Implement DynamicPenaltyScorer.

Author: tnull

lightning/src/routing/scoring.rs

@@ -259,6 +259,62 @@ impl ReadableArgs<u64> for FixedPenaltyScorer {
 	}
 }
 
+/// [`Score`] implementation that uses a dynamic penalty.
+pub struct DynamicPenaltyScorer<F>
+where
+	F: Fn(u64, u64, u64, &NodeId, &NodeId) -> u64,
+{
+	penalty_func: F,
+}
+
+impl<F> DynamicPenaltyScorer<F>
+where
+	F: Fn(u64, u64, u64, &NodeId, &NodeId) -> u64,
+{
+	/// Creates a new scorer using `penalty_func`.
+	pub fn with_penalty_func(penalty_func: F) -> Self
+	{
+		Self { penalty_func }
+	}
+}
+
+impl<F> Score for DynamicPenaltyScorer<F>
+where
+	F: Fn(u64, u64, u64, &NodeId, &NodeId) -> u64,
+{
+	fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, capacity_msat: u64,
+		source: &NodeId, target: &NodeId) -> u64
+	{
+		(self.penalty_func)(short_channel_id, send_amt_msat, capacity_msat, source, target)
+	}
+
+	fn payment_path_failed(&mut self, _path: &[&RouteHop], _short_channel_id: u64) {}
+
+	fn payment_path_successful(&mut self, _path: &[&RouteHop]) {}
+}
+
+impl<F> Writeable for DynamicPenaltyScorer<F>
+where
+	F: Fn(u64, u64, u64, &NodeId, &NodeId) -> u64,
+{
+	#[inline]
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		write_tlv_fields!(w, {});
+		Ok(())
+	}
+}
+
+impl<F> ReadableArgs<F> for DynamicPenaltyScorer<F>
+where
+	F: Fn(u64, u64, u64, &NodeId, &NodeId) -> u64,
+{
+	#[inline]
+	fn read<R: Read>(r: &mut R, penalty_func: F) -> Result<Self, DecodeError> {
+		read_tlv_fields!(r, {});
+		Ok(Self { penalty_func })
+	}
+}
+
 /// [`Score`] implementation that provides reasonable default behavior.
 ///
 /// Used to apply a fixed penalty to each channel, thus avoiding long paths when shorter paths with