Add LZ4 decompressor

README.md

@@ -19,6 +19,6 @@ Current status:
 * Handles password-protected versions of both of the above (`7za a -mhc=on|off -mhe=on -ppassword test.7z ...`).
 * Handles archives split into multiple volumes, (`7za a -v100m test.7z ...`).
 * Validates CRC values as it parses the file.
-* Supports BCJ2, Bzip2, Copy, Deflate, Delta, LZMA and LZMA2 methods.
+* Supports BCJ2, Bzip2, Copy, Deflate, Delta, LZ4, LZMA and LZMA2 methods.
 
 More examples of 7-zip archives are needed to test all of the different combinations/algorithms possible.

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/bodgit/windows v1.0.0
 	github.com/connesc/cipherio v0.2.1
 	github.com/hashicorp/go-multierror v1.1.1
+	github.com/pierrec/lz4/v4 v4.1.14
 	github.com/ulikunitz/xz v0.5.10
 	go4.org v0.0.0-20200411211856-f5505b9728dd
 	golang.org/x/text v0.3.7

go.sum

@@ -74,6 +74,8 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pierrec/lz4/v4 v4.1.14 h1:+fL8AQEZtz/ijeNnpduH0bROTu0O3NZAlPjQxGn8LwE=
+github.com/pierrec/lz4/v4 v4.1.14/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=

internal/lz4/reader.go

@@ -0,0 +1,54 @@
+package lz4
+
+import (
+	"errors"
+	"io"
+	"sync"
+
+	lz4 "github.com/pierrec/lz4/v4"
+)
+
+//nolint:gochecknoglobals
+var lz4ReaderPool sync.Pool
+
+type readCloser struct {
+	c io.Closer
+	r *lz4.Reader
+}
+
+func (rc *readCloser) Close() (err error) {
+	if rc.c != nil {
+		lz4ReaderPool.Put(rc.r)
+		err = rc.c.Close()
+		rc.c, rc.r = nil, nil
+	}
+
+	return
+}
+
+func (rc *readCloser) Read(p []byte) (int, error) {
+	if rc.r == nil {
+		return 0, errors.New("lz4: Read after Close")
+	}
+
+	return rc.r.Read(p)
+}
+
+// NewReader returns a new LZ4 io.ReadCloser.
+func NewReader(_ []byte, _ uint64, readers []io.ReadCloser) (io.ReadCloser, error) {
+	if len(readers) != 1 {
+		return nil, errors.New("lz4: need exactly one reader")
+	}
+
+	r, ok := lz4ReaderPool.Get().(*lz4.Reader)
+	if ok {
+		r.Reset(readers[0])
+	} else {
+		r = lz4.NewReader(readers[0])
+	}
+
+	return &readCloser{
+		c: readers[0],
+		r: r,
+	}, nil
+}

reader_test.go

@@ -93,6 +93,10 @@ func TestOpenReader(t *testing.T) {
 			name: "complex",
 			file: "lzma1900.7z",
 		},
+		{
+			name: "lz4",
+			file: "lz4.7z",
+		},
 	}
 
 	for _, table := range tables {
@@ -234,3 +238,7 @@ func BenchmarkBCJ2(b *testing.B) {
 func BenchmarkComplex(b *testing.B) {
 	benchmarkArchive(b, "lzma1900.7z")
 }
+
+func BenchmarkLZ4(b *testing.B) {
+	benchmarkArchive(b, "lz4.7z")
+}

register.go

@@ -10,6 +10,7 @@ import (
 	"github.com/bodgit/sevenzip/internal/bzip2"
 	"github.com/bodgit/sevenzip/internal/deflate"
 	"github.com/bodgit/sevenzip/internal/delta"
+	"github.com/bodgit/sevenzip/internal/lz4"
 	"github.com/bodgit/sevenzip/internal/lzma"
 	"github.com/bodgit/sevenzip/internal/lzma2"
 )
@@ -45,6 +46,8 @@ func init() {
 	RegisterDecompressor([]byte{0x04, 0x01, 0x08}, Decompressor(deflate.NewReader))
 	// Bzip2
 	RegisterDecompressor([]byte{0x04, 0x02, 0x02}, Decompressor(bzip2.NewReader))
+	// LZ4
+	RegisterDecompressor([]byte{0x04, 0xf7, 0x11, 0x04}, Decompressor(lz4.NewReader))
 	// AES-CBC-256 & SHA-256
 	RegisterDecompressor([]byte{0x06, 0xf1, 0x07, 0x01}, Decompressor(aes7z.NewReader))
 	// LZMA2