Merge pull request #40 from CalebQ42/go-unsquashfs-hardlinks

go-unsquashfs hardlinks & squashfslow access

README.md

@@ -28,15 +28,14 @@ As of `v1.0`, FUSE capabilities has been moved to [a separate library](https://g
 
 ## Issues
 
-* Significantly slower then `unsquashfs` when nested images
+* Noticably slower then `unsquashfs` for extraction, especially on larger images.
   * This seems to be related to above along with the general optimization of `unsquashfs` and it's compression libraries.
-    * Not to mention it's written in C
   * Times seem to be largely dependent on file tree size and compression type.
-    * My main testing image (~100MB) using Zstd takes about 5x longer.
-    * An Arch Linux airootfs image (~780MB) using XZ compression with LZMA filters takes about 30x longer.
-    * A Tensorflow docker image (~3.3GB) using Zstd takes about 12x longer.
+    * My main testing image (~100MB) using Zstd takes ~2x longer.
+    * An Arch Linux airootfs image (~780MB) using XZ compression with LZMA filters takes ~28x longer.
+    * A Tensorflow docker image (~3.3GB) using Zstd takes ~3x longer.
 
-Note: These numbers are using `FastOptions()`. `DefaultOptions()` takes about 2x longer.
+Note: These numbers are using `FastOptions()`. `DefaultOptions()` takes ~2x longer.
 
 ## Recommendations on Usage
 

cmd/go-unsquashfs/main.go

@@ -3,7 +3,6 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io/fs"
 	"os"
 	"os/user"
 	"path/filepath"
@@ -12,6 +11,7 @@ import (
 	"time"
 
 	"github.com/CalebQ42/squashfs"
+	squashfslow "github.com/CalebQ42/squashfs/low"
 )
 
 func userName(uid int, numeric bool) string {
@@ -36,32 +36,84 @@ func groupName(gid int, numeric bool) string {
 	return gs
 }
 
-func printEntry(root, path string, d fs.DirEntry, numeric bool) {
-	fi, _ := d.Info()
+var hardLinks = make(map[uint32]string)
+
+func printFile(rdr *squashfs.Reader, path string, f *squashfs.File) {
+	path = filepath.Join(path, f.Low.Name)
+	fi, _ := f.Stat()
 	sfi := fi.(squashfs.FileInfo)
 	owner := fmt.Sprintf("%s/%s",
-		userName(sfi.Uid(), numeric),
-		groupName(sfi.Gid(), numeric))
-	link := ""
+		userName(sfi.Uid(), *numeric),
+		groupName(sfi.Gid(), *numeric))
+	var link string
+	var isHardLink bool
+	if *showHardLinks {
+		link, isHardLink = hardLinks[f.Low.Inode.Num]
+		if !isHardLink {
+			hardLinks[f.Low.Inode.Num] = path
+		}
+	}
+	var size int64
+	if isHardLink {
+		size = 0
+	} else {
+		size = fi.Size()
+	}
 	if sfi.IsSymlink() {
 		link = " -> " + sfi.SymlinkPath()
+	} else if isHardLink {
+		link = " link to " + link
 	}
 	fmt.Printf("%s %s %*d %s %s%s\n",
 		strings.ToLower(fi.Mode().String()),
-		owner, 26-len(owner), fi.Size(),
+		owner, 26-len(owner), size,
 		fi.ModTime().Format("2006-01-02 15:04"),
-		filepath.Join(root, path), link)
+		path, link)
+	if f.IsDir() {
+		fs, _ := f.FS()
+		printDir(rdr, path, fs)
+	}
 }
 
+func printDir(rdr *squashfs.Reader, path string, f squashfs.FS) {
+	var base squashfslow.FileBase
+	var fil squashfs.File
+	var err error
+	for _, e := range f.LowDir.Entries {
+		base, err = rdr.Low.BaseFromEntry(e)
+		if err != nil {
+			panic(err)
+		}
+		fil = rdr.FileFromBase(base, f)
+		printFile(rdr, path, &fil)
+	}
+}
+
+var (
+	verbose       *bool
+	list          *bool
+	long          *bool
+	numeric       *bool
+	offset        *int64
+	ignore        *bool
+	file          *string
+	showHardLinks *bool
+)
+
 func main() {
-	verbose := flag.Bool("v", false, "Verbose")
-	list := flag.Bool("l", false, "List")
-	long := flag.Bool("ll", false, "List with attributes")
-	numeric := flag.Bool("lln", false, "List with attributes and numeric ids")
-	offset := flag.Int64("o", 0, "Offset")
-	ignore := flag.Bool("ip", false, "Ignore Permissions and extract all files/folders with 0755")
+	verbose = flag.Bool("v", false, "Verbose")
+	list = flag.Bool("l", false, "List")
+	long = flag.Bool("ll", false, "List with attributes")
+	numeric = flag.Bool("lln", false, "List with attributes and numeric ids")
+	showHardLinks = flag.Bool("show-hard-links", false, "When used with ll or lln, shows hard links")
+	offset = flag.Int64("o", 0, "Offset")
+	ignore = flag.Bool("ip", false, "Ignore Permissions and extract all files/folders with 0755")
+	file = flag.String("e", "", "File or folder to extract")
 	flag.Parse()
-	if len(flag.Args()) < 2 {
+	if (*list || *long || *numeric) && flag.NArg() < 1 {
+		fmt.Println("Please provide a file name")
+		os.Exit(0)
+	} else if (!*list && !*long && !*numeric) && flag.NArg() < 2 {
 		fmt.Println("Please provide a file name and extraction path")
 		os.Exit(0)
 	}
@@ -73,26 +125,22 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+	extractFil := r.File()
+	if *file != "" {
+		extractFil, err = r.OpenFile(*file)
+		if err != nil {
+			panic(err)
+		}
+	}
 	if *list || *long || *numeric {
-		root := flag.Arg(1)
-		fs.WalkDir(r, ".", func(path string, d fs.DirEntry, err error) error {
-			if err != nil {
-				panic(err)
-			}
-			if *long || *numeric {
-				printEntry(root, path, d, *numeric)
-			} else {
-				fmt.Println(filepath.Join(root, path))
-			}
-			return nil
-		})
+		printFile(&r, "", extractFil)
 		return
 	}
 	op := squashfs.DefaultOptions()
 	op.Verbose = *verbose
 	op.IgnorePerm = *ignore
 	n := time.Now()
-	err = r.ExtractWithOptions(flag.Arg(1), op)
+	err = extractFil.ExtractWithOptions(flag.Arg(1), op)
 	if err != nil {
 		panic(err)
 	}

file.go

@@ -19,49 +19,47 @@ import (
 
 // File represents a file inside a squashfs archive.
 type File struct {
-	full     *data.FullReader
-	rdr      *data.Reader
-	parent   *FS
+	full     data.FullReader
+	rdr      data.Reader
+	rdrInit  bool
+	parent   FS
 	r        *Reader
-	b        squashfslow.FileBase
+	Low      squashfslow.FileBase
 	dirsRead int
 }
 
 // Creates a new *File from the given *squashfs.Base
-func (r *Reader) FileFromBase(b squashfslow.FileBase, parent *FS) *File {
-	return &File{
-		b:      b,
+func (r *Reader) FileFromBase(b squashfslow.FileBase, parent FS) File {
+	return File{
+		Low:    b,
 		parent: parent,
 		r:      r,
 	}
 }
 
-func (f *File) FS() (*FS, error) {
+func (f File) FS() (FS, error) {
 	if !f.IsDir() {
-		return nil, errors.New("not a directory")
+		return FS{}, errors.New("not a directory")
 	}
-	d, err := f.b.ToDir(&f.r.Low)
+	d, err := f.Low.ToDir(f.r.Low)
 	if err != nil {
-		return nil, err
+		return FS{}, err
 	}
-	return &FS{d: d, parent: f.parent, r: f.r}, nil
+	return FS{LowDir: d, parent: &f.parent, r: f.r}, nil
 }
 
 // Closes the underlying readers.
 // Further calls to Read and WriteTo will re-create the readers.
 // Never returns an error.
 func (f *File) Close() error {
-	if f.rdr != nil {
-		return f.rdr.Close()
-	}
-	f.rdr = nil
-	f.full = nil
+	f.rdr.Close()
+	f.full.Close()
 	return nil
 }
 
 // Returns the file the symlink points to.
 // If the file isn't a symlink, or points to a file outside the archive, returns nil.
-func (f *File) GetSymlinkFile() fs.File {
+func (f File) GetSymlinkFile() fs.File {
 	if !f.IsSymlink() {
 		return nil
 	}
@@ -76,22 +74,22 @@ func (f *File) GetSymlinkFile() fs.File {
 }
 
 // Returns whether the file is a directory.
-func (f *File) IsDir() bool {
-	return f.b.IsDir()
+func (f File) IsDir() bool {
+	return f.Low.IsDir()
 }
 
 // Returns whether the file is a regular file.
-func (f *File) IsRegular() bool {
-	return f.b.IsRegular()
+func (f File) IsRegular() bool {
+	return f.Low.IsRegular()
 }
 
 // Returns whether the file is a symlink.
-func (f *File) IsSymlink() bool {
-	return f.b.Inode.Type == inode.Sym || f.b.Inode.Type == inode.ESym
+func (f File) IsSymlink() bool {
+	return f.Low.Inode.Type == inode.Sym || f.Low.Inode.Type == inode.ESym
 }
 
-func (f *File) Mode() fs.FileMode {
-	return f.b.Inode.Mode()
+func (f File) Mode() fs.FileMode {
+	return f.Low.Inode.Mode()
 }
 
 // Read reads the data from the file. Only works if file is a normal file.
@@ -99,7 +97,7 @@ func (f *File) Read(b []byte) (int, error) {
 	if !f.IsRegular() {
 		return 0, errors.New("file is not a regular file")
 	}
-	if f.rdr == nil {
+	if !f.rdrInit {
 		err := f.initializeReaders()
 		if err != nil {
 			return 0, err
@@ -114,7 +112,7 @@ func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
 	if !f.IsDir() {
 		return nil, errors.New("file is not a directory")
 	}
-	d, err := f.b.ToDir(&f.r.Low)
+	d, err := f.Low.ToDir(f.r.Low)
 	if err != nil {
 		return nil, err
 	}
@@ -141,25 +139,25 @@ func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
 }
 
 // Returns the file's fs.FileInfo
-func (f *File) Stat() (fs.FileInfo, error) {
-	uid, err := f.b.Uid(&f.r.Low)
+func (f File) Stat() (fs.FileInfo, error) {
+	uid, err := f.Low.Uid(&f.r.Low)
 	if err != nil {
 		return nil, err
 	}
-	gid, err := f.b.Gid(&f.r.Low)
+	gid, err := f.Low.Gid(&f.r.Low)
 	if err != nil {
 		return nil, err
 	}
-	return newFileInfo(f.b.Name, uid, gid, &f.b.Inode), nil
+	return newFileInfo(f.Low.Name, uid, gid, &f.Low.Inode), nil
 }
 
 // SymlinkPath returns the symlink's target path. Is the File isn't a symlink, returns an empty string.
-func (f *File) SymlinkPath() string {
-	switch f.b.Inode.Type {
+func (f File) SymlinkPath() string {
+	switch f.Low.Inode.Type {
 	case inode.Sym:
-		return string(f.b.Inode.Data.(inode.Symlink).Target)
+		return string(f.Low.Inode.Data.(inode.Symlink).Target)
 	case inode.ESym:
-		return string(f.b.Inode.Data.(inode.ESymlink).Target)
+		return string(f.Low.Inode.Data.(inode.ESymlink).Target)
 	}
 	return ""
 }
@@ -170,7 +168,7 @@ func (f *File) WriteTo(w io.Writer) (int64, error) {
 	if !f.IsRegular() {
 		return 0, errors.New("file is not a regular file")
 	}
-	if f.full == nil {
+	if !f.rdrInit {
 		err := f.initializeReaders()
 		if err != nil {
 			return 0, err
@@ -181,37 +179,43 @@ func (f *File) WriteTo(w io.Writer) (int64, error) {
 
 func (f *File) initializeReaders() error {
 	var err error
-	f.rdr, f.full, err = f.b.GetRegFileReaders(&f.r.Low)
+	f.rdr, f.full, err = f.Low.GetRegFileReaders(f.r.Low)
+	if err == nil {
+		f.rdrInit = true
+	} else {
+		f.rdr.Close()
+		f.full.Close()
+	}
 	return err
 }
 
-func (f *File) deviceDevices() (maj uint32, min uint32) {
+func (f File) deviceDevices() (maj uint32, min uint32) {
 	var dev uint32
-	switch f.b.Inode.Type {
+	switch f.Low.Inode.Type {
 	case inode.Char, inode.Block:
-		dev = f.b.Inode.Data.(inode.Device).Dev
+		dev = f.Low.Inode.Data.(inode.Device).Dev
 	case inode.EChar, inode.EBlock:
-		dev = f.b.Inode.Data.(inode.EDevice).Dev
+		dev = f.Low.Inode.Data.(inode.EDevice).Dev
 	}
 	return dev >> 8, dev & 0x000FF
 }
 
-func (f *File) path() string {
-	if f.parent == nil {
-		return f.b.Name
+func (f File) path() string {
+	if f.parent.LowDir.Name == "" {
+		return f.Low.Name
 	}
-	return filepath.Join(f.parent.path(), f.b.Name)
+	return filepath.Join(f.parent.path(), f.Low.Name)
 }
 
 // Extract the file to the given folder. If the file is a folder, the folder's contents will be extracted to the folder.
 // Uses default extraction options.
-func (f *File) Extract(folder string) error {
+func (f File) Extract(folder string) error {
 	return f.ExtractWithOptions(folder, DefaultOptions())
 }
 
 // Extract the file to the given folder. If the file is a folder, the folder's contents will be extracted to the folder.
 // Allows setting various extraction options via ExtractionOptions.
-func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
+func (f File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 	if op.manager == nil {
 		op.manager = routinemanager.NewManager(op.SimultaneousFiles)
 		if op.LogOutput != nil {
@@ -225,9 +229,9 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 			return err
 		}
 	}
-	switch f.b.Inode.Type {
+	switch f.Low.Inode.Type {
 	case inode.Dir, inode.EDir:
-		d, err := f.b.ToDir(&f.r.Low)
+		d, err := f.Low.ToDir(f.r.Low)
 		if err != nil {
 			if op.Verbose {
 				log.Println("Failed to create squashfs.Directory for", path)
@@ -285,7 +289,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 			return errors.Join(errors.New("failed to extract folder: "+path), errors.Join(errCache...))
 		}
 	case inode.Fil, inode.EFil:
-		path = filepath.Join(path, f.b.Name)
+		path = filepath.Join(path, f.Low.Name)
 		outFil, err := os.Create(path)
 		if err != nil {
 			if op.Verbose {
@@ -294,7 +298,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 			return errors.Join(errors.New("failed to create file: "+path), err)
 		}
 		defer outFil.Close()
-		full, err := f.b.GetFullReader(&f.r.Low)
+		full, err := f.Low.GetFullReader(&f.r.Low)
 		if err != nil {
 			if op.Verbose {
 				log.Println("Failed to create full reader for", path)
@@ -320,11 +324,11 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 				return errors.New("failed to get symlink's file")
 			}
 			fil := filTmp.(*File)
-			fil.b.Name = f.b.Name
+			fil.Low.Name = f.Low.Name
 			err := fil.ExtractWithOptions(path, op)
 			if err != nil {
 				if op.Verbose {
-					log.Println("Failed to extract symlink's file:", filepath.Join(path, f.b.Name))
+					log.Println("Failed to extract symlink's file:", filepath.Join(path, f.Low.Name))
 				}
 				return errors.Join(errors.New("failed to extract symlink's file: "+path), err)
 			}
@@ -347,7 +351,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 					return errors.Join(errors.New("failed to extract symlink's file: "+extractLoc), err)
 				}
 			}
-			path = filepath.Join(path, f.b.Name)
+			path = filepath.Join(path, f.Low.Name)
 			err := os.Symlink(f.SymlinkPath(), path)
 			if err != nil {
 				if op.Verbose {
@@ -370,9 +374,9 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 			}
 			return errors.Join(errors.New("mknot command not found"), err)
 		}
-		path = filepath.Join(path, f.b.Name)
+		path = filepath.Join(path, f.Low.Name)
 		var typ string
-		switch f.b.Inode.Type {
+		switch f.Low.Inode.Type {
 		case inode.Char, inode.EChar:
 			typ = "c"
 		case inode.Block, inode.EBlock:
@@ -408,7 +412,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 		}
 		return nil
 	default:
-		return errors.New("Unsupported file type. Inode type: " + strconv.Itoa(int(f.b.Inode.Type)))
+		return errors.New("Unsupported file type. Inode type: " + strconv.Itoa(int(f.Low.Inode.Type)))
 	}
 	if op.Verbose {
 		log.Println(f.path(), "extracted to", path)
@@ -416,7 +420,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 	if op.IgnorePerm {
 		return nil
 	}
-	uid, err := f.b.Uid(&f.r.Low)
+	uid, err := f.Low.Uid(&f.r.Low)
 	if err != nil {
 		if op.Verbose {
 			log.Println("Failed to get uid for", path)
@@ -424,7 +428,7 @@ func (f *File) ExtractWithOptions(path string, op *ExtractionOptions) error {
 		}
 		return nil
 	}
-	gid, err := f.b.Gid(&f.r.Low)
+	gid, err := f.Low.Gid(&f.r.Low)
 	if err != nil {
 		if op.Verbose {
 			log.Println("Failed to get gid for", path)

fs.go

@@ -17,15 +17,15 @@ import (
 type FS struct {
 	r      *Reader
 	parent *FS
-	d      squashfslow.Directory
+	LowDir squashfslow.Directory
 }
 
 // Creates a new *FS from the given squashfs.directory
-func (r *Reader) FSFromDirectory(d squashfslow.Directory, parent *FS) *FS {
-	return &FS{
-		d:      d,
+func (r *Reader) FSFromDirectory(d squashfslow.Directory, parent FS) FS {
+	return FS{
+		LowDir: d,
 		r:      r,
-		parent: parent,
+		parent: &parent,
 	}
 }
 
@@ -42,10 +42,10 @@ func (f *FS) Glob(pattern string) (out []string, err error) {
 		}
 	}
 	split := strings.Split(pattern, "/")
-	for i := range f.d.Entries {
-		if match, _ := path.Match(split[0], f.d.Entries[i].Name); match {
+	for i := range f.LowDir.Entries {
+		if match, _ := path.Match(split[0], f.LowDir.Entries[i].Name); match {
 			if len(split) == 1 {
-				out = append(out, f.d.Entries[i].Name)
+				out = append(out, f.LowDir.Entries[i].Name)
 				continue
 			}
 			sub, err := f.Sub(split[0])
@@ -81,7 +81,7 @@ func (f *FS) Glob(pattern string) (out []string, err error) {
 				}
 			}
 			for i := range subGlob {
-				subGlob[i] = f.d.Name + "/" + subGlob[i]
+				subGlob[i] = f.LowDir.Name + "/" + subGlob[i]
 			}
 			out = append(out, subGlob...)
 		}
@@ -90,7 +90,11 @@ func (f *FS) Glob(pattern string) (out []string, err error) {
 }
 
 // Opens the file at name. Returns a *File as an fs.File.
-func (f *FS) Open(name string) (fs.File, error) {
+func (f FS) Open(name string) (fs.File, error) {
+	return f.OpenFile(name)
+}
+
+func (f FS) OpenFile(name string) (*File, error) {
 	name = filepath.Clean(name)
 	if !fs.ValidPath(name) {
 		return nil, &fs.PathError{
@@ -111,10 +115,10 @@ func (f *FS) Open(name string) (fs.File, error) {
 				Err:  fs.ErrNotExist,
 			}
 		} else {
-			return f.parent.Open(strings.Join(split[1:], "/"))
+			return f.parent.OpenFile(strings.Join(split[1:], "/"))
 		}
 	}
-	i, found := slices.BinarySearchFunc(f.d.Entries, split[0], func(e directory.Entry, name string) int {
+	i, found := slices.BinarySearchFunc(f.LowDir.Entries, split[0], func(e directory.Entry, name string) int {
 		return strings.Compare(e.Name, name)
 	})
 	if !found {
@@ -124,13 +128,13 @@ func (f *FS) Open(name string) (fs.File, error) {
 			Err:  fs.ErrNotExist,
 		}
 	}
-	b, err := f.r.Low.BaseFromEntry(f.d.Entries[i])
+	b, err := f.r.Low.BaseFromEntry(f.LowDir.Entries[i])
 	if err != nil {
 		return nil, err
 	}
 	if len(split) == 1 {
 		return &File{
-			b:      b,
+			Low:    b,
 			r:      f.r,
 			parent: f,
 		}, nil
@@ -142,16 +146,16 @@ func (f *FS) Open(name string) (fs.File, error) {
 			Err:  fs.ErrNotExist,
 		}
 	}
-	d, err := b.ToDir(&f.r.Low)
+	d, err := b.ToDir(f.r.Low)
 	if err != nil {
 		return nil, err
 	}
-	return f.r.FSFromDirectory(d, f).Open(strings.Join(split[1:], "/"))
+	return f.r.FSFromDirectory(d, f).OpenFile(strings.Join(split[1:], "/"))
 }
 
 // Returns all DirEntry's for the directory at name.
 // If name is not a directory, returns an error.
-func (f *FS) ReadDir(name string) ([]fs.DirEntry, error) {
+func (f FS) ReadDir(name string) ([]fs.DirEntry, error) {
 	name = filepath.Clean(name)
 	if !fs.ValidPath(name) {
 		return nil, &fs.PathError{
@@ -171,7 +175,7 @@ func (f *FS) ReadDir(name string) ([]fs.DirEntry, error) {
 }
 
 // Returns the contents of the file at name.
-func (f *FS) ReadFile(name string) (out []byte, err error) {
+func (f FS) ReadFile(name string) (out []byte, err error) {
 	name = filepath.Clean(name)
 	if !fs.ValidPath(name) {
 		return nil, &fs.PathError{
@@ -194,7 +198,7 @@ func (f *FS) ReadFile(name string) (out []byte, err error) {
 }
 
 // Returns the fs.FileInfo for the file at name.
-func (f *FS) Stat(name string) (fs.FileInfo, error) {
+func (f FS) Stat(name string) (fs.FileInfo, error) {
 	name = filepath.Clean(name)
 	if !fs.ValidPath(name) {
 		return nil, &fs.PathError{
@@ -214,7 +218,7 @@ func (f *FS) Stat(name string) (fs.FileInfo, error) {
 }
 
 // Returns the FS at dir
-func (f *FS) Sub(dir string) (fs.FS, error) {
+func (f FS) Sub(dir string) (fs.FS, error) {
 	dir = filepath.Clean(dir)
 	if !fs.ValidPath(dir) {
 		return nil, &fs.PathError{
@@ -242,28 +246,34 @@ func (f *FS) Sub(dir string) (fs.FS, error) {
 
 // Extract the FS to the given folder. If the file is a folder, the folder's contents will be extracted to the folder.
 // Uses default extraction options.
-func (f *FS) Extract(folder string) error {
+func (f FS) Extract(folder string) error {
 	return f.File().Extract(folder)
 }
 
 // Extract the FS to the given folder. If the file is a folder, the folder's contents will be extracted to the folder.
 // Allows setting various extraction options via ExtractionOptions.
-func (f *FS) ExtractWithOptions(folder string, op *ExtractionOptions) error {
+func (f FS) ExtractWithOptions(folder string, op *ExtractionOptions) error {
 	return f.File().ExtractWithOptions(folder, op)
 }
 
 // Returns the FS as a *File
-func (f *FS) File() *File {
+func (f FS) File() *File {
+	if f.parent != nil {
+		return &File{
+			Low:    f.LowDir.FileBase,
+			parent: *f.parent,
+			r:      f.r,
+		}
+	}
 	return &File{
-		b:      f.d.FileBase,
-		parent: f.parent,
-		r:      f.r,
+		Low: f.LowDir.FileBase,
+		r:   f.r,
 	}
 }
 
-func (f *FS) path() string {
+func (f FS) path() string {
 	if f.parent == nil {
-		return f.d.Name
+		return f.LowDir.Name
 	}
-	return filepath.Join(f.parent.path(), f.d.Name)
+	return filepath.Join(f.parent.path(), f.LowDir.Name)
 }

internal/decompress/lz4.go

@@ -3,13 +3,28 @@ package decompress
 import (
 	"bytes"
 	"io"
+	"sync"
 
 	"github.com/pierrec/lz4/v4"
 )
 
-type Lz4 struct{}
+type Lz4 struct {
+	pool sync.Pool
+}
 
-func (l Lz4) Decompress(data []byte) ([]byte, error) {
-	rdr := lz4.NewReader(bytes.NewReader(data))
+func NewLz4() *Lz4 {
+	return &Lz4{
+		pool: sync.Pool{
+			New: func() any {
+				return lz4.NewReader(nil)
+			},
+		},
+	}
+}
+
+func (l *Lz4) Decompress(data []byte) ([]byte, error) {
+	rdr := l.pool.Get().(*lz4.Reader)
+	defer l.pool.Put(rdr)
+	rdr.Reset(bytes.NewReader(data))
 	return io.ReadAll(rdr)
 }

internal/decompress/xz.go

@@ -3,14 +3,30 @@ package decompress
 import (
 	"bytes"
 	"io"
+	"sync"
 
 	"github.com/therootcompany/xz"
 )
 
-type Xz struct{}
+type Xz struct {
+	pool sync.Pool
+}
 
-func (x Xz) Decompress(data []byte) ([]byte, error) {
-	rdr, err := xz.NewReader(bytes.NewReader(data), 0)
+func NewXz() *Xz {
+	return &Xz{
+		pool: sync.Pool{
+			New: func() any {
+				rdr, _ := xz.NewReader(nil, 0)
+				return rdr
+			},
+		},
+	}
+}
+
+func (x *Xz) Decompress(data []byte) ([]byte, error) {
+	rdr := x.pool.Get().(*xz.Reader)
+	defer x.pool.Put(rdr)
+	err := rdr.Reset(bytes.NewReader(data))
 	if err != nil {
 		return nil, err
 	}

internal/decompress/zlib.go

@@ -2,17 +2,31 @@ package decompress
 
 import (
 	"bytes"
-	"compress/zlib"
 	"io"
+	"sync"
+
+	"github.com/klauspost/compress/zlib"
 )
 
-type Zlib struct{}
+type Zlib struct {
+	pool sync.Pool
+}
 
-func (z Zlib) Decompress(data []byte) ([]byte, error) {
-	rdr, err := zlib.NewReader(bytes.NewReader(data))
+func NewZlib() *Zlib {
+	return &Zlib{}
+}
+
+func (z *Zlib) Decompress(data []byte) ([]byte, error) {
+	rdr := z.pool.Get()
+	defer z.pool.Put(rdr)
+	var err error
+	if rdr == nil {
+		rdr, err = zlib.NewReader(bytes.NewReader(data))
+	} else {
+		err = rdr.(zlib.Resetter).Reset(bytes.NewReader(data), nil)
+	}
 	if err != nil {
 		return nil, err
 	}
-	defer rdr.Close()
-	return io.ReadAll(rdr)
+	return io.ReadAll(rdr.(io.ReadCloser))
 }

internal/decompress/zstd.go

@@ -1,19 +1,20 @@
 package decompress
 
 import (
-	"bytes"
-	"io"
-
 	"github.com/klauspost/compress/zstd"
 )
 
-type Zstd struct{}
+type Zstd struct {
+	rdr *zstd.Decoder
+}
+
+func NewZstd() Zstd {
+	rdr, _ := zstd.NewReader(nil, zstd.WithDecoderLowmem(true))
+	return Zstd{
+		rdr: rdr,
+	}
+}
 
 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)
+	return z.rdr.DecodeAll(data, nil)
 }

internal/metadata/reader.go

@@ -14,8 +14,8 @@ type Reader struct {
 	curOffset uint16
 }
 
-func NewReader(r io.Reader, d decompress.Decompressor) *Reader {
-	return &Reader{
+func NewReader(r io.Reader, d decompress.Decompressor) Reader {
+	return Reader{
 		r: r,
 		d: d,
 	}
@@ -23,14 +23,15 @@ func NewReader(r io.Reader, d decompress.Decompressor) *Reader {
 
 func (r *Reader) advance() error {
 	r.curOffset = 0
-	var size uint16
-	err := binary.Read(r.r, binary.LittleEndian, &size)
+	dat := make([]byte, 2)
+	_, err := r.r.Read(dat)
 	if err != nil {
 		return err
 	}
+	size := binary.LittleEndian.Uint16(dat)
 	realSize := size &^ 0x8000
 	r.dat = make([]byte, realSize)
-	err = binary.Read(r.r, binary.LittleEndian, &r.dat)
+	_, err = r.r.Read(r.dat)
 	if err != nil {
 		return err
 	}

low/data/fullreader.go

@@ -1,15 +1,14 @@
 package data
 
 import (
-	"encoding/binary"
 	"errors"
 	"io"
+	"io/fs"
 	"math"
 	"runtime"
 	"sync"
 
 	"github.com/CalebQ42/squashfs/internal/decompress"
-	"github.com/CalebQ42/squashfs/internal/toreader"
 )
 
 type FragReaderConstructor func() (io.Reader, error)
@@ -23,10 +22,11 @@ type FullReader struct {
 	finalBlockSize uint64
 	blockSize      uint32
 	goroutineLimit uint16
+	closed         bool
 }
 
-func NewFullReader(r io.ReaderAt, initialOffset int64, d decompress.Decompressor, sizes []uint32, finalBlockSize uint64, blockSize uint32) *FullReader {
-	return &FullReader{
+func NewFullReader(r io.ReaderAt, initialOffset int64, d decompress.Decompressor, sizes []uint32, finalBlockSize uint64, blockSize uint32) FullReader {
+	return FullReader{
 		r:              r,
 		d:              d,
 		sizes:          sizes,
@@ -37,6 +37,15 @@ func NewFullReader(r io.ReaderAt, initialOffset int64, d decompress.Decompressor
 	}
 }
 
+func (r *FullReader) Close() error {
+	r.closed = true
+	r.r = nil
+	r.d = nil
+	r.frag = nil
+	r.sizes = nil
+	return nil
+}
+
 func (r *FullReader) AddFrag(frag FragReaderConstructor) {
 	r.frag = frag
 }
@@ -69,7 +78,7 @@ func (r FullReader) process(index uint64, fileOffset uint64, pool *sync.Pool, re
 		return
 	}
 	ret.data = make([]byte, realSize)
-	ret.err = binary.Read(toreader.NewReader(r.r, int64(r.initialOffset)+int64(fileOffset)), binary.LittleEndian, &ret.data)
+	_, ret.err = r.r.ReadAt(ret.data, r.initialOffset+int64(fileOffset))
 	if r.sizes[index] == realSize {
 		ret.data, ret.err = r.d.Decompress(ret.data)
 	}
@@ -77,6 +86,9 @@ func (r FullReader) process(index uint64, fileOffset uint64, pool *sync.Pool, re
 }
 
 func (r FullReader) WriteTo(w io.Writer) (int64, error) {
+	if r.closed {
+		return 0, fs.ErrClosed
+	}
 	// if wa, is := w.(io.WriterAt); is {
 	// 	return r.writeToWriteAt(wa)
 	// }

low/data/reader.go

@@ -1,8 +1,8 @@
 package data
 
 import (
-	"encoding/binary"
 	"io"
+	"io/fs"
 
 	"github.com/CalebQ42/squashfs/internal/decompress"
 )
@@ -17,10 +17,11 @@ type Reader struct {
 	curIndex       uint64
 	finalBlockSize uint64
 	blockSize      uint32
+	closed         bool
 }
 
-func NewReader(r io.Reader, d decompress.Decompressor, sizes []uint32, finalBlockSize uint64, blockSize uint32) *Reader {
-	return &Reader{
+func NewReader(r io.Reader, d decompress.Decompressor, sizes []uint32, finalBlockSize uint64, blockSize uint32) Reader {
+	return Reader{
 		r:              r,
 		d:              d,
 		sizes:          sizes,
@@ -54,7 +55,7 @@ func (r *Reader) advance() error {
 		return nil
 	}
 	r.dat = make([]byte, realSize)
-	err = binary.Read(r.r, binary.LittleEndian, &r.dat)
+	_, err = r.r.Read(r.dat)
 	if err != nil {
 		return err
 	}
@@ -66,6 +67,9 @@ func (r *Reader) advance() error {
 }
 
 func (r *Reader) Read(b []byte) (int, error) {
+	if r.closed {
+		return 0, fs.ErrClosed
+	}
 	curRead := 0
 	var toRead int
 	for curRead < len(b) {
@@ -83,6 +87,9 @@ func (r *Reader) Read(b []byte) (int, error) {
 }
 
 func (r *Reader) Close() error {
+	r.closed = true
+	r.r = nil
+	r.d = nil
 	if r.frag != nil {
 		if l, ok := r.frag.(*io.LimitedReader); ok {
 			if cl, ok := l.R.(io.Closer); ok {
@@ -90,6 +97,8 @@ func (r *Reader) Close() error {
 			}
 		}
 	}
+	r.frag = nil
+	r.sizes = nil
 	r.dat = nil
 	return nil
 }

low/directory.go

@@ -18,7 +18,7 @@ type Directory struct {
 	Entries []directory.Entry
 }
 
-func (r *Reader) directoryFromRef(ref uint64, name string) (Directory, error) {
+func (r Reader) directoryFromRef(ref uint64, name string) (Directory, error) {
 	i, err := r.InodeFromRef(ref)
 	if err != nil {
 		return Directory{}, err
@@ -44,7 +44,7 @@ func (r *Reader) directoryFromRef(ref uint64, name string) (Directory, error) {
 	if err != nil {
 		return Directory{}, err
 	}
-	entries, err := directory.ReadDirectory(dirRdr, size)
+	entries, err := directory.ReadDirectory(&dirRdr, size)
 	if err != nil {
 		return Directory{}, err
 	}
@@ -54,7 +54,7 @@ func (r *Reader) directoryFromRef(ref uint64, name string) (Directory, error) {
 	}, nil
 }
 
-func (d *Directory) Open(r *Reader, path string) (FileBase, error) {
+func (d Directory) Open(r Reader, path string) (FileBase, error) {
 	path = filepath.Clean(path)
 	if path == "." || path == "" {
 		return d.FileBase, nil

low/file_base.go

@@ -16,11 +16,11 @@ type FileBase struct {
 	Name  string
 }
 
-func (r *Reader) BaseFromInode(i inode.Inode, name string) FileBase {
+func (r Reader) BaseFromInode(i inode.Inode, name string) FileBase {
 	return FileBase{Inode: i, Name: name}
 }
 
-func (r *Reader) BaseFromEntry(e directory.Entry) (FileBase, error) {
+func (r Reader) BaseFromEntry(e directory.Entry) (FileBase, error) {
 	in, err := r.InodeFromEntry(e)
 	if err != nil {
 		return FileBase{}, err
@@ -28,7 +28,7 @@ func (r *Reader) BaseFromEntry(e directory.Entry) (FileBase, error) {
 	return FileBase{Inode: in, Name: e.Name}, nil
 }
 
-func (r *Reader) BaseFromRef(ref uint64, name string) (FileBase, error) {
+func (r Reader) BaseFromRef(ref uint64, name string) (FileBase, error) {
 	in, err := r.InodeFromRef(ref)
 	if err != nil {
 		return FileBase{}, err
@@ -36,19 +36,19 @@ func (r *Reader) BaseFromRef(ref uint64, name string) (FileBase, error) {
 	return FileBase{Inode: in, Name: name}, nil
 }
 
-func (b *FileBase) Uid(r *Reader) (uint32, error) {
+func (b FileBase) Uid(r *Reader) (uint32, error) {
 	return r.Id(b.Inode.UidInd)
 }
 
-func (b *FileBase) Gid(r *Reader) (uint32, error) {
+func (b FileBase) Gid(r *Reader) (uint32, error) {
 	return r.Id(b.Inode.GidInd)
 }
 
-func (b *FileBase) IsDir() bool {
+func (b FileBase) IsDir() bool {
 	return b.Inode.Type == inode.Dir || b.Inode.Type == inode.EDir
 }
 
-func (b *FileBase) ToDir(r *Reader) (Directory, error) {
+func (b FileBase) ToDir(r Reader) (Directory, error) {
 	var blockStart uint32
 	var size uint32
 	var offset uint16
@@ -70,23 +70,23 @@ func (b *FileBase) ToDir(r *Reader) (Directory, error) {
 	if err != nil {
 		return Directory{}, err
 	}
-	entries, err := directory.ReadDirectory(dirRdr, size)
+	entries, err := directory.ReadDirectory(&dirRdr, size)
 	if err != nil {
 		return Directory{}, err
 	}
 	return Directory{
-		FileBase: *b,
+		FileBase: b,
 		Entries:  entries,
 	}, nil
 }
 
-func (b *FileBase) IsRegular() bool {
+func (b FileBase) IsRegular() bool {
 	return b.Inode.Type == inode.Fil || b.Inode.Type == inode.EFil
 }
 
-func (b *FileBase) GetRegFileReaders(r *Reader) (*data.Reader, *data.FullReader, error) {
+func (b FileBase) GetRegFileReaders(r Reader) (data.Reader, data.FullReader, error) {
 	if !b.IsRegular() {
-		return nil, nil, errors.New("not a regular file")
+		return data.Reader{}, data.FullReader{}, errors.New("not a regular file")
 	}
 	var blockStart uint64
 	var fragIndex uint32
@@ -113,13 +113,13 @@ func (b *FileBase) GetRegFileReaders(r *Reader) (*data.Reader, *data.FullReader,
 		}
 		frag := data.NewReader(toreader.NewReader(r.r, int64(ent.Start)), r.d, []uint32{ent.Size}, uint64(r.Superblock.BlockSize), r.Superblock.BlockSize)
 		frag.Read(make([]byte, fragOffset))
-		return io.LimitReader(frag, int64(fragSize)), nil
+		return io.LimitReader(&frag, int64(fragSize)), nil
 	}
 	outRdr := data.NewReader(toreader.NewReader(r.r, int64(blockStart)), r.d, sizes, fragSize, r.Superblock.BlockSize)
 	if fragIndex != 0xffffffff {
 		f, err := frag()
 		if err != nil {
-			return nil, nil, err
+			return data.Reader{}, data.FullReader{}, err
 		}
 		outRdr.AddFrag(f)
 	}
@@ -130,9 +130,9 @@ func (b *FileBase) GetRegFileReaders(r *Reader) (*data.Reader, *data.FullReader,
 	return outRdr, outFull, nil
 }
 
-func (b *FileBase) GetFullReader(r *Reader) (*data.FullReader, error) {
+func (b FileBase) GetFullReader(r *Reader) (data.FullReader, error) {
 	if !b.IsRegular() {
-		return nil, errors.New("not a regular file")
+		return data.FullReader{}, errors.New("not a regular file")
 	}
 	var blockStart uint64
 	var fragIndex uint32
@@ -161,15 +161,15 @@ func (b *FileBase) GetFullReader(r *Reader) (*data.FullReader, error) {
 			}
 			frag := data.NewReader(toreader.NewReader(r.r, int64(ent.Start)), r.d, []uint32{ent.Size}, uint64(r.Superblock.BlockSize), r.Superblock.BlockSize)
 			frag.Read(make([]byte, fragOffset))
-			return io.LimitReader(frag, int64(fragSize)), nil
+			return io.LimitReader(&frag, int64(fragSize)), nil
 		})
 	}
 	return outFull, nil
 }
 
-func (b *FileBase) GetReader(r *Reader) (*data.Reader, error) {
+func (b FileBase) GetReader(r *Reader) (data.Reader, error) {
 	if !b.IsRegular() {
-		return nil, errors.New("not a regular file")
+		return data.Reader{}, errors.New("not a regular file")
 	}
 	var blockStart uint64
 	var fragIndex uint32
@@ -193,11 +193,11 @@ func (b *FileBase) GetReader(r *Reader) (*data.Reader, error) {
 	if fragIndex != 0xffffffff {
 		ent, err := r.fragEntry(fragIndex)
 		if err != nil {
-			return nil, err
+			return data.Reader{}, err
 		}
 		frag := data.NewReader(toreader.NewReader(r.r, int64(ent.Start)), r.d, []uint32{ent.Size}, uint64(r.Superblock.BlockSize), r.Superblock.BlockSize)
 		frag.Read(make([]byte, fragOffset))
-		outRdr.AddFrag(io.LimitReader(frag, int64(fragSize)))
+		outRdr.AddFrag(io.LimitReader(&frag, int64(fragSize)))
 	}
 	return outRdr, nil
 }

low/inode.go

@@ -7,7 +7,7 @@ import (
 	"github.com/CalebQ42/squashfs/low/inode"
 )
 
-func (r *Reader) InodeFromRef(ref uint64) (inode.Inode, error) {
+func (r Reader) InodeFromRef(ref uint64) (inode.Inode, error) {
 	offset, meta := (ref>>16)+r.Superblock.InodeTableStart, ref&0xFFFF
 	rdr := metadata.NewReader(toreader.NewReader(r.r, int64(offset)), r.d)
 	defer rdr.Close()
@@ -15,12 +15,12 @@ func (r *Reader) InodeFromRef(ref uint64) (inode.Inode, error) {
 	if err != nil {
 		return inode.Inode{}, err
 	}
-	return inode.Read(rdr, r.Superblock.BlockSize)
+	return inode.Read(&rdr, r.Superblock.BlockSize)
 }
 
-func (r *Reader) InodeFromEntry(e directory.Entry) (inode.Inode, error) {
+func (r Reader) InodeFromEntry(e directory.Entry) (inode.Inode, error) {
 	rdr := metadata.NewReader(toreader.NewReader(r.r, int64(r.Superblock.InodeTableStart)+int64(e.BlockStart)), r.d)
 	defer rdr.Close()
 	rdr.Read(make([]byte, e.Offset))
-	return inode.Read(rdr, r.Superblock.BlockSize)
+	return inode.Read(&rdr, r.Superblock.BlockSize)
 }

low/inode/dir.go

@@ -13,7 +13,7 @@ type Directory struct {
 	ParentNum  uint32
 }
 
-type eDirectoryInit struct {
+type EDirectory struct {
 	LinkCount  uint32
 	Size       uint32
 	BlockStart uint32
@@ -21,42 +21,55 @@ type eDirectoryInit struct {
 	IndCount   uint16
 	Offset     uint16
 	XattrInd   uint32
-}
-
-type EDirectory struct {
-	eDirectoryInit
-	Indexes []DirectoryIndex
-}
-
-type directoryIndexInit struct {
-	Ind      uint32
-	Start    uint32
-	NameSize uint32
+	Indexes    []DirectoryIndex
 }
 
 type DirectoryIndex struct {
-	directoryIndexInit
-	Name []byte
+	Ind      uint32
+	Start    uint32
+	NameSize uint32
+	Name     []byte
 }
 
 func ReadDir(r io.Reader) (d Directory, err error) {
-	err = binary.Read(r, binary.LittleEndian, &d)
+	dat := make([]byte, 16)
+	_, err = r.Read(dat)
+	if err != nil {
+		return
+	}
+	d.BlockStart = binary.LittleEndian.Uint32(dat)
+	d.LinkCount = binary.LittleEndian.Uint32(dat[4:])
+	d.Size = binary.LittleEndian.Uint16(dat[8:])
+	d.Offset = binary.LittleEndian.Uint16(dat[10:])
+	d.ParentNum = binary.LittleEndian.Uint32(dat[12:])
 	return
 }
 
 func ReadEDir(r io.Reader) (d EDirectory, err error) {
-	err = binary.Read(r, binary.LittleEndian, &d.eDirectoryInit)
+	dat := make([]byte, 24)
+	_, err = r.Read(dat)
 	if err != nil {
 		return
 	}
+	d.LinkCount = binary.LittleEndian.Uint32(dat)
+	d.Size = binary.LittleEndian.Uint32(dat[4:])
+	d.BlockStart = binary.LittleEndian.Uint32(dat[8:])
+	d.ParentNum = binary.LittleEndian.Uint32(dat[12:])
+	d.IndCount = binary.LittleEndian.Uint16(dat[16:])
+	d.Offset = binary.LittleEndian.Uint16(dat[18:])
+	d.XattrInd = binary.LittleEndian.Uint32(dat[20:])
 	d.Indexes = make([]DirectoryIndex, d.IndCount)
-	for i := range d.Indexes {
-		err = binary.Read(r, binary.LittleEndian, &d.Indexes[i].directoryIndexInit)
+	for i := range d.IndCount {
+		dat = make([]byte, 12)
+		_, err = r.Read(dat)
 		if err != nil {
 			return
 		}
+		d.Indexes[i].Ind = binary.LittleEndian.Uint32(dat)
+		d.Indexes[i].Start = binary.LittleEndian.Uint32(dat[4:])
+		d.Indexes[i].NameSize = binary.LittleEndian.Uint32(dat[8:])
 		d.Indexes[i].Name = make([]byte, d.Indexes[i].NameSize+1)
-		err = binary.Read(r, binary.LittleEndian, &d.Indexes[i].Name)
+		_, err = r.Read(d.Indexes[i].Name)
 		if err != nil {
 			return
 		}

low/inode/file.go

@@ -6,15 +6,11 @@ import (
 	"math"
 )
 
-type fileInit struct {
+type File struct {
 	BlockStart uint32
 	FragInd    uint32
 	FragOffset uint32
 	Size       uint32
-}
-
-type File struct {
-	fileInit
 	BlockSizes []uint32
 }
 
@@ -34,16 +30,28 @@ type EFile struct {
 }
 
 func ReadFile(r io.Reader, blockSize uint32) (f File, err error) {
-	err = binary.Read(r, binary.LittleEndian, &f.fileInit)
+	dat := make([]byte, 16)
+	_, err = r.Read(dat)
 	if err != nil {
 		return
 	}
+	f.BlockStart = binary.LittleEndian.Uint32(dat)
+	f.FragInd = binary.LittleEndian.Uint32(dat[4:])
+	f.FragOffset = binary.LittleEndian.Uint32(dat[8:])
+	f.Size = binary.LittleEndian.Uint32(dat[12:])
 	toRead := int(math.Floor(float64(f.Size) / float64(blockSize)))
 	if f.FragInd == 0xFFFFFFFF && f.Size%blockSize > 0 {
 		toRead++
 	}
+	dat = make([]byte, toRead*4)
+	_, err = r.Read(dat)
+	if err != nil {
+		return
+	}
 	f.BlockSizes = make([]uint32, toRead)
-	err = binary.Read(r, binary.LittleEndian, &f.BlockSizes)
+	for i := range toRead {
+		f.BlockSizes[i] = binary.LittleEndian.Uint32(dat[i*4:])
+	}
 	return
 }
 

low/reader.go

@@ -39,47 +39,46 @@ type Reader struct {
 	Superblock  superblock
 }
 
-func NewReader(r io.ReaderAt) (rdr *Reader, err error) {
-	rdr = new(Reader)
+func NewReader(r io.ReaderAt) (rdr Reader, err error) {
 	rdr.r = r
 	err = binary.Read(toreader.NewReader(r, 0), binary.LittleEndian, &rdr.Superblock)
 	if err != nil {
-		return nil, errors.Join(errors.New("failed to read superblock"), err)
+		return rdr, errors.Join(errors.New("failed to read superblock"), err)
 	}
 	if !rdr.Superblock.ValidMagic() {
-		return nil, ErrorMagic
+		return rdr, ErrorMagic
 	}
 	if !rdr.Superblock.ValidBlockLog() {
-		return nil, ErrorLog
+		return rdr, ErrorLog
 	}
 	if !rdr.Superblock.ValidVersion() {
-		return nil, ErrorVersion
+		return rdr, ErrorVersion
 	}
 	switch rdr.Superblock.CompType {
 	case ZlibCompression:
-		rdr.d = decompress.Zlib{}
+		rdr.d = decompress.NewZlib()
 	case LZMACompression:
 		rdr.d, err = decompress.NewLzma()
 		if err != nil {
-			return nil, err
+			return rdr, err
 		}
 	case LZOCompression:
 		rdr.d, err = decompress.NewLzo()
 		if err != nil {
-			return nil, err
+			return rdr, err
 		}
 	case XZCompression:
-		rdr.d = decompress.Xz{}
+		rdr.d = decompress.NewXz()
 	case LZ4Compression:
-		rdr.d = decompress.Lz4{}
+		rdr.d = decompress.NewLz4()
 	case ZSTDCompression:
-		rdr.d = decompress.Zstd{}
+		rdr.d = decompress.NewZstd()
 	default:
-		return nil, errors.New("invalid compression type. possible corrupted archive")
+		return rdr, errors.New("invalid compression type. possible corrupted archive")
 	}
 	rdr.Root, err = rdr.directoryFromRef(rdr.Superblock.RootInodeRef, "")
 	if err != nil {
-		return nil, errors.Join(errors.New("failed to read root directory"), err)
+		return rdr, errors.Join(errors.New("failed to read root directory"), err)
 	}
 	return
 }
@@ -105,7 +104,8 @@ func (r *Reader) Id(i uint16) (uint32, error) {
 	var idsToRead uint16
 	var idsTmp []uint32
 	var err error
-	var rdr *metadata.Reader
+	var rdr metadata.Reader
+	// We can *maybe* have a slight speed increase by manually decoding instead of using reflection via binary.Read
 	for i := blocksRead; i < int(blocksRead)+blocksToRead; i++ {
 		err = binary.Read(toreader.NewReader(r.r, int64(r.Superblock.IdTableStart)+int64(8*i)), binary.LittleEndian, &offset)
 		if err != nil {
@@ -114,7 +114,7 @@ func (r *Reader) Id(i uint16) (uint32, error) {
 		idsToRead = min(r.Superblock.IdCount-uint16(len(r.idTable)), 2048)
 		idsTmp = make([]uint32, idsToRead)
 		rdr = metadata.NewReader(toreader.NewReader(r.r, int64(offset)), r.d)
-		err = binary.Read(rdr, binary.LittleEndian, &idsTmp)
+		err = binary.Read(&rdr, binary.LittleEndian, &idsTmp)
 		rdr.Close()
 		if err != nil {
 			return 0, err
@@ -145,7 +145,8 @@ func (r *Reader) fragEntry(i uint32) (fragEntry, error) {
 	var fragsToRead uint32
 	var fragsTmp []fragEntry
 	var err error
-	var rdr *metadata.Reader
+	var rdr metadata.Reader
+	// We can *maybe* have a slight speed increase by manually decoding instead of using reflection via binary.Read
 	for i := blocksRead; i < int(blocksRead)+blocksToRead; i++ {
 		err = binary.Read(toreader.NewReader(r.r, int64(r.Superblock.FragTableStart)+int64(8*i)), binary.LittleEndian, &offset)
 		if err != nil {
@@ -154,7 +155,7 @@ func (r *Reader) fragEntry(i uint32) (fragEntry, error) {
 		fragsToRead = min(r.Superblock.FragCount-uint32(len(r.fragTable)), 512)
 		fragsTmp = make([]fragEntry, fragsToRead)
 		rdr = metadata.NewReader(toreader.NewReader(r.r, int64(offset)), r.d)
-		err = binary.Read(rdr, binary.LittleEndian, &fragsTmp)
+		err = binary.Read(&rdr, binary.LittleEndian, &fragsTmp)
 		rdr.Close()
 		if err != nil {
 			return fragEntry{}, err
@@ -188,7 +189,8 @@ func (r *Reader) inodeRef(i uint32) (uint64, error) {
 	var refsToRead uint32
 	var refsTmp []uint64
 	var err error
-	var rdr *metadata.Reader
+	var rdr metadata.Reader
+	// We can *maybe* have a slight speed increase by manually decoding instead of using reflection via binary.Read
 	for i := blocksRead; i < int(blocksRead)+blocksToRead; i++ {
 		err = binary.Read(toreader.NewReader(r.r, int64(r.Superblock.ExportTableStart)+int64(8*i)), binary.LittleEndian, &offset)
 		if err != nil {
@@ -197,7 +199,7 @@ func (r *Reader) inodeRef(i uint32) (uint64, error) {
 		refsToRead = min(r.Superblock.InodeCount-uint32(len(r.exportTable)), 1024)
 		refsTmp = make([]uint64, refsToRead)
 		rdr = metadata.NewReader(toreader.NewReader(r.r, int64(offset)), r.d)
-		err = binary.Read(rdr, binary.LittleEndian, &refsTmp)
+		err = binary.Read(&rdr, binary.LittleEndian, &refsTmp)
 		rdr.Close()
 		if err != nil {
 			return 0, err
@@ -207,7 +209,7 @@ func (r *Reader) inodeRef(i uint32) (uint64, error) {
 	return r.exportTable[i], nil
 }
 
-func (r *Reader) Inode(i uint32) (inode.Inode, error) {
+func (r Reader) Inode(i uint32) (inode.Inode, error) {
 	ref, err := r.inodeRef(i)
 	if err != nil {
 		return inode.Inode{}, err

low/reader_test.go

@@ -77,7 +77,7 @@ func TestReader(t *testing.T) {
 	path := filepath.Join(tmpDir, "extractTest")
 	os.RemoveAll(path)
 	os.MkdirAll(path, 0777)
-	err = extractToDir(rdr, &rdr.Root.FileBase, path)
+	err = extractToDir(rdr, rdr.Root.FileBase, path)
 	t.Fatal(err)
 }
 
@@ -101,11 +101,11 @@ func TestSingleFile(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = extractToDir(rdr, &b, path)
+	err = extractToDir(rdr, b, path)
 	t.Fatal(err)
 }
 
-func extractToDir(rdr *Reader, b *FileBase, folder string) error {
+func extractToDir(rdr Reader, b FileBase, folder string) error {
 	path := filepath.Join(folder, b.Name)
 	if b.IsDir() {
 		d, err := b.ToDir(rdr)
@@ -122,7 +122,7 @@ func extractToDir(rdr *Reader, b *FileBase, folder string) error {
 			if err != nil {
 				return err
 			}
-			err = extractToDir(rdr, &nestBast, path)
+			err = extractToDir(rdr, nestBast, path)
 			if err != nil {
 				return err
 			}

reader.go

@@ -9,26 +9,26 @@ import (
 )
 
 type Reader struct {
-	*FS
+	FS
 	Low squashfslow.Reader
 }
 
-func NewReader(r io.ReaderAt) (*Reader, error) {
+func NewReader(r io.ReaderAt) (Reader, error) {
 	rdr, err := squashfslow.NewReader(r)
 	if err != nil {
-		return nil, err
+		return Reader{}, err
 	}
-	out := &Reader{
-		Low: *rdr,
+	out := Reader{
+		Low: rdr,
 	}
-	out.FS = &FS{
-		d: rdr.Root,
-		r: out,
+	out.FS = FS{
+		LowDir: rdr.Root,
+		r:   &out,
 	}
 	return out, nil
 }
 
-func NewReaderAtOffset(r io.ReaderAt, offset int64) (*Reader, error) {
+func NewReaderAtOffset(r io.ReaderAt, offset int64) (Reader, error) {
 	return NewReader(toreader.NewOffsetReader(r, offset))
 }
 

squashfs_test.go

@@ -17,7 +17,7 @@ import (
 
 const (
 	squashfsURL  = "https://darkstorm.tech/files/LinuxPATest.sfs"
-	squashfsName = "LinuxPATest.sfs"
+	squashfsName = "tensorflow.sqfs"
 )
 
 func preTest(dir string) (fil *os.File, err error) {
@@ -68,6 +68,24 @@ func TestMisc(t *testing.T) {
 	// t.Fatal("UM")
 }
 
+func BenchmarkExtract(b *testing.B) {
+	tmpDir := "testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		b.Fatal(err)
+	}
+	libPath := filepath.Join(tmpDir, "ExtractLib")
+	os.RemoveAll(libPath)
+	rdr, err := NewReader(fil)
+	if err != nil {
+		b.Fatal(err)
+	}
+	err = rdr.ExtractWithOptions(libPath, FastOptions())
+	if err != nil {
+		b.Fatal(err)
+	}
+}
+
 func BenchmarkRace(b *testing.B) {
 	tmpDir := "testing"
 	fil, err := preTest(tmpDir)
@@ -79,19 +97,17 @@ func BenchmarkRace(b *testing.B) {
 	os.RemoveAll(libPath)
 	os.RemoveAll(unsquashPath)
 	var libTime, unsquashTime time.Duration
-	op := FastOptions()
-	op.IgnorePerm = true
 	start := time.Now()
 	rdr, err := NewReader(fil)
 	if err != nil {
 		b.Fatal(err)
 	}
-	err = rdr.ExtractWithOptions(libPath, op)
+	err = rdr.ExtractWithOptions(libPath, FastOptions())
 	if err != nil {
 		b.Fatal(err)
 	}
 	libTime = time.Since(start)
-	cmd := exec.Command("unsquashfs", "-d", unsquashPath, fil.Name())
+	cmd := exec.Command("unsquashfs", "-q", "-d", unsquashPath, fil.Name())
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 	start = time.Now()
@@ -167,7 +183,7 @@ func TestExtractQuick(t *testing.T) {
 	}
 }
 
-var filePath = "Start.exe"
+var filePath = "usr/sbin/add-shell"
 
 func TestSingleFile(t *testing.T) {
 	tmpDir := "testing"
@@ -175,7 +191,7 @@ func TestSingleFile(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	os.Remove(filepath.Join(tmpDir, filePath))
+	os.RemoveAll("testing/stuff")
 	rdr, err := NewReader(fil)
 	if err != nil {
 		t.Fatal(err)
@@ -186,7 +202,7 @@ func TestSingleFile(t *testing.T) {
 	}
 	op := DefaultOptions()
 	op.Verbose = true
-	err = f.(*File).ExtractWithOptions("testing", op)
+	err = f.(*File).ExtractWithOptions("testing/stuff", op)
 	if err != nil {
 		t.Fatal(err)
 	}