package local import ( "errors" "fmt" "io" "io/ioutil" "os" "path/filepath" "sort" "sync" "github.com/restic/restic/backend" ) var ErrWrongData = errors.New("wrong data returned by backend, checksum does not match") type Local struct { p string mu sync.Mutex open map[string][]*os.File // Contains open files. Guarded by 'mu'. } // Open opens the local backend as specified by config. func Open(dir string) (*Local, error) { items := []string{ dir, filepath.Join(dir, backend.Paths.Data), filepath.Join(dir, backend.Paths.Snapshots), filepath.Join(dir, backend.Paths.Index), filepath.Join(dir, backend.Paths.Locks), filepath.Join(dir, backend.Paths.Keys), filepath.Join(dir, backend.Paths.Temp), } // test if all necessary dirs are there for _, d := range items { if _, err := os.Stat(d); err != nil { return nil, fmt.Errorf("%s does not exist", d) } } return &Local{p: dir, open: make(map[string][]*os.File)}, nil } // Create creates all the necessary files and directories for a new local // backend at dir. Afterwards a new config blob should be created. func Create(dir string) (*Local, error) { dirs := []string{ dir, filepath.Join(dir, backend.Paths.Data), filepath.Join(dir, backend.Paths.Snapshots), filepath.Join(dir, backend.Paths.Index), filepath.Join(dir, backend.Paths.Locks), filepath.Join(dir, backend.Paths.Keys), filepath.Join(dir, backend.Paths.Temp), } // test if config file already exists _, err := os.Lstat(filepath.Join(dir, backend.Paths.Config)) if err == nil { return nil, errors.New("config file already exists") } // create paths for data, refs and temp for _, d := range dirs { err := os.MkdirAll(d, backend.Modes.Dir) if err != nil { return nil, err } } // open backend return Open(dir) } // Location returns this backend's location (the directory name). func (b *Local) Location() string { return b.p } // Return temp directory in correct directory for this backend. func (b *Local) tempFile() (*os.File, error) { return ioutil.TempFile(filepath.Join(b.p, backend.Paths.Temp), "temp-") } type localBlob struct { f *os.File size uint final bool basedir string } func (lb *localBlob) Write(p []byte) (int, error) { if lb.final { return 0, errors.New("blob already closed") } n, err := lb.f.Write(p) lb.size += uint(n) return n, err } func (lb *localBlob) Size() uint { return lb.size } func (lb *localBlob) Finalize(t backend.Type, name string) error { if lb.final { return errors.New("Already finalized") } lb.final = true err := lb.f.Close() if err != nil { return fmt.Errorf("local: file.Close: %v", err) } f := filename(lb.basedir, t, name) // create directories if necessary, ignore errors if t == backend.Data { os.MkdirAll(filepath.Dir(f), backend.Modes.Dir) } // test if new path already exists if _, err := os.Stat(f); err == nil { return fmt.Errorf("Close(): file %v already exists", f) } if err := os.Rename(lb.f.Name(), f); err != nil { return err } // set mode to read-only fi, err := os.Stat(f) if err != nil { return err } return setNewFileMode(f, fi) } // Create creates a new Blob. The data is available only after Finalize() // has been called on the returned Blob. func (b *Local) Create() (backend.Blob, error) { // TODO: make sure that tempfile is removed upon error // create tempfile in backend file, err := b.tempFile() if err != nil { return nil, err } blob := localBlob{ f: file, basedir: b.p, } b.mu.Lock() open, _ := b.open["blobs"] b.open["blobs"] = append(open, file) b.mu.Unlock() return &blob, nil } // Construct path for given Type and name. func filename(base string, t backend.Type, name string) string { if t == backend.Config { return filepath.Join(base, "config") } return filepath.Join(dirname(base, t, name), name) } // Construct directory for given Type. func dirname(base string, t backend.Type, name string) string { var n string switch t { case backend.Data: n = backend.Paths.Data if len(name) > 2 { n = filepath.Join(n, name[:2]) } case backend.Snapshot: n = backend.Paths.Snapshots case backend.Index: n = backend.Paths.Index case backend.Lock: n = backend.Paths.Locks case backend.Key: n = backend.Paths.Keys } return filepath.Join(base, n) } // Get returns a reader that yields the content stored under the given // name. The reader should be closed after draining it. func (b *Local) Get(t backend.Type, name string) (io.ReadCloser, error) { file, err := os.Open(filename(b.p, t, name)) if err != nil { return nil, err } b.mu.Lock() open, _ := b.open[filename(b.p, t, name)] b.open[filename(b.p, t, name)] = append(open, file) b.mu.Unlock() return file, nil } // GetReader returns an io.ReadCloser for the Blob with the given name of // type t at offset and length. If length is 0, the reader reads until EOF. func (b *Local) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) { f, err := os.Open(filename(b.p, t, name)) if err != nil { return nil, err } b.mu.Lock() open, _ := b.open[filename(b.p, t, name)] b.open[filename(b.p, t, name)] = append(open, f) b.mu.Unlock() if offset > 0 { _, err = f.Seek(int64(offset), 0) if err != nil { return nil, err } } if length == 0 { return f, nil } return backend.LimitReadCloser(f, int64(length)), nil } // Test returns true if a blob of the given type and name exists in the backend. func (b *Local) Test(t backend.Type, name string) (bool, error) { _, err := os.Stat(filename(b.p, t, name)) if err != nil { if os.IsNotExist(err) { return false, nil } return false, err } return true, nil } // Remove removes the blob with the given name and type. func (b *Local) Remove(t backend.Type, name string) error { // close all open files we may have. fn := filename(b.p, t, name) b.mu.Lock() open, _ := b.open[fn] for _, file := range open { file.Close() } b.open[fn] = nil b.mu.Unlock() // reset read-only flag err := os.Chmod(fn, 0666) if err != nil { return err } return os.Remove(fn) } // List returns a channel that yields all names of blobs of type t. A // goroutine is started for this. If the channel done is closed, sending // stops. func (b *Local) List(t backend.Type, done <-chan struct{}) <-chan string { // TODO: use os.Open() and d.Readdirnames() instead of Glob() var pattern string if t == backend.Data { pattern = filepath.Join(dirname(b.p, t, ""), "*", "*") } else { pattern = filepath.Join(dirname(b.p, t, ""), "*") } ch := make(chan string) matches, err := filepath.Glob(pattern) if err != nil { close(ch) return ch } for i := range matches { matches[i] = filepath.Base(matches[i]) } sort.Strings(matches) go func() { defer close(ch) for _, m := range matches { if m == "" { continue } select { case ch <- m: case <-done: return } } }() return ch } // Delete removes the repository and all files. func (b *Local) Delete() error { b.Close() return os.RemoveAll(b.p) } // Close closes all open files. // They may have been closed already, // so we ignore all errors. func (b *Local) Close() error { b.mu.Lock() for _, open := range b.open { for _, file := range open { file.Close() } } b.open = make(map[string][]*os.File) b.mu.Unlock() return nil }