Merge pull request #201 from syncthing/fix-200

Fixes for non-recursive tree when dirs are deleted (fixes #200)

go.mod

@@ -1,3 +1,5 @@
 module github.com/rjeczalik/notify
 
+go 1.11
+
 require golang.org/x/sys v0.0.0-20180926160741-c2ed4eda69e7

node.go

@@ -49,7 +49,7 @@ func (nd node) addchild(name, base string) node {
 }
 
 func (nd node) Add(name string) node {
-	i := indexbase(nd.Name, name)
+	i := indexrel(nd.Name, name)
 	if i == -1 {
 		return node{}
 	}
@@ -93,7 +93,7 @@ Traverse:
 }
 
 func (nd node) Get(name string) (node, error) {
-	i := indexbase(nd.Name, name)
+	i := indexrel(nd.Name, name)
 	if i == -1 {
 		return node{}, errnotexist(name)
 	}
@@ -111,7 +111,7 @@ func (nd node) Get(name string) (node, error) {
 }
 
 func (nd node) Del(name string) error {
-	i := indexbase(nd.Name, name)
+	i := indexrel(nd.Name, name)
 	if i == -1 {
 		return errnotexist(name)
 	}
@@ -122,13 +122,13 @@ func (nd node) Del(name string) error {
 			return errnotexist(name[:i+j])
 		}
 		stack = append(stack, nd)
+		i += j + 1
 	}
-	if nd, ok = nd.Child[name[i:]]; !ok {
+	if _, ok = nd.Child[name[i:]]; !ok {
 		return errnotexist(name)
 	}
-	nd.Child = nil
-	nd.Watch = nil
-	for name, i = base(nd.Name), len(stack); i != 0; name, i = base(nd.Name), i-1 {
+	delete(nd.Child, name[i:])
+	for name, i = name[i:], len(stack); i != 0; name, i = base(nd.Name), i-1 {
 		nd = stack[i-1]
 		if nd := nd.Child[name]; len(nd.Watch) > 1 || len(nd.Child) != 0 {
 			break
@@ -167,7 +167,7 @@ Traverse:
 }
 
 func (nd node) WalkPath(name string, fn walkPathFunc) error {
-	i := indexbase(nd.Name, name)
+	i := indexrel(nd.Name, name)
 	if i == -1 {
 		return errnotexist(name)
 	}

notify_test.go

@@ -147,6 +147,68 @@ func TestRenameInRoot(t *testing.T) {
 	}
 }
 
+func TestRecreated(t *testing.T) {
+	tmpDir, err := ioutil.TempDir("", "notify_test-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	dir := filepath.Join(tmpDir, "folder")
+	file := filepath.Join(dir, "file")
+
+	// Start watching
+	eventChan := make(chan EventInfo, 1000)
+	mustT(t, Watch(tmpDir+"/...", eventChan, All))
+	defer Stop(eventChan)
+
+	recreateFolder := func() {
+		// Give the sync some time to process events
+		_ = os.RemoveAll(dir)
+		mustT(t, os.Mkdir(dir, 0777))
+		time.Sleep(100 * time.Millisecond)
+
+		// Create a file
+		mustT(t, ioutil.WriteFile(file, []byte("abc"), 0666))
+	}
+	timeout := time.After(5 * time.Second)
+	checkCreated := func() {
+		for {
+			select {
+			case ev := <-eventChan:
+				t.Log(ev.Path(), ev.Event())
+				if ev.Path() == file && ev.Event() == Create {
+					return
+				}
+			case <-timeout:
+				t.Fatal("timed out before receiving event")
+			}
+		}
+	}
+
+	// 1. Create a folder and a file within it
+	// This will create a node in the internal tree for the subfolder test/folder
+	// Will create a new inotify watch for the folder
+	t.Log("######## First ########")
+	recreateFolder()
+	checkCreated()
+
+	// 2. Create a folder and a file within it again
+	// This will set the events for the subfolder test/folder in the internal tree
+	// Will create a new inotify watch for the folder because events differ
+	t.Log("######## Second ########")
+	recreateFolder()
+	checkCreated()
+
+	// 3. Create a folder and a file within it yet again
+	// This time no new inotify watch will be created, because the events
+	// and node already exist in the internal tree and all subsequent events
+	// are lost, hence there is no event for the created file here anymore
+	t.Log("######## Third ########")
+	recreateFolder()
+	checkCreated()
+}
+
 func mustT(t testing.TB, err error) {
 	t.Helper()
 	if err != nil {

tree_nonrecursive.go

@@ -65,7 +65,7 @@ func (t *nonrecursiveTree) dispatch(c <-chan EventInfo) {
 			}
 			t.rw.RUnlock()
 			// If the event describes newly leaf directory created within
-			if !isrec || ei.Event() != Create {
+			if !isrec || ei.Event()&(Create|Remove) == 0 {
 				return
 			}
 			if ok, err := ei.(isDirer).isDir(); !ok || err != nil {
@@ -79,9 +79,23 @@ func (t *nonrecursiveTree) dispatch(c <-chan EventInfo) {
 // internal TODO(rjeczalik)
 func (t *nonrecursiveTree) internal(rec <-chan EventInfo) {
 	for ei := range rec {
+		t.rw.Lock()
+		if ei.Event() == Remove {
+			nd, err := t.root.Get(ei.Path())
+			if err != nil {
+				t.rw.Unlock()
+				continue
+			}
+			t.walkWatchpoint(nd, func(_ Event, nd node) error {
+				t.w.Unwatch(nd.Name)
+				return nil
+			})
+			t.root.Del(ei.Path())
+			t.rw.Unlock()
+			continue
+		}
 		var nd node
 		var eset = internal
-		t.rw.Lock()
 		t.root.WalkPath(ei.Path(), func(it node, _ bool) error {
 			if e := it.Watch[t.rec]; e != 0 && e > eset {
 				eset = e
@@ -93,7 +107,10 @@ func (t *nonrecursiveTree) internal(rec <-chan EventInfo) {
 			t.rw.Unlock()
 			continue
 		}
-		err := nd.Add(ei.Path()).AddDir(t.recFunc(eset))
+		if ei.Path() != nd.Name {
+			nd = nd.Add(ei.Path())
+		}
+		err := nd.AddDir(t.recFunc(eset))
 		t.rw.Unlock()
 		if err != nil {
 			dbgprintf("internal(%p) error: %v", rec, err)

util.go

@@ -123,10 +123,12 @@ func base(s string) string {
 	return s
 }
 
-func indexbase(root, name string) int {
-	if n, m := len(root), len(name); m >= n && name[:n] == root &&
-		(n == m || name[n] == os.PathSeparator) {
-		return min(n+1, m)
+// indexrel returns the index of the first char of name that is
+// below/relative to root. It returns -1 if name is not a child of root.
+func indexrel(root, name string) int {
+	if n, m := len(root), len(name); m > n && name[:n] == root &&
+		name[n] == os.PathSeparator {
+		return n + 1
 	}
 	return -1
 }