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| author | 2025-03-02 16:42:51 +0100 | |
|---|---|---|
| committer | 2025-03-02 16:42:51 +0100 | |
| commit | 8488ac928651656c6f7bebf5eaabce62c2b9fb66 (patch) | |
| tree | 94357311026e5ed96862a647400375a4543dd815 /vendor/github.com/klauspost/compress/zstd/bitreader.go | |
| parent | [chore] go-swagger -> codeberg (#3856) (diff) | |
| download | gotosocial-8488ac928651656c6f7bebf5eaabce62c2b9fb66.tar.xz | |
[chore] migrate oauth2 -> codeberg (#3857)
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/bitreader.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/zstd/bitreader.go | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/bitreader.go b/vendor/github.com/klauspost/compress/zstd/bitreader.go index 25ca98394..d41e3e170 100644 --- a/vendor/github.com/klauspost/compress/zstd/bitreader.go +++ b/vendor/github.com/klauspost/compress/zstd/bitreader.go @@ -5,11 +5,12 @@ package zstd import ( - "encoding/binary" "errors" "fmt" "io" "math/bits" + + "github.com/klauspost/compress/internal/le" ) // bitReader reads a bitstream in reverse. @@ -18,6 +19,7 @@ import ( type bitReader struct { in []byte value uint64 // Maybe use [16]byte, but shifting is awkward. + cursor int // offset where next read should end bitsRead uint8 } @@ -32,6 +34,7 @@ func (b *bitReader) init(in []byte) error { if v == 0 { return errors.New("corrupt stream, did not find end of stream") } + b.cursor = len(in) b.bitsRead = 64 b.value = 0 if len(in) >= 8 { @@ -67,18 +70,15 @@ func (b *bitReader) fillFast() { if b.bitsRead < 32 { return } - v := b.in[len(b.in)-4:] - b.in = b.in[:len(b.in)-4] - low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) - b.value = (b.value << 32) | uint64(low) + b.cursor -= 4 + b.value = (b.value << 32) | uint64(le.Load32(b.in, b.cursor)) b.bitsRead -= 32 } // fillFastStart() assumes the bitreader is empty and there is at least 8 bytes to read. func (b *bitReader) fillFastStart() { - v := b.in[len(b.in)-8:] - b.in = b.in[:len(b.in)-8] - b.value = binary.LittleEndian.Uint64(v) + b.cursor -= 8 + b.value = le.Load64(b.in, b.cursor) b.bitsRead = 0 } @@ -87,25 +87,23 @@ func (b *bitReader) fill() { if b.bitsRead < 32 { return } - if len(b.in) >= 4 { - v := b.in[len(b.in)-4:] - b.in = b.in[:len(b.in)-4] - low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) - b.value = (b.value << 32) | uint64(low) + if b.cursor >= 4 { + b.cursor -= 4 + b.value = (b.value << 32) | uint64(le.Load32(b.in, b.cursor)) b.bitsRead -= 32 return } - b.bitsRead -= uint8(8 * len(b.in)) - for len(b.in) > 0 { - b.value = (b.value << 8) | uint64(b.in[len(b.in)-1]) - b.in = b.in[:len(b.in)-1] + b.bitsRead -= uint8(8 * b.cursor) + for b.cursor > 0 { + b.cursor -= 1 + b.value = (b.value << 8) | uint64(b.in[b.cursor]) } } // finished returns true if all bits have been read from the bit stream. func (b *bitReader) finished() bool { - return len(b.in) == 0 && b.bitsRead >= 64 + return b.cursor == 0 && b.bitsRead >= 64 } // overread returns true if more bits have been requested than is on the stream. @@ -115,13 +113,14 @@ func (b *bitReader) overread() bool { // remain returns the number of bits remaining. func (b *bitReader) remain() uint { - return 8*uint(len(b.in)) + 64 - uint(b.bitsRead) + return 8*uint(b.cursor) + 64 - uint(b.bitsRead) } // close the bitstream and returns an error if out-of-buffer reads occurred. func (b *bitReader) close() error { // Release reference. b.in = nil + b.cursor = 0 if !b.finished() { return fmt.Errorf("%d extra bits on block, should be 0", b.remain()) } |
