Initial work

Create Reader
Pulled back in Inode decoding and superblock
New Data and Metadata readers
Added getting of id, fragment, and export table data lazily
Added README to squashfs/squashfs

internal/decompress/decompress.go

@@ -0,0 +1,5 @@
+package decompress
+
+type Decompressor interface {
+	Decompress([]byte) ([]byte, error)
+}

internal/decompress/lz4.go

@@ -0,0 +1,15 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/pierrec/lz4/v4"
+)
+
+type Lz4 struct{}
+
+func (l Lz4) Decompress(data []byte) ([]byte, error) {
+	rdr := lz4.NewReader(bytes.NewReader(data))
+	return io.ReadAll(rdr)
+}

internal/decompress/lzma.go

@@ -0,0 +1,18 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/ulikunitz/xz/lzma"
+)
+
+type Lzma struct{}
+
+func (l Lzma) Decompress(data []byte) ([]byte, error) {
+	rdr, err := lzma.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+	return io.ReadAll(rdr)
+}

internal/decompress/lzo.go

@@ -0,0 +1,13 @@
+package decompress
+
+import (
+	"bytes"
+
+	"github.com/rasky/go-lzo"
+)
+
+type Lzo struct{}
+
+func (l Lzo) Decompress(data []byte) ([]byte, error) {
+	return lzo.Decompress1X(bytes.NewReader(data), len(data), 0)
+}

internal/decompress/xz.go

@@ -0,0 +1,18 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/therootcompany/xz"
+)
+
+type Xz struct{}
+
+func (x Xz) Decompress(data []byte) ([]byte, error) {
+	rdr, err := xz.NewReader(bytes.NewReader(data), 0)
+	if err != nil {
+		return nil, err
+	}
+	return io.ReadAll(rdr)
+}

internal/decompress/zlib.go

@@ -0,0 +1,18 @@
+package decompress
+
+import (
+	"bytes"
+	"compress/zlib"
+	"io"
+)
+
+type Zlib struct{}
+
+func (z Zlib) Decompress(data []byte) ([]byte, error) {
+	rdr, err := zlib.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+	defer rdr.Close()
+	return io.ReadAll(rdr)
+}

internal/decompress/zstd.go

@@ -0,0 +1,19 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/klauspost/compress/zstd"
+)
+
+type Zstd struct{}
+
+func (z Zstd) Decompress(data []byte) ([]byte, error) {
+	rdr, err := zstd.NewReader(bytes.NewReader(data))
+	if err != nil {
+		return nil, err
+	}
+	defer rdr.Close()
+	return io.ReadAll(rdr)
+}