/
compression.go
289 lines (241 loc) · 5.66 KB
/
compression.go
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package compression
import (
"bytes"
"compress/flate"
"compress/gzip"
"compress/zlib"
"fmt"
"io"
"github.com/JoshVarga/blast"
lzss "github.com/fbonhomm/LZSS/source"
"github.com/pierrec/lz4/v4"
"github.com/rasky/go-lzo"
"github.com/spf13/afero"
"github.com/ulikunitz/xz/lzma"
"github.com/martinlindhe/feng/compression/lzf"
)
// The Extractor handles compression and decompression for a specific compression format
type Extractor interface {
// Extracts compressed data from input stream `f`.
Extract(f afero.File) ([]byte, error)
// Compresses `in` data.
Compress(in []byte, w io.Writer) error
}
func ExtractorFactory(name string) (Extractor, error) {
switch name {
case "zlib":
return Zlib{}, nil
case "zlib_loose":
return ZlibLoose{}, nil
case "gzip":
return Gzip{}, nil
case "deflate":
return Deflate{}, nil
case "lzma":
return Lzma{}, nil
case "lzma2":
return Lzma2{}, nil
case "lzo1x":
return Lzo1x{}, nil
case "lz4":
return Lz4{}, nil
case "lzf":
return Lzf{}, nil
case "lzss":
return Lzss{}, nil
case "pkware":
return Pkware{}, nil
}
panic(fmt.Sprintf("unknown extractor '%s'", name))
}
type Deflate struct{}
func (o Deflate) Extract(f afero.File) ([]byte, error) {
reader := flate.NewReader(f)
defer reader.Close()
out := new(bytes.Buffer)
_, err := io.Copy(out, reader)
return out.Bytes(), err
}
func (o Deflate) Compress(in []byte, w io.Writer) error {
zw, err := flate.NewWriter(w, flate.BestCompression)
if err != nil {
return err
}
_, err = zw.Write(in)
zw.Close()
return err
}
type Zlib struct{}
func (o Zlib) Extract(f afero.File) ([]byte, error) {
reader, err := zlib.NewReader(f)
if err != nil {
return nil, err
}
defer reader.Close()
out := new(bytes.Buffer)
_, err = io.Copy(out, reader)
return out.Bytes(), err
}
func (o Zlib) Compress(in []byte, w io.Writer) error {
zw := zlib.NewWriter(w)
_, err := zw.Write(in)
zw.Close()
return err
}
// ignores compression errors
type ZlibLoose struct{}
func (o ZlibLoose) Extract(f afero.File) ([]byte, error) {
reader, err := zlib.NewReader(f)
if err != nil {
return nil, err
}
defer reader.Close()
out := new(bytes.Buffer)
_, err = io.Copy(out, reader)
return out.Bytes(), err
}
func (o ZlibLoose) Compress(in []byte, w io.Writer) error {
zw := zlib.NewWriter(w)
_, err := zw.Write(in)
zw.Close()
return err
}
type Gzip struct{}
func (o Gzip) Extract(f afero.File) ([]byte, error) {
reader, err := gzip.NewReader(f)
if err != nil {
return nil, err
}
defer reader.Close()
out := new(bytes.Buffer)
_, err = io.Copy(out, reader)
return out.Bytes(), err
}
func (o Gzip) Compress(in []byte, w io.Writer) error {
zw := gzip.NewWriter(w)
_, err := zw.Write(in)
zw.Close()
return err
}
type Lzma struct{}
func (o Lzma) Extract(f afero.File) ([]byte, error) {
reader, err := lzma.NewReader(f)
if err != nil {
return nil, err
}
out := new(bytes.Buffer)
_, err = io.Copy(out, reader)
return out.Bytes(), err
}
func (o Lzma) Compress(in []byte, w io.Writer) error {
zw, err := lzma.NewWriter(w)
if err != nil {
return err
}
_, err = zw.Write(in)
zw.Close()
return err
}
type Lzma2 struct{}
func (o Lzma2) Extract(f afero.File) ([]byte, error) {
reader, err := lzma.NewReader2(f)
if err != nil {
return nil, err
}
out := new(bytes.Buffer)
_, err = io.Copy(out, reader)
return out.Bytes(), err
}
func (o Lzma2) Compress(in []byte, w io.Writer) error {
zw, err := lzma.NewWriter2(w)
if err != nil {
return err
}
_, err = zw.Write(in)
zw.Close()
return err
}
type Lzo1x struct{}
func (o Lzo1x) Extract(f afero.File) ([]byte, error) {
b, err := lzo.Decompress1X(f, 0, 0)
if err != nil {
return nil, err
}
return b, nil
}
func (o Lzo1x) Compress(in []byte, w io.Writer) error {
_, err := w.Write(lzo.Compress1X(in))
return err
}
type Lz4 struct{}
func (o Lz4) Extract(f afero.File) ([]byte, error) {
out := new(bytes.Buffer)
reader := lz4.NewReader(f)
_, err := io.Copy(out, reader)
return out.Bytes(), err
}
func (o Lz4) Compress(in []byte, w io.Writer) error {
zw := lz4.NewWriter(w)
_, err := zw.Write(in)
zw.Close()
return err
}
type Lzf struct {
CompressedSize uint // deduced from field size
}
func (o Lzf) Extract(f afero.File) ([]byte, error) {
uncompressed, err := lzf.Decompress(f, o.CompressedSize)
return uncompressed, err
}
func (o Lzf) Compress(in []byte, w io.Writer) error {
panic("lzf compression TODO")
/*
buf := make([]byte, len(in)-1)
n, err := lzf.Compress(in, buf)
w.Write(buf[:n])
return err
*/
}
// LZSS is not really working ???, need a better impl.
type Lzss struct {
CompressedSize uint // deduced from field size
}
func (o Lzss) Extract(f afero.File) ([]byte, error) {
// TODO need github.com/fbonhomm/LZSS to support reader interface
// https://github.com/fbonhomm/LZSS/pull/1
data := make([]byte, o.CompressedSize)
if _, err := io.ReadFull(f, data); err != nil {
return nil, err
}
lzssMode := lzss.LZSS{Mode: 1, PositionMode: 1}
expanded := lzssMode.Decompress(data)
return expanded, nil
}
func (o Lzss) Compress(in []byte, w io.Writer) error {
lzssMode := lzss.LZSS{Mode: 1, PositionMode: 0}
_, err := w.Write(lzssMode.Compress(in))
return err
}
// PKWARE DCL compressed data (aka blast/explode/implode)
type Pkware struct{}
func (o Pkware) Extract(f afero.File) ([]byte, error) {
out := new(bytes.Buffer)
r, err := blast.NewReader(f)
if err != nil {
return nil, err
}
_, err = io.Copy(out, r)
r.Close()
return out.Bytes(), err
}
func (o Pkware) Compress(in []byte, w io.Writer) error {
var b bytes.Buffer
z := blast.NewWriter(&b, blast.Binary, blast.DictionarySize1024)
_, err := z.Write(in)
z.Close()
if err != nil {
return err
}
_, err = w.Write(b.Bytes())
return err
}