Merge branch 'restore-pattern', closes #69

cmd/restic/cmd_restore.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"github.com/restic/restic"
 	"github.com/restic/restic/backend"
@@ -21,11 +22,11 @@ func init() {
 }
 
 func (cmd CmdRestore) Usage() string {
-	return "snapshot-ID TARGETDIR"
+	return "snapshot-ID TARGETDIR [PATTERN]"
 }
 
 func (cmd CmdRestore) Execute(args []string) error {
-	if len(args) != 2 {
+	if len(args) < 2 || len(args) > 3 {
 		return fmt.Errorf("wrong number of arguments, Usage: %s", cmd.Usage())
 	}
 
@@ -64,6 +65,18 @@ func (cmd CmdRestore) Execute(args []string) error {
 		return err
 	}
 
+	// TODO: a filter against the full path sucks as filepath.Match doesn't match
+	// directory separators on '*'. still, it's better than nothing.
+	if len(args) > 2 {
+		res.Filter = func(item string, dstpath string, node *restic.Node) bool {
+			matched, err := filepath.Match(item, args[2])
+			if err != nil {
+				panic(err)
+			}
+			return matched
+		}
+	}
+
 	fmt.Printf("restoring %s to %s\n", res.Snapshot(), target)
 
 	err = res.RestoreTo(target)

restorer.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"syscall"
 
 	"github.com/juju/arrar"
 	"github.com/restic/restic/backend"
@@ -16,7 +17,7 @@ type Restorer struct {
 	sn *Snapshot
 
 	Error  func(dir string, node *Node, err error) error
-	Filter func(item string, node *Node) bool
+	Filter func(item string, dstpath string, node *Node) bool
 }
 
 // NewRestorer creates a restorer preloaded with the content from the snapshot snid.
@@ -36,13 +37,11 @@ func NewRestorer(s Server, snid backend.ID) (*Restorer, error) {
 
 	// 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 {
+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 {
@@ -50,16 +49,32 @@ func (res *Restorer) to(dir string, tree_id backend.ID) error {
 	}
 
 	for _, node := range tree {
-		p := filepath.Join(dir, node.Name)
-		if !res.Filter(p, node) {
-			continue
-		}
+		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)
+				}
+			}
 
-		err := node.CreateAt(res.ch, p)
-		if err != nil {
-			err = res.Error(p, node, arrar.Annotate(err, "create node"))
 			if err != nil {
-				return err
+				err = res.Error(dstpath, node, arrar.Annotate(err, "create node"))
+				if err != nil {
+					return err
+				}
 			}
 		}
 
@@ -68,9 +83,10 @@ func (res *Restorer) to(dir string, tree_id backend.ID) error {
 				return errors.New(fmt.Sprintf("Dir without subtree in tree %s", tree_id))
 			}
 
-			err = res.to(p, node.Subtree)
+			subp := filepath.Join(dir, node.Name)
+			err = res.to(dst, subp, node.Subtree)
 			if err != nil {
-				err = res.Error(p, node, arrar.Annotate(err, "restore subtree"))
+				err = res.Error(subp, node, arrar.Annotate(err, "restore subtree"))
 				if err != nil {
 					return err
 				}
@@ -84,12 +100,7 @@ func (res *Restorer) to(dir string, tree_id backend.ID) error {
 // 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.Tree)
+	return res.to(dir, "", res.sn.Tree)
 }
 
 func (res *Restorer) Snapshot() *Snapshot {