package restic import ( "errors" "fmt" "os" "path/filepath" "syscall" "github.com/juju/arrar" "github.com/restic/restic/backend" ) type Restorer struct { s Server ch *ContentHandler sn *Snapshot Error func(dir string, node *Node, err error) error Filter func(item string, dstpath string, node *Node) bool } // NewRestorer creates a restorer preloaded with the content from the snapshot snid. func NewRestorer(s Server, snid backend.ID) (*Restorer, error) { r := &Restorer{s: s} var err error r.ch, err = NewContentHandler(s) if err != nil { return nil, arrar.Annotate(err, "create contenthandler for restorer") } r.sn, err = r.ch.LoadSnapshot(snid) if err != nil { return nil, arrar.Annotate(err, "load snapshot for restorer") } // abort on all errors r.Error = func(string, *Node, error) error { return err } return r, nil } func (res *Restorer) to(dst string, dir string, tree_id backend.ID) error { tree := Tree{} err := res.ch.LoadJSON(backend.Tree, tree_id, &tree) if err != nil { return res.Error(dir, nil, arrar.Annotate(err, "LoadJSON")) } for _, node := range tree { dstpath := filepath.Join(dst, dir, node.Name) if res.Filter == nil || res.Filter(filepath.Join(res.sn.Dir, dir, node.Name), dstpath, node) { err := node.CreateAt(res.ch, dstpath) // Did it fail because of ENOENT? if arrar.Check(err, func(err error) bool { if pe, ok := err.(*os.PathError); ok { errn, ok := pe.Err.(syscall.Errno) return ok && errn == syscall.ENOENT } return false }) { // Create parent directories and retry err = os.MkdirAll(filepath.Dir(dstpath), 0700) if err == nil || err == os.ErrExist { err = node.CreateAt(res.ch, dstpath) } } if err != nil { err = res.Error(dstpath, node, arrar.Annotate(err, "create node")) if err != nil { return err } } } if node.Type == "dir" { if node.Subtree == nil { return errors.New(fmt.Sprintf("Dir without subtree in tree %s", tree_id)) } subp := filepath.Join(dir, node.Name) err = res.to(dst, subp, node.Subtree) if err != nil { err = res.Error(subp, node, arrar.Annotate(err, "restore subtree")) if err != nil { return err } } } } return nil } // RestoreTo creates the directories and files in the snapshot below dir. // Before an item is created, res.Filter is called. func (res *Restorer) RestoreTo(dir string) error { return res.to(dir, "", res.sn.Tree) } func (res *Restorer) Snapshot() *Snapshot { return res.sn }