Add default empty ChannelScorer impl

Author: sourabhmarathe

lightning/src/routing/network_graph.rs

@@ -282,6 +282,12 @@ impl_writeable!(ChannelInfo, 0, {
 	minimum_fee_penalty
 });
 
+/// By default, these methods do nothing. A user may override them to write to their metadata as needed
+impl ChannelScorer for ChannelInfo {
+	fn calculate_minimum_fee_penalty(&self, channel_id: u64) {}
+	fn score_payment_failure(&self, route: Vec<Vec<RouteHop>>, faulty_nodes: Vec<PublicKey>) {}
+	fn score_payment_success(&self, route: Vec<Vec<RouteHop>>) {}
+}
 
 /// Fees for routing via a given channel or a node
 #[derive(Eq, PartialEq, Copy, Clone, Debug)]
@@ -437,7 +443,7 @@ impl Readable for NodeInfo {
 /// route-finding algorithm.
 pub trait ChannelScorer {
 	/// Returns penalty fee for a given channel ID based on user's channel metadata
-	fn calculate_minimum_fee_penalty(&self, channel_id: u64) -> u64;
+	fn calculate_minimum_fee_penalty(&self, channel_id: u64);
 	/// Optional: allows user to count PaymentSent events for channels
 	fn score_payment_success(&self, route: Vec<Vec<RouteHop>>);
 	/// Optional: allows user to count PaymentFailed events for channels
@@ -504,6 +510,12 @@ impl std::fmt::Display for NetworkGraph {
 	}
 }
 
+impl ChannelScorer for NetworkGraph {
+	fn calculate_minimum_fee_penalty(&self, channel_id: u64) {}
+	fn score_payment_success(&self, route: Vec<Vec<RouteHop>>) {}
+	fn score_payment_failure(&self, route: Vec<Vec<RouteHop>>, faulty_nodes: Vec<PublicKey>) {}
+}
+
 impl NetworkGraph {
 	/// Returns all known valid channels' short ids along with announced channel info.
 	pub fn get_channels<'a>(&'a self) -> &'a BTreeMap<u64, ChannelInfo> { &self.channels }