Files
squashfs/internal/compression/zstd.go
T
2021-01-08 14:35:32 -06:00

52 lines
1.1 KiB
Go

package compression
import (
"bytes"
"encoding/binary"
"io"
"github.com/klauspost/compress/zstd"
)
//Zstd is a zstd compressor/decompressor
type Zstd struct {
CompressionLevel int32
}
//NewZstdCompressorWithOptions creates a new Zstd with options read from the given reader
func NewZstdCompressorWithOptions(r io.Reader) (*Zstd, error) {
var zstd Zstd
err := binary.Read(r, binary.LittleEndian, &zstd)
if err != nil {
return nil, err
}
return &zstd, nil
}
//Decompress decompresses all data from the reader and returns the uncompressed data
func (z *Zstd) Decompress(r io.Reader) ([]byte, error) {
rdr, err := zstd.NewReader(r)
if err != nil {
return nil, err
}
defer rdr.Close()
var buf bytes.Buffer
_, err = io.Copy(&buf, rdr)
return buf.Bytes(), err
}
//Compress impelements compression.Compress
func (z *Zstd) Compress(data []byte) ([]byte, error) {
var buf bytes.Buffer
w, err := zstd.NewWriter(&buf, zstd.WithEncoderLevel(zstd.EncoderLevel(z.CompressionLevel)))
if err != nil {
return nil, err
}
_, err = w.Write(data)
if err != nil {
return nil, err
}
w.Close()
return buf.Bytes(), nil
}