files2.0: return errors from ufsIterator properly

License: MIT
Signed-off-by: Łukasz Magiera <magik6k@gmail.com>

core/coreapi/unixfile.go

@@ -31,7 +31,8 @@ type ufsIterator struct {
 	curName string
 	curFile files.Node
 
-	err error
+	err   error
+	errCh chan error
 }
 
 func (it *ufsIterator) Name() string {
@@ -43,11 +44,31 @@ func (it *ufsIterator) Node() files.Node {
 }
 
 func (it *ufsIterator) Next() bool {
-	l, ok := <-it.files
-	if !ok {
+	if it.err != nil {
 		return false
 	}
 
+	var l *ipld.Link
+	var ok bool
+	for !ok {
+		if it.files == nil && it.errCh == nil {
+			return false
+		}
+		select {
+		case l, ok = <-it.files:
+			if !ok {
+				it.files = nil
+			}
+		case err := <-it.errCh:
+			it.errCh = nil
+			it.err = err
+
+			if err != nil {
+				return false
+			}
+		}
+	}
+
 	it.curFile = nil
 
 	nd, err := l.GetNode(it.ctx, it.dserv)
@@ -71,8 +92,12 @@ func (d *ufsDirectory) Close() error {
 
 func (d *ufsDirectory) Entries() files.DirIterator {
 	fileCh := make(chan *ipld.Link, prefetchFiles)
+	errCh := make(chan error, 1)
 	go func() {
-		d.dir.ForEachLink(d.ctx, func(link *ipld.Link) error {
+		errCh <- d.dir.ForEachLink(d.ctx, func(link *ipld.Link) error {
+			if d.ctx.Err() != nil {
+				return d.ctx.Err()
+			}
 			select {
 			case fileCh <- link:
 			case <-d.ctx.Done():
@@ -81,12 +106,14 @@ func (d *ufsDirectory) Entries() files.DirIterator {
 			return nil
 		})
 
+		close(errCh)
 		close(fileCh)
 	}()
 
 	return &ufsIterator{
 		ctx:   d.ctx,
 		files: fileCh,
+		errCh: errCh,
 		dserv: d.dserv,
 	}
 }

core/coreapi/unixfs_test.go

@@ -776,6 +776,53 @@ func TestLs(t *testing.T) {
 	}
 }
 
+func TestEntriesExpired(t *testing.T) {
+	ctx := context.Background()
+	node, api, err := makeAPI(ctx)
+	if err != nil {
+		t.Error(err)
+	}
+
+	r := strings.NewReader("content-of-file")
+	k, _, err := coreunix.AddWrapped(node, r, "name-of-file")
+	if err != nil {
+		t.Error(err)
+	}
+	parts := strings.Split(k, "/")
+	if len(parts) != 2 {
+		t.Errorf("unexpected path: %s", k)
+	}
+	p, err := coreiface.ParsePath("/ipfs/" + parts[0])
+	if err != nil {
+		t.Error(err)
+	}
+
+	ctx, cancel := context.WithCancel(ctx)
+
+	nd, err := api.Unixfs().Get(ctx, p)
+	if err != nil {
+		t.Error(err)
+	}
+	cancel()
+
+	it := files.ToDir(nd).Entries()
+	if it == nil {
+		t.Fatal("it was nil")
+	}
+
+	if it.Next() {
+		t.Fatal("Next succeeded")
+	}
+
+	if it.Err() != context.Canceled {
+		t.Fatalf("unexpected error %s", it.Err())
+	}
+
+	if it.Next() {
+		t.Fatal("Next succeeded")
+	}
+}
+
 func TestLsEmptyDir(t *testing.T) {
 	ctx := context.Background()
 	node, api, err := makeAPI(ctx)