iterator technique for unixfs dir listing

License: MIT
Signed-off-by: Jeromy <[email protected]>

Author: whyrusleeping

mfs/dir.go

@@ -433,5 +433,5 @@ func (d *Directory) GetNode() (node.Node, error) {
 		return nil, err
 	}
 
-	return nd, err
+	return nd.Copy(), err
 }

unixfs/hamt/hamt.go

@@ -83,7 +83,7 @@ func NewHamtFromDag(dserv dag.DAGService, nd node.Node) (*HamtShard, error) {
 	}
 
 	ds := makeHamtShard(dserv, int(pbd.GetFanout()))
-	ds.nd = pbnd.Copy()
+	ds.nd = pbnd.Copy().(*dag.ProtoNode)
 	ds.children = make([]child, len(pbnd.Links()))
 	ds.bitfield = new(big.Int).SetBytes(pbd.GetData())
 	ds.hashFunc = pbd.GetHashType()
@@ -321,22 +321,24 @@ func (ds *HamtShard) getValue(ctx context.Context, hv *hashBits, key string, cb
 
 func (ds *HamtShard) EnumLinks() ([]*node.Link, error) {
 	var links []*node.Link
-	err := ds.walkTrie(func(sv *shardValue) error {
+	err := ds.ForEachLink(func(l *node.Link) error {
+		links = append(links, l)
+		return nil
+	})
+	return links, err
+}
+
+func (ds *HamtShard) ForEachLink(f func(*node.Link) error) error {
+	return ds.walkTrie(func(sv *shardValue) error {
 		lnk, err := node.MakeLink(sv.val)
 		if err != nil {
 			return err
 		}
 
 		lnk.Name = sv.key
 
-		links = append(links, lnk)
-		return nil
+		return f(lnk)
 	})
-	if err != nil {
-		return nil, err
-	}
-
-	return links, nil
 }
 
 func (ds *HamtShard) walkTrie(cb func(*shardValue) error) error {

unixfs/io/dirbuilder.go

@@ -10,7 +10,6 @@ import (
 	hamt "github.com/ipfs/go-ipfs/unixfs/hamt"
 
 	node "gx/ipfs/QmUsVJ7AEnGyjX8YWnrwq9vmECVGwBQNAKPpgz5KSg8dcq/go-ipld-node"
-	cid "gx/ipfs/QmcEcrBAMrwMyhSjXt4yfyPpzgSuV8HLHavnfmiKCSRqZU/go-cid"
 )
 
 // ShardSplitThreshold specifies how large of an unsharded directory
@@ -51,7 +50,7 @@ func NewDirectoryFromNode(dserv mdag.DAGService, nd node.Node) (*Directory, erro
 	case format.TDirectory:
 		return &Directory{
 			dserv:   dserv,
-			dirnode: pbnd.Copy(),
+			dirnode: pbnd.Copy().(*mdag.ProtoNode),
 		}, nil
 	case format.THAMTShard:
 		shard, err := hamt.NewHamtFromDag(dserv, nd)
@@ -103,6 +102,19 @@ func (d *Directory) switchToSharding(ctx context.Context) error {
 	return nil
 }
 
+func (d *Directory) ForEachLink(f func(*node.Link) error) error {
+	if d.shard == nil {
+		for _, l := range d.dirnode.Links() {
+			if err := f(l); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	return d.shard.ForEachLink(f)
+}
+
 func (d *Directory) Links() ([]*node.Link, error) {
 	if d.shard == nil {
 		return d.dirnode.Links(), nil