diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/flate/token.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/flate/token.go | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/token.go b/vendor/github.com/klauspost/compress/flate/token.go index 3a9618ee1..8005a5ca8 100644 --- a/vendor/github.com/klauspost/compress/flate/token.go +++ b/vendor/github.com/klauspost/compress/flate/token.go @@ -13,11 +13,10 @@ import ( ) const ( - // From top - // 2 bits: type 0 = literal 1=EOF 2=Match 3=Unused - // 8 bits: xlength = length - MIN_MATCH_LENGTH - // 5 bits offsetcode - // 16 bits xoffset = offset - MIN_OFFSET_SIZE, or literal + // bits 0-16 xoffset = offset - MIN_OFFSET_SIZE, or literal - 16 bits + // bits 16-22 offsetcode - 5 bits + // bits 22-30 xlength = length - MIN_MATCH_LENGTH - 8 bits + // bits 30-32 type 0 = literal 1=EOF 2=Match 3=Unused - 2 bits lengthShift = 22 offsetMask = 1<<lengthShift - 1 typeMask = 3 << 30 @@ -276,7 +275,7 @@ func (t *tokens) AddMatch(xlength uint32, xoffset uint32) { xoffset |= oCode << 16 t.extraHist[lengthCodes1[uint8(xlength)]]++ - t.offHist[oCode]++ + t.offHist[oCode&31]++ t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset) t.n++ } @@ -300,7 +299,7 @@ func (t *tokens) AddMatchLong(xlength int32, xoffset uint32) { xlength -= xl xl -= baseMatchLength t.extraHist[lengthCodes1[uint8(xl)]]++ - t.offHist[oc]++ + t.offHist[oc&31]++ t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset) t.n++ } @@ -356,8 +355,8 @@ func (t token) offset() uint32 { return uint32(t) & offsetMask } func (t token) length() uint8 { return uint8(t >> lengthShift) } -// The code is never more than 8 bits, but is returned as uint32 for convenience. -func lengthCode(len uint8) uint32 { return uint32(lengthCodes[len]) } +// Convert length to code. +func lengthCode(len uint8) uint8 { return lengthCodes[len] } // Returns the offset code corresponding to a specific offset func offsetCode(off uint32) uint32 { |