diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/flate/token.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/flate/token.go | 27 |
1 files changed, 9 insertions, 18 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/token.go b/vendor/github.com/klauspost/compress/flate/token.go index 4f275ea61..141299b97 100644 --- a/vendor/github.com/klauspost/compress/flate/token.go +++ b/vendor/github.com/klauspost/compress/flate/token.go @@ -4,8 +4,6 @@ package flate -import "fmt" - const ( // 2 bits: type 0 = literal 1=EOF 2=Match 3=Unused // 8 bits: xlength = length - MIN_MATCH_LENGTH @@ -19,7 +17,7 @@ const ( // The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH) // is lengthCodes[length - MIN_MATCH_LENGTH] -var lengthCodes = [...]uint32{ +var lengthCodes = [256]uint8{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, @@ -48,7 +46,7 @@ var lengthCodes = [...]uint32{ 27, 27, 27, 27, 27, 28, } -var offsetCodes = [...]uint32{ +var offsetCodes = [256]uint32{ 0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, @@ -82,34 +80,27 @@ func matchToken(xlength uint32, xoffset uint32) token { return token(matchType + xlength<<lengthShift + xoffset) } -func matchTokend(xlength uint32, xoffset uint32) token { - if xlength > maxMatchLength || xoffset > maxMatchOffset { - panic(fmt.Sprintf("Invalid match: len: %d, offset: %d\n", xlength, xoffset)) - return token(matchType) - } - return token(matchType + xlength<<lengthShift + xoffset) -} - // Returns the type of a token func (t token) typ() uint32 { return uint32(t) & typeMask } // Returns the literal of a literal token -func (t token) literal() uint32 { return uint32(t - literalType) } +func (t token) literal() uint8 { return uint8(t) } // Returns the extra offset of a match token func (t token) offset() uint32 { return uint32(t) & offsetMask } -func (t token) length() uint32 { return uint32((t - matchType) >> lengthShift) } +func (t token) length() uint8 { return uint8(t >> lengthShift) } -func lengthCode(len uint32) uint32 { return lengthCodes[len] } +// The code is never more than 8 bits, but is returned as uint32 for convenience. +func lengthCode(len uint8) uint32 { return uint32(lengthCodes[len]) } // Returns the offset code corresponding to a specific offset func offsetCode(off uint32) uint32 { if off < uint32(len(offsetCodes)) { - return offsetCodes[off] + return offsetCodes[off&255] } else if off>>7 < uint32(len(offsetCodes)) { - return offsetCodes[off>>7] + 14 + return offsetCodes[(off>>7)&255] + 14 } else { - return offsetCodes[off>>14] + 28 + return offsetCodes[(off>>14)&255] + 28 } } |