channeldb: take serialized key to fetch lightning node

This prevents inefficient key conversions in a follow up commit that
change the inner pathfinding loop.

routing/pathfind.go

@@ -7,7 +7,6 @@ import (
 	"math"
 	"time"
 
-	"github.com/btcsuite/btcd/btcec"
 	"github.com/coreos/bbolt"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/feature"
@@ -447,12 +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 {
-		targetKey, err := btcec.ParsePubKey(target[:], btcec.S256())
-		if err != nil {
-			return nil, err
-		}
-
-		targetNode, err := g.graph.FetchLightningNode(targetKey)
+		targetNode, err := g.graph.FetchLightningNode(target)
 		switch {
 
 		// If the node exists and has features, use them directly.

routing/pathfind_test.go

@@ -2070,11 +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"]
-	bobKey, err := btcec.ParsePubKey(bob[:], btcec.S256())
-	if err != nil {
-		t.Fatal(err)
-	}
-	bobNode, err := ctx.graph.FetchLightningNode(bobKey)
+	bobNode, err := ctx.graph.FetchLightningNode(bob)
 	if err != nil {
 		t.Fatalf("unable to find bob: %v", err)
 	}
@@ -2123,11 +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"]
-	aliceKey, err := btcec.ParsePubKey(alice[:], btcec.S256())
-	if err != nil {
-		t.Fatal(err)
-	}
-	aliceNode, err := ctx.graph.FetchLightningNode(aliceKey)
+	aliceNode, err := ctx.graph.FetchLightningNode(alice)
 	if err != nil {
 		t.Fatalf("unable to find alice: %v", err)
 	}

routing/router.go

@@ -2089,11 +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) {
-	pubKey, err := btcec.ParsePubKey(node[:], btcec.S256())
-	if err != nil {
-		return nil, fmt.Errorf("unable to parse raw public key: %v", err)
-	}
-	return r.cfg.Graph.FetchLightningNode(pubKey)
+	return r.cfg.Graph.FetchLightningNode(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(priv1.PubKey())
+	copy1, err := ctx.graph.FetchLightningNode(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(priv2.PubKey())
+	copy2, err := ctx.graph.FetchLightningNode(pub2)
 	if err != nil {
 		t.Fatalf("unable to fetch node: %v", err)
 	}