Rename squashfs/squashfs to squashfs/low

squashfs/low library name is now squashfslow

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 {
+	Base
+	Entries []directory.Entry
+}
+
+func (r *Reader) directoryFromRef(ref uint64, name string) (*Directory, error) {
+	i, err := r.InodeFromRef(ref)
+	if err != nil {
+		return nil, 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 nil, 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 nil, err
+	}
+	entries, err := directory.ReadDirectory(dirRdr, size)
+	if err != nil {
+		return nil, err
+	}
+	return &Directory{
+		Base:    *r.BaseFromInode(i, name),
+		Entries: entries,
+	}, nil
+}
+
+func (d *Directory) Open(r *Reader, path string) (*Base, error) {
+	path = filepath.Clean(path)
+	if path == "." || path == "" {
+		return &d.Base, 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 nil, fs.ErrNotExist
+	}
+	b, err := r.BaseFromEntry(d.Entries[i])
+	if err != nil {
+		return nil, err
+	}
+	if len(split) == 1 {
+		return b, nil
+	} else if !b.IsDir() {
+		return nil, fs.ErrNotExist
+	}
+	dir, err := b.ToDir(r)
+	if err != nil {
+		return nil, err
+	}
+	return dir.Open(r, strings.Join(split[1:], "/"))
+}