graph/db: let ForEachNodeCached maybe fetch node addresses

Here we adjust the ForEachNodeCached graph DB method to pass in a node's
addresses into the provided call-back if requested. This will allow us
to improve the performance of node/channel iteration in the autopilot
subserver.

graph/db/sql_store.go

@@ -1058,17 +1058,19 @@ func (s *SQLStore) ChanUpdatesInHorizon(startTime,
 }
 
 // ForEachNodeCached is similar to forEachNode, but it returns DirectedChannel
-// data to the call-back.
-//
-// NOTE: The callback contents MUST not be modified.
+// data to the call-back. If withAddrs is true, then the call-back will also be
+// provided with the addresses associated with the node. The address retrieval
+// result in an additional round-trip to the database, so it should only be used
+// if the addresses are actually needed.
 //
 // NOTE: part of the V1Store interface.
-func (s *SQLStore) ForEachNodeCached(ctx context.Context,
-	cb func(node route.Vertex, chans map[uint64]*DirectedChannel) error,
-	reset func()) error {
+func (s *SQLStore) ForEachNodeCached(ctx context.Context, withAddrs bool,
+	cb func(ctx context.Context, node route.Vertex, addrs []net.Addr,
+		chans map[uint64]*DirectedChannel) error, reset func()) error {
 
 	type nodeCachedBatchData struct {
 		features      map[int64][]int
+		addrs         map[int64][]nodeAddress
 		chanBatchData *batchChannelData
 		chanMap       map[int64][]sqlc.ListChannelsForNodeIDsRow
 	}
@@ -1101,6 +1103,19 @@ func (s *SQLStore) ForEachNodeCached(ctx context.Context,
 					"node features: %w", err)
 			}
 
+			// Maybe fetch the node's addresses if requested.
+			var nodeAddrs map[int64][]nodeAddress
+			if withAddrs {
+				nodeAddrs, err = batchLoadNodeAddressesHelper(
+					ctx, s.cfg.QueryCfg, db, nodeIDs,
+				)
+				if err != nil {
+					return nil, fmt.Errorf("unable to "+
+						"batch load node "+
+						"addresses: %w", err)
+				}
+			}
+
 			// Batch load ALL unique channels for ALL nodes in this
 			// page.
 			allChannels, err := db.ListChannelsForNodeIDs(
@@ -1189,6 +1204,7 @@ func (s *SQLStore) ForEachNodeCached(ctx context.Context,
 
 			return &nodeCachedBatchData{
 				features:      nodeFeatures,
+				addrs:         nodeAddrs,
 				chanBatchData: channelBatchData,
 				chanMap:       nodeChannelMap,
 			}, nil
@@ -1232,7 +1248,15 @@ func (s *SQLStore) ForEachNodeCached(ctx context.Context,
 				channels[directedChan.ChannelID] = directedChan
 			}
 
-			return cb(nodePub, channels)
+			addrs, err := buildNodeAddresses(
+				batchData.addrs[nodeData.ID],
+			)
+			if err != nil {
+				return fmt.Errorf("unable to build node "+
+					"addresses: %w", err)
+			}
+
+			return cb(ctx, nodePub, addrs, channels)
 		}
 
 		return sqldb.ExecuteCollectAndBatchWithSharedDataQuery(