Consume node_id from CandidateRouteHop

Author: jbesraa

lightning/src/routing/router.rs

@@ -1031,8 +1031,6 @@ pub enum CandidateRouteHop<'a> {
 		/// Provided to uniquely identify a hop as we are
 		/// route building.
 		hint_idx: usize,
-		/// The node id of the payer.
-		source_node_id: NodeId,
 	},
 	/// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided
 	/// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the
@@ -1048,8 +1046,6 @@ pub enum CandidateRouteHop<'a> {
 		/// Provided to uniquely identify a hop as we are
 		/// route building.
 		hint_idx: usize,
-		/// The node id of the payer.
-		source_node_id: NodeId,
 	},
 }
 
@@ -1162,8 +1158,8 @@ impl<'a> CandidateRouteHop<'a> {
 				*source_node_id
 			},
 			CandidateRouteHop::PrivateHop { hint, .. } => hint.src_node_id.into(),
-			CandidateRouteHop::Blinded { source_node_id, .. } => *source_node_id,
-			CandidateRouteHop::OneHopBlinded { source_node_id, .. } => *source_node_id,
+			CandidateRouteHop::Blinded { hint, .. } => hint.1.introduction_node_id.into(),
+			CandidateRouteHop::OneHopBlinded { hint, .. } => hint.1.introduction_node_id.into(),
 		}
 	}
 	/// Returns the target node id of this hop, if known.
@@ -1228,7 +1224,7 @@ fn iter_equal<I1: Iterator, I2: Iterator>(mut iter_a: I1, mut iter_b: I2)
 pub struct PathBuildingHop<'a> {
 	// Note that this should be dropped in favor of loading it from CandidateRouteHop, but doing so
 	// is a larger refactor and will require careful performance analysis.
-	node_id: NodeId,
+	// node_id: NodeId,
 	candidate: CandidateRouteHop<'a>,
 	fee_msat: u64,
 
@@ -1266,7 +1262,7 @@ impl<'a> core::fmt::Debug for PathBuildingHop<'a> {
 	fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 		let mut debug_struct = f.debug_struct("PathBuildingHop");
 		debug_struct
-			.field("node_id", &self.node_id)
+			.field("node_id", &self.candidate.source())
 			.field("short_channel_id", &self.candidate.short_channel_id())
 			.field("total_fee_msat", &self.total_fee_msat)
 			.field("next_hops_fee_msat", &self.next_hops_fee_msat)
@@ -1888,7 +1884,7 @@ where L::Target: Logger {
 							// This will affect our decision on selecting short_channel_id
 							// as a way to reach the $dest_node_id.
 							PathBuildingHop {
-								node_id: $dest_node_id.clone(),
+								// node_id: $dest_node_id.clone(),
 								candidate: $candidate.clone(),
 								fee_msat: 0,
 								next_hops_fee_msat: u64::max_value(),
@@ -1970,7 +1966,7 @@ where L::Target: Logger {
 								old_entry.next_hops_fee_msat = $next_hops_fee_msat;
 								old_entry.hop_use_fee_msat = hop_use_fee_msat;
 								old_entry.total_fee_msat = total_fee_msat;
-								old_entry.node_id = $dest_node_id.clone();
+								// old_entry.node_id = $dest_node_id.clone();
 								old_entry.candidate = $candidate.clone();
 								old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
 								old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
@@ -2135,8 +2131,8 @@ where L::Target: Logger {
 				network_nodes.get(&intro_node_id).is_some();
 			if !have_intro_node_in_graph { continue }
 			let candidate = if hint.1.blinded_hops.len() == 1 {
-				CandidateRouteHop::OneHopBlinded { hint, hint_idx, source_node_id: our_node_id }
-			} else { CandidateRouteHop::Blinded { hint, hint_idx, source_node_id: intro_node_id } };
+				CandidateRouteHop::OneHopBlinded { hint, hint_idx }
+			} else { CandidateRouteHop::Blinded { hint, hint_idx } };
 			let mut path_contribution_msat = path_value_msat;
 			if let Some(hop_used_msat) = add_entry!(&candidate, intro_node_id, maybe_dummy_payee_node_id,
 				0, path_contribution_msat, 0, 0_u64, 0, 0)
@@ -2317,7 +2313,11 @@ where L::Target: Logger {
 
 				'path_walk: loop {
 					let mut features_set = false;
-					if let Some(first_channels) = first_hop_targets.get(&ordered_hops.last().unwrap().0.node_id) {
+					let target = match ordered_hops.last().unwrap().0.candidate.target() {
+						Some(target) => target,
+						None => break,
+					};
+					if let Some(first_channels) = first_hop_targets.get(&target) {
 						for details in first_channels {
 							if let Some(scid) = ordered_hops.last().unwrap().0.candidate.short_channel_id() {
 								if details.get_outbound_payment_scid().unwrap() == scid {
@@ -2329,7 +2329,7 @@ where L::Target: Logger {
 						}
 					}
 					if !features_set {
-						if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.node_id) {
+						if let Some(node) = network_nodes.get(&ordered_hops.last().unwrap().0.candidate.target().unwrap()) {
 							if let Some(node_info) = node.announcement_info.as_ref() {
 								ordered_hops.last_mut().unwrap().1 = node_info.features.clone();
 							} else {
@@ -2346,11 +2346,11 @@ where L::Target: Logger {
 					// save this path for the payment route. Also, update the liquidity
 					// remaining on the used hops, so that we take them into account
 					// while looking for more paths.
-					if ordered_hops.last().unwrap().0.node_id == maybe_dummy_payee_node_id {
+					if ordered_hops.last().unwrap().0.candidate.target().unwrap() == maybe_dummy_payee_node_id {
 						break 'path_walk;
 					}
 
-					new_entry = match dist.remove(&ordered_hops.last().unwrap().0.node_id) {
+					new_entry = match dist.remove(&ordered_hops.last().unwrap().0.candidate.target().unwrap()) {
 						Some(payment_hop) => payment_hop,
 						// We can't arrive at None because, if we ever add an entry to targets,
 						// we also fill in the entry in dist (see add_entry!).
@@ -2389,12 +2389,16 @@ where L::Target: Logger {
 				// Remember that we used these channels so that we don't rely
 				// on the same liquidity in future paths.
 				let mut prevented_redundant_path_selection = false;
-				let prev_hop_iter = core::iter::once(&our_node_id)
-					.chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
+				let prev_hop_iter = core::iter::once(our_node_id)
+					.chain(payment_path.hops.iter().map(|(hop, _)| hop.candidate.target().unwrap()));
 				for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
+					let target = match hop.candidate.target() {
+						Some(target) => target,
+						None => break,
+					};
 					let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
 					let used_liquidity_msat = used_liquidities
-						.entry(hop.candidate.id(*prev_hop < hop.node_id))
+						.entry(hop.candidate.id(prev_hop < target))
 						.and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
 						.or_insert(spent_on_hop_msat);
 					let hop_capacity = hop.candidate.effective_capacity();
@@ -2558,8 +2562,8 @@ where L::Target: Logger {
 	});
 	for idx in 0..(selected_route.len() - 1) {
 		if idx + 1 >= selected_route.len() { break; }
-		if iter_equal(selected_route[idx    ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)),
-		              selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) {
+		if iter_equal(selected_route[idx].hops.iter().map(|h| (h.0.candidate.id(true), h.0.candidate.target())),
+		              selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.candidate.target()))) {
 			let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
 			selected_route[idx].update_value_and_recompute_fees(new_value);
 			selected_route.remove(idx + 1);
@@ -2584,14 +2588,15 @@ where L::Target: Logger {
 				// there are announced channels between the endpoints. If so, the hop might be
 				// referring to any of the announced channels, as its `short_channel_id` might be
 				// an alias, in which case we don't take any chances here.
-				network_graph.node(&hop.node_id).map_or(false, |hop_node|
+				let hop_node_id = hop.candidate.source();
+				network_graph.node(&hop_node_id).map_or(false, |hop_node|
 					hop_node.channels.iter().any(|scid| network_graph.channel(*scid)
-							.map_or(false, |c| c.as_directed_from(&prev_hop_node_id).is_some()))
+						.map_or(false, |c| c.as_directed_from(&prev_hop_node_id).is_some()))
 				)
 			};
 
 			hops.push(RouteHop {
-				pubkey: PublicKey::from_slice(hop.node_id.as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.node_id), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
+				pubkey: PublicKey::from_slice(hop.candidate.target().unwrap().as_slice()).map_err(|_| LightningError{err: format!("Public key {:?} is invalid", &hop.candidate.target().unwrap()), action: ErrorAction::IgnoreAndLog(Level::Trace)})?,
 				node_features: node_features.clone(),
 				short_channel_id: hop.candidate.short_channel_id().unwrap(),
 				channel_features: hop.candidate.features(),
@@ -2600,7 +2605,7 @@ where L::Target: Logger {
 				maybe_announced_channel,
 			});
 
-			prev_hop_node_id = hop.node_id;
+			prev_hop_node_id = hop.candidate.source();
 		}
 		let mut final_cltv_delta = final_cltv_expiry_delta;
 		let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {