Files
squashfs/internal/compression/lz4.go
T
2021-01-08 14:35:32 -06:00

56 lines
1.1 KiB
Go

package compression
import (
"bytes"
"encoding/binary"
"io"
"github.com/pierrec/lz4/v4"
)
//Lz4 is a Lz4 Compressor/Decompressor
type Lz4 struct {
HC bool
}
//NewLz4CompressorWithOptions creates a new lz4 compressor/decompressor with options read from the given reader.
func NewLz4CompressorWithOptions(r io.Reader) (*Lz4, error) {
var lz4 Lz4
var init struct {
Version int32
Flags int32
}
err := binary.Read(r, binary.LittleEndian, &init)
if err != nil {
return nil, err
}
lz4.HC = init.Flags == 1
return &lz4, nil
}
//Decompress decompresses all data from r and returns the uncompressed bytes
func (l *Lz4) Decompress(r io.Reader) ([]byte, error) {
rdr := lz4.NewReader(r)
var buf bytes.Buffer
_, err := io.Copy(&buf, rdr)
return buf.Bytes(), err
}
//Compress implements compression.Compress
func (l *Lz4) Compress(data []byte) ([]byte, error) {
var buf bytes.Buffer
w := lz4.NewWriter(&buf)
if l.HC {
err := w.Apply(lz4.CompressionLevelOption(lz4.Level9))
if err != nil {
return nil, err
}
}
_, err := w.Write(data)
if err != nil {
return nil, err
}
w.Close()
return buf.Bytes(), nil
}