReader{}
if err := br.init(in); err != nil {
return err
}
- // TODO: Investigate if sending history without decoders are faster.
- // This would allow the sequences to be decoded async and only have to construct stream history.
- // If only recent offsets were not transferred, this would be an obvious win.
- // Also, if first 3 sequences don't reference recent offsets, all sequences can be decoded.
+ if err := seqs.initialize(br, hist, b.dst); err != nil {
+ println("initializing sequences:", err)
+ return err
+ }
+ return nil
+}
+
+func (b *blockDec) decodeSequences(hist *history) error {
+ if cap(b.sequence) < hist.decoders.nSeqs {
+ if b.lowMem {
+ b.sequence = make([]seqVals, 0, hist.decoders.nSeqs)
+ } else {
+ b.sequence = make([]seqVals, 0, 0x7F00+0xffff)
+ }
+ }
+ b.sequence = b.sequence[:hist.decoders.nSeqs]
+ if hist.decoders.nSeqs == 0 {
+ hist.decoders.seqSize = len(hist.decoders.literals)
+ return nil
+ }
+ hist.decoders.prevOffset = hist.recentOffsets
+ err := hist.decoders.decode(b.sequence)
+ hist.recentOffsets = hist.decoders.prevOffset
+ return err
+}
+func (b *blockDec) executeSequences(hist *history) error {
hbytes := hist.b
if len(hbytes) > hist.windowSize {
hbytes = hbytes[len(hbytes)-hist.windowSize:]
- // We do not need history any more.
+ // We do not need history anymore.
if hist.dict != nil {
hist.dict.content = nil
}
}
-
- if err := seqs.initialize(br, hist, literals, b.dst); err != nil {
- println("initializing sequences:", err)
- return err
- }
-
- err = seqs.decode(nSeqs, br, hbytes)
+ hist.decoders.windowSize = hist.windowSize
+ hist.decoders.out = b.dst[:0]
+ err := hist.decoders.execute(b.sequence, hbytes)
if err != nil {
return err
}
- if !br.finished() {
- return fmt.Errorf("%d extra bits on block, should be 0", br.remain())
- }
+ return b.updateHistory(hist)
+}
- err = br.close()
- if err != nil {
- printf("Closing sequences: %v, %+v\n", err, *br)
- }
+func (b *blockDec) updateHistory(hist *history) error {
if len(b.data) > maxCompressedBlockSize {
return fmt.Errorf("compressed block size too large (%d)", len(b.data))
}
// Set output and release references.
- b.dst = seqs.out
- seqs.out, seqs.literals, seqs.hist = nil, nil, nil
+ b.dst = hist.decoders.out
+ hist.recentOffsets = hist.decoders.prevOffset
- if !delayedHistory {
- // If we don't have delayed history, no need to update.
- hist.recentOffsets = seqs.prevOffset
- return nil
- }
if b.Last {
// if last block we don't care about history.
println("Last block, no history returned")
hist.b = hist.b[:0]
return nil
+ } else {
+ hist.append(b.dst)
+ if debugDecoder {
+ println("Finished block with ", len(b.sequence), "sequences. Added", len(b.dst), "to history, now length", len(hist.b))
+ }
}
- hist.append(b.dst)
- hist.recentOffsets = seqs.prevOffset
- if debugDecoder {
- println("Finished block with literals:", len(literals), "and", nSeqs, "sequences.")
- }
+ hist.decoders.out, hist.decoders.literals = nil, nil
return nil
}
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-10-06 10:23:46 +0000