Use default impl of ChannelScorer for NetworkGraph

The user will be responsible for overriding the ChannelScorer
trait functions.

Author: sourabhmarathe

lightning/src/routing/network_graph.rs

@@ -282,13 +282,6 @@ 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)]
 pub struct RoutingFees {
@@ -443,11 +436,11 @@ 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);
+	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>>);
+	fn score_payment_success(&self, _route: Vec<Vec<RouteHop>>) {}
 	/// Optional: allows user to count PaymentFailed events for channels
-	fn score_payment_failure(&self, route: Vec<Vec<RouteHop>>, faulty_nodes: Vec<PublicKey>);
+	fn score_payment_failure(&self, _route: Vec<Vec<RouteHop>>, _faulty_nodes: Vec<PublicKey>) {}
 }
 
 /// Represents the network as nodes and channels between them
@@ -510,11 +503,7 @@ 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 ChannelScorer for NetworkGraph {}
 
 impl NetworkGraph {
 	/// Returns all known valid channels' short ids along with announced channel info.