Merge pull request #1044 from lloeki/982-improve-restore

Improve restore

cmd/restic/cmd_backup.go

@@ -417,7 +417,7 @@ func runBackup(opts BackupOptions, gopts GlobalOptions, args []string) error {
 	}
 
 	selectFilter := func(item string, fi os.FileInfo) bool {
-		matched, err := filter.List(opts.Excludes, item)
+		matched, _, err := filter.List(opts.Excludes, item)
 		if err != nil {
 			Warnf("error for exclude pattern: %v", err)
 		}

cmd/restic/cmd_restore.go

@@ -113,22 +113,32 @@ func runRestore(opts RestoreOptions, gopts GlobalOptions, args []string) error {
 		return nil
 	}
 
-	selectExcludeFilter := func(item string, dstpath string, node *restic.Node) bool {
-		matched, err := filter.List(opts.Exclude, item)
+	selectExcludeFilter := func(item string, dstpath string, node *restic.Node) (selectedForRestore bool, childMayBeSelected bool) {
+		matched, _, err := filter.List(opts.Exclude, item)
 		if err != nil {
 			Warnf("error for exclude pattern: %v", err)
 		}
 
-		return !matched
+		// An exclude filter is basically a 'wildcard but foo',
+		// so even if a childMayMatch, other children of a dir may not,
+		// therefore childMayMatch does not matter, but we should not go down
+		// unless the dir is selected for restore
+		selectedForRestore = !matched
+		childMayBeSelected = selectedForRestore && node.Type == "dir"
+
+		return selectedForRestore, childMayBeSelected
 	}
 
-	selectIncludeFilter := func(item string, dstpath string, node *restic.Node) bool {
-		matched, err := filter.List(opts.Include, item)
+	selectIncludeFilter := func(item string, dstpath string, node *restic.Node) (selectedForRestore bool, childMayBeSelected bool) {
+		matched, childMayMatch, err := filter.List(opts.Include, item)
 		if err != nil {
 			Warnf("error for include pattern: %v", err)
 		}
 
-		return matched
+		selectedForRestore = matched
+		childMayBeSelected = childMayMatch && node.Type == "dir"
+
+		return selectedForRestore, childMayBeSelected
 	}
 
 	if len(opts.Exclude) > 0 {

internal/filter/filter.go

@@ -40,6 +40,51 @@ func Match(pattern, str string) (matched bool, err error) {
 	return match(patterns, strs)
 }
 
+// ChildMatch returns true if children of str can match the pattern. When the pattern is
+// malformed, filepath.ErrBadPattern is returned. The empty pattern matches
+// everything, when str is the empty string ErrBadString is returned.
+//
+// Pattern can be a combination of patterns suitable for filepath.Match, joined
+// by filepath.Separator.
+func ChildMatch(pattern, str string) (matched bool, err error) {
+	if pattern == "" {
+		return true, nil
+	}
+
+	pattern = filepath.Clean(pattern)
+
+	if str == "" {
+		return false, ErrBadString
+	}
+
+	// convert file path separator to '/'
+	if filepath.Separator != '/' {
+		pattern = strings.Replace(pattern, string(filepath.Separator), "/", -1)
+		str = strings.Replace(str, string(filepath.Separator), "/", -1)
+	}
+
+	patterns := strings.Split(pattern, "/")
+	strs := strings.Split(str, "/")
+
+	return childMatch(patterns, strs)
+}
+
+func childMatch(patterns, strs []string) (matched bool, err error) {
+	if patterns[0] != "" {
+		// relative pattern can always be nested down
+		return true, nil
+	}
+
+	// match path against absolute pattern prefix
+	l := 0
+	if len(strs) > len(patterns) {
+		l = len(patterns)
+	} else {
+		l = len(strs)
+	}
+	return match(patterns[0:l], strs)
+}
+
 func hasDoubleWildcard(list []string) (ok bool, pos int) {
 	for i, item := range list {
 		if item == "**" {
@@ -102,21 +147,29 @@ func match(patterns, strs []string) (matched bool, err error) {
 
 // List returns true if str matches one of the patterns. Empty patterns are
 // ignored.
-func List(patterns []string, str string) (matched bool, err error) {
+func List(patterns []string, str string) (matched bool, childMayMatch bool, err error) {
 	for _, pat := range patterns {
 		if pat == "" {
 			continue
 		}
 
-		matched, err = Match(pat, str)
+		m, err := Match(pat, str)
 		if err != nil {
-			return false, err
+			return false, false, err
 		}
 
-		if matched {
-			return true, nil
+		c, err := ChildMatch(pat, str)
+		if err != nil {
+			return false, false, err
+		}
+
+		matched = matched || m
+		childMayMatch = childMayMatch || c
+
+		if matched && childMayMatch {
+			return true, true, nil
 		}
 	}
 
-	return false, nil
+	return matched, childMayMatch, nil
 }

internal/filter/filter_test.go

@@ -124,6 +124,77 @@ func TestMatch(t *testing.T) {
 	}
 }
 
+var childMatchTests = []struct {
+	pattern string
+	path    string
+	match   bool
+}{
+	{"", "", true},
+	{"", "/foo", true},
+	{"", "/x/y/z/foo", true},
+	{"foo/bar", "/foo", true},
+	{"baz/bar", "/foo", true},
+	{"foo", "/foo/bar", true},
+	{"bar", "/foo", true},
+	{"baz", "/foo/bar", true},
+	{"*", "/foo", true},
+	{"*", "/foo/bar", true},
+	{"/foo/bar", "/foo", true},
+	{"/foo/bar/baz", "/foo", true},
+	{"/foo/bar/baz", "/foo/bar", true},
+	{"/foo/bar/baz", "/foo/baz", false},
+	{"/foo/**/baz", "/foo/bar/baz", true},
+	{"/foo/**/qux", "/foo/bar/baz/qux", true},
+	{"/baz/bar", "/foo", false},
+	{"/foo", "/foo/bar", true},
+	{"/*", "/foo", true},
+	{"/*", "/foo/bar", true},
+	{"/foo", "/foo/bar", true},
+	{"/**", "/foo", true},
+	{"/*/**", "/foo", true},
+	{"/*/**", "/foo/bar", true},
+	{"/*/bar", "/foo", true},
+	{"/bar/*", "/foo", false},
+	{"/foo/*/baz", "/foo/bar", true},
+	{"/foo/*/baz", "/foo/baz", true},
+	{"/foo/*/baz", "/bar/baz", false},
+	{"/**/*", "/foo", true},
+	{"/**/bar", "/foo/bar", true},
+}
+
+func testchildpattern(t *testing.T, pattern, path string, shouldMatch bool) {
+	match, err := filter.ChildMatch(pattern, path)
+	if err != nil {
+		t.Errorf("test child pattern %q failed: expected no error for path %q, but error returned: %v",
+			pattern, path, err)
+	}
+
+	if match != shouldMatch {
+		t.Errorf("test: filter.ChildMatch(%q, %q): expected %v, got %v",
+			pattern, path, shouldMatch, match)
+	}
+}
+
+func TestChildMatch(t *testing.T) {
+	for _, test := range childMatchTests {
+		testchildpattern(t, test.pattern, test.path, test.match)
+
+		// Test with native path separator
+		if filepath.Separator != '/' {
+			// Test with pattern as native
+			pattern := strings.Replace(test.pattern, "/", string(filepath.Separator), -1)
+			testchildpattern(t, pattern, test.path, test.match)
+
+			// Test with path as native
+			path := strings.Replace(test.path, "/", string(filepath.Separator), -1)
+			testchildpattern(t, test.pattern, path, test.match)
+
+			// Test with both pattern and path as native
+			testchildpattern(t, pattern, path, test.match)
+		}
+	}
+}
+
 func ExampleMatch() {
 	match, _ := filter.Match("*.go", "/home/user/file.go")
 	fmt.Printf("match: %v\n", match)
@@ -157,7 +228,7 @@ var filterListTests = []struct {
 
 func TestList(t *testing.T) {
 	for i, test := range filterListTests {
-		match, err := filter.List(test.patterns, test.path)
+		match, _, err := filter.List(test.patterns, test.path)
 		if err != nil {
 			t.Errorf("test %d failed: expected no error for patterns %q, but error returned: %v",
 				i, test.patterns, err)
@@ -172,7 +243,7 @@ func TestList(t *testing.T) {
 }
 
 func ExampleList() {
-	match, _ := filter.List([]string{"*.c", "*.go"}, "/home/user/file.go")
+	match, _, _ := filter.List([]string{"*.c", "*.go"}, "/home/user/file.go")
 	fmt.Printf("match: %v\n", match)
 	// Output:
 	// match: true
@@ -271,7 +342,7 @@ func BenchmarkFilterPatterns(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		c = 0
 		for _, line := range lines {
-			match, err := filter.List(patterns, line)
+			match, _, err := filter.List(patterns, line)
 			if err != nil {
 				b.Fatal(err)
 			}

internal/restic/restorer.go

@@ -17,7 +17,7 @@ type Restorer struct {
 	sn   *Snapshot
 
 	Error        func(dir string, node *Node, err error) error
-	SelectFilter func(item string, dstpath string, node *Node) bool
+	SelectFilter func(item string, dstpath string, node *Node) (selectedForRestore bool, childMayBeSelected bool)
 }
 
 var restorerAbortOnAllErrors = func(str string, node *Node, err error) error { return err }
@@ -26,7 +26,7 @@ var restorerAbortOnAllErrors = func(str string, node *Node, err error) error { r
 func NewRestorer(repo Repository, id ID) (*Restorer, error) {
 	r := &Restorer{
 		repo: repo, Error: restorerAbortOnAllErrors,
-		SelectFilter: func(string, string, *Node) bool { return true },
+		SelectFilter: func(string, string, *Node) (bool, bool) { return true, true },
 	}
 
 	var err error
@@ -46,9 +46,9 @@ func (res *Restorer) restoreTo(ctx context.Context, dst string, dir string, tree
 	}
 
 	for _, node := range tree.Nodes {
-		selectedForRestore := res.SelectFilter(filepath.Join(dir, node.Name),
+		selectedForRestore, childMayBeSelected := res.SelectFilter(filepath.Join(dir, node.Name),
 			filepath.Join(dst, dir, node.Name), node)
-		debug.Log("SelectForRestore returned %v", selectedForRestore)
+		debug.Log("SelectFilter returned %v %v", selectedForRestore, childMayBeSelected)
 
 		if selectedForRestore {
 			err := res.restoreNodeTo(ctx, node, dir, dst, idx)
@@ -57,7 +57,7 @@ func (res *Restorer) restoreTo(ctx context.Context, dst string, dir string, tree
 			}
 		}
 
-		if node.Type == "dir" {
+		if node.Type == "dir" && childMayBeSelected {
 			if node.Subtree == nil {
 				return errors.Errorf("Dir without subtree in tree %v", treeID.Str())
 			}