iteratively decay with half life

Author: joostjager

lightning/src/routing/scoring.rs

@@ -492,14 +492,18 @@ impl ChannelLiquidities {
 				liquidity.decayed_offset(liquidity.max_liquidity_offset_msat, duration_since_epoch, decay_params);
 			liquidity.last_updated = duration_since_epoch;
 
-			// TODO: Call decay multiple times.
-			let elapsed_time =
-				duration_since_epoch.saturating_sub(liquidity.offset_history_last_updated);
-			if elapsed_time > decay_params.historical_no_updates_half_life {
-				let half_life = decay_params.historical_no_updates_half_life.as_secs_f64();
-				if half_life != 0.0 {
+			// Iteratively decay the liquidity history until we've caught up to the current time.
+			let half_life = decay_params.historical_no_updates_half_life.as_secs_f64();
+			if half_life != 0.0 {
+				loop {
+					let elapsed_time =
+						duration_since_epoch.saturating_sub(liquidity.offset_history_last_updated);
+					if elapsed_time <= decay_params.historical_no_updates_half_life {
+						break;
+					}
+
 					liquidity.liquidity_history.decay_buckets(elapsed_time.as_secs_f64() / half_life);
-					liquidity.offset_history_last_updated = duration_since_epoch;
+					liquidity.offset_history_last_updated += decay_params.historical_no_updates_half_life;
 				}
 			}
 			liquidity.min_liquidity_offset_msat != 0 || liquidity.max_liquidity_offset_msat != 0 ||