Move ScorerAccountingForInFlightHtlcs to router + make public

[rust-lightning] / lightning / src / routing / router.rs

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index aa265e531367669dc35d6f16a80a4ecbe26fba5b..fa841d892313b064691d9e11e2f7686a70427610 100644 (file)
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -56,6 +56,66 @@ pub trait Router {
        fn notify_payment_probe_failed(&self, path: &[&RouteHop], short_channel_id: u64);
 }
 
+/// [`Score`] implementation that factors in in-flight HTLC liquidity.
+///
+/// Useful for custom [`Router`] implementations to wrap their [`Score`] on-the-fly when calling
+/// [`find_route`].
+///
+/// [`Score`]: crate::routing::scoring::Score
+pub struct ScorerAccountingForInFlightHtlcs<'a, S: Score> {
+       scorer: &'a mut S,
+       // Maps a channel's short channel id and its direction to the liquidity used up.
+       inflight_htlcs: InFlightHtlcs,
+}
+
+impl<'a, S: Score> ScorerAccountingForInFlightHtlcs<'a, S> {
+       /// Initialize a new `ScorerAccountingForInFlightHtlcs`.
+       pub fn new(scorer: &'a mut S, inflight_htlcs: InFlightHtlcs) -> Self {
+               ScorerAccountingForInFlightHtlcs {
+                       scorer,
+                       inflight_htlcs
+               }
+       }
+}
+
+#[cfg(c_bindings)]
+impl<'a, S:Score> Writeable for ScorerAccountingForInFlightHtlcs<'a, S> {
+       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { self.scorer.write(writer) }
+}
+
+impl<'a, S: Score> Score for ScorerAccountingForInFlightHtlcs<'a, S> {
+       fn channel_penalty_msat(&self, short_channel_id: u64, source: &NodeId, target: &NodeId, usage: ChannelUsage) -> u64 {
+               if let Some(used_liquidity) = self.inflight_htlcs.used_liquidity_msat(
+                       source, target, short_channel_id
+               ) {
+                       let usage = ChannelUsage {
+                               inflight_htlc_msat: usage.inflight_htlc_msat + used_liquidity,
+                               ..usage
+                       };
+
+                       self.scorer.channel_penalty_msat(short_channel_id, source, target, usage)
+               } else {
+                       self.scorer.channel_penalty_msat(short_channel_id, source, target, usage)
+               }
+       }
+
+       fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
+               self.scorer.payment_path_failed(path, short_channel_id)
+       }
+
+       fn payment_path_successful(&mut self, path: &[&RouteHop]) {
+               self.scorer.payment_path_successful(path)
+       }
+
+       fn probe_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
+               self.scorer.probe_failed(path, short_channel_id)
+       }
+
+       fn probe_successful(&mut self, path: &[&RouteHop]) {
+               self.scorer.probe_successful(path)
+       }
+}
+
 /// A data structure for tracking in-flight HTLCs. May be used during pathfinding to account for
 /// in-use channel liquidity.
 pub struct InFlightHtlcs(