channeldb/graph: refactor UpdateEdgePolicy to use existing db transaction

channeldb/graph.go

@@ -1618,6 +1618,15 @@ func (c *ChannelGraph) UpdateEdgePolicy(edge *ChannelEdgePolicy) error {
 			return err
 		}
 
+		return updateEdgePolicy(edges, edgeIndex, edge)
+	})
+}
+
+// updateEdgePolicy attempts to update an edge's policy within the relevant
+// buckets using an existing database transaction.
+func updateEdgePolicy(edges, edgeIndex *bolt.Bucket,
+	edge *ChannelEdgePolicy) error {
+
 	// Create the channelID key be converting the channel ID
 	// integer into a byte slice.
 	var chanID [8]byte
@@ -1644,7 +1653,6 @@ func (c *ChannelGraph) UpdateEdgePolicy(edge *ChannelEdgePolicy) error {
 	// Finally, with the direction of the edge being updated
 	// identified, we update the on-disk edge representation.
 	return putChanEdgePolicy(edges, edge, fromNode, toNode)
-	})
 }
 
 // LightningNode represents an individual vertex/node within the channel graph.