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author | Daniel J Walsh <dwalsh@redhat.com> | 2020-09-10 09:31:28 -0400 |
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committer | Daniel J Walsh <dwalsh@redhat.com> | 2020-09-10 09:34:31 -0400 |
commit | 98620c56d6ad0d896308a4e5858c5d1913476eaf (patch) | |
tree | df24f9bb53b8b455cf79cb57594987c7c0054b16 /vendor/github.com/klauspost/compress/zstd/enc_better.go | |
parent | 08b602043ec07601b9be23c449c7773067683d90 (diff) | |
download | podman-98620c56d6ad0d896308a4e5858c5d1913476eaf.tar.gz podman-98620c56d6ad0d896308a4e5858c5d1913476eaf.tar.bz2 podman-98620c56d6ad0d896308a4e5858c5d1913476eaf.zip |
vendor containers/storage v1.23.5
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/enc_better.go')
-rw-r--r-- | vendor/github.com/klauspost/compress/zstd/enc_better.go | 81 |
1 files changed, 79 insertions, 2 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_better.go b/vendor/github.com/klauspost/compress/zstd/enc_better.go index c120d9054..94a5343d0 100644 --- a/vendor/github.com/klauspost/compress/zstd/enc_better.go +++ b/vendor/github.com/klauspost/compress/zstd/enc_better.go @@ -31,8 +31,10 @@ type prevEntry struct { // and that it is longer (lazy matching). type betterFastEncoder struct { fastBase - table [betterShortTableSize]tableEntry - longTable [betterLongTableSize]prevEntry + table [betterShortTableSize]tableEntry + longTable [betterLongTableSize]prevEntry + dictTable []tableEntry + dictLongTable []prevEntry } // Encode improves compression... @@ -516,3 +518,78 @@ encodeLoop: func (e *betterFastEncoder) EncodeNoHist(blk *blockEnc, src []byte) { e.Encode(blk, src) } + +// ResetDict will reset and set a dictionary if not nil +func (e *betterFastEncoder) Reset(d *dict, singleBlock bool) { + e.resetBase(d, singleBlock) + if d == nil { + return + } + // Init or copy dict table + if len(e.dictTable) != len(e.table) || d.id != e.lastDictID { + if len(e.dictTable) != len(e.table) { + e.dictTable = make([]tableEntry, len(e.table)) + } + end := int32(len(d.content)) - 8 + e.maxMatchOff + for i := e.maxMatchOff; i < end; i += 4 { + const hashLog = betterShortTableBits + + cv := load6432(d.content, i-e.maxMatchOff) + nextHash := hash5(cv, hashLog) // 0 -> 4 + nextHash1 := hash5(cv>>8, hashLog) // 1 -> 5 + nextHash2 := hash5(cv>>16, hashLog) // 2 -> 6 + nextHash3 := hash5(cv>>24, hashLog) // 3 -> 7 + e.dictTable[nextHash] = tableEntry{ + val: uint32(cv), + offset: i, + } + e.dictTable[nextHash1] = tableEntry{ + val: uint32(cv >> 8), + offset: i + 1, + } + e.dictTable[nextHash2] = tableEntry{ + val: uint32(cv >> 16), + offset: i + 2, + } + e.dictTable[nextHash3] = tableEntry{ + val: uint32(cv >> 24), + offset: i + 3, + } + } + e.lastDictID = d.id + } + + // Init or copy dict table + if len(e.dictLongTable) != len(e.longTable) || d.id != e.lastDictID { + if len(e.dictLongTable) != len(e.longTable) { + e.dictLongTable = make([]prevEntry, len(e.longTable)) + } + if len(d.content) >= 8 { + cv := load6432(d.content, 0) + h := hash8(cv, betterLongTableBits) + e.dictLongTable[h] = prevEntry{ + offset: e.maxMatchOff, + prev: e.dictLongTable[h].offset, + } + + end := int32(len(d.content)) - 8 + e.maxMatchOff + off := 8 // First to read + for i := e.maxMatchOff + 1; i < end; i++ { + cv = cv>>8 | (uint64(d.content[off]) << 56) + h := hash8(cv, betterLongTableBits) + e.dictLongTable[h] = prevEntry{ + offset: i, + prev: e.dictLongTable[h].offset, + } + off++ + } + } + e.lastDictID = d.id + } + // Reset table to initial state + copy(e.longTable[:], e.dictLongTable) + + e.cur = e.maxMatchOff + // Reset table to initial state + copy(e.table[:], e.dictTable) +} |