diff options
author | Wim <wim@42.be> | 2023-03-09 22:48:00 +0100 |
---|---|---|
committer | GitHub <noreply@github.com> | 2023-03-09 22:48:00 +0100 |
commit | 08779c29099e8940493df56d28d8aa131ac8342e (patch) | |
tree | 7ad8ce25cf371e582137e1706dd671a6bf4342d0 /vendor/github.com/klauspost/compress/s2/encode_all.go | |
parent | d5f9cdf912d43cd2a5cb243e086fbdab9a9073b0 (diff) | |
download | matterbridge-msglm-08779c29099e8940493df56d28d8aa131ac8342e.tar.gz matterbridge-msglm-08779c29099e8940493df56d28d8aa131ac8342e.tar.bz2 matterbridge-msglm-08779c29099e8940493df56d28d8aa131ac8342e.zip |
Update dependencies (#2007)
* Update dependencies
Diffstat (limited to 'vendor/github.com/klauspost/compress/s2/encode_all.go')
-rw-r--r-- | vendor/github.com/klauspost/compress/s2/encode_all.go | 595 |
1 files changed, 594 insertions, 1 deletions
diff --git a/vendor/github.com/klauspost/compress/s2/encode_all.go b/vendor/github.com/klauspost/compress/s2/encode_all.go index 8b16c38a..11657f09 100644 --- a/vendor/github.com/klauspost/compress/s2/encode_all.go +++ b/vendor/github.com/klauspost/compress/s2/encode_all.go @@ -8,6 +8,7 @@ package s2 import ( "bytes" "encoding/binary" + "fmt" "math/bits" ) @@ -58,8 +59,9 @@ func encodeGo(dst, src []byte) []byte { // been written. // // It also assumes that: +// // len(dst) >= MaxEncodedLen(len(src)) && -// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize +// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize func encodeBlockGo(dst, src []byte) (d int) { // Initialize the hash table. const ( @@ -454,3 +456,594 @@ emitRemainder: } return d } + +// encodeBlockGo encodes a non-empty src to a guaranteed-large-enough dst. It +// assumes that the varint-encoded length of the decompressed bytes has already +// been written. +// +// It also assumes that: +// +// len(dst) >= MaxEncodedLen(len(src)) && +// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize +func encodeBlockDictGo(dst, src []byte, dict *Dict) (d int) { + // Initialize the hash table. + const ( + tableBits = 14 + maxTableSize = 1 << tableBits + maxAhead = 8 // maximum bytes ahead without checking sLimit + + debug = false + ) + dict.initFast() + + var table [maxTableSize]uint32 + + // 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 := len(src) - inputMargin + if sLimit > MaxDictSrcOffset-maxAhead { + sLimit = MaxDictSrcOffset - maxAhead + } + + // Bail if we can't compress to at least this. + dstLimit := len(src) - len(src)>>5 - 5 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := 0 + + // The encoded form can start with a dict entry (copy or repeat). + s := 0 + + // Convert dict repeat to offset + repeat := len(dict.dict) - dict.repeat + cv := load64(src, 0) + + // While in dict +searchDict: + for { + // Next src position to check + nextS := s + (s-nextEmit)>>6 + 4 + hash0 := hash6(cv, tableBits) + hash1 := hash6(cv>>8, tableBits) + if nextS > sLimit { + if debug { + fmt.Println("slimit reached", s, nextS) + } + break searchDict + } + candidateDict := int(dict.fastTable[hash0]) + candidateDict2 := int(dict.fastTable[hash1]) + candidate2 := int(table[hash1]) + candidate := int(table[hash0]) + table[hash0] = uint32(s) + table[hash1] = uint32(s + 1) + hash2 := hash6(cv>>16, tableBits) + + // Check repeat at offset checkRep. + const checkRep = 1 + + if repeat > s { + candidate := len(dict.dict) - repeat + s + if repeat-s >= 4 && uint32(cv) == load32(dict.dict, candidate) { + // Extend back + base := s + for i := candidate; base > nextEmit && i > 0 && dict.dict[i-1] == src[base-1]; { + i-- + base-- + } + d += emitLiteral(dst[d:], src[nextEmit:base]) + if debug && nextEmit != base { + fmt.Println("emitted ", base-nextEmit, "literals") + } + s += 4 + candidate += 4 + for candidate < len(dict.dict)-8 && s <= len(src)-8 { + if diff := load64(src, s) ^ load64(dict.dict, candidate); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidate += 8 + } + d += emitRepeat(dst[d:], repeat, s-base) + if debug { + fmt.Println("emitted dict repeat length", s-base, "offset:", repeat, "s:", s) + } + nextEmit = s + if s >= sLimit { + break searchDict + } + cv = load64(src, s) + continue + } + } else if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) { + base := s + checkRep + // Extend back + for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; { + i-- + base-- + } + d += emitLiteral(dst[d:], src[nextEmit:base]) + if debug && nextEmit != base { + fmt.Println("emitted ", base-nextEmit, "literals") + } + + // Extend forward + candidate := s - repeat + 4 + checkRep + s += 4 + checkRep + for s <= sLimit { + if diff := load64(src, s) ^ load64(src, candidate); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidate += 8 + } + if debug { + // Validate match. + if s <= candidate { + panic("s <= candidate") + } + a := src[base:s] + b := src[base-repeat : base-repeat+(s-base)] + if !bytes.Equal(a, b) { + panic("mismatch") + } + } + + if nextEmit > 0 { + // same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset. + d += emitRepeat(dst[d:], repeat, s-base) + } else { + // First match, cannot be repeat. + d += emitCopy(dst[d:], repeat, s-base) + } + + nextEmit = s + if s >= sLimit { + break searchDict + } + if debug { + fmt.Println("emitted reg repeat", s-base, "s:", s) + } + cv = load64(src, s) + continue searchDict + } + if s == 0 { + cv = load64(src, nextS) + s = nextS + continue searchDict + } + // Start with table. These matches will always be closer. + if uint32(cv) == load32(src, candidate) { + goto emitMatch + } + candidate = int(table[hash2]) + if uint32(cv>>8) == load32(src, candidate2) { + table[hash2] = uint32(s + 2) + candidate = candidate2 + s++ + goto emitMatch + } + + // Check dict. Dicts have longer offsets, so we want longer matches. + if cv == load64(dict.dict, candidateDict) { + table[hash2] = uint32(s + 2) + goto emitDict + } + + candidateDict = int(dict.fastTable[hash2]) + // Check if upper 7 bytes match + if candidateDict2 >= 1 { + if cv^load64(dict.dict, candidateDict2-1) < (1 << 8) { + table[hash2] = uint32(s + 2) + candidateDict = candidateDict2 + s++ + goto emitDict + } + } + + table[hash2] = uint32(s + 2) + if uint32(cv>>16) == load32(src, candidate) { + s += 2 + goto emitMatch + } + if candidateDict >= 2 { + // Check if upper 6 bytes match + if cv^load64(dict.dict, candidateDict-2) < (1 << 16) { + s += 2 + goto emitDict + } + } + + cv = load64(src, nextS) + s = nextS + continue searchDict + + emitDict: + { + if debug { + if load32(dict.dict, candidateDict) != load32(src, s) { + panic("dict emit mismatch") + } + } + // Extend backwards. + // The top bytes will be rechecked to get the full match. + for candidateDict > 0 && s > nextEmit && dict.dict[candidateDict-1] == src[s-1] { + candidateDict-- + s-- + } + + // Bail if we exceed the maximum size. + if d+(s-nextEmit) > dstLimit { + return 0 + } + + // 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. + + d += emitLiteral(dst[d:], src[nextEmit:s]) + if debug && nextEmit != s { + fmt.Println("emitted ", s-nextEmit, "literals") + } + { + // Invariant: we have a 4-byte match at s, and no need to emit any + // literal bytes prior to s. + base := s + repeat = s + (len(dict.dict)) - candidateDict + + // Extend the 4-byte match as long as possible. + s += 4 + candidateDict += 4 + for s <= len(src)-8 && len(dict.dict)-candidateDict >= 8 { + if diff := load64(src, s) ^ load64(dict.dict, candidateDict); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidateDict += 8 + } + + // Matches longer than 64 are split. + if s <= sLimit || s-base < 8 { + d += emitCopy(dst[d:], repeat, s-base) + } else { + // Split to ensure we don't start a copy within next block + d += emitCopy(dst[d:], repeat, 4) + d += emitRepeat(dst[d:], repeat, s-base-4) + } + if false { + // Validate match. + if s <= candidate { + panic("s <= candidate") + } + a := src[base:s] + b := dict.dict[base-repeat : base-repeat+(s-base)] + if !bytes.Equal(a, b) { + panic("mismatch") + } + } + if debug { + fmt.Println("emitted dict copy, length", s-base, "offset:", repeat, "s:", s) + } + nextEmit = s + if s >= sLimit { + break searchDict + } + + if d > dstLimit { + // Do we have space for more, if not bail. + return 0 + } + + // Index and continue loop to try new candidate. + x := load64(src, s-2) + m2Hash := hash6(x, tableBits) + currHash := hash6(x>>8, tableBits) + candidate = int(table[currHash]) + table[m2Hash] = uint32(s - 2) + table[currHash] = uint32(s - 1) + cv = load64(src, s) + } + continue + } + emitMatch: + + // Extend backwards. + // The top bytes will be rechecked to get the full match. + for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] { + candidate-- + s-- + } + + // Bail if we exceed the maximum size. + if d+(s-nextEmit) > dstLimit { + return 0 + } + + // 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. + + d += emitLiteral(dst[d:], src[nextEmit:s]) + if debug && nextEmit != s { + fmt.Println("emitted ", s-nextEmit, "literals") + } + // Call emitCopy, and then see if another emitCopy could be our next + // move. Repeat until we find no match for the input immediately after + // what was consumed by the last emitCopy call. + // + // If we exit this loop normally then we need to call emitLiteral next, + // though we don't yet know how big the literal will be. We handle that + // by proceeding to the next iteration of the main loop. We also can + // exit this loop via goto if we get close to exhausting the input. + for { + // Invariant: we have a 4-byte match at s, and no need to emit any + // literal bytes prior to s. + base := s + repeat = base - candidate + + // Extend the 4-byte match as long as possible. + s += 4 + candidate += 4 + for s <= len(src)-8 { + if diff := load64(src, s) ^ load64(src, candidate); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidate += 8 + } + + d += emitCopy(dst[d:], repeat, s-base) + if debug { + // Validate match. + if s <= candidate { + panic("s <= candidate") + } + a := src[base:s] + b := src[base-repeat : base-repeat+(s-base)] + if !bytes.Equal(a, b) { + panic("mismatch") + } + } + if debug { + fmt.Println("emitted src copy, length", s-base, "offset:", repeat, "s:", s) + } + nextEmit = s + if s >= sLimit { + break searchDict + } + + if d > dstLimit { + // Do we have space for more, if not bail. + return 0 + } + // Check for an immediate match, otherwise start search at s+1 + x := load64(src, s-2) + m2Hash := hash6(x, tableBits) + currHash := hash6(x>>16, tableBits) + candidate = int(table[currHash]) + table[m2Hash] = uint32(s - 2) + table[currHash] = uint32(s) + if debug && s == candidate { + panic("s == candidate") + } + if uint32(x>>16) != load32(src, candidate) { + cv = load64(src, s+1) + s++ + break + } + } + } + + // Search without dict: + if repeat > s { + repeat = 0 + } + + // No more dict + sLimit = len(src) - inputMargin + if s >= sLimit { + goto emitRemainder + } + if debug { + fmt.Println("non-dict matching at", s, "repeat:", repeat) + } + cv = load64(src, s) + if debug { + fmt.Println("now", s, "->", sLimit, "out:", d, "left:", len(src)-s, "nextemit:", nextEmit, "dstLimit:", dstLimit, "s:", s) + } + for { + candidate := 0 + for { + // Next src position to check + nextS := s + (s-nextEmit)>>6 + 4 + if nextS > sLimit { + goto emitRemainder + } + hash0 := hash6(cv, tableBits) + hash1 := hash6(cv>>8, tableBits) + candidate = int(table[hash0]) + candidate2 := int(table[hash1]) + table[hash0] = uint32(s) + table[hash1] = uint32(s + 1) + hash2 := hash6(cv>>16, tableBits) + + // Check repeat at offset checkRep. + const checkRep = 1 + if repeat > 0 && uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) { + base := s + checkRep + // Extend back + for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; { + i-- + base-- + } + d += emitLiteral(dst[d:], src[nextEmit:base]) + if debug && nextEmit != base { + fmt.Println("emitted ", base-nextEmit, "literals") + } + // Extend forward + candidate := s - repeat + 4 + checkRep + s += 4 + checkRep + for s <= sLimit { + if diff := load64(src, s) ^ load64(src, candidate); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidate += 8 + } + if debug { + // Validate match. + if s <= candidate { + panic("s <= candidate") + } + a := src[base:s] + b := src[base-repeat : base-repeat+(s-base)] + if !bytes.Equal(a, b) { + panic("mismatch") + } + } + if nextEmit > 0 { + // same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset. + d += emitRepeat(dst[d:], repeat, s-base) + } else { + // First match, cannot be repeat. + d += emitCopy(dst[d:], repeat, s-base) + } + if debug { + fmt.Println("emitted src repeat length", s-base, "offset:", repeat, "s:", s) + } + nextEmit = s + if s >= sLimit { + goto emitRemainder + } + + cv = load64(src, s) + continue + } + + if uint32(cv) == load32(src, candidate) { + break + } + candidate = int(table[hash2]) + if uint32(cv>>8) == load32(src, candidate2) { + table[hash2] = uint32(s + 2) + candidate = candidate2 + s++ + break + } + table[hash2] = uint32(s + 2) + if uint32(cv>>16) == load32(src, candidate) { + s += 2 + break + } + + cv = load64(src, nextS) + s = nextS + } + + // Extend backwards. + // The top bytes will be rechecked to get the full match. + for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] { + candidate-- + s-- + } + + // Bail if we exceed the maximum size. + if d+(s-nextEmit) > dstLimit { + return 0 + } + + // 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. + + d += emitLiteral(dst[d:], src[nextEmit:s]) + if debug && nextEmit != s { + fmt.Println("emitted ", s-nextEmit, "literals") + } + // Call emitCopy, and then see if another emitCopy could be our next + // move. Repeat until we find no match for the input immediately after + // what was consumed by the last emitCopy call. + // + // If we exit this loop normally then we need to call emitLiteral next, + // though we don't yet know how big the literal will be. We handle that + // by proceeding to the next iteration of the main loop. We also can + // exit this loop via goto if we get close to exhausting the input. + for { + // Invariant: we have a 4-byte match at s, and no need to emit any + // literal bytes prior to s. + base := s + repeat = base - candidate + + // Extend the 4-byte match as long as possible. + s += 4 + candidate += 4 + for s <= len(src)-8 { + if diff := load64(src, s) ^ load64(src, candidate); diff != 0 { + s += bits.TrailingZeros64(diff) >> 3 + break + } + s += 8 + candidate += 8 + } + + d += emitCopy(dst[d:], repeat, s-base) + if debug { + // Validate match. + if s <= candidate { + panic("s <= candidate") + } + a := src[base:s] + b := src[base-repeat : base-repeat+(s-base)] + if !bytes.Equal(a, b) { + panic("mismatch") + } + } + if debug { + fmt.Println("emitted src copy, length", s-base, "offset:", repeat, "s:", s) + } + nextEmit = s + if s >= sLimit { + goto emitRemainder + } + + if d > dstLimit { + // Do we have space for more, if not bail. + return 0 + } + // Check for an immediate match, otherwise start search at s+1 + x := load64(src, s-2) + m2Hash := hash6(x, tableBits) + currHash := hash6(x>>16, tableBits) + candidate = int(table[currHash]) + table[m2Hash] = uint32(s - 2) + table[currHash] = uint32(s) + if debug && s == candidate { + panic("s == candidate") + } + if uint32(x>>16) != load32(src, candidate) { + cv = load64(src, s+1) + s++ + break + } + } + } + +emitRemainder: + if nextEmit < len(src) { + // Bail if we exceed the maximum size. + if d+len(src)-nextEmit > dstLimit { + return 0 + } + d += emitLiteral(dst[d:], src[nextEmit:]) + if debug && nextEmit != s { + fmt.Println("emitted ", len(src)-nextEmit, "literals") + } + } + return d +} |