Don't fail when listing dir content that is ignored (syncthing#1)

node.go

@@ -6,7 +6,6 @@ package notify
 
 import (
 	"errors"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 )
@@ -60,7 +59,7 @@ func (nd node) Add(name string) node {
 	return nd.addchild(name, name[i:])
 }
 
-func (nd node) AddDir(fn walkFunc) error {
+func (nd node) AddDir(fn walkFunc, doNotWatch DoNotWatchFn) error {
 	stack := []node{nd}
 Traverse:
 	for n := len(stack); n != 0; n = len(stack) {
@@ -78,13 +77,25 @@ Traverse:
 		}
 		// TODO(rjeczalik): tolerate open failures - add failed names to
 		// AddDirError and notify users which names are not added to the tree.
-		fi, err := ioutil.ReadDir(nd.Name)
+		f, err := os.Open(nd.Name)
 		if err != nil {
 			return err
 		}
-		for _, fi := range fi {
+		names, err := f.Readdirnames(-1)
+		f.Close()
+		if err != nil {
+			return err
+		}
+		for _, name := range names {
+			name = filepath.Join(nd.Name, name)
+			if doNotWatch != nil && doNotWatch(name) {
+				continue
+			}
+			fi, err := os.Lstat(name)
+			if err != nil {
+				return err
+			}
 			if fi.Mode()&(os.ModeSymlink|os.ModeDir) == os.ModeDir {
-				name := filepath.Join(nd.Name, fi.Name())
 				stack = append(stack, nd.addchild(name, name[len(nd.Name)+1:]))
 			}
 		}
@@ -141,7 +152,7 @@ func (nd node) Del(name string) error {
 	return nil
 }
 
-func (nd node) Walk(fn walkFunc) error {
+func (nd node) Walk(fn walkFunc, doNotWatch DoNotWatchFn) error {
 	stack := []node{nd}
 Traverse:
 	for n := len(stack); n != 0; n = len(stack) {
@@ -160,6 +171,9 @@ Traverse:
 				// never has a parent node.
 				continue
 			}
+			if doNotWatch != nil && doNotWatch(nd.Name) {
+				continue
+			}
 			stack = append(stack, nd)
 		}
 	}
@@ -233,8 +247,8 @@ func (r root) Add(name string) node {
 	return r.addroot(name).Add(name)
 }
 
-func (r root) AddDir(dir string, fn walkFunc) error {
-	return r.Add(dir).AddDir(fn)
+func (r root) AddDir(dir string, fn walkFunc, doNotWatch DoNotWatchFn) error {
+	return r.Add(dir).AddDir(fn, doNotWatch)
 }
 
 func (r root) Del(name string) error {
@@ -258,12 +272,12 @@ func (r root) Get(name string) (node, error) {
 	return nd, nil
 }
 
-func (r root) Walk(name string, fn walkFunc) error {
+func (r root) Walk(name string, fn walkFunc, doNotWatch DoNotWatchFn) error {
 	nd, err := r.Get(name)
 	if err != nil {
 		return err
 	}
-	return nd.Walk(fn)
+	return nd.Walk(fn, doNotWatch)
 }
 
 func (r root) WalkPath(name string, fn walkPathFunc) error {

notify.go

@@ -23,6 +23,8 @@ import "fmt"
 
 var defaultTree tree // lazy init
 
+type DoNotWatchFn func(string) bool
+
 func lazyInitDefaultTree() (err error) {
 	if defaultTree != nil {
 		// already initialized
@@ -96,7 +98,7 @@ func Watch(path string, c chan<- EventInfo, events ...Event) error {
 // doNotWatch. Given a path as argument doNotWatch should return true if the
 // file or directory should not be watched.
 func WatchWithFilter(path string, c chan<- EventInfo,
-	doNotWatch func(string) bool, events ...Event) error {
+	doNotWatch DoNotWatchFn, events ...Event) error {
 	if err := lazyInitDefaultTree(); err != nil {
 		return err
 	}

testing_test.go

@@ -946,11 +946,11 @@ func (n *N) ExpectNotifyEvents(cases []NCase, all Chans) {
 func (n *N) Walk(fn walkFunc) {
 	switch t := n.tree.(type) {
 	case *recursiveTree:
-		if err := t.root.Walk("", fn); err != nil {
+		if err := t.root.Walk("", fn, nil); err != nil {
 			n.w.Fatal(err)
 		}
 	case *nonrecursiveTree:
-		if err := t.root.Walk("", fn); err != nil {
+		if err := t.root.Walk("", fn, nil); err != nil {
 			n.w.Fatal(err)
 		}
 	default:

tree.go

@@ -7,7 +7,7 @@ package notify
 const buffer = 128
 
 type tree interface {
-	Watch(string, chan<- EventInfo, func(string) bool, ...Event) error
+	Watch(string, chan<- EventInfo, DoNotWatchFn, ...Event) error
 	Stop(chan<- EventInfo)
 	Close() error
 }

tree_nonrecursive.go

@@ -93,7 +93,7 @@ func (t *nonrecursiveTree) internal(rec <-chan EventInfo) {
 			t.rw.Unlock()
 			continue
 		}
-		err := nd.Add(ei.Path()).AddDir(t.recFunc(eset, nil))
+		err := nd.Add(ei.Path()).AddDir(t.recFunc(eset), nil)
 		t.rw.Unlock()
 		if err != nil {
 			dbgprintf("internal(%p) error: %v", rec, err)
@@ -146,7 +146,7 @@ func (t *nonrecursiveTree) watchDel(nd node, c chan<- EventInfo, e Event) eventD
 
 // Watch TODO(rjeczalik)
 func (t *nonrecursiveTree) Watch(path string, c chan<- EventInfo,
-	doNotWatch func(string) bool, events ...Event) error {
+	doNotWatch DoNotWatchFn, events ...Event) error {
 	if c == nil {
 		panic("notify: Watch using nil channel")
 	}
@@ -188,8 +188,8 @@ func (t *nonrecursiveTree) watch(nd node, c chan<- EventInfo, e Event) (err erro
 	return nil
 }
 
-func (t *nonrecursiveTree) recFunc(e Event, doNotWatch func(string) bool) walkFunc {
-	addWatch := func(nd node) (err error) {
+func (t *nonrecursiveTree) recFunc(e Event) walkFunc {
+	return func(nd node) (err error) {
 		switch diff := nd.Watch.Add(t.rec, e|omit|Create); {
 		case diff == none:
 		case diff[1] == 0:
@@ -202,20 +202,11 @@ func (t *nonrecursiveTree) recFunc(e Event, doNotWatch func(string) bool) walkFu
 		}
 		return
 	}
-	if doNotWatch != nil {
-		return func(nd node) (err error) {
-			if doNotWatch(nd.Name) {
-				return errSkip
-			}
-			return addWatch(nd)
-		}
-	}
-	return addWatch
 }
 
 func (t *nonrecursiveTree) watchrec(nd node, c chan<- EventInfo, e Event,
-	doNotWatch func(string) bool) error {
-	var traverse func(walkFunc) error
+	doNotWatch DoNotWatchFn) error {
+	var traverse func(walkFunc, DoNotWatchFn) error
 	// Non-recursive tree listens on Create event for every recursive
 	// watchpoint in order to automagically set a watch for every
 	// created directory.
@@ -236,7 +227,7 @@ func (t *nonrecursiveTree) watchrec(nd node, c chan<- EventInfo, e Event,
 	}
 	// TODO(rjeczalik): account every path that failed to be (re)watched
 	// and retry.
-	if err := traverse(t.recFunc(e, doNotWatch)); err != nil {
+	if err := traverse(t.recFunc(e), doNotWatch); err != nil {
 		return err
 	}
 	t.watchAdd(nd, c, e)

tree_recursive.go

@@ -154,7 +154,7 @@ func (t *recursiveTree) dispatch() {
 
 // Watch TODO(rjeczalik)
 func (t *recursiveTree) Watch(path string, c chan<- EventInfo,
-	doNotWatch func(string) bool, events ...Event) error {
+	_ DoNotWatchFn, events ...Event) error {
 	if c == nil {
 		panic("notify: Watch using nil channel")
 	}
@@ -233,7 +233,7 @@ func (t *recursiveTree) Watch(path string, c chan<- EventInfo,
 		children = append(children, nd)
 		return errSkip
 	}
-	switch must(cur.Walk(fn)); len(children) {
+	switch must(cur.Walk(fn, nil)); len(children) {
 	case 0:
 		// no child watches, cur holds a new watch
 	case 1:
@@ -332,14 +332,14 @@ func (t *recursiveTree) Stop(c chan<- EventInfo) {
 			watchDel(nd, c, all)
 			return nil
 		}
-		err = nonil(err, e, nd.Walk(fn))
+		err = nonil(err, e, nd.Walk(fn, nil))
 		// TODO(rjeczalik): if e != nil store dummy chan in nd.Watch just to
 		// retry un/rewatching next time and/or let the user handle the failure
 		// vie Error event?
 		return errSkip
 	}
 	t.rw.Lock()
-	e := t.root.Walk("", fn) // TODO(rjeczalik): use max root per c
+	e := t.root.Walk("", fn, nil) // TODO(rjeczalik): use max root per c
 	t.rw.Unlock()
 	if e != nil {
 		err = nonil(err, e)