Pass cids instead of nodes around in EnumerateChildrenAsync

License: MIT
Signed-off-by: Iaroslav Gridin <voker57@gmail.com>

merkledag/merkledag.go

@@ -394,38 +394,21 @@ func EnumerateChildren(ctx context.Context, ds LinkService, root *cid.Cid, visit
 var FetchGraphConcurrency = 8
 
 func EnumerateChildrenAsync(ctx context.Context, ds DAGService, c *cid.Cid, visit func(*cid.Cid) bool) error {
-	if !visit(c) {
-		return nil
-	}
-
-	root, err := ds.Get(ctx, c)
-	if err != nil {
-		return err
-	}
-
-	feed := make(chan node.Node)
-	out := make(chan *NodeOption)
+	feed := make(chan *cid.Cid)
+	out := make(chan *cid.Cid)
 	done := make(chan struct{})
 
 	var setlk sync.Mutex
 
 	for i := 0; i < FetchGraphConcurrency; i++ {
 		go func() {
-			for n := range feed {
-				links := n.Links()
-				cids := make([]*cid.Cid, 0, len(links))
-				for _, l := range links {
-					setlk.Lock()
-					unseen := visit(l.Cid)
-					setlk.Unlock()
-					if unseen {
-						cids = append(cids, l.Cid)
-					}
-				}
-
-				for nopt := range ds.GetMany(ctx, cids) {
+			for l := range feed {
+				setlk.Lock()
+				unseen := visit(l)
+				setlk.Unlock()
+				if unseen {
 					select {
-					case out <- nopt:
+					case out <- l:
 					case <-ctx.Done():
 						return
 					}
@@ -440,10 +423,10 @@ func EnumerateChildrenAsync(ctx context.Context, ds DAGService, c *cid.Cid, visi
 	defer close(feed)
 
 	send := feed
-	var todobuffer []node.Node
+	var todobuffer []*cid.Cid
 	var inProgress int
 
-	next := root
+	next := c
 	for {
 		select {
 		case send <- next:
@@ -460,16 +443,25 @@ func EnumerateChildrenAsync(ctx context.Context, ds DAGService, c *cid.Cid, visi
 			if inProgress == 0 && next == nil {
 				return nil
 			}
-		case nc := <-out:
-			if nc.Err != nil {
-				return nc.Err
+		case l := <-out:
+			n, err := ds.Get(ctx, l)
+			if err != nil {
+				return err
 			}
 
-			if next == nil {
-				next = nc.Node
-				send = feed
-			} else {
-				todobuffer = append(todobuffer, nc.Node)
+			links := n.Links()
+			if len(links) > 0 {
+				cids := make([]*cid.Cid, len(links), len(links))
+				for i, l := range links {
+					cids[i] = l.Cid
+				}
+				if next == nil {
+					next = cids[0]
+					todobuffer = append(todobuffer, cids[1:]...)
+					send = feed
+				} else {
+					todobuffer = append(todobuffer, cids...)
+				}
 			}
 
 		case <-ctx.Done():