package local import ( "context" "io" "os" "path/filepath" "github.com/restic/restic/internal/errors" "github.com/restic/restic/internal/restic" "github.com/restic/restic/internal/backend" "github.com/restic/restic/internal/debug" "github.com/restic/restic/internal/fs" ) // Local is a backend in a local directory. type Local struct { Config backend.Layout } // ensure statically that *Local implements restic.Backend. var _ restic.Backend = &Local{} const defaultLayout = "default" // dirExists returns true if the name exists and is a directory. func dirExists(name string) bool { f, err := fs.Open(name) if err != nil { return false } fi, err := f.Stat() if err != nil { return false } if err = f.Close(); err != nil { return false } return fi.IsDir() } // Open opens the local backend as specified by config. func Open(cfg Config) (*Local, error) { debug.Log("open local backend at %v (layout %q)", cfg.Path, cfg.Layout) l, err := backend.ParseLayout(&backend.LocalFilesystem{}, cfg.Layout, defaultLayout, cfg.Path) if err != nil { return nil, err } be := &Local{Config: cfg, Layout: l} // if data dir exists, make sure that all subdirs also exist datadir := be.Dirname(restic.Handle{Type: restic.DataFile}) if dirExists(datadir) { for _, d := range be.Paths() { if _, err := filepath.Rel(datadir, d); err != nil { continue } err := fs.MkdirAll(d, backend.Modes.Dir) if err != nil { return nil, errors.Wrap(err, "MkdirAll") } } } return be, 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(cfg Config) (*Local, error) { debug.Log("create local backend at %v (layout %q)", cfg.Path, cfg.Layout) l, err := backend.ParseLayout(&backend.LocalFilesystem{}, cfg.Layout, defaultLayout, cfg.Path) if err != nil { return nil, err } be := &Local{ Config: cfg, Layout: l, } // test if config file already exists _, err = fs.Lstat(be.Filename(restic.Handle{Type: restic.ConfigFile})) if err == nil { return nil, errors.New("config file already exists") } // create paths for data and refs for _, d := range be.Paths() { err := fs.MkdirAll(d, backend.Modes.Dir) if err != nil { return nil, errors.Wrap(err, "MkdirAll") } } return be, nil } // Location returns this backend's location (the directory name). func (b *Local) Location() string { return b.Path } // IsNotExist returns true if the error is caused by a non existing file. func (b *Local) IsNotExist(err error) bool { return os.IsNotExist(errors.Cause(err)) } // Save stores data in the backend at the handle. func (b *Local) Save(ctx context.Context, h restic.Handle, rd io.Reader) (err error) { debug.Log("Save %v", h) if err := h.Valid(); err != nil { return err } filename := b.Filename(h) // create new file f, err := fs.OpenFile(filename, os.O_CREATE|os.O_EXCL|os.O_WRONLY, backend.Modes.File) if err != nil { return errors.Wrap(err, "OpenFile") } // save data, then sync _, err = io.Copy(f, rd) if err != nil { _ = f.Close() return errors.Wrap(err, "Write") } if err = f.Sync(); err != nil { _ = f.Close() return errors.Wrap(err, "Sync") } err = f.Close() if err != nil { return errors.Wrap(err, "Close") } // set mode to read-only fi, err := fs.Stat(filename) if err != nil { return errors.Wrap(err, "Stat") } return setNewFileMode(filename, fi) } // Load returns a reader that yields the contents of the file at h at the // given offset. If length is nonzero, only a portion of the file is // returned. rd must be closed after use. func (b *Local) Load(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error) { debug.Log("Load %v, length %v, offset %v", h, length, offset) if err := h.Valid(); err != nil { return nil, err } if offset < 0 { return nil, errors.New("offset is negative") } f, err := fs.Open(b.Filename(h)) if err != nil { return nil, err } if offset > 0 { _, err = f.Seek(offset, 0) if err != nil { _ = f.Close() return nil, err } } if length > 0 { return backend.LimitReadCloser(f, int64(length)), nil } return f, nil } // Stat returns information about a blob. func (b *Local) Stat(ctx context.Context, h restic.Handle) (restic.FileInfo, error) { debug.Log("Stat %v", h) if err := h.Valid(); err != nil { return restic.FileInfo{}, err } fi, err := fs.Stat(b.Filename(h)) if err != nil { return restic.FileInfo{}, errors.Wrap(err, "Stat") } return restic.FileInfo{Size: fi.Size()}, nil } // Test returns true if a blob of the given type and name exists in the backend. func (b *Local) Test(ctx context.Context, h restic.Handle) (bool, error) { debug.Log("Test %v", h) _, err := fs.Stat(b.Filename(h)) if err != nil { if os.IsNotExist(errors.Cause(err)) { return false, nil } return false, errors.Wrap(err, "Stat") } return true, nil } // Remove removes the blob with the given name and type. func (b *Local) Remove(ctx context.Context, h restic.Handle) error { debug.Log("Remove %v", h) fn := b.Filename(h) // reset read-only flag err := fs.Chmod(fn, 0666) if err != nil { return errors.Wrap(err, "Chmod") } return fs.Remove(fn) } func isFile(fi os.FileInfo) bool { return fi.Mode()&(os.ModeType|os.ModeCharDevice) == 0 } // List returns a channel that yields all names of blobs of type t. A // goroutine is started for this. func (b *Local) List(ctx context.Context, t restic.FileType) <-chan string { debug.Log("List %v", t) ch := make(chan string) go func() { defer close(ch) fs.Walk(b.Basedir(t), func(path string, fi os.FileInfo, err error) error { if err != nil { return err } if !isFile(fi) { return err } select { case ch <- filepath.Base(path): case <-ctx.Done(): return err } return err }) }() return ch } // Delete removes the repository and all files. func (b *Local) Delete() error { debug.Log("Delete()") return fs.RemoveAll(b.Path) } // Close closes all open files. func (b *Local) Close() error { debug.Log("Close()") // this does not need to do anything, all open files are closed within the // same function. return nil }