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

go-unsquashfs hardlinks & squashfslow access

.github/FUNDING.yml

@@ -0,0 +1,3 @@
+# These are supported funding model platforms
+
+github: CalebQ42

.gitignore

@@ -1 +1,2 @@
-testing
+testing
+/go-unsquashfs

README.md

@@ -1,14 +1,44 @@
-# squashfs (WIP)
+# squashfs
 
 [![PkgGoDev](https://pkg.go.dev/badge/github.com/CalebQ42/squashfs)](https://pkg.go.dev/github.com/CalebQ42/squashfs) [![Go Report Card](https://goreportcard.com/badge/github.com/CalebQ42/squashfs)](https://goreportcard.com/report/github.com/CalebQ42/squashfs)
 
-A PURE Go library to read and write squashfs.
+A PURE Go library to read squashfs. There is currently no plans to add archive creation support as it will almost always be better to just call `mksquashfs`. I could see some possible use cases, but probably won't spend time on it unless it's requested (open a discussion if you want this feature).
 
-Currently has support for reading squashfs files and extracting files and folders. Supports all compression types except LZO, but additional compression options are hit or miss.
+The library has two parts with this `github.com/CalebQ42/squashfs` being easy to use as it implements `io/fs` interfaces and doesn't expose unnecessary information. 95% this is the library you want. If you need lower level access to the information, use `github.com/CalebQ42/squashfs/low` where far more information is exposed.
 
-The only major thing missing from squashfs reading is Xattr parsing.
+Currently has support for reading squashfs files and extracting files and folders.
 
-Special thanks to https://dr-emann.github.io/squashfs/ for some VERY important information in an easy to understand format.
+Special thanks to <https://dr-emann.github.io/squashfs/> for some VERY important information in an easy to understand format.
 Thanks also to [distri's squashfs library](https://github.com/distr1/distri/tree/master/internal/squashfs) as I referenced it to figure some things out (and double check others).
 
-# [TODO](https://github.com/CalebQ42/squashfs/projects/1?fullscreen=true)
+## Build tags
+
+As of `v1.1.0` this library has two optional build tags: `no_gpl` and `no_obsolete`. `no_gpl` disables the ability to read archives with lzo compression due to the library's gpl license. `no_obsolete` removes "obsolete" compression types for a reduced compilation size; currently this only disable lzma compression since it's superseded by xz.
+
+## FUSE
+
+As of `v1.0`, FUSE capabilities has been moved to [a separate library](https://github.com/CalebQ42/squashfuse).
+
+## Limitations
+
+* No Xattr parsing.
+* Socket files are not extracted.
+  * From my research, it seems like a socket file would be useless if it could be created.
+* Fifo files are ignored on `darwin`
+
+## Issues
+
+* 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.
+  * Times seem to be largely dependent on file tree size and compression type.
+    * 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 ~2x longer.
+
+## Recommendations on Usage
+
+Due to the above performance consideration, this library should only be used to access files within the archive without extraction, or to mount it via Fuse.
+
+* Neither of these use cases are largely effected by the issue above.

cmd/go-unsquashfs/main.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"os/user"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/CalebQ42/squashfs"
+	squashfslow "github.com/CalebQ42/squashfs/low"
+)
+
+func userName(uid int, numeric bool) string {
+	us := strconv.Itoa(uid)
+	if numeric {
+		return us
+	}
+	if u, err := user.LookupId(us); err == nil {
+		return u.Username
+	}
+	return us
+}
+
+func groupName(gid int, numeric bool) string {
+	gs := strconv.Itoa(gid)
+	if numeric {
+		return gs
+	}
+	if g, err := user.LookupGroupId(gs); err == nil {
+		return g.Name
+	}
+	return gs
+}
+
+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))
+	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), size,
+		fi.ModTime().Format("2006-01-02 15:04"),
+		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")
+	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 (*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)
+	}
+	f, err := os.Open(flag.Arg(0))
+	if err != nil {
+		panic(err)
+	}
+	r, err := squashfs.NewReaderAtOffset(f, *offset)
+	if err != nil {
+		panic(err)
+	}
+	extractFil := r.File()
+	if *file != "" {
+		extractFil, err = r.OpenFile(*file)
+		if err != nil {
+			panic(err)
+		}
+	}
+	if *list || *long || *numeric {
+		printFile(&r, "", extractFil)
+		return
+	}
+	op := squashfs.DefaultOptions()
+	op.Verbose = *verbose
+	op.IgnorePerm = *ignore
+	n := time.Now()
+	err = extractFil.ExtractWithOptions(flag.Arg(1), op)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Println("Took:", time.Since(n))
+}

datareader.go

@@ -1,190 +0,0 @@
-package squashfs
-
-import (
-	"bytes"
-	"errors"
-	"io"
-
-	"github.com/CalebQ42/squashfs/internal/inode"
-)
-
-var (
-	//ErrInodeNotFile is given when giving an inode, but the function requires a file inode.
-	errInodeNotFile = errors.New("Given inode is NOT a file type")
-	//ErrInodeOnlyFragment is given when trying to make a DataReader from an inode, but the inode only had data in a fragment
-	errInodeOnlyFragment = errors.New("Given inode ONLY has fragment data")
-)
-
-//DataReader reads data from data blocks.
-type dataReader struct {
-	r             *Reader
-	offset        int64 //offset relative to the beginning of the squash file
-	blocks        []dataBlock
-	curBlock      int //Which block in sizes is currently cached
-	curData       []byte
-	curReadOffset int //offset relative to the currently cached data
-}
-
-//DataBlock holds info about a given data block from it's size
-type dataBlock struct {
-	begOffset        int64 //The offset relative to the beginning of the squash file. Makes it easier to seek to it.
-	size             uint32
-	compressed       bool
-	uncompressedSize uint32
-}
-
-//NewDataBlock creates a new squashfs.datablock from a given size.
-func newDataBlock(raw uint32) (dbs dataBlock) {
-	dbs.compressed = raw&(1<<24) != (1 << 24)
-	dbs.size = raw &^ (1 << 24)
-	if !dbs.compressed {
-		dbs.uncompressedSize = dbs.size
-	}
-	return
-}
-
-//NewDataReader creates a new data reader at the given offset, with the blocks defined by sizes
-func (r *Reader) newDataReader(offset int64, sizes []uint32) (*dataReader, error) {
-	var dr dataReader
-	dr.r = r
-	dr.offset = offset
-	for _, size := range sizes {
-		dr.blocks = append(dr.blocks, newDataBlock(size))
-	}
-	err := dr.readCurBlock()
-	if err != nil {
-		return nil, err
-	}
-	return &dr, nil
-}
-
-//NewDataReaderFromInode creates a new DataReader from a given inode. Inode must be of BasicFile or ExtendedFile types
-func (r *Reader) newDataReaderFromInode(i *inode.Inode) (*dataReader, error) {
-	var rdr dataReader
-	rdr.r = r
-	switch i.Type {
-	case inode.BasicFileType:
-		fil := i.Info.(inode.BasicFile)
-		if fil.Init.BlockStart == 0 {
-			return nil, errInodeOnlyFragment
-		}
-		rdr.offset = int64(fil.Init.BlockStart)
-		for _, sizes := range fil.BlockSizes {
-			rdr.blocks = append(rdr.blocks, newDataBlock(sizes))
-		}
-		if fil.Fragmented {
-			rdr.blocks = rdr.blocks[:len(rdr.blocks)-1]
-		}
-	case inode.ExtFileType:
-		fil := i.Info.(inode.ExtendedFile)
-		if fil.Init.BlockStart == 0 {
-			return nil, errInodeOnlyFragment
-		}
-		rdr.offset = int64(fil.Init.BlockStart)
-		for _, sizes := range fil.BlockSizes {
-			rdr.blocks = append(rdr.blocks, newDataBlock(sizes))
-		}
-		if fil.Fragmented {
-			rdr.blocks = rdr.blocks[:len(rdr.blocks)-1]
-		}
-	default:
-		return nil, errInodeNotFile
-	}
-	err := rdr.readCurBlock()
-	if err != nil {
-		return nil, err
-	}
-	return &rdr, nil
-}
-
-func (d *dataReader) readNextBlock() error {
-	d.curBlock++
-	if d.curBlock >= len(d.blocks) {
-		d.curBlock--
-		return io.EOF
-	}
-	err := d.readCurBlock()
-	if err != nil {
-		d.curBlock--
-		d.readCurBlock()
-		return err
-	}
-	return nil
-}
-
-func (d *dataReader) readCurBlock() error {
-	if d.curBlock >= len(d.blocks) {
-		return io.EOF
-	}
-	if d.blocks[d.curBlock].size == 0 {
-		d.curData = make([]byte, d.r.super.BlockSize)
-		d.blocks[d.curBlock].uncompressedSize = d.r.super.BlockSize
-		d.blocks[d.curBlock].begOffset = d.offset
-		return nil
-	}
-	sec := io.NewSectionReader(d.r.r, d.offset, int64(d.blocks[d.curBlock].size))
-	if d.blocks[d.curBlock].compressed {
-		btys, err := d.r.decompressor.Decompress(sec)
-		if err != nil {
-			return err
-		}
-		d.blocks[d.curBlock].uncompressedSize = uint32(len(btys))
-		d.curData = btys
-		d.blocks[d.curBlock].begOffset = d.offset
-		d.offset += int64(d.blocks[d.curBlock].size)
-		return nil
-	}
-	var buf bytes.Buffer
-	_, err := io.Copy(&buf, sec)
-	if err != nil {
-		return err
-	}
-	d.curData = buf.Bytes()
-	d.blocks[d.curBlock].begOffset = d.offset
-	d.offset += int64(d.blocks[d.curBlock].size)
-	return err
-}
-
-//Close frees up the curData from memory
-func (d *dataReader) Close() error {
-	d.curData = nil
-	return nil
-}
-
-func (d *dataReader) Read(p []byte) (int, error) {
-	if d.curData == nil {
-		err := d.readCurBlock()
-		if err != nil {
-			return 0, err
-		}
-	}
-	if d.curReadOffset+len(p) <= len(d.curData) {
-		for i := 0; i < len(p); i++ {
-			p[i] = d.curData[d.curReadOffset+i]
-		}
-		d.curReadOffset += len(p)
-		return len(p), nil
-	}
-	read := 0
-	for read < len(p) {
-		if d.curReadOffset == len(d.curData) {
-			err := d.readNextBlock()
-			if err != nil {
-				return read, err
-			}
-			d.curReadOffset = 0
-		}
-		for ; read < len(p); read++ {
-			d.curReadOffset++
-			if d.curReadOffset < len(d.curData) {
-				p[read] = d.curData[d.curReadOffset]
-			} else {
-				break
-			}
-		}
-	}
-	if read != len(p) {
-		return read, errors.New("Didn't read enough data")
-	}
-	return read, nil
-}

extraction_options.go

@@ -0,0 +1,49 @@
+package squashfs
+
+import (
+	"io"
+	"io/fs"
+	"runtime"
+
+	"github.com/CalebQ42/squashfs/internal/routinemanager"
+)
+
+type ExtractionOptions struct {
+	manager            *routinemanager.Manager
+	LogOutput          io.Writer   //Where the verbose log should write.
+	DereferenceSymlink bool        //Replace symlinks with the target file.
+	UnbreakSymlink     bool        //Try to make sure symlinks remain unbroken when extracted, without changing the symlink.
+	Verbose            bool        //Prints extra info to log on an error.
+	IgnorePerm         bool        //Ignore file's permissions and instead use Perm.
+	Perm               fs.FileMode //Permission to use when IgnorePerm. Defaults to 0777.
+	SimultaneousFiles  uint16      //Number of files to process in parallel. Default set based on runtime.NumCPU().
+	ExtractionRoutines uint16      //Number of goroutines to use for each file's extraction. Only applies to regular files. Default set based on runtime.NumCPU().
+}
+
+// The default extraction options.
+func DefaultOptions() *ExtractionOptions {
+	cores := uint16(runtime.NumCPU() / 2)
+	var files, routines uint16
+	if cores <= 4 {
+		files = 1
+		routines = cores
+	} else {
+		files = cores - 4
+		routines = 4
+	}
+	return &ExtractionOptions{
+		Perm:               0777,
+		SimultaneousFiles:  files,
+		ExtractionRoutines: routines,
+	}
+}
+
+// Less limited default options. Can run up 2x faster than DefaultOptions.
+// Tends to use all available CPU resources.
+func FastOptions() *ExtractionOptions {
+	return &ExtractionOptions{
+		Perm:               0777,
+		SimultaneousFiles:  uint16(runtime.NumCPU()),
+		ExtractionRoutines: uint16(runtime.NumCPU()),
+	}
+}

file.go

@@ -2,559 +2,441 @@ package squashfs
 
 import (
 	"errors"
-	"fmt"
 	"io"
+	"io/fs"
+	"log"
 	"os"
-	"path"
-	"strings"
-	"time"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
 
-	"github.com/CalebQ42/squashfs/internal/directory"
-	"github.com/CalebQ42/squashfs/internal/inode"
+	"github.com/CalebQ42/squashfs/internal/routinemanager"
+	squashfslow "github.com/CalebQ42/squashfs/low"
+	"github.com/CalebQ42/squashfs/low/data"
+	"github.com/CalebQ42/squashfs/low/inode"
 )
 
-var (
-	//ErrNotDirectory is returned when you're trying to do directory things with a non-directory
-	errNotDirectory = errors.New("File is not a directory")
-	//ErrNotFile is returned when you're trying to do file things with a directory
-	errNotFile = errors.New("File is not a file")
-	//ErrNotReading is returned when running functions that are only meant to be used when reading a squashfs
-	errNotReading = errors.New("Function only supported when reading a squashfs")
-	//ErrBrokenSymlink is returned when using ExtractWithOptions with the unbreakSymlink set to true, but the symlink's file cannot be extracted.
-	ErrBrokenSymlink = errors.New("Extracted symlink is probably broken")
-)
-
-//File is the main way to interact with files within squashfs, or when putting files into a squashfs.
-//File can be either a file or folder. When reading from a squashfs, it reads from the datablocks.
-//When writing, this holds the information on WHERE the file will be placed inside the archive.
-//
-//Implements os.FileInfo and io.ReadCloser
+// File represents a file inside a squashfs archive.
 type File struct {
-	Parent  *File        //The parent directory. Should ALWAYS be a folder. If it's the root directory, will be nil
-	Reader  io.Reader    //Underlying reader. When writing, will probably be an os.File. When reading this is kept nil UNTIL reading to save memory.
-	name    string       //The name of the file or folder. Root folder will not have a name ("")
-	path    string       //The path to the folder the File is located in.
-	r       *Reader      //The squashfs.Reader where this file is contained.
-	in      *inode.Inode //Underlyting inode when reading.
-	filType int          //The file's type, using inode types.
+	full     data.FullReader
+	rdr      data.Reader
+	rdrInit  bool
+	parent   FS
+	r        *Reader
+	Low      squashfslow.FileBase
+	dirsRead int
 }
 
-//get a File from a directory.entry
-func (r *Reader) newFileFromDirEntry(entry *directory.Entry) (fil *File, err error) {
-	fil = new(File)
-	fil.in, err = r.getInodeFromEntry(entry)
-	if err != nil {
-		return nil, err
-	}
-	fil.name = entry.Name
-	fil.r = r
-	fil.filType = fil.in.Type
-	return
-}
-
-//Name is the file's name
-func (f *File) Name() string {
-	return f.name
-}
-
-//Size is the complete size of the file. Zero if it's not a file.
-func (f *File) Size() int64 {
-	switch f.filType {
-	case inode.BasicFileType:
-		return int64(f.in.Info.(inode.BasicFile).Init.Size)
-	case inode.ExtFileType:
-		return int64(f.in.Info.(inode.ExtendedFile).Init.Size)
-	default:
-		return 0
+// Creates a new *File from the given *squashfs.Base
+func (r *Reader) FileFromBase(b squashfslow.FileBase, parent FS) File {
+	return File{
+		Low:    b,
+		parent: parent,
+		r:      r,
 	}
 }
 
-//ModTime is the time of last modification.
-func (f *File) ModTime() time.Time {
-	return time.Unix(int64(f.in.Header.ModifiedTime), 0)
-}
-
-//Sys returns the underlying reader, file.Reader. If the reader isn't initialized, it will initialize it.
-//If called on something other then a file, returns nil.
-func (f *File) Sys() interface{} {
-	if f.IsFile() {
-		if f.Reader == nil && f.r != nil {
-			var err error
-			f.Reader, err = f.r.newFileReader(f.in)
-			if err != nil {
-				return nil
-			}
-		}
-		return f.Reader
-	}
-	return nil
-}
-
-//GetChildren returns a *squashfs.File slice of every direct child of the directory. If the File is not a directory, will return ErrNotDirectory
-func (f *File) GetChildren() (children []*File, err error) {
-	children = make([]*File, 0)
-	if f.r == nil {
-		return nil, errNotReading
-	}
+func (f File) FS() (FS, error) {
 	if !f.IsDir() {
-		return nil, errNotDirectory
+		return FS{}, errors.New("not a directory")
 	}
-	dir, err := f.r.readDirFromInode(f.in)
+	d, err := f.Low.ToDir(f.r.Low)
 	if err != nil {
-		return
+		return FS{}, err
 	}
-	var fil *File
-	for _, entry := range dir.Entries {
-		fil, err = f.r.newFileFromDirEntry(&entry)
-		if err != nil {
-			return
-		}
-		fil.Parent = f
-		if f.name != "" {
-			fil.path = f.Path()
-		}
-		children = append(children, fil)
-	}
-	return
+	return FS{LowDir: d, parent: &f.parent, r: f.r}, nil
 }
 
-//GetChildrenRecursively returns ALL children. Goes down ALL folder paths.
-func (f *File) GetChildrenRecursively() (children []*File, err error) {
-	children = make([]*File, 0)
-	if f.r == nil {
-		return nil, errNotReading
-	}
-	if !f.IsDir() {
-		return nil, errNotDirectory
-	}
-	children, err = f.GetChildren()
-	if err != nil {
-		return
-	}
-	var childFolders []*File
-	for _, child := range children {
-		if child.IsDir() {
-			childFolders = append(childFolders, child)
-		}
-	}
-	foldChil := make(chan []*File)
-	errChan := make(chan error)
-	for _, folds := range childFolders {
-		go func(fil *File) {
-			childs, err := fil.GetChildrenRecursively()
-			errChan <- err
-			foldChil <- childs
-		}(folds)
-	}
-	for range childFolders {
-		err = <-errChan
-		if err != nil {
-			return
-		}
-		children = append(children, <-foldChil...)
-	}
-	return
-}
-
-//Path returns the path of the file within the archive.
-func (f *File) Path() string {
-	if f.name == "" {
-		return f.path
-	}
-	return f.path + "/" + f.name
-}
-
-//GetFileAtPath tries to return the File at the given path, relative to the file.
-//Returns nil if called on something other then a folder, OR if the path goes oustide the archive.
-//Allows wildcards supported by path.Match (namely * and ?).
-func (f *File) GetFileAtPath(dirPath string) *File {
-	if dirPath == "" {
-		return f
-	}
-	dirPath = strings.TrimSuffix(strings.TrimPrefix(dirPath, "/"), "/")
-	if dirPath != "" && !f.IsDir() {
-		return nil
-	}
-	for strings.HasSuffix(dirPath, "./") {
-		//since you can TECHNICALLY have an infinite amount of ./ and it would still be valid.
-		dirPath = strings.TrimPrefix(dirPath, "./")
-	}
-	split := strings.Split(dirPath, "/")
-	if split[0] == ".." && f.name == "" {
-		return nil
-	} else if split[0] == ".." {
-		if f.Parent != nil {
-			return f.Parent.GetFileAtPath(strings.Join(split[1:], "/"))
-		}
-		return nil
-	}
-	children, err := f.GetChildren()
-	if err != nil {
-		return nil
-	}
-	for _, child := range children {
-		eq, _ := path.Match(split[0], child.name)
-		if eq {
-			return child.GetFileAtPath(strings.Join(split[1:], "/"))
-		}
-	}
-	return nil
-}
-
-//IsDir returns if the file is a directory.
-func (f *File) IsDir() bool {
-	return f.filType == inode.BasicDirectoryType || f.filType == inode.ExtDirType
-}
-
-//IsSymlink returns if the file is a symlink.
-func (f *File) IsSymlink() bool {
-	return f.filType == inode.BasicSymlinkType || f.filType == inode.ExtSymlinkType
-}
-
-//IsFile returns if the file is a file.
-func (f *File) IsFile() bool {
-	return f.filType == inode.BasicFileType || f.filType == inode.ExtFileType
-}
-
-//SymlinkPath returns the path the symlink is pointing to. If the file ISN'T a symlink, will return an empty string.
-//If a path begins with "/" then the symlink is pointing to an absolute path (starting from root, and not a file inside the archive)
-func (f *File) SymlinkPath() string {
-	switch f.filType {
-	case inode.BasicSymlinkType:
-		return f.in.Info.(inode.BasicSymlink).Path
-	case inode.ExtSymlinkType:
-		return f.in.Info.(inode.ExtendedSymlink).Path
-	default:
-		return ""
-	}
-}
-
-//GetSymlinkFile tries to return the squashfs.File associated with the symlink. If the file isn't a symlink
-//or the symlink points to a location outside the archive, nil is returned.
-func (f *File) GetSymlinkFile() *File {
-	if !f.IsSymlink() {
-		return nil
-	}
-	if strings.HasSuffix(f.SymlinkPath(), "/") {
-		return nil
-	}
-	return f.Parent.GetFileAtPath(f.SymlinkPath())
-}
-
-//GetSymlinkFileRecursive tries to return the squasfs.File associated with the symlink. It will recursively
-//try to get the symlink's file. This will return either a non-symlink File, or nil.
-func (f *File) GetSymlinkFileRecursive() *File {
-	if !f.IsSymlink() {
-		return nil
-	}
-	if strings.HasSuffix(f.SymlinkPath(), "/") {
-		return nil
-	}
-	sym := f
-	for {
-		sym = sym.GetSymlinkFile()
-		if sym == nil {
-			return nil
-		}
-		if !sym.IsSymlink() {
-			return sym
-		}
-	}
-}
-
-//Mode returns the os.FileMode of the File. Sets mode bits for directories and symlinks.
-func (f *File) Mode() os.FileMode {
-	mode := os.FileMode(f.in.Header.Permissions)
-	switch {
-	case f.IsDir():
-		mode = mode | os.ModeDir
-	case f.IsSymlink():
-		mode = mode | os.ModeSymlink
-	}
-	return mode
-}
-
-//ExtractTo extracts the file to the given path. This is the same as ExtractWithOptions(path, false, false, os.ModePerm, false).
-//Will NOT try to keep symlinks valid, folders extracted will have the permissions set by the squashfs, but the folder to make path will have full permissions (777).
-//
-//Will try it's best to extract all files, and if any errors come up, they will be appended to the error slice that's returned.
-func (f *File) ExtractTo(path string) []error {
-	return f.ExtractWithOptions(path, false, false, os.ModePerm, false)
-}
-
-//ExtractSymlink is similar to ExtractTo, but when it extracts a symlink, it instead extracts the file associated with the symlink in it's place.
-//This is the same as ExtractWithOptions(path, true, false, os.ModePerm, false)
-func (f *File) ExtractSymlink(path string) []error {
-	return f.ExtractWithOptions(path, true, false, os.ModePerm, false)
-}
-
-//ExtractWithOptions will extract the file to the given path, while allowing customization on how it works. ExtractTo is the "default" options.
-//Will try it's best to extract all files, and if any errors come up, they will be appended to the error slice that's returned.
-//Should only return multiple errors if extracting a folder.
-//
-//If dereferenceSymlink is set, instead of extracting a symlink, it will extract the file the symlink is pointed to in it's place.
-//If both dereferenceSymlink and unbreakSymlink is set, dereferenceSymlink takes precendence.
-//
-//If unbreakSymlink is set, it will also try to extract the symlink's associated file. WARNING: the symlink's file may have to go up the directory to work.
-//If unbreakSymlink is set and the file cannot be extracted, a ErrBrokenSymlink will be appended to the returned error slice.
-//
-//folderPerm only applies to the folders created to get to path. Folders from the archive are given the correct permissions defined by the archive.
-func (f *File) ExtractWithOptions(path string, dereferenceSymlink, unbreakSymlink bool, folderPerm os.FileMode, verbose bool) (errs []error) {
-	errs = make([]error, 0)
-	err := os.MkdirAll(path, folderPerm)
-	if err != nil {
-		return []error{err}
-	}
-	switch {
-	case f.IsDir():
-		if f.name != "" {
-			//TODO: check if folder is present, and if so, try to set it's permission
-			err = os.Mkdir(path+"/"+f.name, os.ModePerm)
-			if err != nil {
-				if verbose {
-					fmt.Println("Error while making: ", path+"/"+f.name)
-					fmt.Println(err)
-				}
-				errs = append(errs, err)
-				return
-			}
-			fil, err := os.Open(path + "/" + f.name)
-			if err != nil {
-				if verbose {
-					fmt.Println("Error while opening:", path+"/"+f.name)
-					fmt.Println(err)
-				}
-				errs = append(errs, err)
-				return
-			}
-			fil.Chown(int(f.r.idTable[f.in.Header.UID]), int(f.r.idTable[f.in.Header.GID]))
-			//don't mention anything when it fails. Because it fails often. Probably has something to do about uid & gid 0
-			// if err != nil {
-			// 	if verbose {
-			// 		fmt.Println("Error while changing owner:", path+"/"+f.Name)
-			// 		fmt.Println(err)
-			// 	}
-			// 	errs = append(errs, err)
-			// }
-			err = fil.Chmod(f.Mode())
-			if err != nil {
-				if verbose {
-					fmt.Println("Error while changing owner:", path+"/"+f.name)
-					fmt.Println(err)
-				}
-				errs = append(errs, err)
-			}
-		}
-		children, err := f.GetChildren()
-		if err != nil {
-			if verbose {
-				fmt.Println("Error getting children for:", f.Path())
-				fmt.Println(err)
-			}
-			errs = append(errs, err)
-			return
-		}
-		finishChan := make(chan []error)
-		defer close(finishChan)
-		for _, child := range children {
-			go func(child *File) {
-				if f.name == "" {
-					finishChan <- child.ExtractWithOptions(path, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
-				} else {
-					finishChan <- child.ExtractWithOptions(path+"/"+f.name, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
-				}
-			}(child)
-		}
-		for range children {
-			errs = append(errs, (<-finishChan)...)
-		}
-		return
-	case f.IsFile():
-		fil, err := os.Create(path + "/" + f.name)
-		if os.IsExist(err) {
-			err = os.Remove(path + "/" + f.name)
-			if err != nil {
-				if verbose {
-					fmt.Println("Error while making:", path+"/"+f.name)
-					fmt.Println(err)
-				}
-				errs = append(errs, err)
-				return
-			}
-			fil, err = os.Create(path + "/" + f.name)
-			if err != nil {
-				if verbose {
-					fmt.Println("Error while making:", path+"/"+f.name)
-					fmt.Println(err)
-				}
-				errs = append(errs, err)
-				return
-			}
-		} else if err != nil {
-			if verbose {
-				fmt.Println("Error while making:", path+"/"+f.name)
-				fmt.Println(err)
-			}
-			errs = append(errs, err)
-			return
-		} //Since we will be reading from the file
-		_, err = io.Copy(fil, f)
-		if err != nil {
-			if verbose {
-				fmt.Println("Error while Copying data to:", path+"/"+f.name)
-				fmt.Println(err)
-			}
-			errs = append(errs, err)
-			return
-		}
-		f.Close()
-		fil.Chown(int(f.r.idTable[f.in.Header.UID]), int(f.r.idTable[f.in.Header.GID]))
-		//don't mention anything when it fails. Because it fails often. Probably has something to do about uid & gid 0
-		// if err != nil {
-		// 	if verbose {
-		// 		fmt.Println("Error while changing owner:", path+"/"+f.Name)
-		// 		fmt.Println(err)
-		// 	}
-		// 	errs = append(errs, err)
-		// 	return
-		// }
-		err = fil.Chmod(f.Mode())
-		if err != nil {
-			if verbose {
-				fmt.Println("Error while setting permissions for:", path+"/"+f.name)
-				fmt.Println(err)
-			}
-			errs = append(errs, err)
-		}
-		return
-	case f.IsSymlink():
-		symPath := f.SymlinkPath()
-		if dereferenceSymlink {
-			fil := f.GetSymlinkFile()
-			if fil == nil {
-				if verbose {
-					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.name)
-				}
-				return
-			}
-			fil.name = f.name
-			extracSymErrs := fil.ExtractWithOptions(path, dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
-			if len(extracSymErrs) > 0 {
-				if verbose {
-					fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.name)
-					fmt.Println(extracSymErrs)
-				}
-				errs = append(errs, extracSymErrs...)
-			}
-			return
-		} else if unbreakSymlink {
-			fil := f.GetSymlinkFile()
-			if fil != nil {
-				symPath = path + "/" + symPath
-				paths := strings.Split(symPath, "/")
-				extracSymErrs := fil.ExtractWithOptions(strings.Join(paths[:len(paths)-1], "/"), dereferenceSymlink, unbreakSymlink, folderPerm, verbose)
-				if len(extracSymErrs) > 0 {
-					if verbose {
-						fmt.Println("Error(s) while extracting the symlink's file:", path+"/"+f.name)
-						fmt.Println(extracSymErrs)
-					}
-					errs = append(errs, extracSymErrs...)
-				}
-			} else {
-				if verbose {
-					fmt.Println("Symlink path(", symPath, ") is outside the archive:"+path+"/"+f.name)
-				}
-				return
-			}
-		}
-		err = os.Symlink(f.SymlinkPath(), path+"/"+f.name)
-		if err != nil {
-			if verbose {
-				fmt.Println("Error while making symlink:", path+"/"+f.name)
-				fmt.Println(err)
-			}
-			errs = append(errs, err)
-		}
-	}
-	return
-}
-
-//Close frees up the memory held up by the underlying reader. Should NOT be called when writing.
-//When reading, Close is safe to use, but any subsequent Read calls resets to the beginning of the file.
+// 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.IsDir() {
-		return errNotFile
-	}
-	if f.Reader != nil {
-		if closer, is := f.Reader.(io.Closer); is {
-			closer.Close()
-		}
-		f.Reader = nil
-	}
+	f.rdr.Close()
+	f.full.Close()
 	return nil
 }
 
-//Read from the file. Doesn't do anything fancy, just pases it to the underlying io.Reader. If a directory, return io.EOF.
-func (f *File) Read(p []byte) (int, error) {
-	if f.IsDir() {
-		return 0, io.EOF
+// 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 {
+	if !f.IsSymlink() {
+		return nil
 	}
-	var err error
-	if f.Reader == nil && f.r != nil {
-		f.Reader, err = f.r.newFileReader(f.in)
+	if filepath.IsAbs(f.SymlinkPath()) {
+		return nil
+	}
+	fil, err := f.parent.Open(f.SymlinkPath())
+	if err != nil {
+		return nil
+	}
+	return fil
+}
+
+// Returns whether the file is a directory.
+func (f File) IsDir() bool {
+	return f.Low.IsDir()
+}
+
+// Returns whether the file is a regular file.
+func (f File) IsRegular() bool {
+	return f.Low.IsRegular()
+}
+
+// Returns whether the file is a symlink.
+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.Low.Inode.Mode()
+}
+
+// Read reads the data from the file. Only works if file is a normal file.
+func (f *File) Read(b []byte) (int, error) {
+	if !f.IsRegular() {
+		return 0, errors.New("file is not a regular file")
+	}
+	if !f.rdrInit {
+		err := f.initializeReaders()
 		if err != nil {
 			return 0, err
 		}
 	}
-	return f.Reader.Read(p)
+	return f.rdr.Read(b)
 }
 
-//ReadDirFromInode returns a fully populated Directory from a given Inode.
-//If the given inode is not a directory it returns an error.
-func (r *Reader) readDirFromInode(i *inode.Inode) (*directory.Directory, error) {
-	var offset uint32
-	var metaOffset uint16
-	var size uint32
-	switch i.Type {
-	case inode.BasicDirectoryType:
-		offset = i.Info.(inode.BasicDirectory).DirectoryIndex
-		metaOffset = i.Info.(inode.BasicDirectory).DirectoryOffset
-		size = uint32(i.Info.(inode.BasicDirectory).DirectorySize)
-	case inode.ExtDirType:
-		offset = i.Info.(inode.ExtendedDirectory).Init.DirectoryIndex
-		metaOffset = i.Info.(inode.ExtendedDirectory).Init.DirectoryOffset
-		size = i.Info.(inode.ExtendedDirectory).Init.DirectorySize
+// ReadDir returns n fs.DirEntry's that's contained in the File (if it's a directory).
+// If n <= 0 all fs.DirEntry's are returned.
+func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
+	if !f.IsDir() {
+		return nil, errors.New("file is not a directory")
+	}
+	d, err := f.Low.ToDir(f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	start, end := 0, len(d.Entries)
+	if n > 0 {
+		start, end = f.dirsRead, f.dirsRead+n
+		if end > len(d.Entries) {
+			end = len(d.Entries)
+			err = io.EOF
+		}
+	}
+	var out []fs.DirEntry
+	var fi FileInfo
+	for _, e := range d.Entries[start:end] {
+		fi, err = f.r.newFileInfo(e)
+		if err != nil {
+			f.dirsRead += len(out)
+			return out, err
+		}
+		out = append(out, fs.FileInfoToDirEntry(fi))
+	}
+	f.dirsRead += len(out)
+	return out, err
+}
+
+// Returns the file's fs.FileInfo
+func (f File) Stat() (fs.FileInfo, error) {
+	uid, err := f.Low.Uid(&f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	gid, err := f.Low.Gid(&f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	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.Low.Inode.Type {
+	case inode.Sym:
+		return string(f.Low.Inode.Data.(inode.Symlink).Target)
+	case inode.ESym:
+		return string(f.Low.Inode.Data.(inode.ESymlink).Target)
+	}
+	return ""
+}
+
+// Writes all data from the file to the given writer in a multi-threaded manner.
+// The underlying reader is separate
+func (f *File) WriteTo(w io.Writer) (int64, error) {
+	if !f.IsRegular() {
+		return 0, errors.New("file is not a regular file")
+	}
+	if !f.rdrInit {
+		err := f.initializeReaders()
+		if err != nil {
+			return 0, err
+		}
+	}
+	return f.full.WriteTo(w)
+}
+
+func (f *File) initializeReaders() error {
+	var err error
+	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) {
+	var dev uint32
+	switch f.Low.Inode.Type {
+	case inode.Char, inode.Block:
+		dev = f.Low.Inode.Data.(inode.Device).Dev
+	case inode.EChar, inode.EBlock:
+		dev = f.Low.Inode.Data.(inode.EDevice).Dev
+	}
+	return dev >> 8, dev & 0x000FF
+}
+
+func (f File) path() string {
+	if f.parent.LowDir.Name == "" {
+		return f.Low.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 {
+	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 {
+	if op.manager == nil {
+		op.manager = routinemanager.NewManager(op.SimultaneousFiles)
+		if op.LogOutput != nil {
+			log.SetOutput(op.LogOutput)
+		}
+		err := os.MkdirAll(path, 0777)
+		if err != nil {
+			if op.Verbose {
+				log.Println("Failed to create initial directory", path)
+			}
+			return err
+		}
+	}
+	switch f.Low.Inode.Type {
+	case inode.Dir, inode.EDir:
+		d, err := f.Low.ToDir(f.r.Low)
+		if err != nil {
+			if op.Verbose {
+				log.Println("Failed to create squashfs.Directory for", path)
+			}
+			return errors.Join(errors.New("failed to create squashfs.Directory: "+path), err)
+		}
+		errChan := make(chan error, len(d.Entries))
+		for i := range d.Entries {
+			b, err := f.r.Low.BaseFromEntry(d.Entries[i])
+			if err != nil {
+				if op.Verbose {
+					log.Println("Failed to get squashfs.Base from entry for", path)
+				}
+				return errors.Join(errors.New("failed to get base from entry: "+path), err)
+			}
+			go func(b squashfslow.FileBase, path string) {
+				i := op.manager.Lock()
+				if b.IsDir() {
+					extDir := filepath.Join(path, b.Name)
+					err = os.Mkdir(extDir, 0777)
+					op.manager.Unlock(i)
+					if err != nil {
+						if op.Verbose {
+							log.Println("Failed to create directory", path)
+						}
+						errChan <- errors.Join(errors.New("failed to create directory: "+path), err)
+						return
+					}
+					err = f.r.FileFromBase(b, f.r.FSFromDirectory(d, f.parent)).ExtractWithOptions(extDir, op)
+					if err != nil {
+						if op.Verbose {
+							log.Println("Failed to extract directory", path)
+						}
+						errChan <- errors.Join(errors.New("failed to extract directory: "+path), err)
+						return
+					}
+					errChan <- nil
+				} else {
+					fil := f.r.FileFromBase(b, f.r.FSFromDirectory(d, f.parent))
+					err = fil.ExtractWithOptions(path, op)
+					op.manager.Unlock(i)
+					fil.Close()
+					errChan <- err
+				}
+			}(b, path)
+		}
+		var errCache []error
+		for range d.Entries {
+			err := <-errChan
+			if err != nil {
+				errCache = append(errCache, err)
+			}
+		}
+		if len(errCache) > 0 {
+			return errors.Join(errors.New("failed to extract folder: "+path), errors.Join(errCache...))
+		}
+	case inode.Fil, inode.EFil:
+		path = filepath.Join(path, f.Low.Name)
+		outFil, err := os.Create(path)
+		if err != nil {
+			if op.Verbose {
+				log.Println("Failed to create file", path)
+			}
+			return errors.Join(errors.New("failed to create file: "+path), err)
+		}
+		defer outFil.Close()
+		full, err := f.Low.GetFullReader(&f.r.Low)
+		if err != nil {
+			if op.Verbose {
+				log.Println("Failed to create full reader for", path)
+			}
+			return errors.Join(errors.New("failed to create full reader: "+path), err)
+		}
+		full.SetGoroutineLimit(op.ExtractionRoutines)
+		_, err = full.WriteTo(outFil)
+		if err != nil {
+			if op.Verbose {
+				log.Println("Failed to write file", path)
+			}
+			return errors.Join(errors.New("failed to write file: "+path), err)
+		}
+	case inode.Sym, inode.ESym:
+		symPath := f.SymlinkPath()
+		if op.DereferenceSymlink {
+			filTmp := f.GetSymlinkFile()
+			if filTmp == nil {
+				if op.Verbose {
+					log.Println("Failed to get symlink's file:", f.path())
+				}
+				return errors.New("failed to get symlink's file")
+			}
+			fil := filTmp.(*File)
+			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.Low.Name))
+				}
+				return errors.Join(errors.New("failed to extract symlink's file: "+path), err)
+			}
+		} else {
+			if op.UnbreakSymlink {
+				filTmp := f.GetSymlinkFile()
+				if filTmp == nil {
+					if op.Verbose {
+						log.Println("Failed to get symlink's file:", f.path())
+					}
+					return errors.New("failed to get symlink's file")
+				}
+				extractLoc := filepath.Join(path, filepath.Dir(symPath))
+				fil := filTmp.(*File)
+				err := fil.ExtractWithOptions(extractLoc, op)
+				if err != nil {
+					if op.Verbose {
+						log.Println("Error while extracting", fil.path(), "to make sure symlink at", f.path(), "is unbroken")
+					}
+					return errors.Join(errors.New("failed to extract symlink's file: "+extractLoc), err)
+				}
+			}
+			path = filepath.Join(path, f.Low.Name)
+			err := os.Symlink(f.SymlinkPath(), path)
+			if err != nil {
+				if op.Verbose {
+					log.Println("Failed to create symlink:", path)
+				}
+				return errors.Join(errors.New("failed to create symlink: "+path), err)
+			}
+		}
+	case inode.Char, inode.EChar, inode.Block, inode.EBlock, inode.Fifo, inode.EFifo:
+		if runtime.GOOS == "windows" {
+			if op.Verbose {
+				log.Println(f.path(), "ignored. A device link and can't be created on Windows.")
+			}
+			return nil
+		}
+		_, err := exec.LookPath("mknod")
+		if err != nil {
+			if op.Verbose {
+				log.Println("mknot command not found, cannot create device link for", f.path())
+			}
+			return errors.Join(errors.New("mknot command not found"), err)
+		}
+		path = filepath.Join(path, f.Low.Name)
+		var typ string
+		switch f.Low.Inode.Type {
+		case inode.Char, inode.EChar:
+			typ = "c"
+		case inode.Block, inode.EBlock:
+			typ = "b"
+		default: //Fifo IPC
+			if runtime.GOOS == "darwin" {
+				if op.Verbose {
+					log.Println(f.path(), "ignored. A Fifo file and can't be created on Darwin.")
+				}
+				return nil
+			}
+			typ = "p"
+		}
+		cmd := exec.Command("mknod", path, typ)
+		if typ != "p" {
+			maj, min := f.deviceDevices()
+			cmd.Args = append(cmd.Args, strconv.Itoa(int(maj)), strconv.Itoa(int(min)))
+		}
+		if op.Verbose {
+			cmd.Stdout = op.LogOutput
+			cmd.Stderr = op.LogOutput
+		}
+		err = cmd.Run()
+		if err != nil {
+			if op.Verbose {
+				log.Println("Error while running mknod for", path)
+			}
+			return errors.Join(errors.New("error while running mknod for "+path), err)
+		}
+	case inode.Sock, inode.ESock:
+		if op.Verbose {
+			log.Println(f.path(), "ignored since it's a socket file.")
+		}
+		return nil
 	default:
-		return nil, errors.New("Not a directory inode")
+		return errors.New("Unsupported file type. Inode type: " + strconv.Itoa(int(f.Low.Inode.Type)))
 	}
-	br, err := r.newMetadataReader(int64(r.super.DirTableStart + uint64(offset)))
+	if op.Verbose {
+		log.Println(f.path(), "extracted to", path)
+	}
+	if op.IgnorePerm {
+		return nil
+	}
+	uid, err := f.Low.Uid(&f.r.Low)
 	if err != nil {
-		return nil, err
+		if op.Verbose {
+			log.Println("Failed to get uid for", path)
+			log.Println(err)
+		}
+		return nil
 	}
-	_, err = br.Seek(int64(metaOffset), io.SeekStart)
+	gid, err := f.Low.Gid(&f.r.Low)
 	if err != nil {
-		return nil, err
+		if op.Verbose {
+			log.Println("Failed to get gid for", path)
+			log.Println(err)
+		}
+		return nil
 	}
-	dir, err := directory.NewDirectory(br, size)
-	if err != nil {
-		return dir, err
-	}
-	return dir, nil
-}
-
-//GetInodeFromEntry returns the inode associated with a given directory.Entry
-func (r *Reader) getInodeFromEntry(en *directory.Entry) (*inode.Inode, error) {
-	br, err := r.newMetadataReader(int64(r.super.InodeTableStart + uint64(en.Header.InodeOffset)))
-	if err != nil {
-		return nil, err
-	}
-	_, err = br.Seek(int64(en.Init.Offset), io.SeekStart)
-	if err != nil {
-		return nil, err
-	}
-	i, err := inode.ProcessInode(br, r.super.BlockSize)
-	if err != nil {
-		return nil, err
-	}
-	return i, nil
+	os.Chmod(path, f.Mode())
+	os.Chown(path, int(uid), int(gid))
+	return nil
 }

file_info.go

@@ -0,0 +1,126 @@
+package squashfs
+
+import (
+	"io/fs"
+	"time"
+
+	"github.com/CalebQ42/squashfs/low/directory"
+	"github.com/CalebQ42/squashfs/low/inode"
+)
+
+type FileInfo struct {
+	name     string
+	uid      uint32
+	gid      uint32
+	size     int64
+	target   string
+	perm     uint32
+	modTime  uint32
+	fileType uint16
+}
+
+func (r Reader) newFileInfo(e directory.Entry) (FileInfo, error) {
+	b, err := r.Low.BaseFromEntry(e)
+	if err != nil {
+		return FileInfo{}, err
+	}
+	uid, err := b.Uid(&r.Low)
+	if err != nil {
+		return FileInfo{}, err
+	}
+	gid, err := b.Gid(&r.Low)
+	if err != nil {
+		return FileInfo{}, err
+	}
+	return newFileInfo(e.Name, uid, gid, &b.Inode), nil
+}
+
+func newFileInfo(name string, uid, gid uint32, i *inode.Inode) FileInfo {
+	var size int64
+	var target string
+	switch i.Type {
+	case inode.Fil:
+		size = int64(i.Data.(inode.File).Size)
+	case inode.EFil:
+		size = int64(i.Data.(inode.EFile).Size)
+	case inode.Sym:
+		target = string(i.Data.(inode.Symlink).Target)
+	case inode.ESym:
+		target = string(i.Data.(inode.ESymlink).Target)
+	}
+	return FileInfo{
+		name:     name,
+		uid:      uid,
+		gid:      gid,
+		size:     size,
+		target:   target,
+		perm:     uint32(i.Perm),
+		modTime:  i.ModTime,
+		fileType: i.Type,
+	}
+}
+
+func (f FileInfo) Name() string {
+	return f.name
+}
+
+func (f FileInfo) Uid() int {
+	return int(f.uid)
+}
+
+func (f FileInfo) Gid() int {
+	return int(f.gid)
+}
+
+func (f FileInfo) Size() int64 {
+	return f.size
+}
+
+func (f FileInfo) SymlinkPath() string {
+	return f.target
+}
+
+func (f FileInfo) Mode() fs.FileMode {
+	switch f.fileType {
+	case inode.Dir, inode.EDir:
+		return fs.FileMode(f.perm | uint32(fs.ModeDir))
+	case inode.Sym, inode.ESym:
+		return fs.FileMode(f.perm | uint32(fs.ModeSymlink))
+	case inode.Char, inode.EChar, inode.Block, inode.EBlock:
+		return fs.FileMode(f.perm | uint32(fs.ModeDevice))
+	case inode.Fifo, inode.EFifo:
+		return fs.FileMode(f.perm | uint32(fs.ModeNamedPipe))
+	case inode.Sock, inode.ESock:
+		return fs.FileMode(f.perm | uint32(fs.ModeSocket))
+	}
+	return fs.FileMode(f.perm)
+}
+
+func (f FileInfo) ModTime() time.Time {
+	return time.Unix(int64(f.modTime), 0)
+}
+
+func (f FileInfo) IsDir() bool {
+	return f.fileType == inode.Dir || f.fileType == inode.EDir
+}
+
+func (f FileInfo) IsSymlink() bool {
+	return f.fileType == inode.Sym || f.fileType == inode.ESym
+}
+
+func (f FileInfo) IsDevice() bool {
+	return f.fileType == inode.Block || f.fileType == inode.EBlock ||
+		f.fileType == inode.Char || f.fileType == inode.EChar
+}
+
+func (f FileInfo) IsFifo() bool {
+	return f.fileType == inode.Fifo || f.fileType == inode.EFifo
+}
+
+func (f FileInfo) IsSocket() bool {
+	return f.fileType == inode.Sock || f.fileType == inode.ESock
+}
+
+func (f FileInfo) Sys() any {
+	return nil
+}

filereader.go

@@ -1,94 +0,0 @@
-package squashfs
-
-import (
-	"bytes"
-	"errors"
-	"io"
-
-	"github.com/CalebQ42/squashfs/internal/inode"
-)
-
-//FileReader provides a io.Reader interface for files within a squashfs archive
-type fileReader struct {
-	r            *Reader
-	data         *dataReader
-	in           *inode.Inode
-	fragmentData []byte
-	fragged      bool
-	fragOnly     bool
-	read         int
-	FileSize     int //FileSize is the total size of the given file
-}
-
-var (
-	//ErrPathIsNotFile returns when trying to read from a file, but the given path is NOT a file.
-	errPathIsNotFile = errors.New("The given path is not a file")
-)
-
-//ReadFile provides a squashfs.FileReader for the file at the given location.
-func (r *Reader) newFileReader(in *inode.Inode) (*fileReader, error) {
-	var rdr fileReader
-	rdr.in = in
-	if in.Type != inode.BasicFileType && in.Type != inode.ExtFileType {
-		return nil, errPathIsNotFile
-	}
-	switch in.Type {
-	case inode.BasicFileType:
-		fil := in.Info.(inode.BasicFile)
-		rdr.fragged = fil.Fragmented
-		rdr.fragOnly = fil.Init.BlockStart == 0
-		rdr.FileSize = int(fil.Init.Size)
-	case inode.ExtFileType:
-		fil := in.Info.(inode.ExtendedFile)
-		rdr.fragged = fil.Fragmented
-		rdr.fragOnly = fil.Init.BlockStart == 0
-		rdr.FileSize = int(fil.Init.Size)
-	}
-	var err error
-	if rdr.fragged {
-		rdr.fragmentData, err = r.getFragmentDataFromInode(in)
-		if err != nil {
-			return nil, err
-		}
-	}
-	if !rdr.fragOnly {
-		rdr.data, err = r.newDataReaderFromInode(in)
-	}
-	return &rdr, nil
-}
-
-//Close runs Close on the data reader and frees the fragmentdata
-func (f *fileReader) Close() error {
-	if f.data != nil {
-		f.data.Close()
-	}
-	f.fragmentData = nil
-	return nil
-}
-
-func (f *fileReader) Read(p []byte) (int, error) {
-	if f.fragOnly {
-		n, err := bytes.NewBuffer(f.fragmentData[f.read:]).Read(p)
-		f.read += n
-		if err != nil {
-			return n, err
-		}
-		return n, nil
-	}
-	var read int
-	n, err := f.data.Read(p)
-	read += n
-	if f.fragged && err == io.EOF {
-		if f.fragmentData == nil {
-			f.fragmentData, err = f.r.getFragmentDataFromInode(f.in)
-		}
-		n, err = bytes.NewBuffer(f.fragmentData).Read(p[read:])
-		read += n
-		if err != nil {
-			return read, err
-		}
-	} else if err != nil {
-		return read, err
-	}
-	return read, nil
-}

fragment.go

@@ -1,80 +0,0 @@
-package squashfs
-
-import (
-	"encoding/binary"
-	"errors"
-	"io"
-
-	"github.com/CalebQ42/squashfs/internal/inode"
-)
-
-//FragmentEntry is an entry in the fragment table
-type fragmentEntry struct {
-	Start  uint64
-	Size   uint32
-	Unused uint32
-}
-
-//GetFragmentDataFromInode returns the fragment data for a given inode.
-//If the inode does not have a fragment, harmlessly returns an empty slice without an error.
-func (r *Reader) getFragmentDataFromInode(in *inode.Inode) ([]byte, error) {
-	var size uint32
-	var fragIndex uint32
-	var fragOffset uint32
-	if in.Type == inode.BasicFileType {
-		bf := in.Info.(inode.BasicFile)
-		if !bf.Fragmented {
-			return make([]byte, 0), nil
-		}
-		if bf.Init.BlockStart == 0 {
-			size = bf.Init.Size
-		} else {
-			size = bf.BlockSizes[len(bf.BlockSizes)-1]
-		}
-		fragIndex = bf.Init.FragmentIndex
-		fragOffset = bf.Init.FragmentOffset
-	} else if in.Type == inode.ExtFileType {
-		bf := in.Info.(inode.ExtendedFile)
-		if !bf.Fragmented {
-			return make([]byte, 0), nil
-		}
-		if bf.Init.BlockStart == 0 {
-			size = bf.Init.Size
-		} else {
-			size = bf.BlockSizes[len(bf.BlockSizes)-1]
-		}
-		fragIndex = bf.Init.FragmentIndex
-		fragOffset = bf.Init.FragmentOffset
-	} else {
-		return nil, errors.New("Inode type not supported")
-	}
-	//reading the fragment entry first
-	fragEntryRdr, err := r.newMetadataReader(int64(r.fragOffsets[int(fragIndex/512)]))
-	if err != nil {
-		return nil, err
-	}
-	_, err = fragEntryRdr.Seek(int64(16*fragIndex), io.SeekStart)
-	if err != nil {
-		return nil, err
-	}
-	var entry fragmentEntry
-	err = binary.Read(fragEntryRdr, binary.LittleEndian, &entry)
-	if err != nil {
-		return nil, err
-	}
-	//now reading the actual fragment
-	dr, err := r.newDataReader(int64(entry.Start), []uint32{entry.Size})
-	if err != nil {
-		return nil, err
-	}
-	_, err = dr.Read(make([]byte, fragOffset))
-	if err != nil {
-		return nil, err
-	}
-	tmp := make([]byte, size)
-	err = binary.Read(dr, binary.LittleEndian, &tmp)
-	if err != nil {
-		return nil, err
-	}
-	return tmp, nil
-}

fs.go

@@ -0,0 +1,279 @@
+package squashfs
+
+import (
+	"io"
+	"io/fs"
+	"path"
+	"path/filepath"
+	"slices"
+	"strings"
+
+	squashfslow "github.com/CalebQ42/squashfs/low"
+	"github.com/CalebQ42/squashfs/low/directory"
+)
+
+// FS is a fs.FS representation of a squashfs directory.
+// Implements fs.GlobFS, fs.ReadDirFS, fs.ReadFileFS, fs.StatFS, and fs.SubFS
+type FS struct {
+	r      *Reader
+	parent *FS
+	LowDir squashfslow.Directory
+}
+
+// Creates a new *FS from the given squashfs.directory
+func (r *Reader) FSFromDirectory(d squashfslow.Directory, parent FS) FS {
+	return FS{
+		LowDir: d,
+		r:      r,
+		parent: &parent,
+	}
+}
+
+// Glob returns the name of the files at the given pattern.
+// All paths are relative to the FS.
+// Uses filepath.Match to compare names.
+func (f *FS) Glob(pattern string) (out []string, err error) {
+	pattern = filepath.Clean(pattern)
+	if !fs.ValidPath(pattern) {
+		return nil, &fs.PathError{
+			Op:   "glob",
+			Path: pattern,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	split := strings.Split(pattern, "/")
+	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.LowDir.Entries[i].Name)
+				continue
+			}
+			sub, err := f.Sub(split[0])
+			if err != nil {
+				if pathErr, ok := err.(*fs.PathError); ok {
+					if pathErr.Err == fs.ErrNotExist {
+						continue
+					}
+					pathErr.Op = "glob"
+					pathErr.Path = pattern
+					return nil, pathErr
+				}
+				return nil, &fs.PathError{
+					Op:   "glob",
+					Path: pattern,
+					Err:  err,
+				}
+			}
+			subGlob, err := sub.(fs.GlobFS).Glob(strings.Join(split[1:], "/"))
+			if err != nil {
+				if pathErr, ok := err.(*fs.PathError); ok {
+					if pathErr.Err == fs.ErrNotExist {
+						continue
+					}
+					pathErr.Op = "glob"
+					pathErr.Path = pattern
+					return nil, pathErr
+				}
+				return nil, &fs.PathError{
+					Op:   "glob",
+					Path: pattern,
+					Err:  err,
+				}
+			}
+			for i := range subGlob {
+				subGlob[i] = f.LowDir.Name + "/" + subGlob[i]
+			}
+			out = append(out, subGlob...)
+		}
+	}
+	return
+}
+
+// Opens the file at name. Returns a *File as an fs.File.
+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{
+			Op:   "open",
+			Path: name,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	if name == "." || name == "" {
+		return f.File(), nil
+	}
+	split := strings.Split(name, "/")
+	if split[0] == ".." {
+		if f.parent == nil { // root directory
+			return nil, &fs.PathError{
+				Op:   "open",
+				Path: name,
+				Err:  fs.ErrNotExist,
+			}
+		} else {
+			return f.parent.OpenFile(strings.Join(split[1:], "/"))
+		}
+	}
+	i, found := slices.BinarySearchFunc(f.LowDir.Entries, split[0], func(e directory.Entry, name string) int {
+		return strings.Compare(e.Name, name)
+	})
+	if !found {
+		return nil, &fs.PathError{
+			Op:   "open",
+			Path: name,
+			Err:  fs.ErrNotExist,
+		}
+	}
+	b, err := f.r.Low.BaseFromEntry(f.LowDir.Entries[i])
+	if err != nil {
+		return nil, err
+	}
+	if len(split) == 1 {
+		return &File{
+			Low:    b,
+			r:      f.r,
+			parent: f,
+		}, nil
+	}
+	if !b.IsDir() {
+		return nil, &fs.PathError{
+			Op:   "open",
+			Path: name,
+			Err:  fs.ErrNotExist,
+		}
+	}
+	d, err := b.ToDir(f.r.Low)
+	if err != nil {
+		return nil, err
+	}
+	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) {
+	name = filepath.Clean(name)
+	if !fs.ValidPath(name) {
+		return nil, &fs.PathError{
+			Op:   "readdir",
+			Path: name,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	if name == "." || name == "" {
+		return f.File().ReadDir(-1)
+	}
+	fil, err := f.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return fil.(*File).ReadDir(-1)
+}
+
+// Returns the contents of the file at name.
+func (f FS) ReadFile(name string) (out []byte, err error) {
+	name = filepath.Clean(name)
+	if !fs.ValidPath(name) {
+		return nil, &fs.PathError{
+			Op:   "readfile",
+			Path: name,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	if name == "." || name == "" {
+		return nil, fs.ErrInvalid
+	}
+	fil, err := f.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	if !fil.(*File).IsRegular() {
+		return nil, fs.ErrInvalid
+	}
+	return io.ReadAll(fil)
+}
+
+// Returns the fs.FileInfo for the file at name.
+func (f FS) Stat(name string) (fs.FileInfo, error) {
+	name = filepath.Clean(name)
+	if !fs.ValidPath(name) {
+		return nil, &fs.PathError{
+			Op:   "stat",
+			Path: name,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	if name == "." || name == "" {
+		return f.File().Stat()
+	}
+	fil, err := f.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return fil.(*File).Stat()
+}
+
+// Returns the FS at dir
+func (f FS) Sub(dir string) (fs.FS, error) {
+	dir = filepath.Clean(dir)
+	if !fs.ValidPath(dir) {
+		return nil, &fs.PathError{
+			Op:   "dir",
+			Path: dir,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	if dir == "." || dir == "" {
+		return f, nil
+	}
+	fil, err := f.Open(dir)
+	if err != nil {
+		return nil, err
+	}
+	if !fil.(*File).IsDir() {
+		return nil, &fs.PathError{
+			Op:   "dir",
+			Path: dir,
+			Err:  fs.ErrInvalid,
+		}
+	}
+	return fil.(*File).FS()
+}
+
+// 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 {
+	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 {
+	return f.File().ExtractWithOptions(folder, op)
+}
+
+// Returns the FS as a *File
+func (f FS) File() *File {
+	if f.parent != nil {
+		return &File{
+			Low:    f.LowDir.FileBase,
+			parent: *f.parent,
+			r:      f.r,
+		}
+	}
+	return &File{
+		Low: f.LowDir.FileBase,
+		r:   f.r,
+	}
+}
+
+func (f FS) path() string {
+	if f.parent == nil {
+		return f.LowDir.Name
+	}
+	return filepath.Join(f.parent.path(), f.LowDir.Name)
+}

go.mod

@@ -1,18 +1,11 @@
 module github.com/CalebQ42/squashfs
 
-go 1.15
+go 1.24.0
 
 require (
-	github.com/CalebQ42/GoAppImage v0.4.0
-	github.com/adrg/xdg v0.2.3 // indirect
-	github.com/google/go-cmp v0.5.4 // indirect
-	github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 // indirect
-	github.com/klauspost/compress v1.11.3
-	github.com/kr/text v0.2.0 // indirect
-	github.com/pierrec/lz4/v4 v4.1.1
-	github.com/smartystreets/assertions v1.2.0 // indirect
-	github.com/ulikunitz/xz v0.5.8
-	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
-	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
-	gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 // indirect
+	github.com/klauspost/compress v1.18.0
+	github.com/pierrec/lz4/v4 v4.1.22
+	github.com/rasky/go-lzo v0.0.0-20200203143853-96a758eda86e
+	github.com/therootcompany/xz v1.0.1
+	github.com/ulikunitz/xz v0.5.12
 )

go.sum

@@ -1,73 +1,10 @@
-github.com/CalebQ42/GoAppImage v0.4.0 h1:aF+Y/vyo/RGhoyZEW1CMY6WyRWrZZO4ydsRFAtIGnaY=
-github.com/CalebQ42/GoAppImage v0.4.0/go.mod h1:qHudJKAn/dlkNWNnH4h1YKXp29EZ7Bppsn7sNP2HuvU=
-github.com/adrg/xdg v0.2.2 h1:A7ZHKRz5KGOLJX/bg7IPzStryhvCzAE1wX+KWawPiAo=
-github.com/adrg/xdg v0.2.2/go.mod h1:7I2hH/IT30IsupOpKZ5ue7/qNi3CoKzD6tL3HwpaRMQ=
-github.com/adrg/xdg v0.2.3 h1:GxXngdYxNDkoUvZXjNJGwqZxWXi43MKbOOlA/00qZi4=
-github.com/adrg/xdg v0.2.3/go.mod h1:7I2hH/IT30IsupOpKZ5ue7/qNi3CoKzD6tL3HwpaRMQ=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
-github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.4 h1:L8R9j+yAqZuZjsqh/z+F1NCffTKKLShY6zXTItVIZ8M=
-github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
-github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
-github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00 h1:l5lAOZEym3oK3SQ2HBHWsJUfbNBiTXJDeW2QDxw9AQ0=
-github.com/gopherjs/gopherjs v0.0.0-20200217142428-fce0ec30dd00/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
-github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
-github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
-github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8h3jc=
-github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
-github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
-github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
-github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
-github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
-github.com/pierrec/lz4/v4 v4.1.1 h1:cS6aGkNLJr4u+UwaA21yp+gbWN3WJWtKo1axmPDObMA=
-github.com/pierrec/lz4/v4 v4.1.1/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/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
-github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
-github.com/smartystreets/assertions v1.2.0 h1:42S6lae5dvLc7BrLu/0ugRtcFVjoJNMC/N3yZFZkDFs=
-github.com/smartystreets/assertions v1.2.0/go.mod h1:tcbTF8ujkAEcZ8TElKY+i30BzYlVhC/LOxJk7iOWnoo=
-github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
-github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
-github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/ulikunitz/xz v0.5.8 h1:ERv8V6GKqVi23rgu5cj9pVfVzJbOqAY2Ntl88O6c2nQ=
-github.com/ulikunitz/xz v0.5.8/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
-go.lsp.dev/uri v0.3.0 h1:KcZJmh6nFIBeJzTugn5JTU6OOyG0lDOo3R9KwTxTYbo=
-go.lsp.dev/uri v0.3.0/go.mod h1:P5sbO1IQR+qySTWOCnhnK7phBx+W3zbLqSMDJNTw88I=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a h1:1BGLXjeY4akVXGgbC9HugT3Jv3hCI0z56oJR5vAMgBU=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20190328211700-ab21143f2384 h1:TFlARGu6Czu1z7q93HTxcP1P+/ZFC/IKythI5RzrnRg=
-golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
-golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b h1:QRR6H1YWRnHb4Y/HeNFCTJLFVxaq6wH4YuVdsUOr75U=
-gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
-gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=
-gopkg.in/ini.v1 v1.62.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776 h1:tQIYjPdBoyREyB9XMu+nnTclpTYkz2zFM+lzLJFO4gQ=
-gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+github.com/klauspost/compress v1.18.0 h1:c/Cqfb0r+Yi+JtIEq73FWXVkRonBlf0CRNYc8Zttxdo=
+github.com/klauspost/compress v1.18.0/go.mod h1:2Pp+KzxcywXVXMr50+X0Q/Lsb43OQHYWRCY2AiWywWQ=
+github.com/pierrec/lz4/v4 v4.1.22 h1:cKFw6uJDK+/gfw5BcDL0JL5aBsAFdsIT18eRtLj7VIU=
+github.com/pierrec/lz4/v4 v4.1.22/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
+github.com/rasky/go-lzo v0.0.0-20200203143853-96a758eda86e h1:dCWirM5F3wMY+cmRda/B1BiPsFtmzXqV9b0hLWtVBMs=
+github.com/rasky/go-lzo v0.0.0-20200203143853-96a758eda86e/go.mod h1:9leZcVcItj6m9/CfHY5Em/iBrCz7js8LcRQGTKEEv2M=
+github.com/therootcompany/xz v1.0.1 h1:CmOtsn1CbtmyYiusbfmhmkpAAETj0wBIH6kCYaX+xzw=
+github.com/therootcompany/xz v1.0.1/go.mod h1:3K3UH1yCKgBneZYhuQUvJ9HPD19UEXEI0BWbMn8qNMY=
+github.com/ulikunitz/xz v0.5.12 h1:37Nm15o69RwBkXM0J6A5OlE67RZTfzUxTj8fB3dfcsc=
+github.com/ulikunitz/xz v0.5.12/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=

internal/compression/gzip.go

@@ -1,66 +0,0 @@
-package compression
-
-import (
-	"bytes"
-	"compress/zlib"
-	"encoding/binary"
-	"io"
-)
-
-type gzipInit struct {
-	CompressionLevel int32
-	WindowSize       int16
-	Strategies       int16
-}
-
-//Gzip is a decompressor for gzip type compression. Uses zlib for compression and decompression
-type Gzip struct {
-	CompressionLevel int32
-	HasCustomWindow  bool
-	HasStrategies    bool
-}
-
-//NewGzipCompressorWithOptions creates a new gzip compressor/decompressor with options read from the given reader.
-func NewGzipCompressorWithOptions(r io.Reader) (*Gzip, error) {
-	var gzip Gzip
-	var init gzipInit
-	err := binary.Read(r, binary.LittleEndian, &init)
-	if err != nil {
-		return nil, err
-	}
-	gzip.CompressionLevel = init.CompressionLevel
-	//TODO: proper support for window size and strategies
-	gzip.HasCustomWindow = init.WindowSize != 15
-	gzip.HasStrategies = init.Strategies != 0 && init.Strategies != 1
-	return &gzip, nil
-}
-
-//Decompress reads the entirety of the given reader and returns it uncompressed as a byte slice.
-func (g *Gzip) Decompress(r io.Reader) ([]byte, error) {
-	rdr, err := zlib.NewReader(r)
-	if err != nil {
-		return nil, err
-	}
-	var data bytes.Buffer
-	_, err = io.Copy(&data, rdr)
-	if err != nil {
-		return nil, err
-	}
-	return data.Bytes(), nil
-}
-
-//Compress compresses the given data (as a byte array) and returns the compressed data.
-func (g *Gzip) Compress(data []byte) ([]byte, error) {
-	var buf bytes.Buffer
-	wrt := zlib.NewWriter(&buf)
-	defer wrt.Close()
-	_, err := wrt.Write(data)
-	if err != nil {
-		return nil, err
-	}
-	err = wrt.Flush()
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}

internal/compression/lz4.go

@@ -1,37 +0,0 @@
-package compression
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-
-	"github.com/pierrec/lz4/v4"
-)
-
-//Lz4 is a Lz4 Compressor/Decompressor
-type Lz4 struct {
-	HC bool
-}
-
-//NewLz4CompressorWithOptions creates a new lz4 compressor/decompressor with options read from the given reader.
-func NewLz4CompressorWithOptions(r io.Reader) (*Lz4, error) {
-	var lz4 Lz4
-	var init struct {
-		Version int32
-		Flags   int32
-	}
-	err := binary.Read(r, binary.LittleEndian, &init)
-	if err != nil {
-		return nil, err
-	}
-	lz4.HC = init.Flags == 1
-	return &lz4, nil
-}
-
-//Decompress decompresses all data from r and returns the uncompressed bytes
-func (l *Lz4) Decompress(r io.Reader) ([]byte, error) {
-	rdr := lz4.NewReader(r)
-	var buf bytes.Buffer
-	_, err := io.Copy(&buf, rdr)
-	return buf.Bytes(), err
-}

internal/compression/lzma.go

@@ -1,25 +0,0 @@
-package compression
-
-import (
-	"bytes"
-	"io"
-
-	"github.com/ulikunitz/xz/lzma"
-)
-
-//Lzma is a lzma decompressor
-type Lzma struct{}
-
-//Decompress decompresses all the data in the given reader and returns the uncompressed bytes.
-func (l *Lzma) Decompress(rdr io.Reader) ([]byte, error) {
-	r, err := lzma.NewReader(rdr)
-	if err != nil {
-		return nil, err
-	}
-	var buf bytes.Buffer
-	_, err = io.Copy(&buf, r)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}

internal/compression/types.go

@@ -1,13 +0,0 @@
-package compression
-
-import "io"
-
-//Compressor is a squashfs decompressor interface. Allows for easy compression.
-type Compressor interface {
-	Compress([]byte) ([]byte, error)
-}
-
-//Decompressor is a squashfs decompressor interface. Allows for easy decompression no matter the type of compression.
-type Decompressor interface {
-	Decompress(io.Reader) ([]byte, error)
-}

internal/compression/xz.go

@@ -1,55 +0,0 @@
-package compression
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-
-	"github.com/ulikunitz/xz"
-)
-
-type xzInit struct {
-	DictionarySize int32
-	Filters        int32
-}
-
-//Xz is a Xz decompressor.
-type Xz struct {
-	DictionarySize int32
-	HasFilters     bool
-}
-
-//NewXzCompressorWithOptions creates a new Xz compressor/decompressor that reads the compressor options from the given reader.
-func NewXzCompressorWithOptions(rdr io.Reader) (*Xz, error) {
-	var x Xz
-	var init xzInit
-	err := binary.Read(rdr, binary.LittleEndian, &init)
-	if err != nil {
-		return nil, err
-	}
-	x.DictionarySize = init.DictionarySize
-	//TODO: When I can do filters, parse the filters
-	if init.Filters != 0 {
-		x.HasFilters = true
-	}
-	return &x, nil
-}
-
-//Decompress decompresses all the data from the rdr and returns the uncompressed bytes.
-func (x *Xz) Decompress(rdr io.Reader) ([]byte, error) {
-	r, err := xz.NewReader(rdr)
-	if err != nil {
-		return nil, err
-	}
-	r.DictCap = int(x.DictionarySize)
-	err = r.Verify()
-	if err != nil {
-		return nil, err
-	}
-	var buf bytes.Buffer
-	_, err = io.Copy(&buf, r)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}

internal/compression/zstd.go

@@ -1,36 +0,0 @@
-package compression
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-
-	"github.com/klauspost/compress/zstd"
-)
-
-//Zstd is a zstd compressor/decompressor
-type Zstd struct {
-	CompressionLevel int32
-}
-
-//NewZstdCompressorWithOptions creates a new Zstd with options read from the given reader
-func NewZstdCompressorWithOptions(r io.Reader) (*Zstd, error) {
-	var zstd Zstd
-	err := binary.Read(r, binary.LittleEndian, &zstd)
-	if err != nil {
-		return nil, err
-	}
-	return &zstd, nil
-}
-
-//Decompress decompresses all data from the reader and returns the uncompressed data
-func (z *Zstd) Decompress(r io.Reader) ([]byte, error) {
-	rdr, err := zstd.NewReader(r)
-	if err != nil {
-		return nil, err
-	}
-	defer rdr.Close()
-	var buf bytes.Buffer
-	_, err = io.Copy(&buf, rdr)
-	return buf.Bytes(), err
-}

internal/decompress/decompress.go

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

internal/decompress/lz4.go

@@ -0,0 +1,30 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+	"sync"
+
+	"github.com/pierrec/lz4/v4"
+)
+
+type Lz4 struct {
+	pool sync.Pool
+}
+
+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/lzma.go

@@ -0,0 +1,24 @@
+//go:build !no_obsolete
+
+package decompress
+
+import (
+	"bytes"
+	"io"
+
+	"github.com/ulikunitz/xz/lzma"
+)
+
+type Lzma struct{}
+
+func NewLzma() (Lzma, error) {
+	return Lzma{}, nil
+}
+
+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/lzma_disabled.go

@@ -0,0 +1,17 @@
+//go:build no_obsolete
+
+package decompress
+
+import (
+	"errors"
+)
+
+type Lzma struct{}
+
+func NewLzma() (Lzma, error) {
+	return Lzma{}, errors.New("lzma compression is disable in this build with no_obsolete")
+}
+
+func (l Lzma) Decompress(data []byte) ([]byte, error) {
+	return nil, errors.New("lzma compression is disable in this build with no_obsolete")
+}

internal/decompress/lzo.go

@@ -0,0 +1,19 @@
+//go:build !no_gpl
+
+package decompress
+
+import (
+	"bytes"
+
+	"github.com/rasky/go-lzo"
+)
+
+type Lzo struct{}
+
+func NewLzo() (Lzo, error) {
+	return Lzo{}, nil
+}
+
+func (l Lzo) Decompress(data []byte) ([]byte, error) {
+	return lzo.Decompress1X(bytes.NewReader(data), len(data), 0)
+}

internal/decompress/lzo_disabled.go

@@ -0,0 +1,15 @@
+//go:build no_gpl
+
+package decompress
+
+import "errors"
+
+type Lzo struct{}
+
+func NewLzo() (Lzo, error) {
+	return Lzo{}, errors.New("lzo compression is disable in this build with no_gpl")
+}
+
+func (l Lzo) Decompress(data []byte) ([]byte, error) {
+	return nil, errors.New("lzo compression is disable in this build with no_gpl")
+}

internal/decompress/xz.go

@@ -0,0 +1,34 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+	"sync"
+
+	"github.com/therootcompany/xz"
+)
+
+type Xz struct {
+	pool sync.Pool
+}
+
+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
+	}
+	return io.ReadAll(rdr)
+}

internal/decompress/zlib.go

@@ -0,0 +1,32 @@
+package decompress
+
+import (
+	"bytes"
+	"io"
+	"sync"
+
+	"github.com/klauspost/compress/zlib"
+)
+
+type Zlib struct {
+	pool sync.Pool
+}
+
+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
+	}
+	return io.ReadAll(rdr.(io.ReadCloser))
+}

internal/decompress/zstd.go

@@ -0,0 +1,20 @@
+package decompress
+
+import (
+	"github.com/klauspost/compress/zstd"
+)
+
+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) {
+	return z.rdr.DecodeAll(data, nil)
+}

internal/directory/directory.go

@@ -1,94 +0,0 @@
-package directory
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-)
-
-//Header is the header for a directory in the directory table
-type Header struct {
-	Count       uint32
-	InodeOffset uint32
-	InodeNumber uint32
-}
-
-//EntryInit is the values that can be easily decoded
-type EntryInit struct {
-	Offset      uint16
-	InodeOffset int16
-	Type        uint16
-	NameSize    uint16
-}
-
-//Entry is an entry in a directory.
-type Entry struct {
-	Init   EntryInit
-	Name   string
-	Header *Header
-}
-
-//NewEntry creates a new directory entry
-func NewEntry(rdr io.Reader) (Entry, error) {
-	var entry Entry
-	err := binary.Read(rdr, binary.LittleEndian, &entry.Init)
-	if err != nil {
-		return Entry{}, err
-	}
-	tmp := make([]byte, entry.Init.NameSize+1)
-	err = binary.Read(rdr, binary.LittleEndian, &tmp)
-	if err != nil {
-		return Entry{}, err
-	}
-	entry.Name = string(tmp)
-	return entry, err
-}
-
-//Directory is an entry in the directory table of a squashfs.
-//Will only have multiple headers if there are more then 256 entries
-type Directory struct {
-	Headers []Header
-	Entries []Entry
-}
-
-//NewDirectory reads the directory from rdr
-func NewDirectory(base io.Reader, size uint32) (*Directory, error) {
-	var dir Directory
-	var err error
-	tmp := make([]byte, size)
-	base.Read(tmp)
-	rdr := bytes.NewBuffer(tmp)
-	for {
-		var hdr Header
-		err = binary.Read(rdr, binary.LittleEndian, &hdr)
-		if err == io.ErrUnexpectedEOF {
-			break
-		} else if err != nil {
-			return nil, err
-		}
-		hdr.Count++
-		headers := hdr.Count / 256
-		if hdr.Count%256 > 0 {
-			headers++
-		}
-		dir.Headers = append(dir.Headers, hdr)
-		for i := uint32(0); i < hdr.Count; i++ {
-			if i != 0 && i%256 == 0 {
-				var newHdr Header
-				err = binary.Read(rdr, binary.LittleEndian, &newHdr)
-				if err != nil {
-					return nil, err
-				}
-				dir.Headers = append(dir.Headers, newHdr)
-			}
-			var ent Entry
-			ent, err = NewEntry(rdr)
-			if err != nil {
-				return nil, err
-			}
-			ent.Header = &dir.Headers[len(dir.Headers)-1]
-			dir.Entries = append(dir.Entries, ent)
-		}
-	}
-	return &dir, nil
-}

internal/inode/inodetypes.go

@@ -1,255 +0,0 @@
-package inode
-
-import (
-	"encoding/binary"
-	"io"
-)
-
-const (
-	BasicDirectoryType = iota + 1
-	BasicFileType
-	BasicSymlinkType
-	BasicBlockDeviceType
-	BasicCharDeviceType
-	BasicFifoType
-	BasicSocketType
-	ExtDirType
-	ExtFileType
-	ExtSymlinkType
-	ExtBlockDeviceType
-	ExtCharDeviceType
-	ExtFifoType
-	ExtSocketType
-)
-
-//Header is the common header for all inodes
-type Header struct {
-	InodeType    uint16
-	Permissions  uint16
-	UID          uint16
-	GID          uint16
-	ModifiedTime uint32
-	Number       uint32
-}
-
-//BasicDirectory is self explainatory
-type BasicDirectory struct {
-	DirectoryIndex    uint32
-	HardLinks         uint32
-	DirectorySize     uint16
-	DirectoryOffset   uint16
-	ParentInodeNumber uint32
-}
-
-//ExtendedDirectoryInit is the information that can be directoy decoded
-type ExtendedDirectoryInit struct {
-	HardLinks         uint32
-	DirectorySize     uint32
-	DirectoryIndex    uint32
-	ParentInodeNumber uint32
-	IndexCount        uint16 //one less then directory indexes following structure
-	DirectoryOffset   uint16
-	XattrIndex        uint32
-}
-
-//ExtendedDirectory is a directory with extra info
-type ExtendedDirectory struct {
-	Init    ExtendedDirectoryInit
-	Indexes []DirectoryIndex
-}
-
-//NewExtendedDirectory creates a new ExtendedDirectory
-func NewExtendedDirectory(rdr io.Reader) (ExtendedDirectory, error) {
-	var inode ExtendedDirectory
-	err := binary.Read(rdr, binary.LittleEndian, &inode.Init)
-	if err != nil {
-		return inode, err
-	}
-	for i := uint16(0); i < inode.Init.IndexCount; i++ {
-		tmp, err := NewDirectoryIndex(rdr)
-		if err != nil {
-			return inode, err
-		}
-		inode.Indexes = append(inode.Indexes, tmp)
-	}
-	return inode, err
-}
-
-//DirectoryIndexInit holds the values that can be easily decoded
-type DirectoryIndexInit struct {
-	Offset         uint32
-	DirTableOffset uint32
-	NameSize       uint32
-}
-
-//DirectoryIndex is a quick lookup provided by an ExtendedDirectory
-type DirectoryIndex struct {
-	Init DirectoryIndexInit
-	Name string
-}
-
-//NewDirectoryIndex return a new DirectoryIndex
-func NewDirectoryIndex(rdr io.Reader) (DirectoryIndex, error) {
-	var index DirectoryIndex
-	err := binary.Read(rdr, binary.LittleEndian, &index.Init)
-	if err != nil {
-		return index, err
-	}
-	tmp := make([]byte, index.Init.NameSize+1, index.Init.NameSize+1)
-	err = binary.Read(rdr, binary.LittleEndian, &tmp)
-	if err != nil {
-		return index, err
-	}
-	index.Name = string(tmp)
-	return index, nil
-}
-
-//BasicFileInit is the information that can be directoy decoded
-type BasicFileInit struct {
-	BlockStart     uint32
-	FragmentIndex  uint32
-	FragmentOffset uint32
-	Size           uint32
-}
-
-//BasicFile is self explainatory
-type BasicFile struct {
-	Init       BasicFileInit
-	BlockSizes []uint32
-	Fragmented bool
-}
-
-//NewBasicFile creates a new BasicFile
-func NewBasicFile(rdr io.Reader, blockSize uint32) (BasicFile, error) {
-	var inode BasicFile
-	err := binary.Read(rdr, binary.LittleEndian, &inode.Init)
-	if err != nil {
-		return inode, err
-	}
-	inode.Fragmented = inode.Init.FragmentIndex != 0xFFFFFFFF
-	blocks := inode.Init.Size / blockSize
-	if inode.Init.Size%blockSize > 0 {
-		blocks++
-	}
-	inode.BlockSizes = make([]uint32, blocks, blocks)
-	err = binary.Read(rdr, binary.LittleEndian, &inode.BlockSizes)
-	return inode, err
-}
-
-//ExtendedFileInit is the information that can be directly decoded
-type ExtendedFileInit struct {
-	BlockStart     uint32
-	Size           uint32
-	Sparse         uint64
-	HardLinks      uint32
-	FragmentIndex  uint32
-	FragmentOffset uint32
-	XattrIndex     uint32
-}
-
-//ExtendedFile is a file with more information
-type ExtendedFile struct {
-	Init       ExtendedFileInit
-	BlockSizes []uint32
-	Fragmented bool
-}
-
-//NewExtendedFile creates a new ExtendedFile
-func NewExtendedFile(rdr io.Reader, blockSize uint32) (ExtendedFile, error) {
-	var inode ExtendedFile
-	err := binary.Read(rdr, binary.LittleEndian, &inode.Init)
-	if err != nil {
-		return inode, err
-	}
-	inode.Fragmented = inode.Init.FragmentIndex != 0xFFFFFFFF
-	blocks := inode.Init.Size / blockSize
-	if inode.Init.Size%blockSize > 0 {
-		blocks++
-	}
-	inode.BlockSizes = make([]uint32, blocks, blocks)
-	err = binary.Read(rdr, binary.LittleEndian, &inode.BlockSizes)
-	return inode, err
-}
-
-//BasicSymlinkInit is all the values that can be directly decoded
-type BasicSymlinkInit struct {
-	HardLinks      uint32
-	TargetPathSize uint32
-}
-
-//BasicSymlink is a symlink
-type BasicSymlink struct {
-	Init       BasicSymlinkInit
-	targetPath []byte //len is TargetPathSize
-	Path       string
-}
-
-//NewBasicSymlink creates a new BasicSymlink
-func NewBasicSymlink(rdr io.Reader) (BasicSymlink, error) {
-	var inode BasicSymlink
-	err := binary.Read(rdr, binary.LittleEndian, &inode.Init)
-	if err != nil {
-		return inode, err
-	}
-	inode.targetPath = make([]byte, inode.Init.TargetPathSize, inode.Init.TargetPathSize)
-	err = binary.Read(rdr, binary.LittleEndian, &inode.targetPath)
-	if err != nil {
-		return inode, err
-	}
-	inode.Path = string(inode.targetPath)
-	return inode, err
-}
-
-//ExtendedSymlinkInit is all the values that can be directly decoded
-type ExtendedSymlinkInit struct {
-	HardLinks      uint32
-	TargetPathSize uint32
-}
-
-//ExtendedSymlink is a symlink with extra information
-type ExtendedSymlink struct {
-	Init       ExtendedSymlinkInit
-	targetPath []uint8
-	Path       string
-	XattrIndex uint32
-}
-
-//NewExtendedSymlink creates a new ExtendedSymlink
-func NewExtendedSymlink(rdr io.Reader) (ExtendedSymlink, error) {
-	var inode ExtendedSymlink
-	err := binary.Read(rdr, binary.LittleEndian, &inode.Init)
-	if err != nil {
-		return inode, err
-	}
-	inode.targetPath = make([]uint8, inode.Init.TargetPathSize, inode.Init.TargetPathSize)
-	err = binary.Read(rdr, binary.LittleEndian, &inode.targetPath)
-	if err != nil {
-		return inode, err
-	}
-	inode.Path = string(inode.targetPath)
-	err = binary.Read(rdr, binary.LittleEndian, &inode.XattrIndex)
-	return inode, err
-}
-
-//BasicDevice is a device
-type BasicDevice struct {
-	HardLinks uint32
-	Device    uint32
-}
-
-//ExtendedDevice is a device with more info
-type ExtendedDevice struct {
-	BasicDevice
-	XattrIndex uint32
-}
-
-//BasicIPC is a Fifo or Socket device
-type BasicIPC struct {
-	HardLink uint32
-}
-
-//ExtendedIPC is a IPC device with extra info
-type ExtendedIPC struct {
-	BasicIPC
-	XattrIndex uint32
-}

internal/inode/process.go

@@ -1,125 +0,0 @@
-package inode
-
-import (
-	"encoding/binary"
-	"io"
-)
-
-//Inode holds an inode. Header is the header that's common for all inodes.
-//
-//Info holds the actual Inode. Due to each inode type being a different type, it's store as an interface{}
-type Inode struct {
-	Header Header
-	Type   int         //Type the inode type defined in the header. Here so it's easy to access
-	Info   interface{} //Info is the parsed specific data. It's type is defined by Type.
-}
-
-//ProcessInode tries to read an inode from the BlockReader
-func ProcessInode(br io.Reader, blockSize uint32) (*Inode, error) {
-	var head Header
-	err := binary.Read(br, binary.LittleEndian, &head)
-	if err != nil {
-		return nil, err
-	}
-	var info interface{}
-	switch head.InodeType {
-	case BasicDirectoryType:
-		var inode BasicDirectory
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicFileType:
-		inode, err := NewBasicFile(br, blockSize)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicSymlinkType:
-		inode, err := NewBasicSymlink(br)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicBlockDeviceType:
-		var inode BasicDevice
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicCharDeviceType:
-		var inode BasicDevice
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicFifoType:
-		var inode BasicIPC
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case BasicSocketType:
-		var inode BasicIPC
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtDirType:
-		inode, err := NewExtendedDirectory(br)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtFileType:
-		inode, err := NewExtendedFile(br, blockSize)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtSymlinkType:
-		inode, err := NewExtendedSymlink(br)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtBlockDeviceType:
-		var inode ExtendedDevice
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtCharDeviceType:
-		var inode ExtendedDevice
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtFifoType:
-		var inode ExtendedIPC
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	case ExtSocketType:
-		var inode ExtendedIPC
-		err = binary.Read(br, binary.LittleEndian, &inode)
-		if err != nil {
-			return nil, err
-		}
-		info = inode
-	}
-	return &Inode{
-		Type:   int(head.InodeType),
-		Header: head,
-		Info:   info,
-	}, nil
-}

internal/metadata/reader.go

@@ -0,0 +1,65 @@
+package metadata
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/CalebQ42/squashfs/internal/decompress"
+)
+
+type Reader struct {
+	r         io.Reader
+	d         decompress.Decompressor
+	dat       []byte
+	curOffset uint16
+}
+
+func NewReader(r io.Reader, d decompress.Decompressor) Reader {
+	return Reader{
+		r: r,
+		d: d,
+	}
+}
+
+func (r *Reader) advance() error {
+	r.curOffset = 0
+	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 = r.r.Read(r.dat)
+	if err != nil {
+		return err
+	}
+	if size != realSize {
+		return nil
+	}
+	r.dat, err = r.d.Decompress(r.dat)
+	return err
+}
+
+func (r *Reader) Read(b []byte) (int, error) {
+	curRead := 0
+	var toRead int
+	for curRead < len(b) {
+		if r.curOffset >= uint16(len(r.dat)) {
+			if err := r.advance(); err != nil {
+				return curRead, err
+			}
+		}
+		toRead = min(len(b)-curRead, len(r.dat)-int(r.curOffset))
+		copy(b[curRead:], r.dat[r.curOffset:int(r.curOffset)+toRead])
+		r.curOffset += uint16(toRead)
+		curRead += toRead
+	}
+	return curRead, nil
+}
+
+func (r *Reader) Close() error {
+	r.dat = nil
+	return nil
+}

internal/routinemanager/manager.go

@@ -0,0 +1,25 @@
+package routinemanager
+
+type Manager struct {
+	channel     chan uint16
+	maxRoutines uint16
+}
+
+func NewManager(maxRoutines uint16) *Manager {
+	m := &Manager{
+		maxRoutines: maxRoutines,
+		channel:     make(chan uint16, maxRoutines),
+	}
+	for i := uint16(0); i < maxRoutines; i++ {
+		m.channel <- i
+	}
+	return m
+}
+
+func (m *Manager) Lock() uint16 {
+	return <-m.channel
+}
+
+func (m *Manager) Unlock(i uint16) {
+	m.channel <- i
+}

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/toreader.go

@@ -0,0 +1,21 @@
+package toreader
+
+import "io"
+
+type Reader struct {
+	r      io.ReaderAt
+	offset int64
+}
+
+func NewReader(r io.ReaderAt, start int64) *Reader {
+	return &Reader{
+		r:      r,
+		offset: start,
+	}
+}
+
+func (r *Reader) Read(b []byte) (int, error) {
+	n, err := r.r.ReadAt(b, r.offset)
+	r.offset += int64(n)
+	return n, err
+}

low/README.md

@@ -0,0 +1,3 @@
+# Lower-Level Squashfs
+
+This library is a lower level version of the main [squashfs](https://github.com/CalebQ42/squashfs) library that doesn't try to be easy to use and exposes a lot of information that is not necesary for must use cases.

low/data/fullreader.go

@@ -0,0 +1,260 @@
+package data
+
+import (
+	"errors"
+	"io"
+	"io/fs"
+	"math"
+	"runtime"
+	"sync"
+
+	"github.com/CalebQ42/squashfs/internal/decompress"
+)
+
+type FragReaderConstructor func() (io.Reader, error)
+
+type FullReader struct {
+	r              io.ReaderAt
+	d              decompress.Decompressor
+	frag           FragReaderConstructor
+	sizes          []uint32
+	initialOffset  int64
+	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{
+		r:              r,
+		d:              d,
+		sizes:          sizes,
+		initialOffset:  initialOffset,
+		goroutineLimit: uint16(runtime.NumCPU()),
+		finalBlockSize: finalBlockSize,
+		blockSize:      blockSize,
+	}
+}
+
+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
+}
+
+func (r *FullReader) SetGoroutineLimit(limit uint16) {
+	if limit <= 0 {
+		r.goroutineLimit = 1
+	}
+	r.goroutineLimit = limit
+}
+
+type retValue struct {
+	err   error
+	data  []byte
+	index uint64
+}
+
+func (r FullReader) process(index uint64, fileOffset uint64, pool *sync.Pool, retChan chan *retValue) {
+	ret := pool.Get().(*retValue)
+	ret.index = index
+	realSize := r.sizes[index] &^ (1 << 24)
+	if realSize == 0 {
+		if index == uint64(len(r.sizes))-1 && r.frag == nil {
+			ret.data = make([]byte, r.finalBlockSize)
+		} else {
+			ret.data = make([]byte, r.blockSize)
+		}
+		ret.err = nil
+		retChan <- ret
+		return
+	}
+	ret.data = make([]byte, realSize)
+	_, 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)
+	}
+	retChan <- ret
+}
+
+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)
+	// }
+	var curIndex uint64
+	var curOffset uint64
+	var toProcess uint16
+	var wrote int64
+	cache := make(map[uint64]*retValue)
+	var errCache []error
+	retChan := make(chan *retValue, r.goroutineLimit)
+	pool := &sync.Pool{
+		New: func() any {
+			return &retValue{}
+		},
+	}
+	for i := uint64(0); i < uint64(math.Ceil(float64(len(r.sizes))/float64(r.goroutineLimit))); i++ {
+		toProcess = min(uint16(len(r.sizes))-(uint16(i)*r.goroutineLimit), r.goroutineLimit)
+		// Start all the goroutines
+		for j := uint16(0); j < toProcess; j++ {
+			go r.process((i*uint64(r.goroutineLimit))+uint64(j), curOffset, pool, retChan)
+			curOffset += uint64(r.sizes[(i*uint64(r.goroutineLimit))+uint64(j)]) &^ (1 << 24)
+		}
+		// Then consume the results on retChan
+		for j := uint16(0); j < toProcess; j++ {
+			res := <-retChan
+			// If there's an error, we don't care about the results.
+			if res.err != nil {
+				errCache = append(errCache, res.err)
+				if len(cache) > 0 {
+					clear(cache)
+				}
+				continue
+			}
+			// If there has been an error previously, we don't care about the results.
+			// We still want to wait for all the goroutines to prevent resources being wasted.
+			if len(errCache) > 0 {
+				continue
+			}
+			// If we don't need the data yet, we cache it and move on
+			if res.index != curIndex {
+				cache[res.index] = res
+				continue
+			}
+			// If we do need the data, we write it
+			wr, err := w.Write(res.data)
+			wrote += int64(wr)
+			if err != nil {
+				errCache = append(errCache, err)
+				if len(cache) > 0 {
+					clear(cache)
+				}
+				continue
+			}
+			pool.Put(res)
+			curIndex++
+			// Now we recursively try to clear the cache
+			for len(cache) > 0 {
+				res, ok := cache[curIndex]
+				if !ok {
+					break
+				}
+				wr, err := w.Write(res.data)
+				wrote += int64(wr)
+				if err != nil {
+					errCache = append(errCache, err)
+					if len(cache) > 0 {
+						clear(cache)
+					}
+					break
+				}
+				delete(cache, curIndex)
+				pool.Put(res)
+				curIndex++
+			}
+		}
+		if len(errCache) > 0 {
+			return wrote, errors.Join(errCache...)
+		}
+	}
+	if r.frag != nil {
+		rdr, err := r.frag()
+		if err != nil {
+			return wrote, err
+		}
+		wr, err := io.Copy(w, rdr)
+		wrote += wr
+		if l, ok := rdr.(*io.LimitedReader); ok {
+			if cl, ok := l.R.(io.Closer); ok {
+				cl.Close()
+			}
+		}
+		if err != nil {
+			return wrote, err
+		}
+	}
+	return wrote, nil
+}
+
+// func (r FullReader) writeToWriteAt(w io.WriterAt) (out int64, outErr error) {
+// 	wait := &sync.WaitGroup{}
+// 	wait.Add(len(r.sizes))
+// 	mgr := routinemanager.NewManager(r.goroutineLimit)
+// 	curOffset := r.initialOffset
+// 	for i := uint64(0); i < uint64(len(r.sizes)); i++ {
+// 		go func(index uint64, fileOffset int64) {
+// 			lckNum := mgr.Lock()
+// 			defer mgr.Unlock(lckNum)
+// 			defer wait.Done()
+// 			realSize := r.sizes[index] &^ (1 << 24)
+// 			if realSize == 0 {
+// 				if index == uint64(len(r.sizes))-1 && r.frag == nil {
+// 					_, err := w.WriteAt([]byte{0}, int64((uint64(r.blockSize)*index)+r.finalBlockSize)-1)
+// 					if err != nil {
+// 						outErr = errors.Join(outErr, err)
+// 						return
+// 					}
+// 					out = max(out, int64((uint64(r.blockSize)*index)+r.finalBlockSize))
+// 				}
+// 				return
+// 			}
+// 			data := make([]byte, realSize)
+// 			err := binary.Read(toreader.NewReader(r.r, int64(fileOffset)), binary.LittleEndian, &data)
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			if r.sizes[index] == realSize {
+// 				data, err = r.d.Decompress(data)
+// 			}
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			_, err = w.WriteAt(data, int64(uint64(r.blockSize)*index))
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			out = max(out, int64(uint64(r.blockSize)*(index+1)))
+// 		}(i, curOffset)
+// 		curOffset += int64(r.sizes[i]) &^ (1 << 24)
+// 	}
+// 	if r.frag != nil {
+// 		wait.Add(1)
+// 		go func() {
+// 			lckNum := mgr.Lock()
+// 			defer mgr.Unlock(lckNum)
+// 			defer wait.Done()
+// 			rdr, err := r.frag()
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			dat, err := io.ReadAll(rdr)
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			_, err = w.WriteAt(dat, int64(int(r.blockSize)*len(r.sizes)))
+// 			if err != nil {
+// 				outErr = errors.Join(outErr, err)
+// 				return
+// 			}
+// 			out = int64(int(r.blockSize)*len(r.sizes)) + int64(r.finalBlockSize)
+// 		}()
+// 	}
+// 	wait.Wait()
+// 	return
+// }

low/data/reader.go

@@ -0,0 +1,104 @@
+package data
+
+import (
+	"io"
+	"io/fs"
+
+	"github.com/CalebQ42/squashfs/internal/decompress"
+)
+
+type Reader struct {
+	r              io.Reader
+	d              decompress.Decompressor
+	frag           io.Reader
+	sizes          []uint32
+	dat            []byte
+	curOffset      int
+	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{
+		r:              r,
+		d:              d,
+		sizes:          sizes,
+		finalBlockSize: finalBlockSize,
+		blockSize:      blockSize,
+	}
+}
+
+func (r *Reader) AddFrag(fragRdr io.Reader) {
+	r.frag = fragRdr
+}
+
+func (r *Reader) advance() error {
+	r.curOffset = 0
+	defer func() { r.curIndex++ }()
+	var err error
+	if r.curIndex == uint64(len(r.sizes)) && r.frag != nil {
+		r.dat, err = io.ReadAll(r.frag)
+		return err
+	} else if r.curIndex >= uint64(len(r.sizes)) {
+		r.dat = []byte{}
+		return io.EOF
+	}
+	realSize := r.sizes[r.curIndex] &^ (1 << 24)
+	if realSize == 0 {
+		if r.curIndex == uint64(len(r.sizes))-1 && r.frag == nil {
+			r.dat = make([]byte, r.finalBlockSize)
+		} else {
+			r.dat = make([]byte, r.blockSize)
+		}
+		return nil
+	}
+	r.dat = make([]byte, realSize)
+	_, err = r.r.Read(r.dat)
+	if err != nil {
+		return err
+	}
+	if r.sizes[r.curIndex] != realSize {
+		return nil
+	}
+	r.dat, err = r.d.Decompress(r.dat)
+	return err
+}
+
+func (r *Reader) Read(b []byte) (int, error) {
+	if r.closed {
+		return 0, fs.ErrClosed
+	}
+	curRead := 0
+	var toRead int
+	for curRead < len(b) {
+		if r.curOffset >= len(r.dat) {
+			if err := r.advance(); err != nil {
+				return curRead, err
+			}
+		}
+		toRead = min(len(b)-curRead, len(r.dat)-r.curOffset)
+		toRead = copy(b[curRead:], r.dat[r.curOffset:r.curOffset+toRead])
+		r.curOffset += toRead
+		curRead += toRead
+	}
+	return curRead, nil
+}
+
+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 {
+				cl.Close()
+			}
+		}
+	}
+	r.frag = nil
+	r.sizes = nil
+	r.dat = nil
+	return nil
+}

low/directory.go

@@ -0,0 +1,83 @@
+package squashfslow
+
+import (
+	"errors"
+	"io/fs"
+	"path/filepath"
+	"slices"
+	"strings"
+
+	"github.com/CalebQ42/squashfs/internal/metadata"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+	"github.com/CalebQ42/squashfs/low/directory"
+	"github.com/CalebQ42/squashfs/low/inode"
+)
+
+type Directory struct {
+	FileBase
+	Entries []directory.Entry
+}
+
+func (r Reader) directoryFromRef(ref uint64, name string) (Directory, error) {
+	i, err := r.InodeFromRef(ref)
+	if err != nil {
+		return Directory{}, err
+	}
+	var blockStart uint32
+	var size uint32
+	var offset uint16
+	switch i.Type {
+	case inode.Dir:
+		blockStart = i.Data.(inode.Directory).BlockStart
+		size = uint32(i.Data.(inode.Directory).Size)
+		offset = i.Data.(inode.Directory).Offset
+	case inode.EDir:
+		blockStart = i.Data.(inode.EDirectory).BlockStart
+		size = i.Data.(inode.EDirectory).Size
+		offset = i.Data.(inode.EDirectory).Offset
+	default:
+		return Directory{}, errors.New("not a directory")
+	}
+	dirRdr := metadata.NewReader(toreader.NewReader(r.r, int64(r.Superblock.DirTableStart)+int64(blockStart)), r.d)
+	defer dirRdr.Close()
+	_, err = dirRdr.Read(make([]byte, offset))
+	if err != nil {
+		return Directory{}, err
+	}
+	entries, err := directory.ReadDirectory(&dirRdr, size)
+	if err != nil {
+		return Directory{}, err
+	}
+	return Directory{
+		FileBase: r.BaseFromInode(i, name),
+		Entries:  entries,
+	}, nil
+}
+
+func (d Directory) Open(r Reader, path string) (FileBase, error) {
+	path = filepath.Clean(path)
+	if path == "." || path == "" {
+		return d.FileBase, nil
+	}
+	split := strings.Split(path, "/")
+	i, found := slices.BinarySearchFunc(d.Entries, split[0], func(e directory.Entry, name string) int {
+		return strings.Compare(e.Name, name)
+	})
+	if !found {
+		return FileBase{}, fs.ErrNotExist
+	}
+	b, err := r.BaseFromEntry(d.Entries[i])
+	if err != nil {
+		return FileBase{}, err
+	}
+	if len(split) == 1 {
+		return b, nil
+	} else if !b.IsDir() {
+		return FileBase{}, fs.ErrNotExist
+	}
+	dir, err := b.ToDir(r)
+	if err != nil {
+		return FileBase{}, err
+	}
+	return dir.Open(r, strings.Join(split[1:], "/"))
+}

low/directory/directory.go

@@ -0,0 +1,62 @@
+package directory
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type header struct {
+	Count      uint32
+	BlockStart uint32
+	Num        uint32
+}
+
+type decEntry struct {
+	Offset    uint16
+	NumOffset int16
+	InodeType uint16
+	NameSize  uint16
+	// Name []byte (not decoded along with decEntry)
+}
+
+type Entry struct {
+	Name       string
+	BlockStart uint32
+	Offset     uint16
+	InodeType  uint16
+	Num        uint32
+}
+
+func ReadDirectory(r io.Reader, size uint32) (out []Entry, err error) {
+	size -= 3
+	var curRead uint32
+	var h header
+	var de decEntry
+	for curRead < size {
+		err = binary.Read(r, binary.LittleEndian, &h)
+		if err != nil {
+			return
+		}
+		curRead += 12
+		for i := uint32(0); i < h.Count+1 && curRead < size; i++ {
+			err = binary.Read(r, binary.LittleEndian, &de)
+			if err != nil {
+				return
+			}
+			nameTmp := make([]byte, de.NameSize+1)
+			err = binary.Read(r, binary.LittleEndian, &nameTmp)
+			if err != nil {
+				return
+			}
+			curRead += 8 + uint32(de.NameSize) + 1
+			out = append(out, Entry{
+				BlockStart: h.BlockStart,
+				Offset:     de.Offset,
+				Name:       string(nameTmp),
+				InodeType:  de.InodeType,
+				Num:        h.Num + uint32(de.NumOffset),
+			})
+		}
+	}
+	return
+}

low/file_base.go

@@ -0,0 +1,203 @@
+package squashfslow
+
+import (
+	"errors"
+	"io"
+
+	"github.com/CalebQ42/squashfs/internal/metadata"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+	"github.com/CalebQ42/squashfs/low/data"
+	"github.com/CalebQ42/squashfs/low/directory"
+	"github.com/CalebQ42/squashfs/low/inode"
+)
+
+type FileBase struct {
+	Inode inode.Inode
+	Name  string
+}
+
+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) {
+	in, err := r.InodeFromEntry(e)
+	if err != nil {
+		return FileBase{}, err
+	}
+	return FileBase{Inode: in, Name: e.Name}, nil
+}
+
+func (r Reader) BaseFromRef(ref uint64, name string) (FileBase, error) {
+	in, err := r.InodeFromRef(ref)
+	if err != nil {
+		return FileBase{}, err
+	}
+	return FileBase{Inode: in, Name: name}, nil
+}
+
+func (b FileBase) Uid(r *Reader) (uint32, error) {
+	return r.Id(b.Inode.UidInd)
+}
+
+func (b FileBase) Gid(r *Reader) (uint32, error) {
+	return r.Id(b.Inode.GidInd)
+}
+
+func (b FileBase) IsDir() bool {
+	return b.Inode.Type == inode.Dir || b.Inode.Type == inode.EDir
+}
+
+func (b FileBase) ToDir(r Reader) (Directory, error) {
+	var blockStart uint32
+	var size uint32
+	var offset uint16
+	switch b.Inode.Type {
+	case inode.Dir:
+		blockStart = b.Inode.Data.(inode.Directory).BlockStart
+		size = uint32(b.Inode.Data.(inode.Directory).Size)
+		offset = b.Inode.Data.(inode.Directory).Offset
+	case inode.EDir:
+		blockStart = b.Inode.Data.(inode.EDirectory).BlockStart
+		size = b.Inode.Data.(inode.EDirectory).Size
+		offset = b.Inode.Data.(inode.EDirectory).Offset
+	default:
+		return Directory{}, errors.New("not a directory")
+	}
+	dirRdr := metadata.NewReader(toreader.NewReader(r.r, int64(r.Superblock.DirTableStart)+int64(blockStart)), r.d)
+	defer dirRdr.Close()
+	_, err := dirRdr.Read(make([]byte, offset))
+	if err != nil {
+		return Directory{}, err
+	}
+	entries, err := directory.ReadDirectory(&dirRdr, size)
+	if err != nil {
+		return Directory{}, err
+	}
+	return Directory{
+		FileBase: b,
+		Entries:  entries,
+	}, nil
+}
+
+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) {
+	if !b.IsRegular() {
+		return data.Reader{}, data.FullReader{}, errors.New("not a regular file")
+	}
+	var blockStart uint64
+	var fragIndex uint32
+	var fragOffset uint32
+	var fragSize uint64
+	var sizes []uint32
+	if b.Inode.Type == inode.Fil {
+		blockStart = uint64(b.Inode.Data.(inode.File).BlockStart)
+		fragIndex = b.Inode.Data.(inode.File).FragInd
+		fragOffset = b.Inode.Data.(inode.File).FragOffset
+		sizes = b.Inode.Data.(inode.File).BlockSizes
+		fragSize = uint64(b.Inode.Data.(inode.File).Size % r.Superblock.BlockSize)
+	} else {
+		blockStart = b.Inode.Data.(inode.EFile).BlockStart
+		fragIndex = b.Inode.Data.(inode.EFile).FragInd
+		fragOffset = b.Inode.Data.(inode.EFile).FragOffset
+		sizes = b.Inode.Data.(inode.EFile).BlockSizes
+		fragSize = b.Inode.Data.(inode.EFile).Size % uint64(r.Superblock.BlockSize)
+	}
+	frag := func() (io.Reader, error) {
+		ent, err := r.fragEntry(fragIndex)
+		if err != nil {
+			return nil, 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))
+		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 data.Reader{}, data.FullReader{}, err
+		}
+		outRdr.AddFrag(f)
+	}
+	outFull := data.NewFullReader(r.r, int64(blockStart), r.d, sizes, fragSize, r.Superblock.BlockSize)
+	if fragIndex != 0xffffffff {
+		outFull.AddFrag(frag)
+	}
+	return outRdr, outFull, nil
+}
+
+func (b FileBase) GetFullReader(r *Reader) (data.FullReader, error) {
+	if !b.IsRegular() {
+		return data.FullReader{}, errors.New("not a regular file")
+	}
+	var blockStart uint64
+	var fragIndex uint32
+	var fragOffset uint32
+	var fragSize uint64
+	var sizes []uint32
+	if b.Inode.Type == inode.Fil {
+		blockStart = uint64(b.Inode.Data.(inode.File).BlockStart)
+		fragIndex = b.Inode.Data.(inode.File).FragInd
+		fragOffset = b.Inode.Data.(inode.File).FragOffset
+		sizes = b.Inode.Data.(inode.File).BlockSizes
+		fragSize = uint64(b.Inode.Data.(inode.File).Size % r.Superblock.BlockSize)
+	} else {
+		blockStart = b.Inode.Data.(inode.EFile).BlockStart
+		fragIndex = b.Inode.Data.(inode.EFile).FragInd
+		fragOffset = b.Inode.Data.(inode.EFile).FragOffset
+		sizes = b.Inode.Data.(inode.EFile).BlockSizes
+		fragSize = b.Inode.Data.(inode.EFile).Size % uint64(r.Superblock.BlockSize)
+	}
+	outFull := data.NewFullReader(r.r, int64(blockStart), r.d, sizes, fragSize, r.Superblock.BlockSize)
+	if fragIndex != 0xffffffff {
+		outFull.AddFrag(func() (io.Reader, error) {
+			ent, err := r.fragEntry(fragIndex)
+			if err != nil {
+				return nil, 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))
+			return io.LimitReader(&frag, int64(fragSize)), nil
+		})
+	}
+	return outFull, nil
+}
+
+func (b FileBase) GetReader(r *Reader) (data.Reader, error) {
+	if !b.IsRegular() {
+		return data.Reader{}, errors.New("not a regular file")
+	}
+	var blockStart uint64
+	var fragIndex uint32
+	var fragOffset uint32
+	var fragSize uint64
+	var sizes []uint32
+	if b.Inode.Type == inode.Fil {
+		blockStart = uint64(b.Inode.Data.(inode.File).BlockStart)
+		fragIndex = b.Inode.Data.(inode.File).FragInd
+		fragOffset = b.Inode.Data.(inode.File).FragOffset
+		sizes = b.Inode.Data.(inode.File).BlockSizes
+		fragSize = uint64(b.Inode.Data.(inode.File).Size % r.Superblock.BlockSize)
+	} else {
+		blockStart = b.Inode.Data.(inode.EFile).BlockStart
+		fragIndex = b.Inode.Data.(inode.EFile).FragInd
+		fragOffset = b.Inode.Data.(inode.EFile).FragOffset
+		sizes = b.Inode.Data.(inode.EFile).BlockSizes
+		fragSize = b.Inode.Data.(inode.EFile).Size % uint64(r.Superblock.BlockSize)
+	}
+	outRdr := data.NewReader(toreader.NewReader(r.r, int64(blockStart)), r.d, sizes, fragSize, r.Superblock.BlockSize)
+	if fragIndex != 0xffffffff {
+		ent, err := r.fragEntry(fragIndex)
+		if err != nil {
+			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)))
+	}
+	return outRdr, nil
+}

low/fragment.go

@@ -0,0 +1,7 @@
+package squashfslow
+
+type fragEntry struct {
+	Start uint64
+	Size  uint32
+	_     uint32
+}

low/inode.go

@@ -0,0 +1,26 @@
+package squashfslow
+
+import (
+	"github.com/CalebQ42/squashfs/internal/metadata"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+	"github.com/CalebQ42/squashfs/low/directory"
+	"github.com/CalebQ42/squashfs/low/inode"
+)
+
+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()
+	_, err := rdr.Read(make([]byte, meta))
+	if err != nil {
+		return inode.Inode{}, err
+	}
+	return inode.Read(&rdr, r.Superblock.BlockSize)
+}
+
+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)
+}

low/inode/dir.go

@@ -0,0 +1,78 @@
+package inode
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type Directory struct {
+	BlockStart uint32
+	LinkCount  uint32
+	Size       uint16
+	Offset     uint16
+	ParentNum  uint32
+}
+
+type EDirectory struct {
+	LinkCount  uint32
+	Size       uint32
+	BlockStart uint32
+	ParentNum  uint32
+	IndCount   uint16
+	Offset     uint16
+	XattrInd   uint32
+	Indexes    []DirectoryIndex
+}
+
+type DirectoryIndex struct {
+	Ind      uint32
+	Start    uint32
+	NameSize uint32
+	Name     []byte
+}
+
+func ReadDir(r io.Reader) (d Directory, err error) {
+	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) {
+	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.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 = r.Read(d.Indexes[i].Name)
+		if err != nil {
+			return
+		}
+	}
+	return
+}

low/inode/file.go

@@ -0,0 +1,70 @@
+package inode
+
+import (
+	"encoding/binary"
+	"io"
+	"math"
+)
+
+type File struct {
+	BlockStart uint32
+	FragInd    uint32
+	FragOffset uint32
+	Size       uint32
+	BlockSizes []uint32
+}
+
+type eFileInit struct {
+	BlockStart uint64
+	Size       uint64
+	Sparse     uint64
+	LinkCount  uint32
+	FragInd    uint32
+	FragOffset uint32
+	XattrInd   uint32
+}
+
+type EFile struct {
+	eFileInit
+	BlockSizes []uint32
+}
+
+func ReadFile(r io.Reader, blockSize uint32) (f File, err error) {
+	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)
+	for i := range toRead {
+		f.BlockSizes[i] = binary.LittleEndian.Uint32(dat[i*4:])
+	}
+	return
+}
+
+func ReadEFile(r io.Reader, blockSize uint32) (f EFile, err error) {
+	err = binary.Read(r, binary.LittleEndian, &f.eFileInit)
+	if err != nil {
+		return
+	}
+	toRead := int(math.Floor(float64(f.Size) / float64(blockSize)))
+	if f.FragInd == 0xFFFFFFFF && f.Size%uint64(blockSize) > 0 {
+		toRead++
+	}
+	f.BlockSizes = make([]uint32, toRead)
+	err = binary.Read(r, binary.LittleEndian, &f.BlockSizes)
+	return
+}

low/inode/inode.go

@@ -0,0 +1,137 @@
+package inode
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"io/fs"
+	"strconv"
+)
+
+const (
+	Dir = uint16(iota + 1)
+	Fil
+	Sym
+	Block
+	Char
+	Fifo
+	Sock
+	EDir
+	EFil
+	ESym
+	EBlock
+	EChar
+	EFifo
+	ESock
+)
+
+type Header struct {
+	Type    uint16
+	Perm    uint16
+	UidInd  uint16
+	GidInd  uint16
+	ModTime uint32
+	Num     uint32
+}
+
+type Inode struct {
+	Header
+	Data any
+}
+
+func Read(r io.Reader, blockSize uint32) (i Inode, err error) {
+	err = binary.Read(r, binary.LittleEndian, &i.Header)
+	if err != nil {
+		return
+	}
+	switch i.Type {
+	case Dir:
+		i.Data, err = ReadDir(r)
+	case Fil:
+		i.Data, err = ReadFile(r, blockSize)
+	case Sym:
+		i.Data, err = ReadSym(r)
+	case Block:
+		fallthrough
+	case Char:
+		i.Data, err = ReadDevice(r)
+	case Fifo:
+		fallthrough
+	case Sock:
+		i.Data, err = ReadIPC(r)
+	case EDir:
+		i.Data, err = ReadEDir(r)
+	case EFil:
+		i.Data, err = ReadEFile(r, blockSize)
+	case ESym:
+		i.Data, err = ReadESym(r)
+	case EBlock:
+		fallthrough
+	case EChar:
+		i.Data, err = ReadEDevice(r)
+	case EFifo:
+		fallthrough
+	case ESock:
+		i.Data, err = ReadEIPC(r)
+	default:
+		return i, errors.New("invalid inode type " + strconv.Itoa(int(i.Type)))
+	}
+	return
+}
+
+func (i Inode) Mode() (out fs.FileMode) {
+	out = fs.FileMode(i.Perm)
+	switch i.Type {
+	case Dir, EDir:
+		out |= fs.ModeDir
+	case Sym, ESym:
+		out |= fs.ModeSymlink
+	case Char, EChar, Block, EBlock:
+		out |= fs.ModeDevice
+	case Fifo, EFifo:
+		out |= fs.ModeNamedPipe
+	case Sock, ESock:
+		out |= fs.ModeSocket
+	}
+	return
+}
+
+func (i Inode) LinkCount() uint32 {
+	switch i.Data.(type) {
+	case EFile:
+		return i.Data.(EFile).LinkCount
+	case Directory:
+		return i.Data.(Directory).LinkCount
+	case EDirectory:
+		return i.Data.(EDirectory).LinkCount
+	case Device:
+		return i.Data.(Device).LinkCount
+	case EDevice:
+		return i.Data.(EDevice).LinkCount
+	case IPC:
+		return i.Data.(IPC).LinkCount
+	case EIPC:
+		return i.Data.(EIPC).LinkCount
+	case Symlink:
+		return i.Data.(Symlink).LinkCount
+	case ESymlink:
+		return i.Data.(ESymlink).LinkCount
+	default:
+		return 0
+	}
+}
+
+func (i Inode) Size() uint64 {
+	switch i.Data.(type) {
+	case File:
+		return uint64(i.Data.(File).Size)
+	case EFile:
+		return i.Data.(EFile).Size
+	// case Directory:
+	// 	return uint64(i.Data.(Directory).Size)
+	// case EDirectory:
+	// 	return uint64(i.Data.(EDirectory).Size)
+	default:
+		return 0
+	}
+}

low/inode/misc.go

@@ -0,0 +1,45 @@
+package inode
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type Device struct {
+	LinkCount uint32
+	Dev       uint32
+}
+
+type EDevice struct {
+	Device
+	XattrInd uint32
+}
+
+func ReadDevice(r io.Reader) (d Device, err error) {
+	err = binary.Read(r, binary.LittleEndian, &d)
+	return
+}
+
+func ReadEDevice(r io.Reader) (d EDevice, err error) {
+	err = binary.Read(r, binary.LittleEndian, &d)
+	return
+}
+
+type IPC struct {
+	LinkCount uint32
+}
+
+type EIPC struct {
+	IPC
+	XattrInd uint32
+}
+
+func ReadIPC(r io.Reader) (i IPC, err error) {
+	err = binary.Read(r, binary.LittleEndian, &i)
+	return
+}
+
+func ReadEIPC(r io.Reader) (i EIPC, err error) {
+	err = binary.Read(r, binary.LittleEndian, &i)
+	return
+}

low/inode/sym.go

@@ -0,0 +1,46 @@
+package inode
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+type symlinkInit struct {
+	LinkCount  uint32
+	TargetSize uint32
+}
+
+type Symlink struct {
+	symlinkInit
+	Target []byte
+}
+
+type ESymlink struct {
+	symlinkInit
+	Target   []byte
+	XattrInd uint32
+}
+
+func ReadSym(r io.Reader) (s Symlink, err error) {
+	err = binary.Read(r, binary.LittleEndian, &s.symlinkInit)
+	if err != nil {
+		return
+	}
+	s.Target = make([]byte, s.TargetSize)
+	err = binary.Read(r, binary.LittleEndian, &s.Target)
+	return
+}
+
+func ReadESym(r io.Reader) (s ESymlink, err error) {
+	err = binary.Read(r, binary.LittleEndian, &s.symlinkInit)
+	if err != nil {
+		return
+	}
+	s.Target = make([]byte, s.TargetSize)
+	err = binary.Read(r, binary.LittleEndian, &s.Target)
+	if err != nil {
+		return
+	}
+	err = binary.Read(r, binary.LittleEndian, &s.XattrInd)
+	return
+}

low/reader.go

@@ -0,0 +1,218 @@
+package squashfslow
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"math"
+
+	"github.com/CalebQ42/squashfs/internal/decompress"
+	"github.com/CalebQ42/squashfs/internal/metadata"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+	"github.com/CalebQ42/squashfs/low/inode"
+)
+
+// The types of compression supported by squashfs
+const (
+	ZlibCompression = uint16(iota + 1)
+	LZMACompression
+	LZOCompression
+	XZCompression
+	LZ4Compression
+	ZSTDCompression
+)
+
+var (
+	ErrorMagic         = errors.New("magic incorrect. probably not reading squashfs archive or archive is corrupted")
+	ErrorLog           = errors.New("block log is incorrect. possible corrupted archive")
+	ErrorVersion       = errors.New("squashfs version of archive is not 4.0. may be corrupted")
+	ErrorNotExportable = errors.New("archive does not have an export table")
+)
+
+type Reader struct {
+	r           io.ReaderAt
+	d           decompress.Decompressor
+	Root        Directory
+	fragTable   []fragEntry
+	idTable     []uint32
+	exportTable []uint64
+	Superblock  superblock
+}
+
+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 rdr, errors.Join(errors.New("failed to read superblock"), err)
+	}
+	if !rdr.Superblock.ValidMagic() {
+		return rdr, ErrorMagic
+	}
+	if !rdr.Superblock.ValidBlockLog() {
+		return rdr, ErrorLog
+	}
+	if !rdr.Superblock.ValidVersion() {
+		return rdr, ErrorVersion
+	}
+	switch rdr.Superblock.CompType {
+	case ZlibCompression:
+		rdr.d = decompress.NewZlib()
+	case LZMACompression:
+		rdr.d, err = decompress.NewLzma()
+		if err != nil {
+			return rdr, err
+		}
+	case LZOCompression:
+		rdr.d, err = decompress.NewLzo()
+		if err != nil {
+			return rdr, err
+		}
+	case XZCompression:
+		rdr.d = decompress.NewXz()
+	case LZ4Compression:
+		rdr.d = decompress.NewLz4()
+	case ZSTDCompression:
+		rdr.d = decompress.NewZstd()
+	default:
+		return rdr, errors.New("invalid compression type. possible corrupted archive")
+	}
+	rdr.Root, err = rdr.directoryFromRef(rdr.Superblock.RootInodeRef, "")
+	if err != nil {
+		return rdr, errors.Join(errors.New("failed to read root directory"), err)
+	}
+	return
+}
+
+// Get a uid/gid at the given index. Lazily populates the reader's Id table as necessary.
+func (r *Reader) Id(i uint16) (uint32, error) {
+	if len(r.idTable) > int(i) {
+		return r.idTable[i], nil
+	} else if i >= r.Superblock.IdCount {
+		return 0, errors.New("id out of bounds")
+	}
+	// Populate the id table as needed
+	var blockNum uint32
+	if i != 0 { // If i == 0, we go negatives causing issues with uint32s
+		blockNum = uint32(math.Ceil(float64(i+1)/2048)) - 1
+	} else {
+		blockNum = 0
+	}
+	blocksRead := len(r.idTable) / 2048
+	blocksToRead := int(blockNum) - blocksRead + 1
+
+	var offset uint64
+	var idsToRead uint16
+	var idsTmp []uint32
+	var err error
+	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 {
+			return 0, err
+		}
+		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)
+		rdr.Close()
+		if err != nil {
+			return 0, err
+		}
+		r.idTable = append(r.idTable, idsTmp...)
+	}
+	return r.idTable[i], nil
+}
+
+// Get a fragment entry at the given index. Lazily populates the reader's fragment table as necessary.
+func (r *Reader) fragEntry(i uint32) (fragEntry, error) {
+	if len(r.fragTable) > int(i) {
+		return r.fragTable[i], nil
+	} else if i >= r.Superblock.FragCount {
+		return fragEntry{}, errors.New("fragment out of bounds")
+	}
+	// Populate the fragment table as needed
+	var blockNum uint32
+	if i != 0 { // If i == 0, we go negatives causing issues with uint32s
+		blockNum = uint32(math.Ceil(float64(i+1)/512)) - 1
+	} else {
+		blockNum = 0
+	}
+	blocksRead := len(r.fragTable) / 512
+	blocksToRead := int(blockNum) - blocksRead + 1
+
+	var offset uint64
+	var fragsToRead uint32
+	var fragsTmp []fragEntry
+	var err error
+	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 {
+			return fragEntry{}, err
+		}
+		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)
+		rdr.Close()
+		if err != nil {
+			return fragEntry{}, err
+		}
+		r.fragTable = append(r.fragTable, fragsTmp...)
+	}
+	return r.fragTable[i], nil
+}
+
+// Get an inode reference at the given index. Lazily populates the reader's export table as necessary.
+func (r *Reader) inodeRef(i uint32) (uint64, error) {
+	if !r.Superblock.Exportable() {
+		return 0, ErrorNotExportable
+	}
+	if len(r.exportTable) > int(i) {
+		return r.exportTable[i], nil
+	} else if i >= r.Superblock.InodeCount {
+		return 0, errors.New("inode out of bounds")
+	}
+	// Populate the export table as needed
+	var blockNum uint32
+	if i != 0 { // If i == 0, we go negatives causing issues with uint32s
+		blockNum = uint32(math.Ceil(float64(i+1)/1024)) - 1
+	} else {
+		blockNum = 0
+	}
+	blocksRead := len(r.exportTable) / 1024
+	blocksToRead := int(blockNum) - blocksRead + 1
+
+	var offset uint64
+	var refsToRead uint32
+	var refsTmp []uint64
+	var err error
+	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 {
+			return 0, err
+		}
+		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)
+		rdr.Close()
+		if err != nil {
+			return 0, err
+		}
+		r.exportTable = append(r.exportTable, refsTmp...)
+	}
+	return r.exportTable[i], nil
+}
+
+func (r Reader) Inode(i uint32) (inode.Inode, error) {
+	ref, err := r.inodeRef(i)
+	if err != nil {
+		return inode.Inode{}, err
+	}
+	return r.InodeFromRef(ref)
+}

low/reader_test.go

@@ -0,0 +1,146 @@
+package squashfslow
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+const (
+	squashfsURL  = "https://darkstorm.tech/files/LinuxPATest.sfs"
+	squashfsName = "airootfs.sfs"
+)
+
+func preTest(dir string) (fil *os.File, err error) {
+	fil, err = os.Open(filepath.Join(dir, squashfsName))
+	if err != nil {
+		_, err = os.Open(dir)
+		if os.IsNotExist(err) {
+			err = os.Mkdir(dir, 0755)
+		}
+		if err != nil {
+			return
+		}
+		os.Remove(filepath.Join(dir, squashfsName))
+		fil, err = os.Create(filepath.Join(dir, squashfsName))
+		if err != nil {
+			return
+		}
+		var resp *http.Response
+		resp, err = http.DefaultClient.Get(squashfsURL)
+		if err != nil {
+			return
+		}
+		_, err = io.Copy(fil, resp.Body)
+		if err != nil {
+			return
+		}
+	}
+	_, err = exec.LookPath("unsquashfs")
+	if err != nil {
+		return
+	}
+	_, err = exec.LookPath("mksquashfs")
+	return
+}
+
+func TestMisc(t *testing.T) {
+	tmpDir := "../testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fil.Close()
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Log(rdr.Superblock.FragCount)
+	t.Fatal(rdr.fragEntry(1233))
+}
+
+func TestReader(t *testing.T) {
+	tmpDir := "../testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fil.Close()
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(tmpDir, "extractTest")
+	os.RemoveAll(path)
+	os.MkdirAll(path, 0777)
+	err = extractToDir(rdr, rdr.Root.FileBase, path)
+	t.Fatal(err)
+}
+
+var singleFile = "PortableApps/CPU-X/CPU-X-v4.2.0-x86_64.AppImage"
+
+func TestSingleFile(t *testing.T) {
+	tmpDir := "../testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fil.Close()
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	path := filepath.Join(tmpDir, "extractTest")
+	os.RemoveAll(path)
+	os.MkdirAll(path, 0777)
+	b, err := rdr.Root.Open(rdr, singleFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = extractToDir(rdr, b, path)
+	t.Fatal(err)
+}
+
+func extractToDir(rdr Reader, b FileBase, folder string) error {
+	path := filepath.Join(folder, b.Name)
+	if b.IsDir() {
+		d, err := b.ToDir(rdr)
+		if err != nil {
+			return err
+		}
+		err = os.MkdirAll(path, 0777)
+		if err != nil {
+			return err
+		}
+		var nestBast FileBase
+		for _, e := range d.Entries {
+			nestBast, err = rdr.BaseFromEntry(e)
+			if err != nil {
+				return err
+			}
+			err = extractToDir(rdr, nestBast, path)
+			if err != nil {
+				return err
+			}
+		}
+	} else if b.IsRegular() {
+		_, full, err := b.GetRegFileReaders(rdr)
+		if err != nil {
+			return err
+		}
+		fil, err := os.Create(path)
+		if err != nil {
+			return err
+		}
+		_, err = full.WriteTo(fil)
+		if err != nil {
+			return err
+		}
+		fmt.Println("Successfully extracted file:", b.Name)
+	}
+	return nil
+}

low/superblock.go

@@ -0,0 +1,80 @@
+package squashfslow
+
+import "math"
+
+type superblock struct {
+	Magic            uint32
+	InodeCount       uint32
+	ModTime          uint32
+	BlockSize        uint32
+	FragCount        uint32
+	CompType         uint16
+	BlockLog         uint16
+	Flags            uint16
+	IdCount          uint16
+	VerMaj           uint16
+	VerMin           uint16
+	RootInodeRef     uint64
+	Size             uint64
+	IdTableStart     uint64
+	XattrTableStart  uint64
+	InodeTableStart  uint64
+	DirTableStart    uint64
+	FragTableStart   uint64
+	ExportTableStart uint64
+}
+
+func (s superblock) ValidMagic() bool {
+	return s.Magic == 0x73717368
+}
+
+func (s superblock) ValidBlockLog() bool {
+	return s.BlockLog == uint16(math.Log2(float64(s.BlockSize)))
+}
+
+func (s superblock) ValidVersion() bool {
+	return s.VerMaj == 4 && s.VerMin == 0
+}
+
+func (s superblock) UncompressedInodes() bool {
+	return s.Flags&0x1 == 0x1
+}
+
+func (s superblock) UncompressedData() bool {
+	return s.Flags&0x2 == 0x2
+}
+func (s superblock) UncompressedFragments() bool {
+	return s.Flags&0x8 == 0x8
+}
+
+func (s superblock) NoFragments() bool {
+	return s.Flags&0x10 == 0x10
+}
+
+func (s superblock) AlwaysFragment() bool {
+	return s.Flags&0x20 == 0x20
+}
+
+func (s superblock) Duplicates() bool {
+	return s.Flags&0x40 == 0x40
+}
+
+func (s superblock) Exportable() bool {
+	return s.Flags&0x80 == 0x80
+}
+
+func (s superblock) UncompressedXattrs() bool {
+	return s.Flags&0x100 == 0x100
+}
+
+func (s superblock) NoXattrs() bool {
+	return s.Flags&0x200 == 0x200
+}
+
+func (s superblock) CompressionOptions() bool {
+	return s.Flags&0x400 == 0x400
+}
+
+func (s superblock) UncompressedIDs() bool {
+	return s.Flags&0x800 == 0x800
+}

metadata.go

@@ -1,188 +0,0 @@
-package squashfs
-
-import (
-	"bytes"
-	"encoding/binary"
-	"errors"
-	"io"
-)
-
-type metadata struct {
-	raw        uint16
-	size       uint16
-	compressed bool
-}
-
-//MetadataReader is a block reader for metadata. It will automatically read the next block, when it reaches the end of a block.
-type metadataReader struct {
-	s          *Reader
-	offset     int64
-	headers    []*metadata
-	data       []byte
-	readOffset int
-}
-
-//NewMetadataReader creates a new MetadataReader, beginning to read at the given offset. It will automatically cache the first block at the location.
-func (s *Reader) newMetadataReader(offset int64) (*metadataReader, error) {
-	var br metadataReader
-	br.s = s
-	br.offset = offset
-	err := br.parseMetadata()
-	if err != nil {
-		return nil, err
-	}
-	err = br.readNextDataBlock()
-	if err != nil {
-		return nil, err
-	}
-	return &br, nil
-}
-
-//NewMetadataReaderFromInodeRef creates a new MetadataReader with the offsets set by the given inode reference.
-func (s *Reader) newMetadataReaderFromInodeRef(ref uint64) (*metadataReader, error) {
-	offset, metaOffset := processInodeRef(ref)
-	br, err := s.newMetadataReader(int64(s.super.InodeTableStart + offset))
-	if err != nil {
-		return nil, err
-	}
-	_, err = br.Seek(int64(metaOffset), io.SeekStart)
-	if err != nil {
-		return nil, err
-	}
-	return br, nil
-}
-
-//ProcessInodeRef processes an inode reference and returns two values
-//
-//The first value is the inode table offset. AKA, it's where the metadata block of the inode STARTS relative to the inode table.
-//
-//The second value is the offset of the inode, INSIDE of the metadata.
-func processInodeRef(inodeRef uint64) (tableOffset uint64, metaOffset uint64) {
-	tableOffset = inodeRef >> 16
-	metaOffset = inodeRef &^ 0xFFFFFFFF0000
-	return
-}
-
-func (br *metadataReader) parseMetadata() error {
-	var raw uint16
-	err := binary.Read(io.NewSectionReader(br.s.r, br.offset, 2), binary.LittleEndian, &raw)
-	if err != nil {
-		return err
-	}
-	br.offset += 2
-	compressed := raw&0x8000 != 0x8000
-	size := raw &^ 0x8000
-	br.headers = append(br.headers, &metadata{
-		raw:        raw,
-		size:       size,
-		compressed: compressed,
-	})
-	return nil
-}
-
-func (br *metadataReader) readNextDataBlock() error {
-	meta := br.headers[len(br.headers)-1]
-	r := io.NewSectionReader(br.s.r, br.offset, int64(meta.size))
-	if meta.compressed {
-		byts, err := br.s.decompressor.Decompress(r)
-		if err != nil {
-			return err
-		}
-		br.offset += int64(meta.size)
-		br.data = append(br.data, byts...)
-		return nil
-	}
-	var buf bytes.Buffer
-	_, err := io.Copy(&buf, r)
-	if err != nil {
-		return err
-	}
-	br.offset += int64(meta.size)
-	br.data = append(br.data, buf.Bytes()...)
-	return nil
-}
-
-//Read reads bytes into the given byte slice. Returns the amount of data read.
-func (br *metadataReader) Read(p []byte) (int, error) {
-	if br.readOffset+len(p) <= len(br.data) {
-		for i := 0; i < len(p); i++ {
-			p[i] = br.data[br.readOffset+i]
-		}
-		br.readOffset += len(p)
-		return len(p), nil
-	}
-	read := 0
-	for read < len(p) {
-		err := br.parseMetadata()
-		if err != nil {
-			br.readOffset += read
-			return read, err
-		}
-		err = br.readNextDataBlock()
-		if err != nil {
-			br.readOffset += read
-			return read, err
-		}
-		for ; read < len(p); read++ {
-			if br.readOffset+read < len(br.data) {
-				p[read] = br.data[br.readOffset+read]
-			} else {
-				break
-			}
-		}
-	}
-	br.readOffset += read
-	if read != len(p) {
-		return read, errors.New("Didn't read enough data")
-	}
-	return read, nil
-}
-
-//Seek will seek to the specified location (if possible). Seeking is relative to the uncompressed data.
-//When io.SeekCurrent or io.SeekStart is set, if seeking would put the offset beyond the current cached data, it will try to read the next data blocks to accomodate. On a failure it will seek to the end of the data.
-//When io.SeekEnd is set, it wil seek reletive to the currently cached data.
-func (br *metadataReader) Seek(offset int64, whence int) (int64, error) {
-	switch whence {
-	case io.SeekCurrent:
-		br.readOffset += int(offset)
-		for {
-			if br.readOffset < len(br.data) {
-				break
-			}
-			err := br.parseMetadata()
-			if err != nil {
-				br.readOffset = len(br.data)
-				return int64(br.readOffset), err
-			}
-			err = br.readNextDataBlock()
-			if err != nil {
-				br.readOffset = len(br.data)
-				return int64(br.readOffset), err
-			}
-		}
-	case io.SeekStart:
-		br.readOffset = int(offset)
-		for {
-			if br.readOffset < len(br.data) {
-				break
-			}
-			err := br.parseMetadata()
-			if err != nil {
-				br.readOffset = len(br.data)
-				return int64(br.readOffset), err
-			}
-			err = br.readNextDataBlock()
-			if err != nil {
-				br.readOffset = len(br.data)
-				return int64(br.readOffset), err
-			}
-		}
-	case io.SeekEnd:
-		br.readOffset = len(br.data) - int(offset)
-		if br.readOffset < 0 {
-			br.readOffset = 0
-			return int64(br.readOffset), errors.New("Trying to seek to a negative value")
-		}
-	}
-	return int64(br.readOffset), nil
-}

reader.go

@@ -1,257 +1,37 @@
 package squashfs
 
 import (
-	"encoding/binary"
-	"errors"
 	"io"
-	"math"
 	"time"
 
-	"github.com/CalebQ42/squashfs/internal/compression"
-	"github.com/CalebQ42/squashfs/internal/inode"
+	"github.com/CalebQ42/squashfs/internal/toreader"
+	squashfslow "github.com/CalebQ42/squashfs/low"
 )
 
-const (
-	magic = 0x73717368
-)
-
-var (
-	//ErrNoMagic is returned if the magic number in the superblock isn't correct.
-	errNoMagic = errors.New("Magic number doesn't match. Either isn't a squashfs or corrupted")
-	//ErrIncompatibleCompression is returned if the compression type in the superblock doesn't work.
-	errIncompatibleCompression = errors.New("Compression type unsupported")
-	//ErrCompressorOptions is returned if compressor options is present. It's not currently supported.
-	errCompressorOptions = errors.New("Compressor options is not currently supported")
-	//ErrOptions is returned when compression options that I haven't tested is set. When this is returned, the Reader is also returned.
-	ErrOptions = errors.New("Possibly incompatible compressor options")
-)
-
-//Reader processes and reads a squashfs archive.
 type Reader struct {
-	r            io.ReaderAt
-	super        superblock
-	flags        superblockFlags
-	decompressor compression.Decompressor
-	fragOffsets  []uint64
-	idTable      []uint32
+	FS
+	Low squashfslow.Reader
 }
 
-//NewSquashfsReader returns a new squashfs.Reader from an io.ReaderAt
-func NewSquashfsReader(r io.ReaderAt) (*Reader, error) {
-	hasUnsupportedOptions := false
-	var rdr Reader
-	rdr.r = r
-	err := binary.Read(io.NewSectionReader(rdr.r, 0, int64(binary.Size(rdr.super))), binary.LittleEndian, &rdr.super)
+func NewReader(r io.ReaderAt) (Reader, error) {
+	rdr, err := squashfslow.NewReader(r)
 	if err != nil {
-		return nil, err
+		return Reader{}, err
 	}
-	if rdr.super.Magic != magic {
-		return nil, errNoMagic
+	out := Reader{
+		Low: rdr,
 	}
-	// if rdr.super.BlockLog == uint16(math.Log2(float64(rdr.super.BlockSize))) {
-	// 	return nil, errors.New("BlockSize and BlockLog doesn't match. The archive is probably corrupt")
-	// }
-	rdr.flags = rdr.super.GetFlags()
-	if rdr.flags.CompressorOptions {
-		switch rdr.super.CompressionType {
-		case gzipCompression:
-			gzip, err := compression.NewGzipCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
-			if err != nil {
-				return nil, err
-			}
-			if gzip.HasCustomWindow || gzip.HasStrategies {
-				hasUnsupportedOptions = true
-			}
-			rdr.decompressor = gzip
-		case xzCompression:
-			xz, err := compression.NewXzCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
-			if err != nil {
-				return nil, err
-			}
-			if xz.HasFilters {
-				return nil, errors.New("XZ compression options has filters. These are not yet supported")
-			}
-			rdr.decompressor = xz
-		case lz4Compression:
-			lz4, err := compression.NewLz4CompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 8))
-			if err != nil {
-				return nil, err
-			}
-			if lz4.HC {
-				hasUnsupportedOptions = true
-			}
-			rdr.decompressor = lz4
-		case zstdCompression:
-			zstd, err := compression.NewZstdCompressorWithOptions(io.NewSectionReader(rdr.r, int64(binary.Size(rdr.super)), 4))
-			if err != nil {
-				return nil, err
-			}
-			rdr.decompressor = zstd
-		default:
-			return nil, errCompressorOptions
-		}
-	} else {
-		switch rdr.super.CompressionType {
-		case gzipCompression:
-			rdr.decompressor = &compression.Gzip{}
-		case lzmaCompression:
-			rdr.decompressor = &compression.Lzma{}
-		case xzCompression:
-			rdr.decompressor = &compression.Xz{}
-		case lz4Compression:
-			rdr.decompressor = &compression.Lz4{}
-		case zstdCompression:
-			rdr.decompressor = &compression.Zstd{}
-		default:
-			//TODO: all compression types.
-			return nil, errIncompatibleCompression
-		}
+	out.FS = FS{
+		LowDir: rdr.Root,
+		r:   &out,
 	}
-	fragBlocks := int(math.Ceil(float64(rdr.super.FragCount) / 512))
-	if fragBlocks > 0 {
-		offset := int64(rdr.super.FragTableStart)
-		for i := 0; i < fragBlocks; i++ {
-			tmp := make([]byte, 8)
-			_, err = r.ReadAt(tmp, offset)
-			if err != nil {
-				return nil, err
-			}
-			rdr.fragOffsets = append(rdr.fragOffsets, binary.LittleEndian.Uint64(tmp))
-			offset += 8
-		}
-	}
-	unread := rdr.super.IDCount
-	blockOffsets := make([]uint64, int(math.Ceil(float64(rdr.super.IDCount)/2048)))
-	for i := range blockOffsets {
-		secRdr := io.NewSectionReader(r, int64(rdr.super.IDTableStart)+(8*int64(i)), 8)
-		err = binary.Read(secRdr, binary.LittleEndian, &blockOffsets[i])
-		if err != nil {
-			return nil, err
-		}
-		idRdr, err := rdr.newMetadataReader(int64(blockOffsets[i]))
-		if err != nil {
-			return nil, err
-		}
-		read := uint16(math.Min(float64(unread), 2048))
-		for i := uint16(0); i < read; i++ {
-			var tmp uint32
-			err = binary.Read(idRdr, binary.LittleEndian, &tmp)
-			if err != nil {
-				return nil, err
-			}
-			rdr.idTable = append(rdr.idTable, tmp)
-		}
-		unread -= read
-	}
-	if hasUnsupportedOptions {
-		return &rdr, ErrOptions
-	}
-	return &rdr, nil
+	return out, nil
+}
+
+func NewReaderAtOffset(r io.ReaderAt, offset int64) (Reader, error) {
+	return NewReader(toreader.NewOffsetReader(r, offset))
 }
 
-//ModTime is the last time the file was modified/created.
 func (r *Reader) ModTime() time.Time {
-	return time.Unix(int64(r.super.CreationTime), 0)
-}
-
-//ExtractTo tries to extract ALL files to the given path. This is the same as getting the root folder and extracting that.
-func (r *Reader) ExtractTo(path string) []error {
-	root, err := r.GetRootFolder()
-	if err != nil {
-		return []error{err}
-	}
-	return root.ExtractTo(path)
-}
-
-//GetRootFolder returns a squashfs.File that references the root directory of the squashfs archive.
-func (r *Reader) GetRootFolder() (root *File, err error) {
-	root = new(File)
-	mr, err := r.newMetadataReaderFromInodeRef(r.super.RootInodeRef)
-	if err != nil {
-		return nil, err
-	}
-	root.in, err = inode.ProcessInode(mr, r.super.BlockSize)
-	if err != nil {
-		return nil, err
-	}
-	root.path = "/"
-	root.filType = root.in.Type
-	root.r = r
-	return root, nil
-}
-
-//GetAllFiles returns a slice of ALL files and folders contained in the squashfs.
-func (r *Reader) GetAllFiles() (fils []*File, err error) {
-	root, err := r.GetRootFolder()
-	if err != nil {
-		return nil, err
-	}
-	return root.GetChildrenRecursively()
-}
-
-//FindFile returns the first file (in the same order as Reader.GetAllFiles) that the given function returns true for. Returns nil if nothing is found.
-func (r *Reader) FindFile(query func(*File) bool) *File {
-	root, err := r.GetRootFolder()
-	if err != nil {
-		return nil
-	}
-	fils, err := root.GetChildren()
-	if err != nil {
-		return nil
-	}
-	var childrenDirs []*File
-	for _, fil := range fils {
-		if query(fil) {
-			return fil
-		}
-		if fil.IsDir() {
-			childrenDirs = append(childrenDirs, fil)
-		}
-	}
-	for len(childrenDirs) != 0 {
-		var tmp []*File
-		for _, dirs := range childrenDirs {
-			chil, err := dirs.GetChildren()
-			if err != nil {
-				return nil
-			}
-			for _, child := range chil {
-				if query(child) {
-					return child
-				}
-				if child.IsDir() {
-					tmp = append(tmp, child)
-				}
-			}
-		}
-		childrenDirs = tmp
-	}
-	return nil
-}
-
-//FindAll returns all files where the given function returns true.
-func (r *Reader) FindAll(query func(*File) bool) (all []*File) {
-	root, err := r.GetRootFolder()
-	if err != nil {
-		return nil
-	}
-	fils, err := root.GetChildrenRecursively()
-	if err != nil {
-		return nil
-	}
-	for _, fil := range fils {
-		if query(fil) {
-			all = append(all, fil)
-		}
-	}
-	return
-}
-
-//GetFileAtPath will return the file at the given path. If the file cannot be found, will return nil.
-func (r *Reader) GetFileAtPath(path string) *File {
-	dir, err := r.GetRootFolder()
-	if err != nil {
-		return nil
-	}
-	return dir.GetFileAtPath(path)
+	return time.Unix(int64(r.Low.Superblock.ModTime), 0)
 }

squash_test.go

@@ -1,132 +0,0 @@
-package squashfs
-
-import (
-	"io"
-	"net/http"
-	"os"
-	"testing"
-
-	goappimage "github.com/CalebQ42/GoAppImage"
-)
-
-const (
-	downloadURL  = "https://github.com/Swordfish90/cool-retro-term/releases/download/1.1.1/Cool-Retro-Term-1.1.1-x86_64.AppImage"
-	appImageName = "Cool-Retro-Term.AppImage"
-	squashfsName = "airootfs.sfs" //testing with a ArchLinux root fs from the live img
-)
-
-//Right now, don't use. Arch linux sfs uses XZ compression with filters, which isn't supported
-func TestSquashfs(t *testing.T) {
-	wd, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-	squashFil, err := os.Open(wd + "/testing/" + squashfsName)
-	if err != nil {
-		t.Fatal(err)
-	}
-	rdr, err := NewSquashfsReader(squashFil)
-	if err != nil {
-		t.Fatal(err)
-	}
-	os.RemoveAll(wd + "/testing/" + squashfsName + ".d")
-	root, _ := rdr.GetRootFolder()
-	errs := root.ExtractWithOptions(wd+"/testing/"+squashfsName+".d", false, false, os.ModePerm, true)
-	t.Fatal(errs)
-}
-
-func TestAppImage(t *testing.T) {
-	t.Parallel()
-	wd, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-	aiFil, err := os.Open(wd + "/testing/" + appImageName)
-	if os.IsNotExist(err) {
-		downloadTestAppImage(t, wd+"/testing")
-		aiFil, err = os.Open(wd + "/testing/" + appImageName)
-		if err != nil {
-			t.Fatal(err)
-		}
-	} else if err != nil {
-		t.Fatal(err)
-	}
-	defer aiFil.Close()
-	stat, _ := aiFil.Stat()
-	ai := goappimage.NewAppImage(wd + "/testing/" + appImageName)
-	rdr, err := NewSquashfsReader(io.NewSectionReader(aiFil, ai.Offset, stat.Size()-ai.Offset))
-	if err != nil {
-		t.Fatal(err)
-	}
-	errs := rdr.ExtractTo(wd + "/testing/cool-retro")
-	if len(errs) > 0 {
-		t.Fatal(errs)
-	}
-	// os.RemoveAll(wd + "/testing/" + appImageName + ".d")
-	// root, _ := rdr.GetRootFolder()
-	// errs := root.ExtractWithOptions(wd+"/testing/"+appImageName+".d", true, os.ModePerm, true)
-	// t.Fatal(errs)
-	t.Fatal("No problemo!")
-}
-
-func downloadTestAppImage(t *testing.T, dir string) {
-	//seems to time out on slow connections. Might fix that at some point... or not. It's just a test...
-	os.Mkdir(dir, os.ModePerm)
-	appImage, err := os.Create(dir + "/" + appImageName)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer appImage.Close()
-	check := http.Client{
-		CheckRedirect: func(r *http.Request, _ []*http.Request) error {
-			r.URL.Opaque = r.URL.Path
-			return nil
-		},
-	}
-	resp, err := check.Get(downloadURL)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer resp.Body.Close()
-	_, err = io.Copy(appImage, resp.Body)
-	if err != nil {
-		t.Fatal(err)
-	}
-}
-
-func TestCreateSquashFromAppImage(t *testing.T) {
-	wd, err := os.Getwd()
-	if err != nil {
-		t.Fatal(err)
-	}
-	err = os.Mkdir(wd+"/testing", 0777)
-	if err != nil && !os.IsExist(err) {
-		t.Fatal(err)
-	}
-	_, err = os.Open(wd + "/testing/" + appImageName)
-	if os.IsNotExist(err) {
-		downloadTestAppImage(t, wd+"/testing")
-		_, err = os.Open(wd + "/testing/" + appImageName)
-		if err != nil {
-			t.Fatal(err)
-		}
-	} else if err != nil {
-		t.Fatal(err)
-	}
-	ai := goappimage.NewAppImage(wd + "/testing/" + appImageName)
-	aiFil, err := os.Open(wd + "/testing/" + appImageName)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer aiFil.Close()
-	aiFil.Seek(ai.Offset, 0)
-	os.Remove(wd + "/testing/" + appImageName + ".squashfs")
-	aiSquash, err := os.Create(wd + "/testing/" + appImageName + ".squashfs")
-	if err != nil {
-		t.Fatal(err)
-	}
-	_, err = io.Copy(aiSquash, aiFil)
-	if err != nil {
-		t.Fatal(err)
-	}
-}

squashfs_test.go

@@ -0,0 +1,209 @@
+package squashfs
+
+//Actually proper tests go here.
+
+import (
+	"errors"
+	"io"
+	"io/fs"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"testing"
+	"time"
+)
+
+const (
+	squashfsURL  = "https://darkstorm.tech/files/LinuxPATest.sfs"
+	squashfsName = "tensorflow.sqfs"
+)
+
+func preTest(dir string) (fil *os.File, err error) {
+	fil, err = os.Open(filepath.Join(dir, squashfsName))
+	if err != nil {
+		_, err = os.Open(dir)
+		if os.IsNotExist(err) {
+			err = os.Mkdir(dir, 0755)
+		}
+		if err != nil {
+			return
+		}
+		os.Remove(filepath.Join(dir, squashfsName))
+		fil, err = os.Create(filepath.Join(dir, squashfsName))
+		if err != nil {
+			return
+		}
+		var resp *http.Response
+		resp, err = http.DefaultClient.Get(squashfsURL)
+		if err != nil {
+			return
+		}
+		_, err = io.Copy(fil, resp.Body)
+		if err != nil {
+			return
+		}
+	}
+	_, err = exec.LookPath("unsquashfs")
+	if err != nil {
+		return
+	}
+	_, err = exec.LookPath("mksquashfs")
+	return
+}
+
+func TestMisc(t *testing.T) {
+	tmpDir := "testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	_ = rdr
+	// Put testing here
+	// 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)
+	if err != nil {
+		b.Fatal(err)
+	}
+	libPath := filepath.Join(tmpDir, "ExtractLib")
+	unsquashPath := filepath.Join(tmpDir, "ExtractSquashfs")
+	os.RemoveAll(libPath)
+	os.RemoveAll(unsquashPath)
+	var libTime, unsquashTime time.Duration
+	start := time.Now()
+	rdr, err := NewReader(fil)
+	if err != nil {
+		b.Fatal(err)
+	}
+	err = rdr.ExtractWithOptions(libPath, FastOptions())
+	if err != nil {
+		b.Fatal(err)
+	}
+	libTime = time.Since(start)
+	cmd := exec.Command("unsquashfs", "-q", "-d", unsquashPath, fil.Name())
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	start = time.Now()
+	err = cmd.Run()
+	if err != nil {
+		b.Log("Unsquashfs error:", err)
+	}
+	unsquashTime = time.Since(start)
+	b.Log("Library took:", libTime.Round(time.Millisecond))
+	b.Log("unsquashfs took:", unsquashTime.Round(time.Millisecond))
+	b.Log("unsquashfs is", strconv.FormatFloat(float64(libTime.Milliseconds())/float64(unsquashTime.Milliseconds()), 'f', 2, 64), "times faster")
+}
+
+func TestExtractQuick(t *testing.T) {
+	//First, setup everything and extract the archive using the library and unsquashfs
+
+	// tmpDir := bTempDir()
+	tmpDir := "testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	libPath := filepath.Join(tmpDir, "ExtractLib")
+	unsquashPath := filepath.Join(tmpDir, "ExtractSquashfs")
+	os.RemoveAll(libPath)
+	os.RemoveAll(unsquashPath)
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.RemoveAll(filepath.Join(tmpDir, "testLog.txt"))
+	logFil, _ := os.Create(filepath.Join(tmpDir, "testLog.txt"))
+	op := FastOptions()
+	op.Verbose = true
+	op.IgnorePerm = true
+	op.LogOutput = logFil
+	err = rdr.ExtractWithOptions(libPath, op)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cmd := exec.Command("unsquashfs", "-d", unsquashPath, fil.Name())
+	err = cmd.Run()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	//Then compare the sizes and existance between the two (using unsquashfs as a reference).
+	//If the file doesn't exist, or the size is different, we exit.
+	//TODO: Add long test that checks contents.
+
+	squashFils := os.DirFS(unsquashPath)
+	err = fs.WalkDir(squashFils, ".", func(path string, _ fs.DirEntry, _ error) error {
+		libFil, e := os.Open(filepath.Join(libPath, path))
+		if e != nil {
+			return e
+		}
+		sfsFile, e := os.Open(filepath.Join(unsquashPath, path))
+		if e != nil {
+			return e
+		}
+		sfsStat, _ := sfsFile.Stat()
+		libStat, _ := libFil.Stat()
+		if sfsStat.Size() != libStat.Size() {
+			t.Log(libFil.Name(), "not the same size between library and unsquashfs")
+			t.Log("File is", libStat.Size())
+			t.Log("Should be", sfsStat.Size())
+			return errors.New("file not the correct size")
+		}
+		return nil
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+var filePath = "usr/sbin/add-shell"
+
+func TestSingleFile(t *testing.T) {
+	tmpDir := "testing"
+	fil, err := preTest(tmpDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	os.RemoveAll("testing/stuff")
+	rdr, err := NewReader(fil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	f, err := rdr.Open(filePath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	op := DefaultOptions()
+	op.Verbose = true
+	err = f.(*File).ExtractWithOptions("testing/stuff", op)
+	if err != nil {
+		t.Fatal(err)
+	}
+}

superblock.go

@@ -1,67 +0,0 @@
-package squashfs
-
-const (
-	gzipCompression = 1 + iota
-	lzmaCompression
-	lzoCompression
-	xzCompression
-	lz4Compression
-	zstdCompression
-)
-
-//Superblock contains important information about a squashfs file. Located at the very front of the archive.
-type superblock struct {
-	Magic            uint32
-	InodeCount       uint32
-	CreationTime     uint32
-	BlockSize        uint32
-	FragCount        uint32
-	CompressionType  uint16
-	BlockLog         uint16
-	Flags            uint16
-	IDCount          uint16
-	MajorVersion     uint16
-	MinorVersion     uint16
-	RootInodeRef     uint64
-	BytesUsed        uint64
-	IDTableStart     uint64
-	XattrTableStart  uint64
-	InodeTableStart  uint64
-	DirTableStart    uint64
-	FragTableStart   uint64
-	ExportTableStart uint64
-}
-
-//SuperblockFlags is the parsed version of Superblock.Flags
-type superblockFlags struct {
-	UncompressedInodes    bool
-	UncompressedData      bool
-	Check                 bool
-	UncompressedFragments bool
-	NoFragments           bool
-	AlwaysFragments       bool
-	Duplicates            bool
-	Exportable            bool
-	UncompressedXattr     bool
-	NoXattr               bool
-	CompressorOptions     bool
-	UncompressedIDs       bool
-}
-
-//GetFlags returns a SuperblockFlags for a given superblock.
-func (s *superblock) GetFlags() superblockFlags {
-	return superblockFlags{
-		UncompressedInodes:    s.Flags&0x1 == 0x1,
-		UncompressedData:      s.Flags&0x2 == 0x2,
-		Check:                 s.Flags&0x4 == 0x4,
-		UncompressedFragments: s.Flags&0x8 == 0x8,
-		NoFragments:           s.Flags&0x10 == 0x10,
-		AlwaysFragments:       s.Flags&0x20 == 0x20,
-		Duplicates:            s.Flags&0x40 == 0x40,
-		Exportable:            s.Flags&0x80 == 0x80,
-		UncompressedXattr:     s.Flags&0x100 == 0x100,
-		NoXattr:               s.Flags&0x200 == 0x200,
-		CompressorOptions:     s.Flags&0x400 == 0x400,
-		UncompressedIDs:       s.Flags&0x800 == 0x800,
-	}
-}