f - Use Instant instead of SystemTime

Author: jkczyz

lightning/src/routing/scorer.rs

@@ -53,7 +53,7 @@ use prelude::*;
 #[cfg(not(feature = "no-std"))]
 use core::time::Duration;
 #[cfg(not(feature = "no-std"))]
-use std::time::SystemTime;
+use std::time::Instant;
 
 /// [`routing::Score`] implementation that provides reasonable default behavior.
 ///
@@ -66,7 +66,7 @@ use std::time::SystemTime;
 pub struct Scorer {
 	params: ScoringParameters,
 	#[cfg(not(feature = "no-std"))]
-	channel_failures: HashMap<u64, (u64, SystemTime)>,
+	channel_failures: HashMap<u64, (u64, Instant)>,
 	#[cfg(feature = "no-std")]
 	channel_failures: HashMap<u64, u64>,
 }
@@ -108,7 +108,7 @@ impl Scorer {
 	}
 
 	#[cfg(not(feature = "no-std"))]
-	fn decay_from(&self, penalty_msat: u64, last_failure: &SystemTime) -> u64 {
+	fn decay_from(&self, penalty_msat: u64, last_failure: &Instant) -> u64 {
 		decay_from(penalty_msat, last_failure, self.params.failure_penalty_half_life)
 	}
 }
@@ -156,9 +156,9 @@ impl routing::Score for Scorer {
 				.and_modify(|(penalty_msat, last_failure)| {
 					let decayed_penalty = decay_from(*penalty_msat, last_failure, half_life);
 					*penalty_msat = decayed_penalty + failure_penalty_msat;
-					*last_failure = SystemTime::now();
+					*last_failure = Instant::now();
 				})
-				.or_insert_with(|| (failure_penalty_msat, SystemTime::now()));
+				.or_insert_with(|| (failure_penalty_msat, Instant::now()));
 		}
 		#[cfg(feature = "no-std")]
 		self.channel_failures
@@ -169,11 +169,8 @@ impl routing::Score for Scorer {
 }
 
 #[cfg(not(feature = "no-std"))]
-fn decay_from(penalty_msat: u64, last_failure: &SystemTime, half_life: Duration) -> u64 {
-	let decays = match last_failure.elapsed().ok() {
-		Some(elapsed) => elapsed.as_secs().checked_div(half_life.as_secs()),
-		None => Some(0),
-	};
+fn decay_from(penalty_msat: u64, last_failure: &Instant, half_life: Duration) -> u64 {
+	let decays = last_failure.elapsed().as_secs().checked_div(half_life.as_secs());
 	match decays {
 		Some(decays) => penalty_msat >> decays,
 		None => 0,