multi: update ChanUpdatesInHorizon and NodeUpdatesInHorizon to return iterators (iter.Seq[T])

discovery/chan_series.go

@@ -120,7 +120,7 @@ func (c *ChanSeries) UpdatesInHorizon(chain chainhash.Hash,
 	if err != nil {
 		return nil, err
 	}
-	for _, channel := range chansInHorizon {
+	for channel := range chansInHorizon {
 		// If the channel hasn't been fully advertised yet, or is a
 		// private channel, then we'll skip it as we can't construct a
 		// full authentication proof if one is requested.
@@ -163,30 +163,12 @@ func (c *ChanSeries) UpdatesInHorizon(chain chainhash.Hash,
 	// within the horizon as well. We send these second to ensure that they
 	// follow any active channels they have.
 	nodeAnnsInHorizon, err := c.graph.NodeUpdatesInHorizon(
-		startTime, endTime,
+		startTime, endTime, graphdb.WithIterPublicNodesOnly(),
 	)
 	if err != nil {
 		return nil, err
 	}
-	for _, nodeAnn := range nodeAnnsInHorizon {
-		nodeAnn := nodeAnn
-
-		// Ensure we only forward nodes that are publicly advertised to
-		// prevent leaking information about nodes.
-		isNodePublic, err := c.graph.IsPublicNode(nodeAnn.PubKeyBytes)
-		if err != nil {
-			log.Errorf("Unable to determine if node %x is "+
-				"advertised: %v", nodeAnn.PubKeyBytes, err)
-			continue
-		}
-
-		if !isNodePublic {
-			log.Tracef("Skipping forwarding announcement for "+
-				"node %x due to being unadvertised",
-				nodeAnn.PubKeyBytes)
-			continue
-		}
-
+	for nodeAnn := range nodeAnnsInHorizon {
 		nodeUpdate, err := nodeAnn.NodeAnnouncement(true)
 		if err != nil {
 			return nil, err

fn/go.mod

@@ -1,6 +1,6 @@
 module github.com/lightningnetwork/lnd/fn/v2
 
-go 1.19
+go 1.23
 
 require (
 	github.com/stretchr/testify v1.8.1

fn/iter.go

@@ -0,0 +1,15 @@
+package fn
+
+import "iter"
+
+// Collect drains all of the elements from the passed iterator, returning a
+// slice of the contents.
+func Collect[T any](seq iter.Seq[T]) []T {
+
+	var ret []T
+	for i := range seq {
+		ret = append(ret, i)
+	}
+
+	return ret
+}

go.mod

@@ -206,6 +206,9 @@ require (
 // store have been included in a tagged sqldb version.
 replace github.com/lightningnetwork/lnd/sqldb => ./sqldb
 
+// Replace fn package to use local version with iterator Collect function.
+replace github.com/lightningnetwork/lnd/fn/v2 => ./fn
+
 // This replace is for https://github.com/advisories/GHSA-25xm-hr59-7c27
 replace github.com/ulikunitz/xz => github.com/ulikunitz/xz v0.5.11
 

graph/builder.go

@@ -599,7 +599,7 @@ func (b *Builder) pruneZombieChans() error {
 			"chans: %v", err)
 	}
 
-	for _, u := range oldEdges {
+	for u := range oldEdges {
 		err = filterPruneChans(u.Info, u.Policy1, u.Policy2)
 		if err != nil {
 			return fmt.Errorf("error filtering channels to "+