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path: root/vendor/github.com/klauspost/compress/s2/encode_go.go
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Diffstat (limited to 'vendor/github.com/klauspost/compress/s2/encode_go.go')
-rw-r--r--vendor/github.com/klauspost/compress/s2/encode_go.go729
1 files changed, 0 insertions, 729 deletions
diff --git a/vendor/github.com/klauspost/compress/s2/encode_go.go b/vendor/github.com/klauspost/compress/s2/encode_go.go
deleted file mode 100644
index dd1c973ca..000000000
--- a/vendor/github.com/klauspost/compress/s2/encode_go.go
+++ /dev/null
@@ -1,729 +0,0 @@
-//go:build !amd64 || appengine || !gc || noasm
-// +build !amd64 appengine !gc noasm
-
-package s2
-
-import (
- "bytes"
- "math/bits"
-)
-
-const hasAmd64Asm = false
-
-// encodeBlock 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))
-func encodeBlock(dst, src []byte) (d int) {
- if len(src) < minNonLiteralBlockSize {
- return 0
- }
- return encodeBlockGo(dst, src)
-}
-
-// encodeBlockBetter 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))
-func encodeBlockBetter(dst, src []byte) (d int) {
- return encodeBlockBetterGo(dst, src)
-}
-
-// encodeBlockBetter 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))
-func encodeBlockBetterSnappy(dst, src []byte) (d int) {
- return encodeBlockBetterSnappyGo(dst, src)
-}
-
-// encodeBlock 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))
-func encodeBlockSnappy(dst, src []byte) (d int) {
- if len(src) < minNonLiteralBlockSize {
- return 0
- }
- return encodeBlockSnappyGo(dst, src)
-}
-
-// emitLiteral writes a literal chunk and returns the number of bytes written.
-//
-// It assumes that:
-//
-// dst is long enough to hold the encoded bytes
-// 0 <= len(lit) && len(lit) <= math.MaxUint32
-func emitLiteral(dst, lit []byte) int {
- if len(lit) == 0 {
- return 0
- }
- const num = 63<<2 | tagLiteral
- i, n := 0, uint(len(lit)-1)
- switch {
- case n < 60:
- dst[0] = uint8(n)<<2 | tagLiteral
- i = 1
- case n < 1<<8:
- dst[1] = uint8(n)
- dst[0] = 60<<2 | tagLiteral
- i = 2
- case n < 1<<16:
- dst[2] = uint8(n >> 8)
- dst[1] = uint8(n)
- dst[0] = 61<<2 | tagLiteral
- i = 3
- case n < 1<<24:
- dst[3] = uint8(n >> 16)
- dst[2] = uint8(n >> 8)
- dst[1] = uint8(n)
- dst[0] = 62<<2 | tagLiteral
- i = 4
- default:
- dst[4] = uint8(n >> 24)
- dst[3] = uint8(n >> 16)
- dst[2] = uint8(n >> 8)
- dst[1] = uint8(n)
- dst[0] = 63<<2 | tagLiteral
- i = 5
- }
- return i + copy(dst[i:], lit)
-}
-
-// emitRepeat writes a repeat chunk and returns the number of bytes written.
-// Length must be at least 4 and < 1<<24
-func emitRepeat(dst []byte, offset, length int) int {
- // Repeat offset, make length cheaper
- length -= 4
- if length <= 4 {
- dst[0] = uint8(length)<<2 | tagCopy1
- dst[1] = 0
- return 2
- }
- if length < 8 && offset < 2048 {
- // Encode WITH offset
- dst[1] = uint8(offset)
- dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
- return 2
- }
- if length < (1<<8)+4 {
- length -= 4
- dst[2] = uint8(length)
- dst[1] = 0
- dst[0] = 5<<2 | tagCopy1
- return 3
- }
- if length < (1<<16)+(1<<8) {
- length -= 1 << 8
- dst[3] = uint8(length >> 8)
- dst[2] = uint8(length >> 0)
- dst[1] = 0
- dst[0] = 6<<2 | tagCopy1
- return 4
- }
- const maxRepeat = (1 << 24) - 1
- length -= 1 << 16
- left := 0
- if length > maxRepeat {
- left = length - maxRepeat + 4
- length = maxRepeat - 4
- }
- dst[4] = uint8(length >> 16)
- dst[3] = uint8(length >> 8)
- dst[2] = uint8(length >> 0)
- dst[1] = 0
- dst[0] = 7<<2 | tagCopy1
- if left > 0 {
- return 5 + emitRepeat(dst[5:], offset, left)
- }
- return 5
-}
-
-// emitCopy writes a copy chunk and returns the number of bytes written.
-//
-// It assumes that:
-//
-// dst is long enough to hold the encoded bytes
-// 1 <= offset && offset <= math.MaxUint32
-// 4 <= length && length <= 1 << 24
-func emitCopy(dst []byte, offset, length int) int {
- if offset >= 65536 {
- i := 0
- if length > 64 {
- // Emit a length 64 copy, encoded as 5 bytes.
- dst[4] = uint8(offset >> 24)
- dst[3] = uint8(offset >> 16)
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = 63<<2 | tagCopy4
- length -= 64
- if length >= 4 {
- // Emit remaining as repeats
- return 5 + emitRepeat(dst[5:], offset, length)
- }
- i = 5
- }
- if length == 0 {
- return i
- }
- // Emit a copy, offset encoded as 4 bytes.
- dst[i+0] = uint8(length-1)<<2 | tagCopy4
- dst[i+1] = uint8(offset)
- dst[i+2] = uint8(offset >> 8)
- dst[i+3] = uint8(offset >> 16)
- dst[i+4] = uint8(offset >> 24)
- return i + 5
- }
-
- // Offset no more than 2 bytes.
- if length > 64 {
- off := 3
- if offset < 2048 {
- // emit 8 bytes as tagCopy1, rest as repeats.
- dst[1] = uint8(offset)
- dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
- length -= 8
- off = 2
- } else {
- // Emit a length 60 copy, encoded as 3 bytes.
- // Emit remaining as repeat value (minimum 4 bytes).
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = 59<<2 | tagCopy2
- length -= 60
- }
- // Emit remaining as repeats, at least 4 bytes remain.
- return off + emitRepeat(dst[off:], offset, length)
- }
- if length >= 12 || offset >= 2048 {
- // Emit the remaining copy, encoded as 3 bytes.
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = uint8(length-1)<<2 | tagCopy2
- return 3
- }
- // Emit the remaining copy, encoded as 2 bytes.
- dst[1] = uint8(offset)
- dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
- return 2
-}
-
-// emitCopyNoRepeat writes a copy chunk and returns the number of bytes written.
-//
-// It assumes that:
-//
-// dst is long enough to hold the encoded bytes
-// 1 <= offset && offset <= math.MaxUint32
-// 4 <= length && length <= 1 << 24
-func emitCopyNoRepeat(dst []byte, offset, length int) int {
- if offset >= 65536 {
- i := 0
- if length > 64 {
- // Emit a length 64 copy, encoded as 5 bytes.
- dst[4] = uint8(offset >> 24)
- dst[3] = uint8(offset >> 16)
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = 63<<2 | tagCopy4
- length -= 64
- if length >= 4 {
- // Emit remaining as repeats
- return 5 + emitCopyNoRepeat(dst[5:], offset, length)
- }
- i = 5
- }
- if length == 0 {
- return i
- }
- // Emit a copy, offset encoded as 4 bytes.
- dst[i+0] = uint8(length-1)<<2 | tagCopy4
- dst[i+1] = uint8(offset)
- dst[i+2] = uint8(offset >> 8)
- dst[i+3] = uint8(offset >> 16)
- dst[i+4] = uint8(offset >> 24)
- return i + 5
- }
-
- // Offset no more than 2 bytes.
- if length > 64 {
- // Emit a length 60 copy, encoded as 3 bytes.
- // Emit remaining as repeat value (minimum 4 bytes).
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = 59<<2 | tagCopy2
- length -= 60
- // Emit remaining as repeats, at least 4 bytes remain.
- return 3 + emitCopyNoRepeat(dst[3:], offset, length)
- }
- if length >= 12 || offset >= 2048 {
- // Emit the remaining copy, encoded as 3 bytes.
- dst[2] = uint8(offset >> 8)
- dst[1] = uint8(offset)
- dst[0] = uint8(length-1)<<2 | tagCopy2
- return 3
- }
- // Emit the remaining copy, encoded as 2 bytes.
- dst[1] = uint8(offset)
- dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
- return 2
-}
-
-// matchLen returns how many bytes match in a and b
-//
-// It assumes that:
-//
-// len(a) <= len(b)
-func matchLen(a []byte, b []byte) int {
- b = b[:len(a)]
- var checked int
- if len(a) > 4 {
- // Try 4 bytes first
- if diff := load32(a, 0) ^ load32(b, 0); diff != 0 {
- return bits.TrailingZeros32(diff) >> 3
- }
- // Switch to 8 byte matching.
- checked = 4
- a = a[4:]
- b = b[4:]
- for len(a) >= 8 {
- b = b[:len(a)]
- if diff := load64(a, 0) ^ load64(b, 0); diff != 0 {
- return checked + (bits.TrailingZeros64(diff) >> 3)
- }
- checked += 8
- a = a[8:]
- b = b[8:]
- }
- }
- b = b[:len(a)]
- for i := range a {
- if a[i] != b[i] {
- return int(i) + checked
- }
- }
- return len(a) + checked
-}
-
-// input must be > inputMargin
-func calcBlockSize(src []byte, _ *[32768]byte) (d int) {
- // Initialize the hash table.
- const (
- tableBits = 13
- maxTableSize = 1 << tableBits
- )
-
- 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
-
- // 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 must start with a literal, as there are no previous
- // bytes to copy, so we start looking for hash matches at s == 1.
- s := 1
- cv := load64(src, s)
-
- // We search for a repeat at -1, but don't output repeats when nextEmit == 0
- repeat := 1
-
- 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 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 += emitLiteralSize(src[nextEmit:base])
-
- // 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
- }
-
- d += emitCopyNoRepeatSize(repeat, s-base)
- 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
- 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 += emitLiteralSize(src[nextEmit:s])
-
- // 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 += emitCopyNoRepeatSize(repeat, s-base)
- if false {
- // Validate match.
- a := src[base:s]
- b := src[base-repeat : base-repeat+(s-base)]
- if !bytes.Equal(a, b) {
- panic("mismatch")
- }
- }
-
- 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 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 += emitLiteralSize(src[nextEmit:])
- }
- return d
-}
-
-// length must be > inputMargin.
-func calcBlockSizeSmall(src []byte, _ *[2048]byte) (d int) {
- // Initialize the hash table.
- const (
- tableBits = 9
- maxTableSize = 1 << tableBits
- )
-
- 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
-
- // 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 must start with a literal, as there are no previous
- // bytes to copy, so we start looking for hash matches at s == 1.
- s := 1
- cv := load64(src, s)
-
- // We search for a repeat at -1, but don't output repeats when nextEmit == 0
- repeat := 1
-
- 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 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 += emitLiteralSize(src[nextEmit:base])
-
- // 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
- }
-
- d += emitCopyNoRepeatSize(repeat, s-base)
- 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
- 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 += emitLiteralSize(src[nextEmit:s])
-
- // 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 += emitCopyNoRepeatSize(repeat, s-base)
- if false {
- // Validate match.
- a := src[base:s]
- b := src[base-repeat : base-repeat+(s-base)]
- if !bytes.Equal(a, b) {
- panic("mismatch")
- }
- }
-
- 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 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 += emitLiteralSize(src[nextEmit:])
- }
- return d
-}
-
-// emitLiteral writes a literal chunk and returns the number of bytes written.
-//
-// It assumes that:
-//
-// dst is long enough to hold the encoded bytes
-// 0 <= len(lit) && len(lit) <= math.MaxUint32
-func emitLiteralSize(lit []byte) int {
- if len(lit) == 0 {
- return 0
- }
- switch {
- case len(lit) <= 60:
- return len(lit) + 1
- case len(lit) <= 1<<8:
- return len(lit) + 2
- case len(lit) <= 1<<16:
- return len(lit) + 3
- case len(lit) <= 1<<24:
- return len(lit) + 4
- default:
- return len(lit) + 5
- }
-}
-
-func cvtLZ4BlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
- panic("cvtLZ4BlockAsm should be unreachable")
-}
-
-func cvtLZ4BlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
- panic("cvtLZ4BlockSnappyAsm should be unreachable")
-}
-
-func cvtLZ4sBlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
- panic("cvtLZ4sBlockAsm should be unreachable")
-}
-
-func cvtLZ4sBlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
- panic("cvtLZ4sBlockSnappyAsm should be unreachable")
-}
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-30 09:38:47 +0000