Replace EventHandler impl for NetworkGraph with reference'd version

This allows us to avoid extra event clones when intercepting events for
the NetworkGraph.

Author: wpaulino

lightning-background-processor/src/lib.rs

@@ -226,7 +226,7 @@ impl<
 where A::Target: chain::Access, L::Target: Logger {
 	fn handle_event(&self, event: Event) {
 		if let Some(network_graph) = self.gossip_sync.network_graph() {
-			network_graph.handle_event(event.clone());
+			network_graph.handle_event(&event);
 		}
 		self.event_handler.handle_event(event);
 	}
@@ -262,7 +262,7 @@ where A::Target: chain::Access, L::Target: Logger {
 	fn handle_event_async<'b>(&'b self, event: Event) -> Pin<Box<dyn StdFuture<Output = ()> + '_>> {
 		Box::pin(async move {
 			if let Some(network_graph) = self.gossip_sync.network_graph() {
-				network_graph.handle_event(event.clone()); // TODO: Also make async?
+				network_graph.handle_event(&event);
 			}
 			self.async_event_handler.handle_event_async(event).await;
 		})

lightning/src/routing/gossip.rs

@@ -29,7 +29,7 @@ use crate::ln::msgs::{QueryChannelRange, ReplyChannelRange, QueryShortChannelIds
 use crate::ln::msgs;
 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer, MaybeReadable};
 use crate::util::logger::{Logger, Level};
-use crate::util::events::{Event, EventHandler, MessageSendEvent, MessageSendEventsProvider};
+use crate::util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
 use crate::util::scid_utils::{block_from_scid, scid_from_parts, MAX_SCID_BLOCK};
 
 use crate::io;
@@ -213,8 +213,8 @@ impl_writeable_tlv_based_enum_upgradable!(NetworkUpdate,
 /// Provides interface to help with initial routing sync by
 /// serving historical announcements.
 ///
-/// Serves as an [`EventHandler`] for applying updates from [`Event::PaymentPathFailed`] to the
-/// [`NetworkGraph`].
+/// Implements a referenced version of [`EventHandler`] for applying updates from
+/// [`Event::PaymentPathFailed`] to the [`NetworkGraph`].
 pub struct P2PGossipSync<G: Deref<Target=NetworkGraph<L>>, C: Deref, L: Deref>
 where C::Target: chain::Access, L::Target: Logger
 {
@@ -274,8 +274,8 @@ where C::Target: chain::Access, L::Target: Logger
 	}
 }
 
-impl<L: Deref> EventHandler for NetworkGraph<L> where L::Target: Logger {
-	fn handle_event(&self, event: Event) {
+impl<L: Deref> NetworkGraph<L> where L::Target: Logger {
+	pub fn handle_event(&self, event: &Event) {
 		if let Event::PaymentPathFailed { network_update, .. } = event {
 			if let Some(network_update) = network_update {
 				match network_update {
@@ -287,12 +287,12 @@ impl<L: Deref> EventHandler for NetworkGraph<L> where L::Target: Logger {
 						let _ = self.update_channel(msg);
 					},
 					NetworkUpdate::ChannelFailure { short_channel_id, is_permanent } => {
-						let action = if is_permanent { "Removing" } else { "Disabling" };
+						let action = if *is_permanent { "Removing" } else { "Disabling" };
 						log_debug!(self.logger, "{} channel graph entry for {} due to a payment failure.", action, short_channel_id);
-						self.channel_failed(short_channel_id, is_permanent);
+						self.channel_failed(*short_channel_id, *is_permanent);
 					},
 					NetworkUpdate::NodeFailure { ref node_id, is_permanent } => {
-						if is_permanent {
+						if *is_permanent {
 							log_debug!(self.logger,
 								"Removed node graph entry for {} due to a payment failure.", log_pubkey!(node_id));
 							self.node_failed_permanent(node_id);
@@ -1980,7 +1980,7 @@ mod tests {
 		ReplyChannelRange, QueryChannelRange, QueryShortChannelIds, MAX_VALUE_MSAT};
 	use crate::util::test_utils;
 	use crate::util::ser::{ReadableArgs, Writeable};
-	use crate::util::events::{Event, EventHandler, MessageSendEvent, MessageSendEventsProvider};
+	use crate::util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
 	use crate::util::scid_utils::scid_from_parts;
 
 	use crate::routing::gossip::REMOVED_ENTRIES_TRACKING_AGE_LIMIT_SECS;
@@ -2424,7 +2424,7 @@ mod tests {
 			let valid_channel_update = get_signed_channel_update(|_| {}, node_1_privkey, &secp_ctx);
 			assert!(network_graph.read_only().channels().get(&short_channel_id).unwrap().one_to_two.is_none());
 
-			network_graph.handle_event(Event::PaymentPathFailed {
+			network_graph.handle_event(&Event::PaymentPathFailed {
 				payment_id: None,
 				payment_hash: PaymentHash([0; 32]),
 				payment_failed_permanently: false,
@@ -2451,7 +2451,7 @@ mod tests {
 				}
 			};
 
-			network_graph.handle_event(Event::PaymentPathFailed {
+			network_graph.handle_event(&Event::PaymentPathFailed {
 				payment_id: None,
 				payment_hash: PaymentHash([0; 32]),
 				payment_failed_permanently: false,
@@ -2476,7 +2476,7 @@ mod tests {
 		}
 
 		// Permanent closing deletes a channel
-		network_graph.handle_event(Event::PaymentPathFailed {
+		network_graph.handle_event(&Event::PaymentPathFailed {
 			payment_id: None,
 			payment_hash: PaymentHash([0; 32]),
 			payment_failed_permanently: false,
@@ -2508,7 +2508,7 @@ mod tests {
 			assert!(network_graph.read_only().channels().get(&short_channel_id).is_some());
 
 			// Non-permanent node failure does not delete any nodes or channels
-			network_graph.handle_event(Event::PaymentPathFailed {
+			network_graph.handle_event(&Event::PaymentPathFailed {
 				payment_id: None,
 				payment_hash: PaymentHash([0; 32]),
 				payment_failed_permanently: false,
@@ -2528,7 +2528,7 @@ mod tests {
 			assert!(network_graph.read_only().nodes().get(&NodeId::from_pubkey(&node_2_id)).is_some());
 
 			// Permanent node failure deletes node and its channels
-			network_graph.handle_event(Event::PaymentPathFailed {
+			network_graph.handle_event(&Event::PaymentPathFailed {
 				payment_id: None,
 				payment_hash: PaymentHash([0; 32]),
 				payment_failed_permanently: false,