routing: add time_pref parameter to queryroutes and sendpayment

lnrpc/routerrpc/router_backend.go

@@ -53,7 +53,8 @@ type RouterBackend struct {
 	// FindRoutes is a closure that abstracts away how we locate/query for
 	// routes.
 	FindRoute func(source, target route.Vertex,
-		amt lnwire.MilliSatoshi, restrictions *routing.RestrictParams,
+		amt lnwire.MilliSatoshi, timePref float64,
+		restrictions *routing.RestrictParams,
 		destCustomRecords record.CustomSet,
 		routeHints map[route.Vertex][]*channeldb.CachedEdgePolicy,
 		finalExpiry uint16) (*route.Route, error)
@@ -324,7 +325,7 @@ func (r *RouterBackend) QueryRoutes(ctx context.Context,
 	// can carry `in.Amt` satoshis _including_ the total fee required on
 	// the route.
 	route, err := r.FindRoute(
-		sourcePubKey, targetPubKey, amt, restrictions,
+		sourcePubKey, targetPubKey, amt, in.TimePref, restrictions,
 		customRecords, routeHintEdges, finalCLTVDelta,
 	)
 	if err != nil {
@@ -559,6 +560,12 @@ func (r *RouterBackend) extractIntentFromSendRequest(
 
 	payIntent := &routing.LightningPayment{}
 
+	// Pass along time preference.
+	if rpcPayReq.TimePref < -1 || rpcPayReq.TimePref > 1 {
+		return nil, errors.New("time preference out of range")
+	}
+	payIntent.TimePref = rpcPayReq.TimePref
+
 	// Pass along restrictions on the outgoing channels that may be used.
 	payIntent.OutgoingChannelIDs = rpcPayReq.OutgoingChanIds