diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/flate/level3.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/flate/level3.go | 41 |
1 files changed, 21 insertions, 20 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/level3.go b/vendor/github.com/klauspost/compress/flate/level3.go index 039639f89..7aa2b72a1 100644 --- a/vendor/github.com/klauspost/compress/flate/level3.go +++ b/vendor/github.com/klauspost/compress/flate/level3.go @@ -11,10 +11,11 @@ type fastEncL3 struct { // Encode uses a similar algorithm to level 2, will check up to two candidates. func (e *fastEncL3) Encode(dst *tokens, src []byte) { const ( - inputMargin = 8 - 1 + inputMargin = 12 - 1 minNonLiteralBlockSize = 1 + 1 + inputMargin tableBits = 16 tableSize = 1 << tableBits + hashBytes = 5 ) if debugDeflate && e.cur < 0 { @@ -69,20 +70,20 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { sLimit := int32(len(src) - inputMargin) // nextEmit is where in src the next emitLiteral should start from. - cv := load3232(src, s) + cv := load6432(src, s) for { - const skipLog = 6 + const skipLog = 7 nextS := s var candidate tableEntry for { - nextHash := hash4u(cv, tableBits) + nextHash := hashLen(cv, tableBits, hashBytes) s = nextS nextS = s + 1 + (s-nextEmit)>>skipLog if nextS > sLimit { goto emitRemainder } candidates := e.table[nextHash] - now := load3232(src, nextS) + now := load6432(src, nextS) // Safe offset distance until s + 4... minOffset := e.cur + s - (maxMatchOffset - 4) @@ -96,8 +97,8 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { continue } - if cv == load3232(src, candidate.offset-e.cur) { - if candidates.Prev.offset < minOffset || cv != load3232(src, candidates.Prev.offset-e.cur) { + if uint32(cv) == load3232(src, candidate.offset-e.cur) { + if candidates.Prev.offset < minOffset || uint32(cv) != load3232(src, candidates.Prev.offset-e.cur) { break } // Both match and are valid, pick longest. @@ -112,7 +113,7 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { // We only check if value mismatches. // Offset will always be invalid in other cases. candidate = candidates.Prev - if candidate.offset > minOffset && cv == load3232(src, candidate.offset-e.cur) { + if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { break } } @@ -164,9 +165,9 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { if s >= sLimit { t += l // Index first pair after match end. - if int(t+4) < len(src) && t > 0 { - cv := load3232(src, t) - nextHash := hash4u(cv, tableBits) + if int(t+8) < len(src) && t > 0 { + cv = load6432(src, t) + nextHash := hashLen(cv, tableBits, hashBytes) e.table[nextHash] = tableEntryPrev{ Prev: e.table[nextHash].Cur, Cur: tableEntry{offset: e.cur + t}, @@ -176,8 +177,8 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { } // Store every 5th hash in-between. - for i := s - l + 2; i < s-5; i += 5 { - nextHash := hash4u(load3232(src, i), tableBits) + for i := s - l + 2; i < s-5; i += 6 { + nextHash := hashLen(load6432(src, i), tableBits, hashBytes) e.table[nextHash] = tableEntryPrev{ Prev: e.table[nextHash].Cur, Cur: tableEntry{offset: e.cur + i}} @@ -185,23 +186,23 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { // We could immediately start working at s now, but to improve // compression we first update the hash table at s-2 to s. x := load6432(src, s-2) - prevHash := hash4u(uint32(x), tableBits) + prevHash := hashLen(x, tableBits, hashBytes) e.table[prevHash] = tableEntryPrev{ Prev: e.table[prevHash].Cur, Cur: tableEntry{offset: e.cur + s - 2}, } x >>= 8 - prevHash = hash4u(uint32(x), tableBits) + prevHash = hashLen(x, tableBits, hashBytes) e.table[prevHash] = tableEntryPrev{ Prev: e.table[prevHash].Cur, Cur: tableEntry{offset: e.cur + s - 1}, } x >>= 8 - currHash := hash4u(uint32(x), tableBits) + currHash := hashLen(x, tableBits, hashBytes) candidates := e.table[currHash] - cv = uint32(x) + cv = x e.table[currHash] = tableEntryPrev{ Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur}, @@ -212,17 +213,17 @@ func (e *fastEncL3) Encode(dst *tokens, src []byte) { minOffset := e.cur + s - (maxMatchOffset - 4) if candidate.offset > minOffset { - if cv == load3232(src, candidate.offset-e.cur) { + if uint32(cv) == load3232(src, candidate.offset-e.cur) { // Found a match... continue } candidate = candidates.Prev - if candidate.offset > minOffset && cv == load3232(src, candidate.offset-e.cur) { + if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) { // Match at prev... continue } } - cv = uint32(x >> 8) + cv = x >> 8 s++ break } |