Refactor Archiver and backup command

Improve incremental backup by first scanning the tree, loading the old
tree and afterwards comparing both trees in memory.

archiver.go

@@ -1,6 +1,7 @@
 package restic
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -58,6 +59,7 @@ func NewArchiver(s Server, p *Progress) (*Archiver, error) {
 	arch.ch = NewContentHandler(s)
 
 	// load all blobs from all snapshots
+	// TODO: only use bloblist from old snapshot if available
 	err = arch.ch.LoadAllMaps()
 	if err != nil {
 		return nil, err
@@ -96,7 +98,28 @@ func (arch *Archiver) SaveFile(node *Node) error {
 	file, err := os.Open(node.path)
 	defer file.Close()
 	if err != nil {
-		return arrar.Annotate(err, "SaveFile()")
+		return arrar.Annotatef(err, "SaveFile(%v)", node.path)
+	}
+
+	// check file again
+	fi, err := file.Stat()
+	if err != nil {
+		return err
+	}
+
+	if fi.ModTime() != node.ModTime {
+		e2 := arch.Error(node.path, fi, errors.New("file changed as we read it\n"))
+
+		if e2 == nil {
+			// create new node
+			n, err := NodeFromFileInfo(node.path, fi)
+			if err != nil {
+				return err
+			}
+
+			// copy node
+			*node = *n
+		}
 	}
 
 	var blobs Blobs
@@ -203,8 +226,8 @@ func (arch *Archiver) saveTree(t *Tree) (Blob, error) {
 	var wg sync.WaitGroup
 
 	for _, node := range *t {
-		if node.Tree != nil && node.Subtree == nil {
-			b, err := arch.saveTree(node.Tree)
+		if node.tree != nil && node.Subtree == nil {
+			b, err := arch.saveTree(node.tree)
 			if err != nil {
 				return Blob{}, err
 			}
@@ -229,8 +252,6 @@ func (arch *Archiver) saveTree(t *Tree) (Blob, error) {
 				}
 				arch.p.Report(Stat{Files: 1})
 			}(node)
-		} else {
-			arch.p.Report(Stat{Other: 1})
 		}
 	}
 

cmd/restic/cmd_backup.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"os"
+	"path/filepath"
 	"strings"
 	"time"
 
@@ -59,9 +60,9 @@ func format_duration(d time.Duration) string {
 
 func print_tree2(indent int, t *restic.Tree) {
 	for _, node := range *t {
-		if node.Tree != nil {
+		if node.Tree() != nil {
 			fmt.Printf("%s%s/\n", strings.Repeat("  ", indent), node.Name)
-			print_tree2(indent+1, node.Tree)
+			print_tree2(indent+1, node.Tree())
 		} else {
 			fmt.Printf("%s%s\n", strings.Repeat("  ", indent), node.Name)
 		}
@@ -94,7 +95,7 @@ func (cmd CmdBackup) Execute(args []string) error {
 		fmt.Printf("found parent snapshot %v\n", parentSnapshotID)
 	}
 
-	fmt.Printf("scanning %s\n", target)
+	fmt.Printf("scan %s\n", target)
 
 	scanProgress := restic.NewProgress(time.Second)
 	if terminal.IsTerminal(int(os.Stdout.Fd())) {
@@ -113,29 +114,51 @@ func (cmd CmdBackup) Execute(args []string) error {
 
 	sc := restic.NewScanner(scanProgress)
 
-	t, err := sc.Scan(target)
+	newTree, err := sc.Scan(target)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		return err
 	}
 
+	if parentSnapshotID != nil {
+		fmt.Printf("load old snapshot\n")
+		ch := restic.NewContentHandler(s)
+		sn, err := ch.LoadSnapshot(parentSnapshotID)
+		if err != nil {
+			return err
+		}
+
+		oldTree, err := restic.LoadTreeRecursive(filepath.Dir(sn.Dir), ch, sn.Tree)
+		if err != nil {
+			return err
+		}
+
+		newTree.CopyFrom(oldTree)
+	}
+
 	archiveProgress := restic.NewProgress(time.Second)
-	targetStat := scanProgress.Current()
+	targetStat := newTree.StatTodo()
 
 	if terminal.IsTerminal(int(os.Stdout.Fd())) {
 		var bps, eta uint64
+		itemsTodo := targetStat.Files + targetStat.Dirs
+
 		archiveProgress.F = func(s restic.Stat, d time.Duration, ticker bool) {
 			sec := uint64(d / time.Second)
-			if sec > 0 && ticker {
+			if targetStat.Bytes > 0 && sec > 0 && ticker {
 				bps = s.Bytes / sec
-				eta = (targetStat.Bytes - s.Bytes) / bps
+				if bps > 0 {
+					eta = (targetStat.Bytes - s.Bytes) / bps
+				}
 			}
 
-			fmt.Printf("\x1b[2K\r[%s] %3.2f%%  %s/s  %s / %s  ETA %s",
+			itemsDone := s.Files + s.Dirs
+			fmt.Printf("\x1b[2K\r[%s] %3.2f%%  %s/s  %s / %s  %d / %d items  ETA %s",
 				format_duration(d),
 				float64(s.Bytes)/float64(targetStat.Bytes)*100,
 				format_bytes(bps),
 				format_bytes(s.Bytes), format_bytes(targetStat.Bytes),
+				itemsDone, itemsTodo,
 				format_seconds(eta))
 		}
 
@@ -154,11 +177,11 @@ func (cmd CmdBackup) Execute(args []string) error {
 
 	arch.Error = func(dir string, fi os.FileInfo, err error) error {
 		// TODO: make ignoring errors configurable
-		fmt.Fprintf(os.Stderr, "\nerror for %s: %v\n%v\n", dir, err, fi)
+		fmt.Fprintf(os.Stderr, "\nerror for %s: %v\n", dir, err)
 		return nil
 	}
 
-	_, id, err := arch.Snapshot(target, t, parentSnapshotID)
+	_, id, err := arch.Snapshot(target, newTree, parentSnapshotID)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 	}

contenthandler.go

@@ -243,3 +243,8 @@ func (ch *ContentHandler) Test(t backend.Type, id backend.ID) (bool, error) {
 
 	return ch.s.Test(t, id)
 }
+
+// BlobList returns the current BlobList.
+func (ch *ContentHandler) BlobList() *BlobList {
+	return ch.bl
+}

progress.go

@@ -25,7 +25,6 @@ type Progress struct {
 type Stat struct {
 	Files uint64
 	Dirs  uint64
-	Other uint64
 	Bytes uint64
 }
 
@@ -162,7 +161,6 @@ func (s *Stat) Add(other Stat) {
 	s.Bytes += other.Bytes
 	s.Dirs += other.Dirs
 	s.Files += other.Files
-	s.Other += other.Other
 }
 
 func (s Stat) String() string {
@@ -182,6 +180,6 @@ func (s Stat) String() string {
 		str = fmt.Sprintf("%dB", s.Bytes)
 	}
 
-	return fmt.Sprintf("Stat(%d files, %d dirs, %d other, %v)",
-		s.Files, s.Dirs, s.Other, str)
+	return fmt.Sprintf("Stat(%d files, %d dirs, %v)",
+		s.Files, s.Dirs, str)
 }

scanner.go

@@ -66,7 +66,7 @@ func scan(filterFn FilterFunc, progress *Progress, dir string) (*Tree, error) {
 
 		if entry.IsDir() {
 			// save all errors in node.err, sort out later
-			node.Tree, node.err = scan(filterFn, progress, path)
+			node.tree, node.err = scan(filterFn, progress, path)
 		}
 	}
 
@@ -80,8 +80,6 @@ func scan(filterFn FilterFunc, progress *Progress, dir string) (*Tree, error) {
 			progress.Report(Stat{Files: 1, Bytes: node.Size})
 		case "dir":
 			progress.Report(Stat{Dirs: 1})
-		default:
-			progress.Report(Stat{Other: 1})
 		}
 	}
 
@@ -112,7 +110,7 @@ func (sc *Scanner) Scan(path string) (*Tree, error) {
 
 	sc.p.Report(Stat{Dirs: 1})
 
-	node.Tree, err = scan(sc.Filter, sc.p, path)
+	node.tree, err = scan(sc.Filter, sc.p, path)
 	if err != nil {
 		return nil, arrar.Annotate(err, "loadTree()")
 	}

tree.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"os"
 	"os/user"
+	"path/filepath"
+	"reflect"
 	"sort"
 	"strconv"
 	"strings"
@@ -37,7 +39,7 @@ type Node struct {
 	Content    []backend.ID `json:"content"`
 	Subtree    backend.ID   `json:"subtree,omitempty"`
 
-	Tree *Tree `json:"-"`
+	tree *Tree
 
 	path string
 	err  error
@@ -92,11 +94,33 @@ func LoadTree(ch *ContentHandler, id backend.ID) (Tree, error) {
 	return tree, nil
 }
 
-// PopulateFrom copies subtrees and content from other when it hasn't changed.
-func (t Tree) PopulateFrom(other Tree) error {
+// LoadTreeRecursive loads the tree and all subtrees via ch.
+func LoadTreeRecursive(path string, ch *ContentHandler, id backend.ID) (Tree, error) {
+	tree, err := LoadTree(ch, id)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, n := range tree {
+		n.path = filepath.Join(path, n.Name)
+		if n.Type == "dir" && n.Subtree != nil {
+			t, err := LoadTreeRecursive(n.path, ch, n.Subtree)
+			if err != nil {
+				return nil, err
+			}
+
+			n.tree = &t
+		}
+	}
+
+	return tree, nil
+}
+
+// CopyFrom recursively copies all content from other to t.
+func (t Tree) CopyFrom(other Tree) {
 	for _, node := range t {
-		// only copy entries for files
-		if node.Type != "file" {
+		// only process files and dirs
+		if node.Type != "file" && node.Type != "dir" {
 			continue
 		}
 
@@ -108,14 +132,32 @@ func (t Tree) PopulateFrom(other Tree) error {
 			continue
 		}
 
-		// compare content
-		if node.SameContent(oldNode) {
-			// copy Content
-			node.Content = oldNode.Content
+		if node.Type == "file" {
+			// compare content
+			if node.SameContent(oldNode) {
+				// copy Content
+				node.Content = oldNode.Content
+			}
+		} else {
+			// fill in all subtrees from old subtree
+			node.tree.CopyFrom(*oldNode.tree)
+
+			// check if tree has changed
+			if node.tree.Equals(*oldNode.tree) {
+				// if nothing has changed, copy subtree ID
+				node.Subtree = oldNode.Subtree
+			}
 		}
 	}
+}
 
-	return nil
+// Equals returns true if t and other have exactly the same nodes.
+func (t Tree) Equals(other Tree) bool {
+	if len(t) != len(other) {
+		return false
+	}
+
+	return reflect.DeepEqual(t, other)
 }
 
 func (t *Tree) Insert(node *Node) error {
@@ -160,15 +202,41 @@ func (t Tree) Stat() Stat {
 			s.Bytes += n.Size
 		case "dir":
 			s.Dirs++
-			s.Add(n.Tree.Stat())
-		default:
-			s.Other++
+			if n.tree != nil {
+				s.Add(n.tree.Stat())
+			}
 		}
 	}
 
 	return s
 }
 
+func (t Tree) StatTodo() Stat {
+	s := Stat{}
+	for _, n := range t {
+		switch n.Type {
+		case "file":
+			if n.Content == nil {
+				s.Files++
+				s.Bytes += n.Size
+			}
+		case "dir":
+			if n.Subtree == nil {
+				s.Dirs++
+				if n.tree != nil {
+					s.Add(n.tree.StatTodo())
+				}
+			}
+		}
+	}
+
+	return s
+}
+
+func (node Node) Tree() *Tree {
+	return node.tree
+}
+
 func (node *Node) fill_extra(path string, fi os.FileInfo) (err error) {
 	stat, ok := fi.Sys().(*syscall.Stat_t)
 	if !ok {