forked from mirror/afero
140 lines
3.0 KiB
Go
140 lines
3.0 KiB
Go
// package tarfs implements a read-only in-memory representation of a tar archive
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package tarfs
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import (
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"archive/tar"
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"bytes"
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"io"
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"os"
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"path/filepath"
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"syscall"
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"time"
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"git.internal/re/afero"
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)
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type Fs struct {
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files map[string]map[string]*File
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}
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func splitpath(name string) (dir, file string) {
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name = filepath.ToSlash(name)
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if len(name) == 0 || name[0] != '/' {
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name = "/" + name
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}
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name = filepath.Clean(name)
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dir, file = filepath.Split(name)
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dir = filepath.Clean(dir)
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return
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}
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func New(t *tar.Reader) *Fs {
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fs := &Fs{files: make(map[string]map[string]*File)}
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for {
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hdr, err := t.Next()
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if err == io.EOF {
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break
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}
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if err != nil {
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return nil
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}
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d, f := splitpath(hdr.Name)
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if _, ok := fs.files[d]; !ok {
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fs.files[d] = make(map[string]*File)
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}
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var buf bytes.Buffer
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size, err := buf.ReadFrom(t)
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if err != nil {
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panic("tarfs: reading from tar:" + err.Error())
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}
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if size != hdr.Size {
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panic("tarfs: size mismatch")
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}
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file := &File{
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h: hdr,
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data: bytes.NewReader(buf.Bytes()),
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fs: fs,
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}
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fs.files[d][f] = file
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}
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if fs.files[afero.FilePathSeparator] == nil {
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fs.files[afero.FilePathSeparator] = make(map[string]*File)
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}
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// Add a pseudoroot
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fs.files[afero.FilePathSeparator][""] = &File{
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h: &tar.Header{
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Name: afero.FilePathSeparator,
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Typeflag: tar.TypeDir,
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Size: 0,
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},
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data: bytes.NewReader(nil),
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fs: fs,
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}
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return fs
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}
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func (fs *Fs) Open(name string) (afero.File, error) {
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d, f := splitpath(name)
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if _, ok := fs.files[d]; !ok {
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return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT}
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}
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file, ok := fs.files[d][f]
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if !ok {
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return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOENT}
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}
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nf := *file
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return &nf, nil
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}
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func (fs *Fs) Name() string { return "tarfs" }
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func (fs *Fs) Create(name string) (afero.File, error) { return nil, syscall.EROFS }
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func (fs *Fs) Mkdir(name string, perm os.FileMode) error { return syscall.EROFS }
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func (fs *Fs) MkdirAll(path string, perm os.FileMode) error { return syscall.EROFS }
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func (fs *Fs) OpenFile(name string, flag int, perm os.FileMode) (afero.File, error) {
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if flag != os.O_RDONLY {
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return nil, &os.PathError{Op: "open", Path: name, Err: syscall.EPERM}
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}
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return fs.Open(name)
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}
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func (fs *Fs) Remove(name string) error { return syscall.EROFS }
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func (fs *Fs) RemoveAll(path string) error { return syscall.EROFS }
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func (fs *Fs) Rename(oldname string, newname string) error { return syscall.EROFS }
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func (fs *Fs) Stat(name string) (os.FileInfo, error) {
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d, f := splitpath(name)
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if _, ok := fs.files[d]; !ok {
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return nil, &os.PathError{Op: "stat", Path: name, Err: syscall.ENOENT}
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}
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file, ok := fs.files[d][f]
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if !ok {
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return nil, &os.PathError{Op: "stat", Path: name, Err: syscall.ENOENT}
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}
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return file.h.FileInfo(), nil
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}
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func (fs *Fs) Chmod(name string, mode os.FileMode) error { return syscall.EROFS }
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func (fs *Fs) Chown(name string, uid, gid int) error { return syscall.EROFS }
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func (fs *Fs) Chtimes(name string, atime time.Time, mtime time.Time) error { return syscall.EROFS }
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