coreapi: asunc ls option

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

core/coreapi/interface/options/unixfs.go

@@ -42,7 +42,12 @@ type UnixfsAddSettings struct {
 	Progress bool
 }
 
+type UnixfsLsSettings struct {
+	Async bool
+}
+
 type UnixfsAddOption func(*UnixfsAddSettings) error
+type UnixfsLsOption func(*UnixfsLsSettings) error
 
 func UnixfsAddOptions(opts ...UnixfsAddOption) (*UnixfsAddSettings, cid.Prefix, error) {
 	options := &UnixfsAddSettings{
@@ -122,6 +127,21 @@ func UnixfsAddOptions(opts ...UnixfsAddOption) (*UnixfsAddSettings, cid.Prefix,
 	return options, prefix, nil
 }
 
+func UnixfsLsOptions(opts ...UnixfsLsOption) (*UnixfsLsSettings, error) {
+	options := &UnixfsLsSettings{
+		Async: true,
+	}
+
+	for _, opt := range opts {
+		err := opt(options)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return options, nil
+}
+
 type unixfsOpts struct{}
 
 var Unixfs unixfsOpts
@@ -290,3 +310,13 @@ func (unixfsOpts) Nocopy(enable bool) UnixfsAddOption {
 		return nil
 	}
 }
+
+// Async tells ls to return results as soon as they are available, which can be
+// useful for listing HAMT directories. When this option is set to true returned
+// results won't be returned in order
+func (unixfsOpts) Async(async bool) UnixfsLsOption {
+	return func(settings *UnixfsLsSettings) error {
+		settings.Async = async
+		return nil
+	}
+}

core/coreapi/interface/tests/unixfs.go

@@ -749,12 +749,12 @@ func (tp *provider) TestLs(t *testing.T) {
 		t.Error(err)
 	}
 
-	links, err := api.Unixfs().Ls(ctx, p)
+	links, err := api.Unixfs().Ls(ctx, p, options.Unixfs.Async(false))
 	if err != nil {
 		t.Error(err)
 	}
 
-	link := <- links
+	link := (<-links).Link
 	if link.Size != 23 {
 		t.Fatalf("expected size = 23, got %d", link.Size)
 	}
@@ -768,6 +768,24 @@ func (tp *provider) TestLs(t *testing.T) {
 		t.Errorf("didn't expect a second link")
 	}
 
+	links, err = api.Unixfs().Ls(ctx, p, options.Unixfs.Async(true))
+	if err != nil {
+		t.Error(err)
+	}
+
+	link = (<-links).Link
+	if link.Size != 23 {
+		t.Fatalf("expected size = 23, got %d", link.Size)
+	}
+	if link.Name != "name-of-file" {
+		t.Fatalf("expected name = name-of-file, got %s", link.Name)
+	}
+	if link.Cid.String() != "QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr" {
+		t.Fatalf("expected cid = QmX3qQVKxDGz3URVC3861Z3CKtQKGBn6ffXRBBWGMFz9Lr, got %s", link.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

@@ -5,8 +5,8 @@ import (
 
 	"github.com/ipfs/go-ipfs/core/coreapi/interface/options"
 
-	ipld "gx/ipfs/QmRL22E4paat7ky7vx9MLpR97JHHbFPrg3ytFQw6qp1y1s/go-ipld-format"
-	files "gx/ipfs/QmaXvvAVAQ5ABqM5xtjYmV85xmN5MkWAZsX9H9Fwo4FVXp/go-ipfs-files"
+	ft "gx/ipfs/QmQ1JnYpnzkaurjW1yxkQxC2w3K1PorNE1nv1vaP5Le7sq/go-unixfs"
+	"gx/ipfs/QmaXvvAVAQ5ABqM5xtjYmV85xmN5MkWAZsX9H9Fwo4FVXp/go-ipfs-files"
 )
 
 type AddEvent struct {
@@ -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) (<-chan *ipld.Link, error)
+	Ls(context.Context, Path, ...options.UnixfsLsOption) (<-chan ft.LinkResult, error)
 }

core/coreapi/unixfs.go

@@ -143,30 +143,49 @@ 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) (<-chan *ipld.Link, error) {
+func (api *UnixfsAPI) Ls(ctx context.Context, p coreiface.Path, opts ...options.UnixfsLsOption) (<-chan ft.LinkResult, error) {
+	settings, err := options.UnixfsLsOptions(opts...)
+	if err != nil {
+		return nil, err
+	}
+
 	dagnode, err := api.core().ResolveNode(ctx, p)
 	if err != nil {
 		return nil, err
 	}
 
-	var ndlinks []*ipld.Link
 	dir, err := uio.NewDirectoryFromNode(api.dag, dagnode)
-	switch err {
-	case nil:
-		l, err := dir.Links(ctx)
-		if err != nil {
-			return nil, err
-		}
-		ndlinks = l
-	case uio.ErrNotADir:
-		ndlinks = dagnode.Links()
-	default:
+	if err == uio.ErrNotADir {
+		return lsFromLinks(dagnode.Links())
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	if !settings.Async {
+		return lsFromDir(ctx, dir)
+	}
+
+	return lsFromLinksAsync(ctx, dir)
+}
+
+func lsFromLinksAsync(ctx context.Context, dir uio.Directory) (<-chan ft.LinkResult, error) {
+
+	return dir.EnumLinksAsync(ctx), nil
+}
+
+func lsFromDir(ctx context.Context, dir uio.Directory) (<-chan ft.LinkResult, error) {
+	l, err := dir.Links(ctx)
+	if err != nil {
 		return nil, err
 	}
+	return lsFromLinks(l)
+}
 
-	links := make(chan *ipld.Link, len(ndlinks))
+func lsFromLinks(ndlinks []*ipld.Link) (<-chan ft.LinkResult, error) {
+	links := make(chan ft.LinkResult, len(ndlinks))
 	for _, l := range ndlinks {
-		links <- &ipld.Link{Name: l.Name, Size: l.Size, Cid: l.Cid}
+		links <- ft.LinkResult{Link: &ipld.Link{Name: l.Name, Size: l.Size, Cid: l.Cid}}
 	}
 	close(links)
 	return links, nil