f - WIP

Author: jkczyz

lightning/src/routing/scoring.rs

@@ -559,8 +559,8 @@ pub struct ProbabilisticScoringParameters {
 	/// Whether an additional penalty should be calculated based on the payment amount in order to
 	/// provide higher penalties for large payments.
 	///
-	/// Default value: false
-	pub include_amount_penalty: bool,
+	/// Default value: 0
+	pub amount_penalty_multiplier_msat: u64,
 }
 
 /// Accounting for channel liquidity balance uncertainty.
@@ -614,7 +614,7 @@ impl Default for ProbabilisticScoringParameters {
 			base_penalty_msat: 500,
 			liquidity_penalty_multiplier_msat: 40_000,
 			liquidity_offset_half_life: Duration::from_secs(3600),
-			include_amount_penalty: false,
+			amount_penalty_multiplier_msat: 0,
 		}
 	}
 }
@@ -711,20 +711,19 @@ impl<L: Deref<Target = u64>, T: Time, U: Deref<Target = T>> DirectedChannelLiqui
 		&self, amount_msat: u64, negative_log10_times_1024: u64,
 		params: ProbabilisticScoringParameters
 	) -> u64 {
-		// Upper bound the liquidity penalty to ensure some channel is selected.
-		let multiplier_msat = params.liquidity_penalty_multiplier_msat;
-		let max_penalty_msat = multiplier_msat.saturating_mul(NEGATIVE_LOG10_UPPER_BOUND);
-		let penalty_msat = (negative_log10_times_1024.saturating_mul(multiplier_msat) / 1024)
-			.min(max_penalty_msat)
-			.saturating_add(params.base_penalty_msat);
-
-		if params.include_amount_penalty {
-			let amount_penalty = negative_log10_times_1024.saturating_mul(amount_msat) / 1024
-				/ AMOUNT_PENALTY_DIVISOR;
-			penalty_msat.saturating_add(amount_penalty)
-		} else {
-			penalty_msat
-		}
+		let liquidity_penalty_msat = {
+			// Upper bound the liquidity penalty to ensure some channel is selected.
+			let multiplier_msat = params.liquidity_penalty_multiplier_msat;
+			let max_penalty_msat = multiplier_msat.saturating_mul(NEGATIVE_LOG10_UPPER_BOUND);
+			(negative_log10_times_1024.saturating_mul(multiplier_msat) / 1024).min(max_penalty_msat)
+		};
+		let amount_penalty_msat = negative_log10_times_1024
+			.saturating_mul(params.amount_penalty_multiplier_msat)
+			.saturating_mul(amount_msat) / 1024 / AMOUNT_PENALTY_DIVISOR;
+
+		params.base_penalty_msat
+			.saturating_add(liquidity_penalty_msat)
+			.saturating_add(amount_penalty_msat)
 	}
 
 	/// Returns the lower bound of the channel liquidity balance in this direction.
@@ -2118,19 +2117,19 @@ mod tests {
 
 		let params = ProbabilisticScoringParameters {
 			liquidity_penalty_multiplier_msat: 1_000,
-			include_amount_penalty: false,
+			amount_penalty_multiplier_msat: 0,
 			..Default::default()
 		};
 		let scorer = ProbabilisticScorer::new(params, &network_graph);
 		assert_eq!(scorer.channel_penalty_msat(42, 512_000, 1_024_000, &source, &target), 800);
 
 		let params = ProbabilisticScoringParameters {
 			liquidity_penalty_multiplier_msat: 1_000,
-			include_amount_penalty: true,
+			amount_penalty_multiplier_msat: 1_000,
 			..Default::default()
 		};
 		let scorer = ProbabilisticScorer::new(params, &network_graph);
-		assert_eq!(scorer.channel_penalty_msat(42, 512_000, 1_024_000, &source, &target), 950);
+		assert_eq!(scorer.channel_penalty_msat(42, 512_000, 1_024_000, &source, &target), 151_190);
 	}
 
 	#[test]