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path: root/vendor/github.com/klauspost/compress/zstd/seqdec.go
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Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/seqdec.go')
-rw-r--r--vendor/github.com/klauspost/compress/zstd/seqdec.go168
1 files changed, 17 insertions, 151 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/seqdec.go b/vendor/github.com/klauspost/compress/zstd/seqdec.go
index 819f1461b..e80139dd9 100644
--- a/vendor/github.com/klauspost/compress/zstd/seqdec.go
+++ b/vendor/github.com/klauspost/compress/zstd/seqdec.go
@@ -73,6 +73,7 @@ type sequenceDecs struct {
seqSize int
windowSize int
maxBits uint8
+ maxSyncLen uint64
}
// initialize all 3 decoders from the stream input.
@@ -98,153 +99,13 @@ func (s *sequenceDecs) initialize(br *bitReader, hist *history, out []byte) erro
return nil
}
-// decode sequences from the stream with the provided history.
-func (s *sequenceDecs) decode(seqs []seqVals) error {
- br := s.br
-
- // Grab full sizes tables, to avoid bounds checks.
- llTable, mlTable, ofTable := s.litLengths.fse.dt[:maxTablesize], s.matchLengths.fse.dt[:maxTablesize], s.offsets.fse.dt[:maxTablesize]
- llState, mlState, ofState := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state
- s.seqSize = 0
- litRemain := len(s.literals)
- maxBlockSize := maxCompressedBlockSize
- if s.windowSize < maxBlockSize {
- maxBlockSize = s.windowSize
- }
- for i := range seqs {
- var ll, mo, ml int
- if br.off > 4+((maxOffsetBits+16+16)>>3) {
- // inlined function:
- // ll, mo, ml = s.nextFast(br, llState, mlState, ofState)
-
- // Final will not read from stream.
- var llB, mlB, moB uint8
- ll, llB = llState.final()
- ml, mlB = mlState.final()
- mo, moB = ofState.final()
-
- // extra bits are stored in reverse order.
- br.fillFast()
- mo += br.getBits(moB)
- if s.maxBits > 32 {
- br.fillFast()
- }
- ml += br.getBits(mlB)
- ll += br.getBits(llB)
-
- if moB > 1 {
- s.prevOffset[2] = s.prevOffset[1]
- s.prevOffset[1] = s.prevOffset[0]
- s.prevOffset[0] = mo
- } else {
- // mo = s.adjustOffset(mo, ll, moB)
- // Inlined for rather big speedup
- if ll == 0 {
- // There is an exception though, when current sequence's literals_length = 0.
- // In this case, repeated offsets are shifted by one, so an offset_value of 1 means Repeated_Offset2,
- // an offset_value of 2 means Repeated_Offset3, and an offset_value of 3 means Repeated_Offset1 - 1_byte.
- mo++
- }
-
- if mo == 0 {
- mo = s.prevOffset[0]
- } else {
- var temp int
- if mo == 3 {
- temp = s.prevOffset[0] - 1
- } else {
- temp = s.prevOffset[mo]
- }
-
- if temp == 0 {
- // 0 is not valid; input is corrupted; force offset to 1
- println("WARNING: temp was 0")
- temp = 1
- }
-
- if mo != 1 {
- s.prevOffset[2] = s.prevOffset[1]
- }
- s.prevOffset[1] = s.prevOffset[0]
- s.prevOffset[0] = temp
- mo = temp
- }
- }
- br.fillFast()
- } else {
- if br.overread() {
- if debugDecoder {
- printf("reading sequence %d, exceeded available data\n", i)
- }
- return io.ErrUnexpectedEOF
- }
- ll, mo, ml = s.next(br, llState, mlState, ofState)
- br.fill()
- }
-
- if debugSequences {
- println("Seq", i, "Litlen:", ll, "mo:", mo, "(abs) ml:", ml)
- }
- // Evaluate.
- // We might be doing this async, so do it early.
- if mo == 0 && ml > 0 {
- return fmt.Errorf("zero matchoff and matchlen (%d) > 0", ml)
- }
- if ml > maxMatchLen {
- return fmt.Errorf("match len (%d) bigger than max allowed length", ml)
- }
- s.seqSize += ll + ml
- if s.seqSize > maxBlockSize {
- return fmt.Errorf("output (%d) bigger than max block size (%d)", s.seqSize, maxBlockSize)
- }
- litRemain -= ll
- if litRemain < 0 {
- return fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", ll, litRemain+ll)
- }
- seqs[i] = seqVals{
- ll: ll,
- ml: ml,
- mo: mo,
- }
- if i == len(seqs)-1 {
- // This is the last sequence, so we shouldn't update state.
- break
- }
-
- // Manually inlined, ~ 5-20% faster
- // Update all 3 states at once. Approx 20% faster.
- nBits := llState.nbBits() + mlState.nbBits() + ofState.nbBits()
- if nBits == 0 {
- llState = llTable[llState.newState()&maxTableMask]
- mlState = mlTable[mlState.newState()&maxTableMask]
- ofState = ofTable[ofState.newState()&maxTableMask]
- } else {
- bits := br.get32BitsFast(nBits)
- lowBits := uint16(bits >> ((ofState.nbBits() + mlState.nbBits()) & 31))
- llState = llTable[(llState.newState()+lowBits)&maxTableMask]
-
- lowBits = uint16(bits >> (ofState.nbBits() & 31))
- lowBits &= bitMask[mlState.nbBits()&15]
- mlState = mlTable[(mlState.newState()+lowBits)&maxTableMask]
-
- lowBits = uint16(bits) & bitMask[ofState.nbBits()&15]
- ofState = ofTable[(ofState.newState()+lowBits)&maxTableMask]
- }
- }
- s.seqSize += litRemain
- if s.seqSize > maxBlockSize {
- return fmt.Errorf("output (%d) bigger than max block size (%d)", s.seqSize, maxBlockSize)
- }
- err := br.close()
- if err != nil {
- printf("Closing sequences: %v, %+v\n", err, *br)
- }
- return err
-}
-
// execute will execute the decoded sequence with the provided history.
// The sequence must be evaluated before being sent.
func (s *sequenceDecs) execute(seqs []seqVals, hist []byte) error {
+ if len(s.dict) == 0 {
+ return s.executeSimple(seqs, hist)
+ }
+
// Ensure we have enough output size...
if len(s.out)+s.seqSize > cap(s.out) {
addBytes := s.seqSize + len(s.out)
@@ -341,14 +202,19 @@ func (s *sequenceDecs) execute(seqs []seqVals, hist []byte) error {
}
// decode sequences from the stream with the provided history.
-func (s *sequenceDecs) decodeSync(history *history) error {
+func (s *sequenceDecs) decodeSync(hist []byte) error {
+ if true {
+ supported, err := s.decodeSyncSimple(hist)
+ if supported {
+ return err
+ }
+ }
br := s.br
seqs := s.nSeqs
startSize := len(s.out)
// Grab full sizes tables, to avoid bounds checks.
llTable, mlTable, ofTable := s.litLengths.fse.dt[:maxTablesize], s.matchLengths.fse.dt[:maxTablesize], s.offsets.fse.dt[:maxTablesize]
llState, mlState, ofState := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state
- hist := history.b[history.ignoreBuffer:]
out := s.out
maxBlockSize := maxCompressedBlockSize
if s.windowSize < maxBlockSize {
@@ -433,7 +299,7 @@ func (s *sequenceDecs) decodeSync(history *history) error {
}
size := ll + ml + len(out)
if size-startSize > maxBlockSize {
- return fmt.Errorf("output (%d) bigger than max block size (%d)", size, maxBlockSize)
+ return fmt.Errorf("output (%d) bigger than max block size (%d)", size-startSize, maxBlockSize)
}
if size > cap(out) {
// Not enough size, which can happen under high volume block streaming conditions
@@ -463,13 +329,13 @@ func (s *sequenceDecs) decodeSync(history *history) error {
if mo > len(out)+len(hist) || mo > s.windowSize {
if len(s.dict) == 0 {
- return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(out)+len(hist))
+ return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(out)+len(hist)-startSize)
}
// we may be in dictionary.
dictO := len(s.dict) - (mo - (len(out) + len(hist)))
if dictO < 0 || dictO >= len(s.dict) {
- return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(out)+len(hist))
+ return fmt.Errorf("match offset (%d) bigger than current history (%d)", mo, len(out)+len(hist)-startSize)
}
end := dictO + ml
if end > len(s.dict) {
@@ -543,8 +409,8 @@ func (s *sequenceDecs) decodeSync(history *history) error {
}
// Check if space for literals
- if len(s.literals)+len(s.out)-startSize > maxBlockSize {
- return fmt.Errorf("output (%d) bigger than max block size (%d)", len(s.out), maxBlockSize)
+ if size := len(s.literals) + len(s.out) - startSize; size > maxBlockSize {
+ return fmt.Errorf("output (%d) bigger than max block size (%d)", size, maxBlockSize)
}
// Add final literals
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-10-04 12:38:51 +0000