coreapi: use chan for returning results in Unixfs.Ls

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

core/coreapi/interface/tests/unixfs.go

@@ -754,18 +754,20 @@ func (tp *provider) TestLs(t *testing.T) {
 		t.Error(err)
 	}
 
-	if len(links) != 1 {
-		t.Fatalf("expected 1 link, got %d", len(links))
+	link := <- links
+	if link.Size != 23 {
+		t.Fatalf("expected size = 23, got %d", link.Size)
 	}
-	if links[0].Size != 23 {
-		t.Fatalf("expected size = 23, got %d", links[0].Size)
+	if link.Name != "name-of-file" {
+		t.Fatalf("expected name = name-of-file, got %s", link.Name)
 	}
-	if links[0].Name != "name-of-file" {
-		t.Fatalf("expected name = name-of-file, got %s", links[0].Name)
+	if link.Cid.String() != "QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr" {
+		t.Fatalf("expected cid = QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr, got %s", link.Cid)
 	}
-	if links[0].Cid.String() != "QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr" {
-		t.Fatalf("expected cid = QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr, got %s", links[0].Cid)
+	if _, ok := <-links; ok {
+		t.Errorf("didn't expect a second link")
 	}
+
 }
 
 func (tp *provider) TestEntriesExpired(t *testing.T) {

core/coreapi/interface/unixfs.go

@@ -31,5 +31,5 @@ type UnixfsAPI interface {
 	Get(context.Context, Path) (files.Node, error)
 
 	// Ls returns the list of links in a directory
-	Ls(context.Context, Path) ([]*ipld.Link, error)
+	Ls(context.Context, Path) (<-chan *ipld.Link, error)
 }

core/coreapi/unixfs.go

@@ -143,7 +143,7 @@ func (api *UnixfsAPI) Get(ctx context.Context, p coreiface.Path) (files.Node, er
 
 // Ls returns the contents of an IPFS or IPNS object(s) at path p, with the format:
 // `<link base58 hash> <link size in bytes> <link name>`
-func (api *UnixfsAPI) Ls(ctx context.Context, p coreiface.Path) ([]*ipld.Link, error) {
+func (api *UnixfsAPI) Ls(ctx context.Context, p coreiface.Path) (<-chan *ipld.Link, error) {
 	dagnode, err := api.core().ResolveNode(ctx, p)
 	if err != nil {
 		return nil, err
@@ -164,10 +164,11 @@ func (api *UnixfsAPI) Ls(ctx context.Context, p coreiface.Path) ([]*ipld.Link, e
 		return nil, err
 	}
 
-	links := make([]*ipld.Link, len(ndlinks))
-	for i, l := range ndlinks {
-		links[i] = &ipld.Link{Name: l.Name, Size: l.Size, Cid: l.Cid}
+	links := make(chan *ipld.Link, len(ndlinks))
+	for _, l := range ndlinks {
+		links <- &ipld.Link{Name: l.Name, Size: l.Size, Cid: l.Cid}
 	}
+	close(links)
 	return links, nil
 }