/
zstd.go
69 lines (55 loc) · 1.46 KB
/
zstd.go
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package compression
import (
"bytes"
"encoding/binary"
"github.com/klauspost/compress/zstd"
"go.ytsaurus.tech/library/go/core/xerrors"
)
type CodecZstd int
func (c CodecZstd) Compress(block []byte) ([]byte, error) {
var out bytes.Buffer
if err := binary.Write(&out, binary.LittleEndian, uint64(len(block))); err != nil {
return nil, err
}
// todo consider bringing CGO zstd: https://pkg.go.dev/github.com/DataDog/zstd that supports all 20+ levels
w, err := zstd.NewWriter(nil, zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(int(c))))
if err != nil {
return nil, err
}
defer func() { _ = w.Close() }()
if _, err := out.Write(w.EncodeAll(block, nil)); err != nil {
return nil, err
}
return out.Bytes(), nil
}
func (c CodecZstd) Decompress(block []byte) ([]byte, error) {
if len(block) < 8 {
return nil, xerrors.Errorf("invalid block length: %d", len(block))
}
decompressedSize := binary.LittleEndian.Uint64(block[:8])
r, err := zstd.NewReader(nil)
if err != nil {
return nil, err
}
defer r.Close()
decompressed, err := r.DecodeAll(block[8:], nil)
if err != nil {
return nil, err
}
if decompressedSize != uint64(len(decompressed)) {
return nil, xerrors.Errorf("decompressed size mismatch: expected %d, got %d",
decompressedSize, len(decompressed))
}
return decompressed, nil
}
func (c CodecZstd) GetID() CodecID {
switch c {
case 1:
return CodecIDZstd1
case 3:
return CodecIDZstd3
case 7:
return CodecIDZstd7
}
return 0
}