1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Utilities for scoring payment channels.
12 //! [`Scorer`] may be given to [`find_route`] to score payment channels during path finding when a
13 //! custom [`Score`] implementation is not needed.
18 //! # extern crate secp256k1;
20 //! # use lightning::routing::network_graph::NetworkGraph;
21 //! # use lightning::routing::router::{RouteParameters, find_route};
22 //! # use lightning::routing::scoring::{Scorer, ScoringParameters};
23 //! # use lightning::util::logger::{Logger, Record};
24 //! # use secp256k1::key::PublicKey;
26 //! # struct FakeLogger {};
27 //! # impl Logger for FakeLogger {
28 //! # fn log(&self, record: &Record) { unimplemented!() }
30 //! # fn find_scored_route(payer: PublicKey, params: RouteParameters, network_graph: NetworkGraph) {
31 //! # let logger = FakeLogger {};
33 //! // Use the default channel penalties.
34 //! let scorer = Scorer::default();
36 //! // Or use custom channel penalties.
37 //! let scorer = Scorer::new(ScoringParameters {
38 //! base_penalty_msat: 1000,
39 //! failure_penalty_msat: 2 * 1024 * 1000,
40 //! ..ScoringParameters::default()
43 //! let route = find_route(&payer, ¶ms, &network_graph, None, &logger, &scorer);
49 //! If persisting [`Scorer`], it must be restored using the same [`Time`] parameterization. Using a
50 //! different type results in undefined behavior. Specifically, persisting when built with feature
51 //! `no-std` and restoring without it, or vice versa, uses different types and thus is undefined.
53 //! [`find_route`]: crate::routing::router::find_route
55 use ln::msgs::DecodeError;
56 use routing::network_graph::NodeId;
57 use routing::router::RouteHop;
58 use util::ser::{Readable, Writeable, Writer};
61 use core::cell::{RefCell, RefMut};
62 use core::ops::{DerefMut, Sub};
63 use core::time::Duration;
64 use io::{self, Read}; use sync::{Mutex, MutexGuard};
66 /// We define Score ever-so-slightly differently based on whether we are being built for C bindings
67 /// or not. For users, `LockableScore` must somehow be writeable to disk. For Rust users, this is
68 /// no problem - you move a `Score` that implements `Writeable` into a `Mutex`, lock it, and now
69 /// you have the original, concrete, `Score` type, which presumably implements `Writeable`.
71 /// For C users, once you've moved the `Score` into a `LockableScore` all you have after locking it
72 /// is an opaque trait object with an opaque pointer with no type info. Users could take the unsafe
73 /// approach of blindly casting that opaque pointer to a concrete type and calling `Writeable` from
74 /// there, but other languages downstream of the C bindings (e.g. Java) can't even do that.
75 /// Instead, we really want `Score` and `LockableScore` to implement `Writeable` directly, which we
76 /// do here by defining `Score` differently for `cfg(c_bindings)`.
77 macro_rules! define_score { ($($supertrait: path)*) => {
78 /// An interface used to score payment channels for path finding.
80 /// Scoring is in terms of fees willing to be paid in order to avoid routing through a channel.
81 pub trait Score $(: $supertrait)* {
82 /// Returns the fee in msats willing to be paid to avoid routing `send_amt_msat` through the
83 /// given channel in the direction from `source` to `target`.
85 /// The channel's capacity (less any other MPP parts which are also being considered for use in
86 /// the same payment) is given by `channel_capacity_msat`. It may be guessed from various
87 /// sources or assumed from no data at all.
89 /// For hints provided in the invoice, we assume the channel has sufficient capacity to accept
90 /// the invoice's full amount, and provide a `channel_capacity_msat` of `None`. In all other
91 /// cases it is set to `Some`, even if we're guessing at the channel value.
93 /// Your code should be overflow-safe through a `channel_capacity_msat` of 21 million BTC.
94 fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option<u64>, source: &NodeId, target: &NodeId) -> u64;
96 /// Handles updating channel penalties after failing to route through a channel.
97 fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64);
100 impl<S: Score, T: DerefMut<Target=S> $(+ $supertrait)*> Score for T {
101 fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option<u64>, source: &NodeId, target: &NodeId) -> u64 {
102 self.deref().channel_penalty_msat(short_channel_id, send_amt_msat, channel_capacity_msat, source, target)
105 fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
106 self.deref_mut().payment_path_failed(path, short_channel_id)
112 define_score!(Writeable);
113 #[cfg(not(c_bindings))]
116 /// A scorer that is accessed under a lock.
118 /// Needed so that calls to [`Score::channel_penalty_msat`] in [`find_route`] can be made while
119 /// having shared ownership of a scorer but without requiring internal locking in [`Score`]
120 /// implementations. Internal locking would be detrimental to route finding performance and could
121 /// result in [`Score::channel_penalty_msat`] returning a different value for the same channel.
123 /// [`find_route`]: crate::routing::router::find_route
124 pub trait LockableScore<'a> {
125 /// The locked [`Score`] type.
126 type Locked: 'a + Score;
128 /// Returns the locked scorer.
129 fn lock(&'a self) -> Self::Locked;
133 impl<'a, T: 'a + Score> LockableScore<'a> for Mutex<T> {
134 type Locked = MutexGuard<'a, T>;
136 fn lock(&'a self) -> MutexGuard<'a, T> {
137 Mutex::lock(self).unwrap()
141 impl<'a, T: 'a + Score> LockableScore<'a> for RefCell<T> {
142 type Locked = RefMut<'a, T>;
144 fn lock(&'a self) -> RefMut<'a, T> {
150 /// A concrete implementation of [`LockableScore`] which supports multi-threading.
151 pub struct MultiThreadedLockableScore<S: Score> {
156 impl<'a, T: Score + 'a> LockableScore<'a> for MultiThreadedLockableScore<T> {
157 type Locked = MutexGuard<'a, T>;
159 fn lock(&'a self) -> MutexGuard<'a, T> {
160 Mutex::lock(&self.score).unwrap()
166 impl<'a, T: Writeable> Writeable for RefMut<'a, T> {
167 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
168 T::write(&**self, writer)
174 impl<'a, S: Writeable> Writeable for MutexGuard<'a, S> {
175 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
176 S::write(&**self, writer)
180 /// [`Score`] implementation that provides reasonable default behavior.
182 /// Used to apply a fixed penalty to each channel, thus avoiding long paths when shorter paths with
183 /// slightly higher fees are available. Will further penalize channels that fail to relay payments.
185 /// See [module-level documentation] for usage.
187 /// [module-level documentation]: crate::routing::scoring
188 pub type Scorer = ScorerUsingTime::<DefaultTime>;
190 /// Time used by [`Scorer`].
191 #[cfg(not(feature = "no-std"))]
192 pub type DefaultTime = std::time::Instant;
194 /// Time used by [`Scorer`].
195 #[cfg(feature = "no-std")]
196 pub type DefaultTime = Eternity;
198 /// [`Score`] implementation parameterized by [`Time`].
200 /// See [`Scorer`] for details.
204 /// Mixing [`Time`] types between serialization and deserialization results in undefined behavior.
205 pub struct ScorerUsingTime<T: Time> {
206 params: ScoringParameters,
207 // TODO: Remove entries of closed channels.
208 channel_failures: HashMap<u64, ChannelFailure<T>>,
211 /// Parameters for configuring [`Scorer`].
212 pub struct ScoringParameters {
213 /// A fixed penalty in msats to apply to each channel.
215 /// Default value: 500 msat
216 pub base_penalty_msat: u64,
218 /// A penalty in msats to apply to a channel upon failing to relay a payment.
220 /// This accumulates for each failure but may be reduced over time based on
221 /// [`failure_penalty_half_life`].
223 /// Default value: 1,024,000 msat
225 /// [`failure_penalty_half_life`]: Self::failure_penalty_half_life
226 pub failure_penalty_msat: u64,
228 /// When the amount being sent over a channel is this many 1024ths of the total channel
229 /// capacity, we begin applying [`overuse_penalty_msat_per_1024th`].
231 /// Default value: 128 1024ths (i.e. begin penalizing when an HTLC uses 1/8th of a channel)
233 /// [`overuse_penalty_msat_per_1024th`]: Self::overuse_penalty_msat_per_1024th
234 pub overuse_penalty_start_1024th: u16,
236 /// A penalty applied, per whole 1024ths of the channel capacity which the amount being sent
237 /// over the channel exceeds [`overuse_penalty_start_1024th`] by.
239 /// Default value: 20 msat (i.e. 2560 msat penalty to use 1/4th of a channel, 7680 msat penalty
240 /// to use half a channel, and 12,560 msat penalty to use 3/4ths of a channel)
242 /// [`overuse_penalty_start_1024th`]: Self::overuse_penalty_start_1024th
243 pub overuse_penalty_msat_per_1024th: u64,
245 /// The time required to elapse before any accumulated [`failure_penalty_msat`] penalties are
250 /// When time is an [`Eternity`], as is default when enabling feature `no-std`, it will never
251 /// elapse. Therefore, this penalty will never decay.
253 /// [`failure_penalty_msat`]: Self::failure_penalty_msat
254 pub failure_penalty_half_life: Duration,
257 impl_writeable_tlv_based!(ScoringParameters, {
258 (0, base_penalty_msat, required),
259 (1, overuse_penalty_start_1024th, (default_value, 128)),
260 (2, failure_penalty_msat, required),
261 (3, overuse_penalty_msat_per_1024th, (default_value, 20)),
262 (4, failure_penalty_half_life, required),
265 /// Accounting for penalties against a channel for failing to relay any payments.
267 /// Penalties decay over time, though accumulate as more failures occur.
268 struct ChannelFailure<T: Time> {
269 /// Accumulated penalty in msats for the channel as of `last_failed`.
270 undecayed_penalty_msat: u64,
272 /// Last time the channel failed. Used to decay `undecayed_penalty_msat`.
276 /// A measurement of time.
277 pub trait Time: Sub<Duration, Output = Self> where Self: Sized {
278 /// Returns an instance corresponding to the current moment.
281 /// Returns the amount of time elapsed since `self` was created.
282 fn elapsed(&self) -> Duration;
284 /// Returns the amount of time passed since the beginning of [`Time`].
286 /// Used during (de-)serialization.
287 fn duration_since_epoch() -> Duration;
290 impl<T: Time> ScorerUsingTime<T> {
291 /// Creates a new scorer using the given scoring parameters.
292 pub fn new(params: ScoringParameters) -> Self {
295 channel_failures: HashMap::new(),
299 /// Creates a new scorer using `penalty_msat` as a fixed channel penalty.
300 #[cfg(any(test, feature = "fuzztarget", feature = "_test_utils"))]
301 pub fn with_fixed_penalty(penalty_msat: u64) -> Self {
302 Self::new(ScoringParameters {
303 base_penalty_msat: penalty_msat,
304 failure_penalty_msat: 0,
305 failure_penalty_half_life: Duration::from_secs(0),
306 overuse_penalty_start_1024th: 1024,
307 overuse_penalty_msat_per_1024th: 0,
312 impl<T: Time> ChannelFailure<T> {
313 fn new(failure_penalty_msat: u64) -> Self {
315 undecayed_penalty_msat: failure_penalty_msat,
316 last_failed: T::now(),
320 fn add_penalty(&mut self, failure_penalty_msat: u64, half_life: Duration) {
321 self.undecayed_penalty_msat = self.decayed_penalty_msat(half_life) + failure_penalty_msat;
322 self.last_failed = T::now();
325 fn decayed_penalty_msat(&self, half_life: Duration) -> u64 {
326 let decays = self.last_failed.elapsed().as_secs().checked_div(half_life.as_secs());
328 Some(decays) => self.undecayed_penalty_msat >> decays,
334 impl<T: Time> Default for ScorerUsingTime<T> {
335 fn default() -> Self {
336 Self::new(ScoringParameters::default())
340 impl Default for ScoringParameters {
341 fn default() -> Self {
343 base_penalty_msat: 500,
344 failure_penalty_msat: 1024 * 1000,
345 failure_penalty_half_life: Duration::from_secs(3600),
346 overuse_penalty_start_1024th: 1024 / 8,
347 overuse_penalty_msat_per_1024th: 20,
352 impl<T: Time> Score for ScorerUsingTime<T> {
353 fn channel_penalty_msat(
354 &self, short_channel_id: u64, send_amt_msat: u64, chan_capacity_opt: Option<u64>, _source: &NodeId, _target: &NodeId
356 let failure_penalty_msat = self.channel_failures
357 .get(&short_channel_id)
358 .map_or(0, |value| value.decayed_penalty_msat(self.params.failure_penalty_half_life));
360 let mut penalty_msat = self.params.base_penalty_msat + failure_penalty_msat;
362 if let Some(chan_capacity_msat) = chan_capacity_opt {
363 let send_1024ths = send_amt_msat.checked_mul(1024).unwrap_or(u64::max_value()) / chan_capacity_msat;
365 if send_1024ths > self.params.overuse_penalty_start_1024th as u64 {
366 penalty_msat = penalty_msat.checked_add(
367 (send_1024ths - self.params.overuse_penalty_start_1024th as u64)
368 .checked_mul(self.params.overuse_penalty_msat_per_1024th).unwrap_or(u64::max_value()))
369 .unwrap_or(u64::max_value());
376 fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
377 let failure_penalty_msat = self.params.failure_penalty_msat;
378 let half_life = self.params.failure_penalty_half_life;
379 self.channel_failures
380 .entry(short_channel_id)
381 .and_modify(|failure| failure.add_penalty(failure_penalty_msat, half_life))
382 .or_insert_with(|| ChannelFailure::new(failure_penalty_msat));
386 #[cfg(not(feature = "no-std"))]
387 impl Time for std::time::Instant {
389 std::time::Instant::now()
392 fn duration_since_epoch() -> Duration {
393 use std::time::SystemTime;
394 SystemTime::now().duration_since(SystemTime::UNIX_EPOCH).unwrap()
397 fn elapsed(&self) -> Duration {
398 std::time::Instant::elapsed(self)
402 /// A state in which time has no meaning.
403 #[derive(Debug, PartialEq, Eq)]
406 impl Time for Eternity {
411 fn duration_since_epoch() -> Duration {
412 Duration::from_secs(0)
415 fn elapsed(&self) -> Duration {
416 Duration::from_secs(0)
420 impl Sub<Duration> for Eternity {
423 fn sub(self, _other: Duration) -> Self {
428 impl<T: Time> Writeable for ScorerUsingTime<T> {
430 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
431 self.params.write(w)?;
432 self.channel_failures.write(w)?;
433 write_tlv_fields!(w, {});
438 impl<T: Time> Readable for ScorerUsingTime<T> {
440 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
442 params: Readable::read(r)?,
443 channel_failures: Readable::read(r)?,
445 read_tlv_fields!(r, {});
450 impl<T: Time> Writeable for ChannelFailure<T> {
452 fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
453 let duration_since_epoch = T::duration_since_epoch() - self.last_failed.elapsed();
454 write_tlv_fields!(w, {
455 (0, self.undecayed_penalty_msat, required),
456 (2, duration_since_epoch, required),
462 impl<T: Time> Readable for ChannelFailure<T> {
464 fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
465 let mut undecayed_penalty_msat = 0;
466 let mut duration_since_epoch = Duration::from_secs(0);
467 read_tlv_fields!(r, {
468 (0, undecayed_penalty_msat, required),
469 (2, duration_since_epoch, required),
472 undecayed_penalty_msat,
473 last_failed: T::now() - (T::duration_since_epoch() - duration_since_epoch),
480 use super::{Eternity, ScoringParameters, ScorerUsingTime, Time};
482 use routing::scoring::Score;
483 use routing::network_graph::NodeId;
484 use util::ser::{Readable, Writeable};
486 use bitcoin::secp256k1::PublicKey;
487 use core::cell::Cell;
489 use core::time::Duration;
492 /// Time that can be advanced manually in tests.
493 #[derive(Debug, PartialEq, Eq)]
494 struct SinceEpoch(Duration);
498 static ELAPSED: Cell<Duration> = core::cell::Cell::new(Duration::from_secs(0));
501 fn advance(duration: Duration) {
502 Self::ELAPSED.with(|elapsed| elapsed.set(elapsed.get() + duration))
506 impl Time for SinceEpoch {
508 Self(Self::duration_since_epoch())
511 fn duration_since_epoch() -> Duration {
512 Self::ELAPSED.with(|elapsed| elapsed.get())
515 fn elapsed(&self) -> Duration {
516 Self::duration_since_epoch() - self.0
520 impl Sub<Duration> for SinceEpoch {
523 fn sub(self, other: Duration) -> Self {
529 fn time_passes_when_advanced() {
530 let now = SinceEpoch::now();
531 assert_eq!(now.elapsed(), Duration::from_secs(0));
533 SinceEpoch::advance(Duration::from_secs(1));
534 SinceEpoch::advance(Duration::from_secs(1));
536 let elapsed = now.elapsed();
537 let later = SinceEpoch::now();
539 assert_eq!(elapsed, Duration::from_secs(2));
540 assert_eq!(later - elapsed, now);
544 fn time_never_passes_in_an_eternity() {
545 let now = Eternity::now();
546 let elapsed = now.elapsed();
547 let later = Eternity::now();
549 assert_eq!(now.elapsed(), Duration::from_secs(0));
550 assert_eq!(later - elapsed, now);
553 /// A scorer for testing with time that can be manually advanced.
554 type Scorer = ScorerUsingTime::<SinceEpoch>;
556 fn source_node_id() -> NodeId {
557 NodeId::from_pubkey(&PublicKey::from_slice(&hex::decode("02eec7245d6b7d2ccb30380bfbe2a3648cd7a942653f5aa340edcea1f283686619").unwrap()[..]).unwrap())
560 fn target_node_id() -> NodeId {
561 NodeId::from_pubkey(&PublicKey::from_slice(&hex::decode("0324653eac434488002cc06bbfb7f10fe18991e35f9fe4302dbea6d2353dc0ab1c").unwrap()[..]).unwrap())
565 fn penalizes_without_channel_failures() {
566 let scorer = Scorer::new(ScoringParameters {
567 base_penalty_msat: 1_000,
568 failure_penalty_msat: 512,
569 failure_penalty_half_life: Duration::from_secs(1),
570 overuse_penalty_start_1024th: 1024,
571 overuse_penalty_msat_per_1024th: 0,
573 let source = source_node_id();
574 let target = target_node_id();
575 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
577 SinceEpoch::advance(Duration::from_secs(1));
578 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
582 fn accumulates_channel_failure_penalties() {
583 let mut scorer = Scorer::new(ScoringParameters {
584 base_penalty_msat: 1_000,
585 failure_penalty_msat: 64,
586 failure_penalty_half_life: Duration::from_secs(10),
587 overuse_penalty_start_1024th: 1024,
588 overuse_penalty_msat_per_1024th: 0,
590 let source = source_node_id();
591 let target = target_node_id();
592 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
594 scorer.payment_path_failed(&[], 42);
595 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_064);
597 scorer.payment_path_failed(&[], 42);
598 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_128);
600 scorer.payment_path_failed(&[], 42);
601 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_192);
605 fn decays_channel_failure_penalties_over_time() {
606 let mut scorer = Scorer::new(ScoringParameters {
607 base_penalty_msat: 1_000,
608 failure_penalty_msat: 512,
609 failure_penalty_half_life: Duration::from_secs(10),
610 overuse_penalty_start_1024th: 1024,
611 overuse_penalty_msat_per_1024th: 0,
613 let source = source_node_id();
614 let target = target_node_id();
615 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
617 scorer.payment_path_failed(&[], 42);
618 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512);
620 SinceEpoch::advance(Duration::from_secs(9));
621 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512);
623 SinceEpoch::advance(Duration::from_secs(1));
624 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256);
626 SinceEpoch::advance(Duration::from_secs(10 * 8));
627 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_001);
629 SinceEpoch::advance(Duration::from_secs(10));
630 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
632 SinceEpoch::advance(Duration::from_secs(10));
633 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
637 fn accumulates_channel_failure_penalties_after_decay() {
638 let mut scorer = Scorer::new(ScoringParameters {
639 base_penalty_msat: 1_000,
640 failure_penalty_msat: 512,
641 failure_penalty_half_life: Duration::from_secs(10),
642 overuse_penalty_start_1024th: 1024,
643 overuse_penalty_msat_per_1024th: 0,
645 let source = source_node_id();
646 let target = target_node_id();
647 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_000);
649 scorer.payment_path_failed(&[], 42);
650 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512);
652 SinceEpoch::advance(Duration::from_secs(10));
653 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256);
655 scorer.payment_path_failed(&[], 42);
656 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_768);
658 SinceEpoch::advance(Duration::from_secs(10));
659 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_384);
663 fn restores_persisted_channel_failure_penalties() {
664 let mut scorer = Scorer::new(ScoringParameters {
665 base_penalty_msat: 1_000,
666 failure_penalty_msat: 512,
667 failure_penalty_half_life: Duration::from_secs(10),
668 overuse_penalty_start_1024th: 1024,
669 overuse_penalty_msat_per_1024th: 0,
671 let source = source_node_id();
672 let target = target_node_id();
674 scorer.payment_path_failed(&[], 42);
675 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512);
677 SinceEpoch::advance(Duration::from_secs(10));
678 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256);
680 scorer.payment_path_failed(&[], 43);
681 assert_eq!(scorer.channel_penalty_msat(43, 1, Some(1), &source, &target), 1_512);
683 let mut serialized_scorer = Vec::new();
684 scorer.write(&mut serialized_scorer).unwrap();
686 let deserialized_scorer = <Scorer>::read(&mut io::Cursor::new(&serialized_scorer)).unwrap();
687 assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256);
688 assert_eq!(deserialized_scorer.channel_penalty_msat(43, 1, Some(1), &source, &target), 1_512);
692 fn decays_persisted_channel_failure_penalties() {
693 let mut scorer = Scorer::new(ScoringParameters {
694 base_penalty_msat: 1_000,
695 failure_penalty_msat: 512,
696 failure_penalty_half_life: Duration::from_secs(10),
697 overuse_penalty_start_1024th: 1024,
698 overuse_penalty_msat_per_1024th: 0,
700 let source = source_node_id();
701 let target = target_node_id();
703 scorer.payment_path_failed(&[], 42);
704 assert_eq!(scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_512);
706 let mut serialized_scorer = Vec::new();
707 scorer.write(&mut serialized_scorer).unwrap();
709 SinceEpoch::advance(Duration::from_secs(10));
711 let deserialized_scorer = <Scorer>::read(&mut io::Cursor::new(&serialized_scorer)).unwrap();
712 assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_256);
714 SinceEpoch::advance(Duration::from_secs(10));
715 assert_eq!(deserialized_scorer.channel_penalty_msat(42, 1, Some(1), &source, &target), 1_128);
719 fn charges_per_1024th_penalty() {
720 let scorer = Scorer::new(ScoringParameters {
721 base_penalty_msat: 0,
722 failure_penalty_msat: 0,
723 failure_penalty_half_life: Duration::from_secs(0),
724 overuse_penalty_start_1024th: 256,
725 overuse_penalty_msat_per_1024th: 100,
727 let source = source_node_id();
728 let target = target_node_id();
730 assert_eq!(scorer.channel_penalty_msat(42, 1_000, None, &source, &target), 0);
731 assert_eq!(scorer.channel_penalty_msat(42, 1_000, Some(1_024_000), &source, &target), 0);
732 assert_eq!(scorer.channel_penalty_msat(42, 256_999, Some(1_024_000), &source, &target), 0);
733 assert_eq!(scorer.channel_penalty_msat(42, 257_000, Some(1_024_000), &source, &target), 100);
734 assert_eq!(scorer.channel_penalty_msat(42, 258_000, Some(1_024_000), &source, &target), 200);
735 assert_eq!(scorer.channel_penalty_msat(42, 512_000, Some(1_024_000), &source, &target), 256 * 100);