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authordependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>2019-11-20 09:18:44 +0000
committerValentin Rothberg <rothberg@redhat.com>2019-11-22 15:03:53 +0100
commit866391bb574f885549f5cf3cec965dc224cb84b3 (patch)
treebd681164ad8e570e8cdcfabf658f986ee436c3b5 /vendor/github.com/klauspost/compress/flate/level6.go
parentc673ff8cb63c71a39e1a1d561373af42bfea7f24 (diff)
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build(deps): bump github.com/containers/storage from 1.13.5 to 1.14.0
Bumps [github.com/containers/storage](https://github.com/containers/storage) from 1.13.5 to 1.14.0. - [Release notes](https://github.com/containers/storage/releases) - [Changelog](https://github.com/containers/storage/blob/master/docs/containers-storage-changes.md) - [Commits](https://github.com/containers/storage/compare/v1.13.5...v1.14.0) Signed-off-by: dependabot-preview[bot] <support@dependabot.com> Signed-off-by: Valentin Rothberg <rothberg@redhat.com>
Diffstat (limited to 'vendor/github.com/klauspost/compress/flate/level6.go')
-rw-r--r--vendor/github.com/klauspost/compress/flate/level6.go279
1 files changed, 279 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/flate/level6.go b/vendor/github.com/klauspost/compress/flate/level6.go
new file mode 100644
index 000000000..cad0c7df7
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/flate/level6.go
@@ -0,0 +1,279 @@
+package flate
+
+import "fmt"
+
+type fastEncL6 struct {
+ fastGen
+ table [tableSize]tableEntry
+ bTable [tableSize]tableEntryPrev
+}
+
+func (e *fastEncL6) Encode(dst *tokens, src []byte) {
+ const (
+ inputMargin = 12 - 1
+ minNonLiteralBlockSize = 1 + 1 + inputMargin
+ )
+
+ // Protect against e.cur wraparound.
+ for e.cur >= bufferReset {
+ if len(e.hist) == 0 {
+ for i := range e.table[:] {
+ e.table[i] = tableEntry{}
+ }
+ for i := range e.bTable[:] {
+ e.bTable[i] = tableEntryPrev{}
+ }
+ e.cur = maxMatchOffset
+ break
+ }
+ // Shift down everything in the table that isn't already too far away.
+ minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
+ for i := range e.table[:] {
+ v := e.table[i].offset
+ if v <= minOff {
+ v = 0
+ } else {
+ v = v - e.cur + maxMatchOffset
+ }
+ e.table[i].offset = v
+ }
+ for i := range e.bTable[:] {
+ v := e.bTable[i]
+ if v.Cur.offset <= minOff {
+ v.Cur.offset = 0
+ v.Prev.offset = 0
+ } else {
+ v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
+ if v.Prev.offset <= minOff {
+ v.Prev.offset = 0
+ } else {
+ v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
+ }
+ }
+ e.bTable[i] = v
+ }
+ e.cur = maxMatchOffset
+ }
+
+ s := e.addBlock(src)
+
+ // This check isn't in the Snappy implementation, but there, the caller
+ // instead of the callee handles this case.
+ if len(src) < minNonLiteralBlockSize {
+ // We do not fill the token table.
+ // This will be picked up by caller.
+ dst.n = uint16(len(src))
+ return
+ }
+
+ // Override src
+ src = e.hist
+ nextEmit := s
+
+ // sLimit is when to stop looking for offset/length copies. The inputMargin
+ // lets us use a fast path for emitLiteral in the main loop, while we are
+ // looking for copies.
+ sLimit := int32(len(src) - inputMargin)
+
+ // nextEmit is where in src the next emitLiteral should start from.
+ cv := load6432(src, s)
+ // Repeat MUST be > 1 and within range
+ repeat := int32(1)
+ for {
+ const skipLog = 7
+ const doEvery = 1
+
+ nextS := s
+ var l int32
+ var t int32
+ for {
+ nextHashS := hash4x64(cv, tableBits)
+ nextHashL := hash7(cv, tableBits)
+ s = nextS
+ nextS = s + doEvery + (s-nextEmit)>>skipLog
+ if nextS > sLimit {
+ goto emitRemainder
+ }
+ // Fetch a short+long candidate
+ sCandidate := e.table[nextHashS]
+ lCandidate := e.bTable[nextHashL]
+ next := load6432(src, nextS)
+ entry := tableEntry{offset: s + e.cur, val: uint32(cv)}
+ e.table[nextHashS] = entry
+ eLong := &e.bTable[nextHashL]
+ eLong.Cur, eLong.Prev = entry, eLong.Cur
+
+ // Calculate hashes of 'next'
+ nextHashS = hash4x64(next, tableBits)
+ nextHashL = hash7(next, tableBits)
+
+ t = lCandidate.Cur.offset - e.cur
+ if s-t < maxMatchOffset {
+ if uint32(cv) == lCandidate.Cur.val {
+ // Long candidate matches at least 4 bytes.
+
+ // Store the next match
+ e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
+ eLong := &e.bTable[nextHashL]
+ eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
+
+ // Check the previous long candidate as well.
+ t2 := lCandidate.Prev.offset - e.cur
+ if s-t2 < maxMatchOffset && uint32(cv) == lCandidate.Prev.val {
+ l = e.matchlen(s+4, t+4, src) + 4
+ ml1 := e.matchlen(s+4, t2+4, src) + 4
+ if ml1 > l {
+ t = t2
+ l = ml1
+ break
+ }
+ }
+ break
+ }
+ // Current value did not match, but check if previous long value does.
+ t = lCandidate.Prev.offset - e.cur
+ if s-t < maxMatchOffset && uint32(cv) == lCandidate.Prev.val {
+ // Store the next match
+ e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
+ eLong := &e.bTable[nextHashL]
+ eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
+ break
+ }
+ }
+
+ t = sCandidate.offset - e.cur
+ if s-t < maxMatchOffset && uint32(cv) == sCandidate.val {
+ // Found a 4 match...
+ l = e.matchlen(s+4, t+4, src) + 4
+
+ // Look up next long candidate (at nextS)
+ lCandidate = e.bTable[nextHashL]
+
+ // Store the next match
+ e.table[nextHashS] = tableEntry{offset: nextS + e.cur, val: uint32(next)}
+ eLong := &e.bTable[nextHashL]
+ eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur, val: uint32(next)}, eLong.Cur
+
+ // Check repeat at s + repOff
+ const repOff = 1
+ t2 := s - repeat + repOff
+ if load3232(src, t2) == uint32(cv>>(8*repOff)) {
+ ml := e.matchlen(s+4+repOff, t2+4, src) + 4
+ if ml > l {
+ t = t2
+ l = ml
+ s += repOff
+ // Not worth checking more.
+ break
+ }
+ }
+
+ // If the next long is a candidate, use that...
+ t2 = lCandidate.Cur.offset - e.cur
+ if nextS-t2 < maxMatchOffset {
+ if lCandidate.Cur.val == uint32(next) {
+ ml := e.matchlen(nextS+4, t2+4, src) + 4
+ if ml > l {
+ t = t2
+ s = nextS
+ l = ml
+ // This is ok, but check previous as well.
+ }
+ }
+ // If the previous long is a candidate, use that...
+ t2 = lCandidate.Prev.offset - e.cur
+ if nextS-t2 < maxMatchOffset && lCandidate.Prev.val == uint32(next) {
+ ml := e.matchlen(nextS+4, t2+4, src) + 4
+ if ml > l {
+ t = t2
+ s = nextS
+ l = ml
+ break
+ }
+ }
+ }
+ break
+ }
+ cv = next
+ }
+
+ // A 4-byte match has been found. We'll later see if more than 4 bytes
+ // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit
+ // them as literal bytes.
+
+ // Extend the 4-byte match as long as possible.
+ if l == 0 {
+ l = e.matchlenLong(s+4, t+4, src) + 4
+ } else if l == maxMatchLength {
+ l += e.matchlenLong(s+l, t+l, src)
+ }
+
+ // Extend backwards
+ for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
+ s--
+ t--
+ l++
+ }
+ if nextEmit < s {
+ emitLiteral(dst, src[nextEmit:s])
+ }
+ if false {
+ if t >= s {
+ panic(fmt.Sprintln("s-t", s, t))
+ }
+ if (s - t) > maxMatchOffset {
+ panic(fmt.Sprintln("mmo", s-t))
+ }
+ if l < baseMatchLength {
+ panic("bml")
+ }
+ }
+
+ dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
+ repeat = s - t
+ s += l
+ nextEmit = s
+ if nextS >= s {
+ s = nextS + 1
+ }
+
+ if s >= sLimit {
+ // Index after match end.
+ for i := nextS + 1; i < int32(len(src))-8; i += 2 {
+ cv := load6432(src, i)
+ e.table[hash4x64(cv, tableBits)] = tableEntry{offset: i + e.cur, val: uint32(cv)}
+ eLong := &e.bTable[hash7(cv, tableBits)]
+ eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur, val: uint32(cv)}, eLong.Cur
+ }
+ goto emitRemainder
+ }
+
+ // Store every long hash in-between and every second short.
+ if true {
+ for i := nextS + 1; i < s-1; i += 2 {
+ cv := load6432(src, i)
+ t := tableEntry{offset: i + e.cur, val: uint32(cv)}
+ t2 := tableEntry{offset: t.offset + 1, val: uint32(cv >> 8)}
+ eLong := &e.bTable[hash7(cv, tableBits)]
+ eLong2 := &e.bTable[hash7(cv>>8, tableBits)]
+ e.table[hash4x64(cv, tableBits)] = t
+ eLong.Cur, eLong.Prev = t, eLong.Cur
+ eLong2.Cur, eLong2.Prev = t2, eLong2.Cur
+ }
+ }
+
+ // We could immediately start working at s now, but to improve
+ // compression we first update the hash table at s-1 and at s.
+ cv = load6432(src, s)
+ }
+
+emitRemainder:
+ if int(nextEmit) < len(src) {
+ // If nothing was added, don't encode literals.
+ if dst.n == 0 {
+ return
+ }
+
+ emitLiteral(dst, src[nextEmit:])
+ }
+}