Take in-flight HTLCs by reference in Router::find_route

Useful in upcoming work when for payment retries.

fuzz/src/chanmon_consistency.rs

@@ -90,7 +90,7 @@ struct FuzzRouter {}
 impl Router for FuzzRouter {
 	fn find_route(
 		&self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-		_inflight_htlcs: InFlightHtlcs
+		_inflight_htlcs: &InFlightHtlcs
 	) -> Result<Route, msgs::LightningError> {
 		Err(msgs::LightningError {
 			err: String::from("Not implemented"),

fuzz/src/full_stack.rs

@@ -132,7 +132,7 @@ struct FuzzRouter {}
 impl Router for FuzzRouter {
 	fn find_route(
 		&self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-		_inflight_htlcs: InFlightHtlcs
+		_inflight_htlcs: &InFlightHtlcs
 	) -> Result<Route, msgs::LightningError> {
 		Err(msgs::LightningError {
 			err: String::from("Not implemented"),

lightning-invoice/src/payment.rs

@@ -76,7 +76,7 @@
 //! # impl Router for FakeRouter {
 //! #     fn find_route(
 //! #         &self, payer: &PublicKey, params: &RouteParameters,
-//! #         first_hops: Option<&[&ChannelDetails]>, _inflight_htlcs: InFlightHtlcs
+//! #         first_hops: Option<&[&ChannelDetails]>, _inflight_htlcs: &InFlightHtlcs
 //! #     ) -> Result<Route, LightningError> { unimplemented!() }
 //! #     fn notify_payment_path_failed(&self, path: &[&RouteHop], short_channel_id: u64) {  unimplemented!() }
 //! #     fn notify_payment_path_successful(&self, path: &[&RouteHop]) {  unimplemented!() }
@@ -510,7 +510,7 @@ where
 		let first_hops = self.payer.first_hops();
 		let inflight_htlcs = self.payer.inflight_htlcs();
 		let route = self.router.find_route(
-			&payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs
+			&payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs
 		).map_err(|e| PaymentError::Routing(e))?;
 
 		match send_payment(&route) {
@@ -578,7 +578,7 @@ where
 		let inflight_htlcs = self.payer.inflight_htlcs();
 
 		let route = self.router.find_route(
-			&payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), inflight_htlcs
+			&payer, &params, Some(&first_hops.iter().collect::<Vec<_>>()), &inflight_htlcs
 		);
 
 		if route.is_err() {
@@ -1670,7 +1670,7 @@ mod tests {
 	impl Router for TestRouter {
 		fn find_route(
 			&self, payer: &PublicKey, route_params: &RouteParameters,
-			_first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
+			_first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
 		) -> Result<Route, LightningError> {
 			// Simulate calling the Scorer just as you would in find_route
 			let route = Self::route_for_value(route_params.final_value_msat);
@@ -1723,7 +1723,7 @@ mod tests {
 	impl Router for FailingRouter {
 		fn find_route(
 			&self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-			_inflight_htlcs: InFlightHtlcs,
+			_inflight_htlcs: &InFlightHtlcs,
 		) -> Result<Route, LightningError> {
 			Err(LightningError { err: String::new(), action: ErrorAction::IgnoreError })
 		}
@@ -2011,7 +2011,7 @@ mod tests {
 	impl Router for ManualRouter {
 		fn find_route(
 			&self, _payer: &PublicKey, _params: &RouteParameters, _first_hops: Option<&[&ChannelDetails]>,
-			_inflight_htlcs: InFlightHtlcs
+			_inflight_htlcs: &InFlightHtlcs
 		) -> Result<Route, LightningError> {
 			self.0.borrow_mut().pop_front().unwrap()
 		}

lightning/src/routing/router.rs

@@ -61,7 +61,7 @@ impl<G: Deref<Target = NetworkGraph<L>>, L: Deref, S: Deref> Router for DefaultR
 {
 	fn find_route(
 		&self, payer: &PublicKey, params: &RouteParameters, first_hops: Option<&[&ChannelDetails]>,
-		inflight_htlcs: InFlightHtlcs
+		inflight_htlcs: &InFlightHtlcs
 	) -> Result<Route, LightningError> {
 		let random_seed_bytes = {
 			let mut locked_random_seed_bytes = self.random_seed_bytes.lock().unwrap();
@@ -98,13 +98,13 @@ pub trait Router {
 	/// Finds a [`Route`] between `payer` and `payee` for a payment with the given values.
 	fn find_route(
 		&self, payer: &PublicKey, route_params: &RouteParameters,
-		first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs
+		first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs
 	) -> Result<Route, LightningError>;
 	/// Finds a [`Route`] between `payer` and `payee` for a payment with the given values. Includes
 	/// `PaymentHash` and `PaymentId` to be able to correlate the request with a specific payment.
 	fn find_route_with_id(
 		&self, payer: &PublicKey, route_params: &RouteParameters,
-		first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: InFlightHtlcs,
+		first_hops: Option<&[&ChannelDetails]>, inflight_htlcs: &InFlightHtlcs,
 		_payment_hash: PaymentHash, _payment_id: PaymentId
 	) -> Result<Route, LightningError> {
 		self.find_route(payer, route_params, first_hops, inflight_htlcs)
@@ -128,12 +128,12 @@ pub trait Router {
 pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score> {
 	scorer: &'a mut S,
 	// Maps a channel's short channel id and its direction to the liquidity used up.
-	inflight_htlcs: InFlightHtlcs,
+	inflight_htlcs: &'a InFlightHtlcs,
 }
 
 impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
 	/// Initialize a new `ScorerAccountingForInFlightHtlcs`.
-	pub fn new(scorer: &'a mut S, inflight_htlcs: InFlightHtlcs) -> Self {
+	pub fn new(scorer: &'a mut S, inflight_htlcs: &'a InFlightHtlcs) -> Self {
 		ScorerAccountingForInFlightHtlcs {
 			scorer,
 			inflight_htlcs

lightning/src/util/test_utils.rs

@@ -86,12 +86,12 @@ impl<'a> TestRouter<'a> {
 impl<'a> Router for TestRouter<'a> {
 	fn find_route(
 		&self, payer: &PublicKey, params: &RouteParameters, first_hops: Option<&[&channelmanager::ChannelDetails]>,
-		inflight_htlcs: InFlightHtlcs
+		inflight_htlcs: &InFlightHtlcs
 	) -> Result<Route, msgs::LightningError> {
 		let logger = TestLogger::new();
 		find_route(
 			payer, params, &self.network_graph, first_hops, &logger,
-			&ScorerAccountingForInFlightHtlcs::new(&mut TestScorer::with_penalty(0), inflight_htlcs),
+			&ScorerAccountingForInFlightHtlcs::new(&mut TestScorer::with_penalty(0), &inflight_htlcs),
 			&[42; 32]
 		)
 	}