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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/decode.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/decode.go')
-rw-r--r-- | vendor/github.com/klauspost/compress/s2/decode.go | 500 |
1 files changed, 470 insertions, 30 deletions
diff --git a/vendor/github.com/klauspost/compress/s2/decode.go b/vendor/github.com/klauspost/compress/s2/decode.go index b5fa4d3f..b7c9adfd 100644 --- a/vendor/github.com/klauspost/compress/s2/decode.go +++ b/vendor/github.com/klauspost/compress/s2/decode.go @@ -11,7 +11,9 @@ import ( "fmt" "io" "io/ioutil" + "math" "runtime" + "strconv" "sync" ) @@ -719,7 +721,11 @@ func (r *Reader) Skip(n int64) error { // decoded[i:j] contains decoded bytes that have not yet been passed on. left := int64(r.j - r.i) if left >= n { - r.i += int(n) + tmp := int64(r.i) + n + if tmp > math.MaxInt32 { + return errors.New("s2: internal overflow in skip") + } + r.i = int(tmp) return nil } n -= int64(r.j - r.i) @@ -875,15 +881,20 @@ func (r *Reader) Skip(n int64) error { // See Reader.ReadSeeker type ReadSeeker struct { *Reader + readAtMu sync.Mutex } -// ReadSeeker will return an io.ReadSeeker compatible version of the reader. +// ReadSeeker will return an io.ReadSeeker and io.ReaderAt +// compatible version of the reader. // If 'random' is specified the returned io.Seeker can be used for // random seeking, otherwise only forward seeking is supported. // Enabling random seeking requires the original input to support // the io.Seeker interface. // A custom index can be specified which will be used if supplied. // When using a custom index, it will not be read from the input stream. +// The ReadAt position will affect regular reads and the current position of Seek. +// So using Read after ReadAt will continue from where the ReadAt stopped. +// No functions should be used concurrently. // The returned ReadSeeker contains a shallow reference to the existing Reader, // meaning changes performed to one is reflected in the other. func (r *Reader) ReadSeeker(random bool, index []byte) (*ReadSeeker, error) { @@ -947,44 +958,61 @@ func (r *Reader) ReadSeeker(random bool, index []byte) (*ReadSeeker, error) { // Seek allows seeking in compressed data. func (r *ReadSeeker) Seek(offset int64, whence int) (int64, error) { if r.err != nil { + if !errors.Is(r.err, io.EOF) { + return 0, r.err + } + // Reset on EOF + r.err = nil + } + + // Calculate absolute offset. + absOffset := offset + + switch whence { + case io.SeekStart: + case io.SeekCurrent: + absOffset = r.blockStart + int64(r.i) + offset + case io.SeekEnd: + if r.index == nil { + return 0, ErrUnsupported + } + absOffset = r.index.TotalUncompressed + offset + default: + r.err = ErrUnsupported return 0, r.err } - if offset == 0 && whence == io.SeekCurrent { - return r.blockStart + int64(r.i), nil + + if absOffset < 0 { + return 0, errors.New("seek before start of file") } + if !r.readHeader { // Make sure we read the header. _, r.err = r.Read([]byte{}) + if r.err != nil { + return 0, r.err + } + } + + // If we are inside current block no need to seek. + // This includes no offset changes. + if absOffset >= r.blockStart && absOffset < r.blockStart+int64(r.j) { + r.i = int(absOffset - r.blockStart) + return r.blockStart + int64(r.i), nil } + rs, ok := r.r.(io.ReadSeeker) if r.index == nil || !ok { - if whence == io.SeekCurrent && offset >= 0 { - err := r.Skip(offset) - return r.blockStart + int64(r.i), err - } - if whence == io.SeekStart && offset >= r.blockStart+int64(r.i) { - err := r.Skip(offset - r.blockStart - int64(r.i)) + currOffset := r.blockStart + int64(r.i) + if absOffset >= currOffset { + err := r.Skip(absOffset - currOffset) return r.blockStart + int64(r.i), err } return 0, ErrUnsupported - - } - - switch whence { - case io.SeekCurrent: - offset += r.blockStart + int64(r.i) - case io.SeekEnd: - if offset > 0 { - return 0, errors.New("seek after end of file") - } - offset = r.index.TotalUncompressed + offset - } - - if offset < 0 { - return 0, errors.New("seek before start of file") } - c, u, err := r.index.Find(offset) + // We can seek and we have an index. + c, u, err := r.index.Find(absOffset) if err != nil { return r.blockStart + int64(r.i), err } @@ -995,12 +1023,57 @@ func (r *ReadSeeker) Seek(offset int64, whence int) (int64, error) { return 0, err } - r.i = r.j // Remove rest of current block. - if u < offset { + r.i = r.j // Remove rest of current block. + r.blockStart = u - int64(r.j) // Adjust current block start for accounting. + if u < absOffset { // Forward inside block - return offset, r.Skip(offset - u) + return absOffset, r.Skip(absOffset - u) + } + if u > absOffset { + return 0, fmt.Errorf("s2 seek: (internal error) u (%d) > absOffset (%d)", u, absOffset) } - return offset, nil + return absOffset, nil +} + +// ReadAt reads len(p) bytes into p starting at offset off in the +// underlying input source. It returns the number of bytes +// read (0 <= n <= len(p)) and any error encountered. +// +// When ReadAt returns n < len(p), it returns a non-nil error +// explaining why more bytes were not returned. In this respect, +// ReadAt is stricter than Read. +// +// Even if ReadAt returns n < len(p), it may use all of p as scratch +// space during the call. If some data is available but not len(p) bytes, +// ReadAt blocks until either all the data is available or an error occurs. +// In this respect ReadAt is different from Read. +// +// If the n = len(p) bytes returned by ReadAt are at the end of the +// input source, ReadAt may return either err == EOF or err == nil. +// +// If ReadAt is reading from an input source with a seek offset, +// ReadAt should not affect nor be affected by the underlying +// seek offset. +// +// Clients of ReadAt can execute parallel ReadAt calls on the +// same input source. This is however not recommended. +func (r *ReadSeeker) ReadAt(p []byte, offset int64) (int, error) { + r.readAtMu.Lock() + defer r.readAtMu.Unlock() + _, err := r.Seek(offset, io.SeekStart) + if err != nil { + return 0, err + } + n := 0 + for n < len(p) { + n2, err := r.Read(p[n:]) + if err != nil { + // This will include io.EOF + return n + n2, err + } + n += n2 + } + return n, nil } // ReadByte satisfies the io.ByteReader interface. @@ -1039,3 +1112,370 @@ func (r *Reader) SkippableCB(id uint8, fn func(r io.Reader) error) error { r.skippableCB[id] = fn return nil } + +// s2DecodeDict 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 s2DecodeDict(dst, src []byte, dict *Dict) int { + if dict == nil { + return s2Decode(dst, src) + } + const debug = false + const debugErrs = debug + + if debug { + fmt.Println("Starting decode, dst len:", len(dst)) + } + var d, s, length int + offset := len(dict.dict) - dict.repeat + + // 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 debug { + fmt.Println("literals, length:", length, "d-after:", d+length) + } + if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) { + if debugErrs { + fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s) + } + return decodeErrCodeCorrupt + } + + 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 || length > len(dst)-d { + if debugErrs { + fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d) + } + return decodeErrCodeCorrupt + } + + // copy from dict + if d < offset { + if d > MaxDictSrcOffset { + if debugErrs { + fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length) + } + return decodeErrCodeCorrupt + } + startOff := len(dict.dict) - offset + d + if startOff < 0 || startOff+length > len(dict.dict) { + if debugErrs { + fmt.Printf("offset (%d) + length (%d) bigger than dict (%d)\n", offset, length, len(dict.dict)) + } + return decodeErrCodeCorrupt + } + if debug { + fmt.Println("dict copy, length:", length, "offset:", offset, "d-after:", d+length, "dict start offset:", startOff) + } + copy(dst[d:d+length], dict.dict[startOff:]) + d += length + continue + } + + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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 debugErrs { + fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s) + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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. + if debugErrs { + fmt.Println("src went oob") + } + 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 || length > len(dst)-d { + if debugErrs { + fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d) + } + return decodeErrCodeCorrupt + } + + // copy from dict + if d < offset { + if d > MaxDictSrcOffset { + if debugErrs { + fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length) + } + return decodeErrCodeCorrupt + } + rOff := len(dict.dict) - (offset - d) + if debug { + fmt.Println("starting dict entry from dict offset", len(dict.dict)-rOff) + } + if rOff+length > len(dict.dict) { + if debugErrs { + fmt.Println("err: END offset", rOff+length, "bigger than dict", len(dict.dict), "dict offset:", rOff, "length:", length) + } + return decodeErrCodeCorrupt + } + if rOff < 0 { + if debugErrs { + fmt.Println("err: START offset", rOff, "less than 0", len(dict.dict), "dict offset:", rOff, "length:", length) + } + return decodeErrCodeCorrupt + } + copy(dst[d:d+length], dict.dict[rOff:]) + d += length + continue + } + + 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) { + if debugErrs { + fmt.Println("wanted length", len(dst), "got", d) + } + return decodeErrCodeCorrupt + } + return 0 +} |