mirror of
https://github.com/go-gitea/gitea.git
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Macaron 1.5 (#12596)
* update macaron to v1.5 of fork * update macaron to v1.5 of fork * test gzip PR * add push method impl to context_tests * use proper gzip commit Co-authored-by: zeripath <art27@cantab.net> Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
This commit is contained in:
techknowlogick
GitHub
518
vendor/github.com/klauspost/compress/zstd/enc_better.go
generated
vendored
Normal file
518
vendor/github.com/klauspost/compress/zstd/enc_better.go
generated
vendored
Normal file
@@ -0,0 +1,518 @@
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// Copyright 2019+ Klaus Post. All rights reserved.
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// License information can be found in the LICENSE file.
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// Based on work by Yann Collet, released under BSD License.
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package zstd
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import "fmt"
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const (
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betterLongTableBits = 19 // Bits used in the long match table
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betterLongTableSize = 1 << betterLongTableBits // Size of the table
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// Note: Increasing the short table bits or making the hash shorter
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// can actually lead to compression degradation since it will 'steal' more from the
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// long match table and match offsets are quite big.
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// This greatly depends on the type of input.
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betterShortTableBits = 13 // Bits used in the short match table
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betterShortTableSize = 1 << betterShortTableBits // Size of the table
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)
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type prevEntry struct {
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offset int32
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prev int32
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}
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// betterFastEncoder uses 2 tables, one for short matches (5 bytes) and one for long matches.
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// The long match table contains the previous entry with the same hash,
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// effectively making it a "chain" of length 2.
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// When we find a long match we choose between the two values and select the longest.
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// When we find a short match, after checking the long, we check if we can find a long at n+1
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// and that it is longer (lazy matching).
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type betterFastEncoder struct {
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fastBase
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table [betterShortTableSize]tableEntry
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longTable [betterLongTableSize]prevEntry
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}
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// Encode improves compression...
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func (e *betterFastEncoder) Encode(blk *blockEnc, src []byte) {
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const (
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// Input margin is the number of bytes we read (8)
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// and the maximum we will read ahead (2)
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inputMargin = 8 + 2
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minNonLiteralBlockSize = 16
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)
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// Protect against e.cur wraparound.
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for e.cur >= bufferReset {
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if len(e.hist) == 0 {
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for i := range e.table[:] {
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e.table[i] = tableEntry{}
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}
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for i := range e.longTable[:] {
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e.longTable[i] = prevEntry{}
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}
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e.cur = e.maxMatchOff
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break
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}
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// Shift down everything in the table that isn't already too far away.
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minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff
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for i := range e.table[:] {
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v := e.table[i].offset
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if v < minOff {
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v = 0
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} else {
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v = v - e.cur + e.maxMatchOff
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}
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e.table[i].offset = v
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}
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for i := range e.longTable[:] {
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v := e.longTable[i].offset
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v2 := e.longTable[i].prev
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if v < minOff {
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v = 0
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v2 = 0
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} else {
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v = v - e.cur + e.maxMatchOff
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if v2 < minOff {
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v2 = 0
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} else {
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v2 = v2 - e.cur + e.maxMatchOff
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}
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}
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e.longTable[i] = prevEntry{
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offset: v,
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prev: v2,
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}
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}
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e.cur = e.maxMatchOff
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break
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}
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s := e.addBlock(src)
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blk.size = len(src)
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if len(src) < minNonLiteralBlockSize {
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blk.extraLits = len(src)
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blk.literals = blk.literals[:len(src)]
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copy(blk.literals, src)
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return
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}
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// Override src
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src = e.hist
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sLimit := int32(len(src)) - inputMargin
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// stepSize is the number of bytes to skip on every main loop iteration.
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// It should be >= 1.
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const stepSize = 1
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const kSearchStrength = 9
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// nextEmit is where in src the next emitLiteral should start from.
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nextEmit := s
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cv := load6432(src, s)
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// Relative offsets
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offset1 := int32(blk.recentOffsets[0])
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offset2 := int32(blk.recentOffsets[1])
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addLiterals := func(s *seq, until int32) {
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if until == nextEmit {
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return
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}
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blk.literals = append(blk.literals, src[nextEmit:until]...)
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s.litLen = uint32(until - nextEmit)
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}
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if debug {
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println("recent offsets:", blk.recentOffsets)
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}
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encodeLoop:
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for {
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var t int32
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// We allow the encoder to optionally turn off repeat offsets across blocks
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canRepeat := len(blk.sequences) > 2
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var matched int32
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for {
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if debugAsserts && canRepeat && offset1 == 0 {
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panic("offset0 was 0")
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}
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nextHashS := hash5(cv, betterShortTableBits)
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nextHashL := hash8(cv, betterLongTableBits)
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candidateL := e.longTable[nextHashL]
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candidateS := e.table[nextHashS]
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const repOff = 1
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repIndex := s - offset1 + repOff
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off := s + e.cur
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e.longTable[nextHashL] = prevEntry{offset: off, prev: candidateL.offset}
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e.table[nextHashS] = tableEntry{offset: off, val: uint32(cv)}
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if canRepeat {
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if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) {
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// Consider history as well.
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var seq seq
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lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src)
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seq.matchLen = uint32(lenght - zstdMinMatch)
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// We might be able to match backwards.
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// Extend as long as we can.
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start := s + repOff
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// We end the search early, so we don't risk 0 literals
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// and have to do special offset treatment.
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startLimit := nextEmit + 1
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tMin := s - e.maxMatchOff
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if tMin < 0 {
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tMin = 0
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}
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for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 {
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repIndex--
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start--
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seq.matchLen++
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}
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addLiterals(&seq, start)
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// rep 0
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seq.offset = 1
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if debugSequences {
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println("repeat sequence", seq, "next s:", s)
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}
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blk.sequences = append(blk.sequences, seq)
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// Index match start+1 (long) -> s - 1
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index0 := s + repOff
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s += lenght + repOff
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nextEmit = s
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if s >= sLimit {
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if debug {
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println("repeat ended", s, lenght)
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}
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break encodeLoop
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}
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// Index skipped...
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for index0 < s-1 {
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cv0 := load6432(src, index0)
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cv1 := cv0 >> 8
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h0 := hash8(cv0, betterLongTableBits)
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off := index0 + e.cur
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e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
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e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
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index0 += 2
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}
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cv = load6432(src, s)
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continue
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}
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const repOff2 = 1
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// We deviate from the reference encoder and also check offset 2.
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// Still slower and not much better, so disabled.
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// repIndex = s - offset2 + repOff2
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if false && repIndex >= 0 && load6432(src, repIndex) == load6432(src, s+repOff) {
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// Consider history as well.
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var seq seq
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lenght := 8 + e.matchlen(s+8+repOff2, repIndex+8, src)
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seq.matchLen = uint32(lenght - zstdMinMatch)
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// We might be able to match backwards.
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// Extend as long as we can.
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start := s + repOff2
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// We end the search early, so we don't risk 0 literals
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// and have to do special offset treatment.
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startLimit := nextEmit + 1
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tMin := s - e.maxMatchOff
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if tMin < 0 {
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tMin = 0
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}
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for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 {
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repIndex--
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start--
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seq.matchLen++
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}
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addLiterals(&seq, start)
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// rep 2
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seq.offset = 2
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if debugSequences {
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println("repeat sequence 2", seq, "next s:", s)
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}
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blk.sequences = append(blk.sequences, seq)
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index0 := s + repOff2
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s += lenght + repOff2
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nextEmit = s
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if s >= sLimit {
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if debug {
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println("repeat ended", s, lenght)
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}
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break encodeLoop
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}
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// Index skipped...
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for index0 < s-1 {
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cv0 := load6432(src, index0)
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cv1 := cv0 >> 8
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h0 := hash8(cv0, betterLongTableBits)
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off := index0 + e.cur
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e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
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e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
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index0 += 2
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}
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cv = load6432(src, s)
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// Swap offsets
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offset1, offset2 = offset2, offset1
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continue
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}
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}
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// Find the offsets of our two matches.
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coffsetL := candidateL.offset - e.cur
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coffsetLP := candidateL.prev - e.cur
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// Check if we have a long match.
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if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
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// Found a long match, at least 8 bytes.
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matched = e.matchlen(s+8, coffsetL+8, src) + 8
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t = coffsetL
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if debugAsserts && s <= t {
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panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
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}
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if debugAsserts && s-t > e.maxMatchOff {
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panic("s - t >e.maxMatchOff")
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}
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if debugMatches {
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println("long match")
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}
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if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) {
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// Found a long match, at least 8 bytes.
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prevMatch := e.matchlen(s+8, coffsetLP+8, src) + 8
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if prevMatch > matched {
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matched = prevMatch
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t = coffsetLP
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}
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if debugAsserts && s <= t {
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panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
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}
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if debugAsserts && s-t > e.maxMatchOff {
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panic("s - t >e.maxMatchOff")
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}
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if debugMatches {
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println("long match")
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}
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}
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break
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}
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// Check if we have a long match on prev.
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if s-coffsetLP < e.maxMatchOff && cv == load6432(src, coffsetLP) {
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// Found a long match, at least 8 bytes.
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matched = e.matchlen(s+8, coffsetLP+8, src) + 8
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t = coffsetLP
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if debugAsserts && s <= t {
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panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
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}
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if debugAsserts && s-t > e.maxMatchOff {
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panic("s - t >e.maxMatchOff")
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}
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if debugMatches {
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println("long match")
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}
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break
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}
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coffsetS := candidateS.offset - e.cur
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// Check if we have a short match.
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if s-coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val {
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// found a regular match
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matched = e.matchlen(s+4, coffsetS+4, src) + 4
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// See if we can find a long match at s+1
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const checkAt = 1
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cv := load6432(src, s+checkAt)
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nextHashL = hash8(cv, betterLongTableBits)
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candidateL = e.longTable[nextHashL]
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coffsetL = candidateL.offset - e.cur
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// We can store it, since we have at least a 4 byte match.
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e.longTable[nextHashL] = prevEntry{offset: s + checkAt + e.cur, prev: candidateL.offset}
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if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
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// Found a long match, at least 8 bytes.
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matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8
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if matchedNext > matched {
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t = coffsetL
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s += checkAt
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matched = matchedNext
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if debugMatches {
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println("long match (after short)")
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}
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break
|
||||
}
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}
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||||
|
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// Check prev long...
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coffsetL = candidateL.prev - e.cur
|
||||
if s-coffsetL < e.maxMatchOff && cv == load6432(src, coffsetL) {
|
||||
// Found a long match, at least 8 bytes.
|
||||
matchedNext := e.matchlen(s+8+checkAt, coffsetL+8, src) + 8
|
||||
if matchedNext > matched {
|
||||
t = coffsetL
|
||||
s += checkAt
|
||||
matched = matchedNext
|
||||
if debugMatches {
|
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println("prev long match (after short)")
|
||||
}
|
||||
break
|
||||
}
|
||||
}
|
||||
t = coffsetS
|
||||
if debugAsserts && s <= t {
|
||||
panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
|
||||
}
|
||||
if debugAsserts && s-t > e.maxMatchOff {
|
||||
panic("s - t >e.maxMatchOff")
|
||||
}
|
||||
if debugAsserts && t < 0 {
|
||||
panic("t<0")
|
||||
}
|
||||
if debugMatches {
|
||||
println("short match")
|
||||
}
|
||||
break
|
||||
}
|
||||
|
||||
// No match found, move forward in input.
|
||||
s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1))
|
||||
if s >= sLimit {
|
||||
break encodeLoop
|
||||
}
|
||||
cv = load6432(src, s)
|
||||
}
|
||||
|
||||
// A 4-byte match has been found. Update recent offsets.
|
||||
// We'll later see if more than 4 bytes.
|
||||
offset2 = offset1
|
||||
offset1 = s - t
|
||||
|
||||
if debugAsserts && s <= t {
|
||||
panic(fmt.Sprintf("s (%d) <= t (%d)", s, t))
|
||||
}
|
||||
|
||||
if debugAsserts && canRepeat && int(offset1) > len(src) {
|
||||
panic("invalid offset")
|
||||
}
|
||||
|
||||
// Extend the n-byte match as long as possible.
|
||||
l := matched
|
||||
|
||||
// Extend backwards
|
||||
tMin := s - e.maxMatchOff
|
||||
if tMin < 0 {
|
||||
tMin = 0
|
||||
}
|
||||
for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength {
|
||||
s--
|
||||
t--
|
||||
l++
|
||||
}
|
||||
|
||||
// Write our sequence
|
||||
var seq seq
|
||||
seq.litLen = uint32(s - nextEmit)
|
||||
seq.matchLen = uint32(l - zstdMinMatch)
|
||||
if seq.litLen > 0 {
|
||||
blk.literals = append(blk.literals, src[nextEmit:s]...)
|
||||
}
|
||||
seq.offset = uint32(s-t) + 3
|
||||
s += l
|
||||
if debugSequences {
|
||||
println("sequence", seq, "next s:", s)
|
||||
}
|
||||
blk.sequences = append(blk.sequences, seq)
|
||||
nextEmit = s
|
||||
if s >= sLimit {
|
||||
break encodeLoop
|
||||
}
|
||||
|
||||
// Index match start+1 (long) -> s - 1
|
||||
index0 := s - l + 1
|
||||
for index0 < s-1 {
|
||||
cv0 := load6432(src, index0)
|
||||
cv1 := cv0 >> 8
|
||||
h0 := hash8(cv0, betterLongTableBits)
|
||||
off := index0 + e.cur
|
||||
e.longTable[h0] = prevEntry{offset: off, prev: e.longTable[h0].offset}
|
||||
e.table[hash5(cv1, betterShortTableBits)] = tableEntry{offset: off + 1, val: uint32(cv1)}
|
||||
index0 += 2
|
||||
}
|
||||
|
||||
cv = load6432(src, s)
|
||||
if !canRepeat {
|
||||
continue
|
||||
}
|
||||
|
||||
// Check offset 2
|
||||
for {
|
||||
o2 := s - offset2
|
||||
if load3232(src, o2) != uint32(cv) {
|
||||
// Do regular search
|
||||
break
|
||||
}
|
||||
|
||||
// Store this, since we have it.
|
||||
nextHashS := hash5(cv, betterShortTableBits)
|
||||
nextHashL := hash8(cv, betterLongTableBits)
|
||||
|
||||
// We have at least 4 byte match.
|
||||
// No need to check backwards. We come straight from a match
|
||||
l := 4 + e.matchlen(s+4, o2+4, src)
|
||||
|
||||
e.longTable[nextHashL] = prevEntry{offset: s + e.cur, prev: e.longTable[nextHashL].offset}
|
||||
e.table[nextHashS] = tableEntry{offset: s + e.cur, val: uint32(cv)}
|
||||
seq.matchLen = uint32(l) - zstdMinMatch
|
||||
seq.litLen = 0
|
||||
|
||||
// Since litlen is always 0, this is offset 1.
|
||||
seq.offset = 1
|
||||
s += l
|
||||
nextEmit = s
|
||||
if debugSequences {
|
||||
println("sequence", seq, "next s:", s)
|
||||
}
|
||||
blk.sequences = append(blk.sequences, seq)
|
||||
|
||||
// Swap offset 1 and 2.
|
||||
offset1, offset2 = offset2, offset1
|
||||
if s >= sLimit {
|
||||
// Finished
|
||||
break encodeLoop
|
||||
}
|
||||
cv = load6432(src, s)
|
||||
}
|
||||
}
|
||||
|
||||
if int(nextEmit) < len(src) {
|
||||
blk.literals = append(blk.literals, src[nextEmit:]...)
|
||||
blk.extraLits = len(src) - int(nextEmit)
|
||||
}
|
||||
blk.recentOffsets[0] = uint32(offset1)
|
||||
blk.recentOffsets[1] = uint32(offset2)
|
||||
if debug {
|
||||
println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits)
|
||||
}
|
||||
}
|
||||
|
||||
// EncodeNoHist will encode a block with no history and no following blocks.
|
||||
// Most notable difference is that src will not be copied for history and
|
||||
// we do not need to check for max match length.
|
||||
func (e *betterFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) {
|
||||
e.Encode(blk, src)
|
||||
}
|
||||
Reference in New Issue
Block a user