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path: root/vendor/github.com/klauspost/compress/s2/decode_other.go
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Diffstat (limited to 'vendor/github.com/klauspost/compress/s2/decode_other.go')
-rw-r--r--vendor/github.com/klauspost/compress/s2/decode_other.go292
1 files changed, 0 insertions, 292 deletions
diff --git a/vendor/github.com/klauspost/compress/s2/decode_other.go b/vendor/github.com/klauspost/compress/s2/decode_other.go
deleted file mode 100644
index 2cb55c2c7..000000000
--- a/vendor/github.com/klauspost/compress/s2/decode_other.go
+++ /dev/null
@@ -1,292 +0,0 @@
-// Copyright 2016 The Snappy-Go Authors. All rights reserved.
-// Copyright (c) 2019 Klaus Post. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build (!amd64 && !arm64) || appengine || !gc || noasm
-// +build !amd64,!arm64 appengine !gc noasm
-
-package s2
-
-import (
- "fmt"
- "strconv"
-)
-
-// decode writes the decoding of src to dst. It assumes that the varint-encoded
-// length of the decompressed bytes has already been read, and that len(dst)
-// equals that length.
-//
-// It returns 0 on success or a decodeErrCodeXxx error code on failure.
-func s2Decode(dst, src []byte) int {
- const debug = false
- if debug {
- fmt.Println("Starting decode, dst len:", len(dst))
- }
- var d, s, length int
- offset := 0
-
- // As long as we can read at least 5 bytes...
- for s < len(src)-5 {
- // Removing bounds checks is SLOWER, when if doing
- // in := src[s:s+5]
- // Checked on Go 1.18
- switch src[s] & 0x03 {
- case tagLiteral:
- x := uint32(src[s] >> 2)
- switch {
- case x < 60:
- s++
- case x == 60:
- s += 2
- x = uint32(src[s-1])
- case x == 61:
- in := src[s : s+3]
- x = uint32(in[1]) | uint32(in[2])<<8
- s += 3
- case x == 62:
- in := src[s : s+4]
- // Load as 32 bit and shift down.
- x = uint32(in[0]) | uint32(in[1])<<8 | uint32(in[2])<<16 | uint32(in[3])<<24
- x >>= 8
- s += 4
- case x == 63:
- in := src[s : s+5]
- x = uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24
- s += 5
- }
- length = int(x) + 1
- if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
- if debug {
- fmt.Println("corrupt: lit size", length)
- }
- return decodeErrCodeCorrupt
- }
- if debug {
- fmt.Println("literals, length:", length, "d-after:", d+length)
- }
-
- copy(dst[d:], src[s:s+length])
- d += length
- s += length
- continue
-
- case tagCopy1:
- s += 2
- toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
- length = int(src[s-2]) >> 2 & 0x7
- if toffset == 0 {
- if debug {
- fmt.Print("(repeat) ")
- }
- // keep last offset
- switch length {
- case 5:
- length = int(src[s]) + 4
- s += 1
- case 6:
- in := src[s : s+2]
- length = int(uint32(in[0])|(uint32(in[1])<<8)) + (1 << 8)
- s += 2
- case 7:
- in := src[s : s+3]
- length = int((uint32(in[2])<<16)|(uint32(in[1])<<8)|uint32(in[0])) + (1 << 16)
- s += 3
- default: // 0-> 4
- }
- } else {
- offset = toffset
- }
- length += 4
- case tagCopy2:
- in := src[s : s+3]
- offset = int(uint32(in[1]) | uint32(in[2])<<8)
- length = 1 + int(in[0])>>2
- s += 3
-
- case tagCopy4:
- in := src[s : s+5]
- offset = int(uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24)
- length = 1 + int(in[0])>>2
- s += 5
- }
-
- if offset <= 0 || d < offset || length > len(dst)-d {
- if debug {
- fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
- }
-
- return decodeErrCodeCorrupt
- }
-
- if debug {
- fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
- }
-
- // Copy from an earlier sub-slice of dst to a later sub-slice.
- // If no overlap, use the built-in copy:
- if offset > length {
- copy(dst[d:d+length], dst[d-offset:])
- d += length
- continue
- }
-
- // Unlike the built-in copy function, this byte-by-byte copy always runs
- // forwards, even if the slices overlap. Conceptually, this is:
- //
- // d += forwardCopy(dst[d:d+length], dst[d-offset:])
- //
- // We align the slices into a and b and show the compiler they are the same size.
- // This allows the loop to run without bounds checks.
- a := dst[d : d+length]
- b := dst[d-offset:]
- b = b[:len(a)]
- for i := range a {
- a[i] = b[i]
- }
- d += length
- }
-
- // Remaining with extra checks...
- for s < len(src) {
- switch src[s] & 0x03 {
- case tagLiteral:
- x := uint32(src[s] >> 2)
- switch {
- case x < 60:
- s++
- case x == 60:
- s += 2
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- x = uint32(src[s-1])
- case x == 61:
- s += 3
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- x = uint32(src[s-2]) | uint32(src[s-1])<<8
- case x == 62:
- s += 4
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
- case x == 63:
- s += 5
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
- }
- length = int(x) + 1
- if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
- if debug {
- fmt.Println("corrupt: lit size", length)
- }
- return decodeErrCodeCorrupt
- }
- if debug {
- fmt.Println("literals, length:", length, "d-after:", d+length)
- }
-
- copy(dst[d:], src[s:s+length])
- d += length
- s += length
- continue
-
- case tagCopy1:
- s += 2
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = int(src[s-2]) >> 2 & 0x7
- toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
- if toffset == 0 {
- if debug {
- fmt.Print("(repeat) ")
- }
- // keep last offset
- switch length {
- case 5:
- s += 1
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = int(uint32(src[s-1])) + 4
- case 6:
- s += 2
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
- case 7:
- s += 3
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
- default: // 0-> 4
- }
- } else {
- offset = toffset
- }
- length += 4
- case tagCopy2:
- s += 3
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = 1 + int(src[s-3])>>2
- offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
-
- case tagCopy4:
- s += 5
- if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
- return decodeErrCodeCorrupt
- }
- length = 1 + int(src[s-5])>>2
- offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
- }
-
- if offset <= 0 || d < offset || length > len(dst)-d {
- if debug {
- fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
- }
- return decodeErrCodeCorrupt
- }
-
- if debug {
- fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
- }
-
- // Copy from an earlier sub-slice of dst to a later sub-slice.
- // If no overlap, use the built-in copy:
- if offset > length {
- copy(dst[d:d+length], dst[d-offset:])
- d += length
- continue
- }
-
- // Unlike the built-in copy function, this byte-by-byte copy always runs
- // forwards, even if the slices overlap. Conceptually, this is:
- //
- // d += forwardCopy(dst[d:d+length], dst[d-offset:])
- //
- // We align the slices into a and b and show the compiler they are the same size.
- // This allows the loop to run without bounds checks.
- a := dst[d : d+length]
- b := dst[d-offset:]
- b = b[:len(a)]
- for i := range a {
- a[i] = b[i]
- }
- d += length
- }
-
- if d != len(dst) {
- return decodeErrCodeCorrupt
- }
- return 0
-}
generated by cgit v1.2.3 (git 2.46.0) at 2025-07-30 18:37:03 +0000