package khepri import ( "errors" "fmt" "os" "path/filepath" "github.com/fd0/khepri/backend" ) type Restorer struct { be backend.Server key *Key ch *ContentHandler sn *Snapshot Error func(dir string, node *Node, err error) error Filter func(item string, node *Node) bool } // NewRestorer creates a restorer preloaded with the content from the snapshot snid. func NewRestorer(be backend.Server, key *Key, snid backend.ID) (*Restorer, error) { r := &Restorer{ be: be, key: key, } var err error r.ch, err = NewContentHandler(be, key) if err != nil { return nil, err } r.sn, err = r.ch.LoadSnapshot(snid) if err != nil { return nil, err } // abort on all errors r.Error = func(string, *Node, error) error { return err } // allow all files r.Filter = func(string, *Node) bool { return true } return r, nil } func (res *Restorer) to(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, err) } for _, node := range tree { p := filepath.Join(dir, node.Name) if !res.Filter(p, node) { continue } err := node.CreateAt(res.ch, p) if err != nil { err = res.Error(p, node, err) 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)) } err = res.to(p, node.Subtree) if err != nil { err = res.Error(p, node, err) 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 { err := os.MkdirAll(dir, 0700) if err != nil && err != os.ErrExist { return err } return res.to(dir, res.sn.Content) } func (res *Restorer) Snapshot() *Snapshot { return res.sn }