diff options
Diffstat (limited to 'src/pkg/compress/flate/deflate.go')
| -rw-r--r-- | src/pkg/compress/flate/deflate.go | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/src/pkg/compress/flate/deflate.go b/src/pkg/compress/flate/deflate.go index e5b2beaef..a02a5e8d9 100644 --- a/src/pkg/compress/flate/deflate.go +++ b/src/pkg/compress/flate/deflate.go @@ -143,10 +143,18 @@ func (d *compressor) fillWindow(index int) (int, os.Error) { d.blockStart = math.MaxInt32 } for i, h := range d.hashHead { - d.hashHead[i] = max(h-wSize, -1) + v := h - wSize + if v < -1 { + v = -1 + } + d.hashHead[i] = v } for i, h := range d.hashPrev { - d.hashPrev[i] = max(h-wSize, -1) + v := -h - wSize + if v < -1 { + v = -1 + } + d.hashPrev[i] = v } } count, err := d.r.Read(d.window[d.windowEnd:]) @@ -177,10 +185,18 @@ func (d *compressor) writeBlock(tokens []token, index int, eof bool) os.Error { // Try to find a match starting at index whose length is greater than prevSize. // We only look at chainCount possibilities before giving up. func (d *compressor) findMatch(pos int, prevHead int, prevLength int, lookahead int) (length, offset int, ok bool) { - win := d.window[0 : pos+min(maxMatchLength, lookahead)] + minMatchLook := maxMatchLength + if lookahead < minMatchLook { + minMatchLook = lookahead + } + + win := d.window[0 : pos+minMatchLook] // We quit when we get a match that's at least nice long - nice := min(d.niceMatch, len(win)-pos) + nice := len(win) - pos + if d.niceMatch < nice { + nice = d.niceMatch + } // If we've got a match that's good enough, only look in 1/4 the chain. tries := d.maxChainLength @@ -344,9 +360,12 @@ Loop: } prevLength := length prevOffset := offset - minIndex := max(index-maxOffset, 0) length = minMatchLength - 1 offset = 0 + minIndex := index - maxOffset + if minIndex < 0 { + minIndex = 0 + } if chainHead >= minIndex && (isFastDeflate && lookahead > minMatchLength-1 || |