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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.go103
1 files changed, 48 insertions, 55 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/seqdec.go b/vendor/github.com/klauspost/compress/zstd/seqdec.go
index cef69e35b..15a45f7b5 100644
--- a/vendor/github.com/klauspost/compress/zstd/seqdec.go
+++ b/vendor/github.com/klauspost/compress/zstd/seqdec.go
@@ -89,6 +89,10 @@ func (s *sequenceDecs) initialize(br *bitReader, hist *history, literals, out []
// decode sequences from the stream with the provided history.
func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error {
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
+
for i := seqs - 1; i >= 0; i-- {
if br.overread() {
printf("reading sequence %d, exceeded available data\n", seqs-i)
@@ -96,10 +100,10 @@ func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error {
}
var litLen, matchOff, matchLen int
if br.off > 4+((maxOffsetBits+16+16)>>3) {
- litLen, matchOff, matchLen = s.nextFast(br)
+ litLen, matchOff, matchLen = s.nextFast(br, llState, mlState, ofState)
br.fillFast()
} else {
- litLen, matchOff, matchLen = s.next(br)
+ litLen, matchOff, matchLen = s.next(br, llState, mlState, ofState)
br.fill()
}
@@ -175,30 +179,25 @@ func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error {
// This is the last sequence, so we shouldn't update state.
break
}
- if true {
- // Manually inlined, ~ 5-20% faster
- // Update all 3 states at once. Approx 20% faster.
- a, b, c := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state
-
- nBits := a.nbBits + b.nbBits + c.nbBits
- if nBits == 0 {
- s.litLengths.state.state = s.litLengths.state.dt[a.newState]
- s.matchLengths.state.state = s.matchLengths.state.dt[b.newState]
- s.offsets.state.state = s.offsets.state.dt[c.newState]
- } else {
- bits := br.getBitsFast(nBits)
- lowBits := uint16(bits >> ((c.nbBits + b.nbBits) & 31))
- s.litLengths.state.state = s.litLengths.state.dt[a.newState+lowBits]
-
- lowBits = uint16(bits >> (c.nbBits & 31))
- lowBits &= bitMask[b.nbBits&15]
- s.matchLengths.state.state = s.matchLengths.state.dt[b.newState+lowBits]
- lowBits = uint16(bits) & bitMask[c.nbBits&15]
- s.offsets.state.state = s.offsets.state.dt[c.newState+lowBits]
- }
+ // 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 {
- s.updateAlt(br)
+ bits := br.getBitsFast(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]
}
}
@@ -230,55 +229,49 @@ func (s *sequenceDecs) updateAlt(br *bitReader) {
// Update all 3 states at once. Approx 20% faster.
a, b, c := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state
- nBits := a.nbBits + b.nbBits + c.nbBits
+ nBits := a.nbBits() + b.nbBits() + c.nbBits()
if nBits == 0 {
- s.litLengths.state.state = s.litLengths.state.dt[a.newState]
- s.matchLengths.state.state = s.matchLengths.state.dt[b.newState]
- s.offsets.state.state = s.offsets.state.dt[c.newState]
+ s.litLengths.state.state = s.litLengths.state.dt[a.newState()]
+ s.matchLengths.state.state = s.matchLengths.state.dt[b.newState()]
+ s.offsets.state.state = s.offsets.state.dt[c.newState()]
return
}
bits := br.getBitsFast(nBits)
- lowBits := uint16(bits >> ((c.nbBits + b.nbBits) & 31))
- s.litLengths.state.state = s.litLengths.state.dt[a.newState+lowBits]
+ lowBits := uint16(bits >> ((c.nbBits() + b.nbBits()) & 31))
+ s.litLengths.state.state = s.litLengths.state.dt[a.newState()+lowBits]
- lowBits = uint16(bits >> (c.nbBits & 31))
- lowBits &= bitMask[b.nbBits&15]
- s.matchLengths.state.state = s.matchLengths.state.dt[b.newState+lowBits]
+ lowBits = uint16(bits >> (c.nbBits() & 31))
+ lowBits &= bitMask[b.nbBits()&15]
+ s.matchLengths.state.state = s.matchLengths.state.dt[b.newState()+lowBits]
- lowBits = uint16(bits) & bitMask[c.nbBits&15]
- s.offsets.state.state = s.offsets.state.dt[c.newState+lowBits]
+ lowBits = uint16(bits) & bitMask[c.nbBits()&15]
+ s.offsets.state.state = s.offsets.state.dt[c.newState()+lowBits]
}
// nextFast will return new states when there are at least 4 unused bytes left on the stream when done.
-func (s *sequenceDecs) nextFast(br *bitReader) (ll, mo, ml int) {
+func (s *sequenceDecs) nextFast(br *bitReader, llState, mlState, ofState decSymbol) (ll, mo, ml int) {
// Final will not read from stream.
- ll, llB := s.litLengths.state.final()
- ml, mlB := s.matchLengths.state.final()
- mo, moB := s.offsets.state.final()
+ ll, llB := llState.final()
+ ml, mlB := mlState.final()
+ mo, moB := ofState.final()
// extra bits are stored in reverse order.
br.fillFast()
- if s.maxBits <= 32 {
- mo += br.getBits(moB)
- ml += br.getBits(mlB)
- ll += br.getBits(llB)
- } else {
- mo += br.getBits(moB)
+ mo += br.getBits(moB)
+ if s.maxBits > 32 {
br.fillFast()
- // matchlength+literal length, max 32 bits
- ml += br.getBits(mlB)
- ll += br.getBits(llB)
}
+ ml += br.getBits(mlB)
+ ll += br.getBits(llB)
- // mo = s.adjustOffset(mo, ll, moB)
- // Inlined for rather big speedup
if moB > 1 {
s.prevOffset[2] = s.prevOffset[1]
s.prevOffset[1] = s.prevOffset[0]
s.prevOffset[0] = mo
return
}
-
+ // 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,
@@ -312,11 +305,11 @@ func (s *sequenceDecs) nextFast(br *bitReader) (ll, mo, ml int) {
return
}
-func (s *sequenceDecs) next(br *bitReader) (ll, mo, ml int) {
+func (s *sequenceDecs) next(br *bitReader, llState, mlState, ofState decSymbol) (ll, mo, ml int) {
// Final will not read from stream.
- ll, llB := s.litLengths.state.final()
- ml, mlB := s.matchLengths.state.final()
- mo, moB := s.offsets.state.final()
+ ll, llB := llState.final()
+ ml, mlB := mlState.final()
+ mo, moB := ofState.final()
// extra bits are stored in reverse order.
br.fill()
generated by cgit v1.2.3-54-g00ecf (git 2.39.0) at 2024-11-17 10:00:34 +0000