channeldb: add tx argument for FetchLightningNode

To allow execution within an existing tx.

routing/pathfind.go

@@ -446,7 +446,7 @@ func findPath(g *graphParams, r *RestrictParams, cfg *PathFindingConfig,
 	// we have for the target node from our graph.
 	features := r.DestFeatures
 	if features == nil {
-		targetNode, err := g.graph.FetchLightningNode(target)
+		targetNode, err := g.graph.FetchLightningNode(tx, target)
 		switch {
 
 		// If the node exists and has features, use them directly.

routing/pathfind_test.go

@@ -2070,7 +2070,7 @@ func TestPathFindSpecExample(t *testing.T) {
 	// Carol, so we set "B" as the source node so path finding starts from
 	// Bob.
 	bob := ctx.aliases["B"]
-	bobNode, err := ctx.graph.FetchLightningNode(bob)
+	bobNode, err := ctx.graph.FetchLightningNode(nil, bob)
 	if err != nil {
 		t.Fatalf("unable to find bob: %v", err)
 	}
@@ -2119,7 +2119,7 @@ func TestPathFindSpecExample(t *testing.T) {
 	// Next, we'll set A as the source node so we can assert that we create
 	// the proper route for any queries starting with Alice.
 	alice := ctx.aliases["A"]
-	aliceNode, err := ctx.graph.FetchLightningNode(alice)
+	aliceNode, err := ctx.graph.FetchLightningNode(nil, alice)
 	if err != nil {
 		t.Fatalf("unable to find alice: %v", err)
 	}

routing/router.go

@@ -2089,7 +2089,7 @@ func (r *ChannelRouter) GetChannelByID(chanID lnwire.ShortChannelID) (
 //
 // NOTE: This method is part of the ChannelGraphSource interface.
 func (r *ChannelRouter) FetchLightningNode(node route.Vertex) (*channeldb.LightningNode, error) {
-	return r.cfg.Graph.FetchLightningNode(node)
+	return r.cfg.Graph.FetchLightningNode(nil, node)
 }
 
 // ForEachNode is used to iterate over every node in router topology.

routing/router_test.go

@@ -1319,7 +1319,7 @@ func TestAddEdgeUnknownVertexes(t *testing.T) {
 		t.Fatalf("unable to find any routes: %v", err)
 	}
 
-	copy1, err := ctx.graph.FetchLightningNode(pub1)
+	copy1, err := ctx.graph.FetchLightningNode(nil, pub1)
 	if err != nil {
 		t.Fatalf("unable to fetch node: %v", err)
 	}
@@ -1328,7 +1328,7 @@ func TestAddEdgeUnknownVertexes(t *testing.T) {
 		t.Fatalf("fetched node not equal to original")
 	}
 
-	copy2, err := ctx.graph.FetchLightningNode(pub2)
+	copy2, err := ctx.graph.FetchLightningNode(nil, pub2)
 	if err != nil {
 		t.Fatalf("unable to fetch node: %v", err)
 	}