Revert changes to fullreader

README.md

@@ -17,6 +17,4 @@ Thanks also to [distri's squashfs library](https://github.com/distr1/distri/tree
 
 ## Performance
 
-This library, decompressing the Firefox AppImage and using go tests, takes about twice as long as `unsquashfs` on my quad core laptop. (~1 second with the library and about half a second with `unsquashfs`).
-
-**My recents tests have shown the Firefox AppImage might be an outlier and this library might be considerably slower (4x ~ 6x time slower then `unsquashfs`)**
+Testing on a zstd compressed file, my library is anywhere from 5x ~ 7x slower then `unsquashfs`

fuse.go

@@ -3,6 +3,7 @@ package squashfs
 import (
 	"bytes"
 	"context"
+	"errors"
 	"io"
 
 	"github.com/CalebQ42/fuse"
@@ -10,15 +11,41 @@ import (
 	"github.com/CalebQ42/squashfs/internal/inode"
 )
 
-func (r *Reader) Mount(mountpoint string) (con *fuse.Conn, err error) {
-	con, err = fuse.Mount(mountpoint, fuse.ReadOnly())
+// Mounts the archive to the given mountpoint using fuse3. Non-blocking.
+// If Unmount does not get called, the mount point must be unmounted using umount before the directory can be used again.
+func (r *Reader) Mount(mountpoint string) (err error) {
+	if r.con != nil {
+		return errors.New("squashfs archive already mounted")
+	}
+	r.con, err = fuse.Mount(mountpoint, fuse.ReadOnly())
 	if err != nil {
 		return
 	}
-	err = fs.Serve(con, &squashFuse{r: r})
+	<-r.con.Ready
+	r.mountDone = make(chan struct{})
+	go func() {
+		fs.Serve(r.con, &squashFuse{r: r})
+		close(r.mountDone)
+	}()
 	return
 }
 
+// Blocks until the mount ends.
+func (r *Reader) MountWait() {
+	if r.mountDone != nil {
+		<-r.mountDone
+	}
+}
+
+// Unmounts the archive.
+func (r *Reader) Unmount() error {
+	if r.con != nil {
+		defer func() { r.con = nil }()
+		return r.con.Close()
+	}
+	return errors.New("squashfs archive is not mounted")
+}
+
 type squashFuse struct {
 	r *Reader
 }

internal/data/fullreader.go

@@ -52,12 +52,11 @@ func (r FullReader) process(index int, offset int64, out chan outDat) {
 	}
 	// rdr := io.LimitReader(toreader.NewReader(r.r, offset), int64(size))
 	if size == r.sizes[index] {
-		//Special workaround for zstd for increased performancce.
-		if zstd, ok := r.d.(*decompress.Zstd); ok {
+		if dec, ok := r.d.(decompress.Decoder); ok {
 			dat = make([]byte, size)
 			_, err = r.r.ReadAt(dat, offset)
 			if err == nil {
-				dat, err = zstd.Decode(dat)
+				dat, err = dec.Decode(dat, int(r.blockSize))
 			}
 		} else {
 			rdr, err = r.d.Reader(io.LimitReader(toreader.NewReader(r.r, offset), int64(size)))

internal/data/reader.go

@@ -53,14 +53,14 @@ func (r *Reader) advance() (err error) {
 		} else {
 			r.cur = io.LimitReader(r.master, int64(size))
 			if size == r.blockSizes[0] {
-				if r.d.Resetable() {
+				if rs, ok := r.d.(decompress.Resetable); ok {
 					if r.comRdr == nil {
 						r.cur, err = r.d.Reader(r.cur)
 						if err != nil {
 							return
 						}
 					} else {
-						err = r.d.Reset(r.comRdr, r.cur)
+						err = rs.Reset(r.comRdr, r.cur)
 						r.cur = r.comRdr
 					}
 				} else {

internal/decompress/gzip.go

@@ -12,8 +12,6 @@ func (g GZip) Reader(src io.Reader) (io.ReadCloser, error) {
 	return zlib.NewReader(src)
 }
 
-func (g GZip) Resetable() bool { return true }
-
 func (g GZip) Reset(old, src io.Reader) error {
 	return old.(zlib.Resetter).Reset(src, nil)
 }

internal/decompress/interface.go

@@ -1,19 +1,22 @@
 package decompress
 
 import (
-	"errors"
 	"io"
 )
 
-var ErrNotResetable = errors.New("decompressor not resetable")
-
 type Decompressor interface {
 	//Creates a new decompressor reading from src.
 	Reader(src io.Reader) (io.ReadCloser, error)
-	//Reports whether Reset will work or not.
-	Resetable() bool
+}
+
+type Resetable interface {
 	//Reset attempts to re-use an old decompressor with new data.
 	//Will return ErrNotResetable if not Resetable().
 	//Must ALWAYS be provided with a reader created with Reader.
 	Reset(old, src io.Reader) error
 }
+
+type Decoder interface {
+	//Decodes a chunk of data all at once.
+	Decode(in []byte, outSize int) ([]byte, error)
+}

internal/decompress/lz4.go

@@ -12,9 +12,16 @@ func (l Lz4) Reader(r io.Reader) (io.ReadCloser, error) {
 	return io.NopCloser(lz4.NewReader(r)), nil
 }
 
-func (l Lz4) Resetable() bool { return true }
-
 func (l Lz4) Reset(old, src io.Reader) error {
 	old.(*lz4.Reader).Reset(src)
 	return nil
 }
+
+func (l Lz4) Decode(in []byte, outSize int) (out []byte, err error) {
+	out = make([]byte, outSize)
+	outLen, err := lz4.UncompressBlock(in, out)
+	if outLen < outSize {
+		out = out[:outLen]
+	}
+	return
+}

internal/decompress/lzma.go

@@ -12,7 +12,3 @@ func (l Lzma) Reader(r io.Reader) (io.ReadCloser, error) {
 	rdr, err := lzma.NewReader(r)
 	return io.NopCloser(rdr), err
 }
-
-func (l Lzma) Resetable() bool { return false }
-
-func (l Lzma) Reset(old, src io.Reader) error { return ErrNotResetable }

internal/decompress/lzo.go

@@ -16,7 +16,3 @@ func (l Lzo) Reader(r io.Reader) (io.ReadCloser, error) {
 	}
 	return io.NopCloser(bytes.NewReader(cache)), nil
 }
-
-func (l Lzo) Resetable() bool { return false }
-
-func (l Lzo) Reset(old, src io.Reader) error { return ErrNotResetable }

internal/decompress/xz.go

@@ -13,8 +13,6 @@ func (x Xz) Reader(r io.Reader) (io.ReadCloser, error) {
 	return io.NopCloser(rdr), err
 }
 
-func (x Xz) Resetable() bool { return true }
-
 func (x Xz) Reset(old, src io.Reader) error {
 	return old.(*xz.Reader).Reset(src)
 }

internal/decompress/zstd.go

@@ -15,15 +15,13 @@ func (z Zstd) Reader(src io.Reader) (io.ReadCloser, error) {
 	return r.IOReadCloser(), err
 }
 
-func (z Zstd) Resetable() bool { return true }
-
 func (z Zstd) Reset(old, src io.Reader) error {
 	return old.(*zstd.Decoder).Reset(src)
 }
 
-func (z *Zstd) Decode(in []byte) (out []byte, err error) {
+func (z Zstd) Decode(in []byte, outSize int) ([]byte, error) {
 	if z.writeToReader == nil {
 		z.writeToReader, _ = zstd.NewReader(nil)
 	}
-	return z.writeToReader.DecodeAll(in, nil)
+	return z.writeToReader.DecodeAll(in, make([]byte, outSize))
 }

internal/metadata/reader.go

@@ -26,7 +26,7 @@ func realSize(siz uint16) uint16 {
 }
 
 func (r *Reader) advance() (err error) {
-	if !r.d.Resetable() {
+	if _, ok := r.d.(decompress.Resetable); !ok {
 		if clr, ok := r.cur.(io.Closer); ok {
 			clr.Close()
 		}
@@ -39,14 +39,14 @@ func (r *Reader) advance() (err error) {
 	size := realSize(raw)
 	r.cur = io.LimitReader(r.master, int64(size))
 	if size == raw {
-		if r.d.Resetable() {
+		if rs, ok := r.d.(decompress.Resetable); ok {
 			if r.comRdr == nil {
 				r.cur, err = r.d.Reader(r.cur)
 				if err != nil {
 					return
 				}
 			} else {
-				err = r.d.Reset(r.comRdr, r.cur)
+				err = rs.Reset(r.comRdr, r.cur)
 				r.cur = r.comRdr
 			}
 		} else {

internal/toreader/offsetreader.go

@@ -0,0 +1,19 @@
+package toreader
+
+import "io"
+
+type OffsetReader struct {
+	r   io.ReaderAt
+	off int64
+}
+
+func NewOffsetReader(r io.ReaderAt, off int64) *OffsetReader {
+	return &OffsetReader{
+		r:   r,
+		off: off,
+	}
+}
+
+func (r OffsetReader) ReadAt(p []byte, off int64) (n int, e error) {
+	return r.r.ReadAt(p, off+r.off)
+}

internal/toreader/readerat.go

@@ -6,7 +6,8 @@ type ReaderAt struct {
 	d []byte
 }
 
-func NewReaderAt(r io.Reader) (ra ReaderAt, err error) {
+func NewReaderAt(r io.Reader) (ra *ReaderAt, err error) {
+	ra = new(ReaderAt)
 	ra.d, err = io.ReadAll(r)
 	return
 }

reader.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"time"
 
+	"github.com/CalebQ42/fuse"
 	"github.com/CalebQ42/squashfs/internal/decompress"
 	"github.com/CalebQ42/squashfs/internal/directory"
 	"github.com/CalebQ42/squashfs/internal/inode"
@@ -16,6 +17,8 @@ import (
 
 type Reader struct {
 	*FS
+	con         *fuse.Conn
+	mountDone   chan struct{}
 	d           decompress.Decompressor
 	r           io.ReaderAt
 	fragEntries []fragEntry
@@ -40,6 +43,10 @@ const (
 	ZSTDCompression
 )
 
+func NewReaderAtOffset(r io.ReaderAt, off int64) (*Reader, error) {
+	return NewReader(toreader.NewOffsetReader(r, off))
+}
+
 // Creates a new squashfs.Reader from the given io.Reader. NOTE: All data from the io.Reader will be read and stored in memory.
 func NewReaderFromReader(r io.Reader) (*Reader, error) {
 	rdr, err := toreader.NewReaderAt(r)

squashfs_test.go

@@ -73,7 +73,6 @@ func TestMisc(t *testing.T) {
 }
 
 func BenchmarkRace(b *testing.B) {
-	// tmpDir := b.TempDir()
 	tmpDir := "testing"
 	fil, err := preTest(tmpDir)
 	if err != nil {
@@ -197,11 +196,11 @@ func TestFuse(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	con, err := rdr.Mount("testing/fuseTest")
+	err = rdr.Mount("testing/fuseTest")
 	if err != nil {
 		t.Fatal(err)
 	}
-	defer con.Close()
-	<-con.Ready
+	defer rdr.Unmount()
+	rdr.MountWait()
 	t.Fatal("testing")
 }