//! #
//! # use lightning::routing::network_graph::NetworkGraph;
//! # use lightning::routing::router::{RouteParameters, find_route};
-//! # use lightning::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters, Scorer, ScoringParameters};
+//! # use lightning::routing::scoring::{ProbabilisticScorer, ProbabilisticScoringParameters};
//! # use lightning::chain::keysinterface::{KeysManager, KeysInterface};
//! # use lightning::util::logger::{Logger, Record};
//! # use bitcoin::secp256k1::PublicKey;
}
}
-/// [`Score`] implementation that provides reasonable default behavior.
-///
-/// Used to apply a fixed penalty to each channel, thus avoiding long paths when shorter paths with
-/// slightly higher fees are available. Will further penalize channels that fail to relay payments.
-///
-/// See [module-level documentation] for usage and [`ScoringParameters`] for customization.
-///
-/// # Note
-///
-/// Mixing the `no-std` feature between serialization and deserialization results in undefined
-/// behavior.
-///
-/// [module-level documentation]: crate::routing::scoring
-#[deprecated(
- since = "0.0.105",
- note = "ProbabilisticScorer should be used instead of Scorer.",
-)]
-pub type Scorer = ScorerUsingTime::<ConfiguredTime>;
-
#[cfg(not(feature = "no-std"))]
type ConfiguredTime = std::time::Instant;
#[cfg(feature = "no-std")]
#[cfg(feature = "no-std")]
type ConfiguredTime = Eternity;
-// Note that ideally we'd hide ScorerUsingTime from public view by sealing it as well, but rustdoc
-// doesn't handle this well - instead exposing a `Scorer` which has no trait implementation(s) or
-// methods at all.
-
-/// [`Score`] implementation.
-///
-/// (C-not exported) generally all users should use the [`Scorer`] type alias.
-pub struct ScorerUsingTime<T: Time> {
- params: ScoringParameters,
- // TODO: Remove entries of closed channels.
- channel_failures: HashMap<u64, ChannelFailure<T>>,
-}
-
-#[derive(Clone)]
-/// Parameters for configuring [`Scorer`].
-pub struct ScoringParameters {
- /// A fixed penalty in msats to apply to each channel.
- ///
- /// Default value: 500 msat
- pub base_penalty_msat: u64,
-
- /// A penalty in msats to apply to a channel upon failing to relay a payment.
- ///
- /// This accumulates for each failure but may be reduced over time based on
- /// [`failure_penalty_half_life`] or when successfully routing through a channel.
- ///
- /// Default value: 1,024,000 msat
- ///
- /// [`failure_penalty_half_life`]: Self::failure_penalty_half_life
- pub failure_penalty_msat: u64,
-
- /// When the amount being sent over a channel is this many 1024ths of the total channel
- /// capacity, we begin applying [`overuse_penalty_msat_per_1024th`].
- ///
- /// Default value: 128 1024ths (i.e. begin penalizing when an HTLC uses 1/8th of a channel)
- ///
- /// [`overuse_penalty_msat_per_1024th`]: Self::overuse_penalty_msat_per_1024th
- pub overuse_penalty_start_1024th: u16,
-
- /// A penalty applied, per whole 1024ths of the channel capacity which the amount being sent
- /// over the channel exceeds [`overuse_penalty_start_1024th`] by.
- ///
- /// Default value: 20 msat (i.e. 2560 msat penalty to use 1/4th of a channel, 7680 msat penalty
- /// to use half a channel, and 12,560 msat penalty to use 3/4ths of a channel)
- ///
- /// [`overuse_penalty_start_1024th`]: Self::overuse_penalty_start_1024th
- pub overuse_penalty_msat_per_1024th: u64,
-
- /// The time required to elapse before any accumulated [`failure_penalty_msat`] penalties are
- /// cut in half.
- ///
- /// Successfully routing through a channel will immediately cut the penalty in half as well.
- ///
- /// Default value: 1 hour
- ///
- /// # Note
- ///
- /// When built with the `no-std` feature, time will never elapse. Therefore, this penalty will
- /// never decay.
- ///
- /// [`failure_penalty_msat`]: Self::failure_penalty_msat
- pub failure_penalty_half_life: Duration,
-}
-
-impl_writeable_tlv_based!(ScoringParameters, {
- (0, base_penalty_msat, required),
- (1, overuse_penalty_start_1024th, (default_value, 128)),
- (2, failure_penalty_msat, required),
- (3, overuse_penalty_msat_per_1024th, (default_value, 20)),
- (4, failure_penalty_half_life, required),
-});
-
-/// Accounting for penalties against a channel for failing to relay any payments.
-///
-/// Penalties decay over time, though accumulate as more failures occur.
-struct ChannelFailure<T: Time> {
- /// Accumulated penalty in msats for the channel as of `last_updated`.
- undecayed_penalty_msat: u64,
-
- /// Last time the channel either failed to route or successfully routed a payment. Used to decay
- /// `undecayed_penalty_msat`.
- last_updated: T,
-}
-
-impl<T: Time> ScorerUsingTime<T> {
- /// Creates a new scorer using the given scoring parameters.
- pub fn new(params: ScoringParameters) -> Self {
- Self {
- params,
- channel_failures: HashMap::new(),
- }
- }
-}
-
-impl<T: Time> ChannelFailure<T> {
- fn new(failure_penalty_msat: u64) -> Self {
- Self {
- undecayed_penalty_msat: failure_penalty_msat,
- last_updated: T::now(),
- }
- }
-
- fn add_penalty(&mut self, failure_penalty_msat: u64, half_life: Duration) {
- self.undecayed_penalty_msat = self.decayed_penalty_msat(half_life) + failure_penalty_msat;
- self.last_updated = T::now();
- }
-
- fn reduce_penalty(&mut self, half_life: Duration) {
- self.undecayed_penalty_msat = self.decayed_penalty_msat(half_life) >> 1;
- self.last_updated = T::now();
- }
-
- fn decayed_penalty_msat(&self, half_life: Duration) -> u64 {
- self.last_updated.elapsed().as_secs()
- .checked_div(half_life.as_secs())
- .and_then(|decays| self.undecayed_penalty_msat.checked_shr(decays as u32))
- .unwrap_or(0)
- }
-}
-
-impl<T: Time> Default for ScorerUsingTime<T> {
- fn default() -> Self {
- Self::new(ScoringParameters::default())
- }
-}
-
-impl Default for ScoringParameters {
- fn default() -> Self {
- Self {
- base_penalty_msat: 500,
- failure_penalty_msat: 1024 * 1000,
- failure_penalty_half_life: Duration::from_secs(3600),
- overuse_penalty_start_1024th: 1024 / 8,
- overuse_penalty_msat_per_1024th: 20,
- }
- }
-}
-
-impl<T: Time> Score for ScorerUsingTime<T> {
- fn channel_penalty_msat(
- &self, short_channel_id: u64, _source: &NodeId, _target: &NodeId, usage: ChannelUsage
- ) -> u64 {
- let failure_penalty_msat = self.channel_failures
- .get(&short_channel_id)
- .map_or(0, |value| value.decayed_penalty_msat(self.params.failure_penalty_half_life));
-
- let mut penalty_msat = self.params.base_penalty_msat + failure_penalty_msat;
- let send_amt_msat = usage.amount_msat;
- let capacity_msat = usage.effective_capacity.as_msat()
- .saturating_sub(usage.inflight_htlc_msat);
- let send_1024ths = send_amt_msat.checked_mul(1024).unwrap_or(u64::max_value()) / capacity_msat;
- if send_1024ths > self.params.overuse_penalty_start_1024th as u64 {
- penalty_msat = penalty_msat.checked_add(
- (send_1024ths - self.params.overuse_penalty_start_1024th as u64)
- .checked_mul(self.params.overuse_penalty_msat_per_1024th).unwrap_or(u64::max_value()))
- .unwrap_or(u64::max_value());
- }
-
- penalty_msat
- }
-
- fn payment_path_failed(&mut self, _path: &[&RouteHop], short_channel_id: u64) {
- let failure_penalty_msat = self.params.failure_penalty_msat;
- let half_life = self.params.failure_penalty_half_life;
- self.channel_failures
- .entry(short_channel_id)
- .and_modify(|failure| failure.add_penalty(failure_penalty_msat, half_life))
- .or_insert_with(|| ChannelFailure::new(failure_penalty_msat));
- }
-
- fn payment_path_successful(&mut self, path: &[&RouteHop]) {
- let half_life = self.params.failure_penalty_half_life;
- for hop in path.iter() {
- self.channel_failures
- .entry(hop.short_channel_id)
- .and_modify(|failure| failure.reduce_penalty(half_life));
- }
- }
-}
-
-impl<T: Time> Writeable for ScorerUsingTime<T> {
- #[inline]
- fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
- self.params.write(w)?;
- self.channel_failures.write(w)?;
- write_tlv_fields!(w, {});
- Ok(())
- }
-}
-
-impl<T: Time> Readable for ScorerUsingTime<T> {
- #[inline]
- fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
- let res = Ok(Self {
- params: Readable::read(r)?,
- channel_failures: Readable::read(r)?,
- });
- read_tlv_fields!(r, {});
- res
- }
-}
-
-impl<T: Time> Writeable for ChannelFailure<T> {
- #[inline]
- fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
- let duration_since_epoch = T::duration_since_epoch() - self.last_updated.elapsed();
- write_tlv_fields!(w, {
- (0, self.undecayed_penalty_msat, required),
- (2, duration_since_epoch, required),
- });
- Ok(())
- }
-}
-
-impl<T: Time> Readable for ChannelFailure<T> {
- #[inline]
- fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
- let mut undecayed_penalty_msat = 0;
- let mut duration_since_epoch = Duration::from_secs(0);
- read_tlv_fields!(r, {
- (0, undecayed_penalty_msat, required),
- (2, duration_since_epoch, required),
- });
- Ok(Self {
- undecayed_penalty_msat,
- last_updated: T::now() - (T::duration_since_epoch() - duration_since_epoch),
- })
- }
-}
-
/// [`Score`] implementation using channel success probability distributions.
///
/// Based on *Optimally Reliable & Cheap Payment Flows on the Lightning Network* by Rene Pickhardt
#[cfg(test)]
mod tests {
- use super::{ChannelLiquidity, ProbabilisticScoringParameters, ProbabilisticScorerUsingTime, ScoringParameters, ScorerUsingTime};
+ use super::{ChannelLiquidity, ProbabilisticScoringParameters, ProbabilisticScorerUsingTime};
use util::time::Time;
use util::time::tests::SinceEpoch;
use routing::scoring::{ChannelUsage, Score};
use routing::network_graph::{EffectiveCapacity, NetworkGraph, NodeId};
use routing::router::RouteHop;
- use util::ser::{Readable, ReadableArgs, Writeable};
+ use util::ser::{ReadableArgs, Writeable};
use util::test_utils::TestLogger;
use bitcoin::blockdata::constants::genesis_block;
use core::time::Duration;
use io;
- /// A scorer for testing with time that can be manually advanced.
- type Scorer = ScorerUsingTime::<SinceEpoch>;
-
fn source_privkey() -> SecretKey {
SecretKey::from_slice(&[42; 32]).unwrap()
}
NodeId::from_pubkey(&target_pubkey())
}
- #[test]
- fn penalizes_without_channel_failures() {
- let scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(1),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- SinceEpoch::advance(Duration::from_secs(1));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
- }
-
- #[test]
- fn accumulates_channel_failure_penalties() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 64,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_064);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_128);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_192);
- }
-
- #[test]
- fn decays_channel_failure_penalties_over_time() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- SinceEpoch::advance(Duration::from_secs(9));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- SinceEpoch::advance(Duration::from_secs(1));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
-
- SinceEpoch::advance(Duration::from_secs(10 * 8));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_001);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
- }
-
- #[test]
- fn decays_channel_failure_penalties_without_shift_overflow() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- // An unchecked right shift 64 bits or more in ChannelFailure::decayed_penalty_msat would
- // cause an overflow.
- SinceEpoch::advance(Duration::from_secs(10 * 64));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
- }
-
- #[test]
- fn accumulates_channel_failure_penalties_after_decay() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_768);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_384);
- }
-
- #[test]
- fn reduces_channel_failure_penalties_after_success() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_000);
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
-
- let hop = RouteHop {
- pubkey: PublicKey::from_slice(target.as_slice()).unwrap(),
- node_features: NodeFeatures::known(),
- short_channel_id: 42,
- channel_features: ChannelFeatures::known(),
- fee_msat: 1,
- cltv_expiry_delta: 18,
- };
- scorer.payment_path_successful(&[&hop]);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_128);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_064);
- }
-
- #[test]
- fn restores_persisted_channel_failure_penalties() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
-
- scorer.payment_path_failed(&[], 43);
- assert_eq!(scorer.channel_penalty_msat(43, &source, &target, usage), 1_512);
-
- let mut serialized_scorer = Vec::new();
- scorer.write(&mut serialized_scorer).unwrap();
-
- let deserialized_scorer = <Scorer>::read(&mut io::Cursor::new(&serialized_scorer)).unwrap();
- assert_eq!(deserialized_scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
- assert_eq!(deserialized_scorer.channel_penalty_msat(43, &source, &target, usage), 1_512);
- }
-
- #[test]
- fn decays_persisted_channel_failure_penalties() {
- let mut scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 1_000,
- failure_penalty_msat: 512,
- failure_penalty_half_life: Duration::from_secs(10),
- overuse_penalty_start_1024th: 1024,
- overuse_penalty_msat_per_1024th: 0,
- });
- let source = source_node_id();
- let target = target_node_id();
- let usage = ChannelUsage {
- amount_msat: 1, inflight_htlc_msat: 0, effective_capacity: EffectiveCapacity::Unknown
- };
-
- scorer.payment_path_failed(&[], 42);
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 1_512);
-
- let mut serialized_scorer = Vec::new();
- scorer.write(&mut serialized_scorer).unwrap();
-
- SinceEpoch::advance(Duration::from_secs(10));
-
- let deserialized_scorer = <Scorer>::read(&mut io::Cursor::new(&serialized_scorer)).unwrap();
- assert_eq!(deserialized_scorer.channel_penalty_msat(42, &source, &target, usage), 1_256);
-
- SinceEpoch::advance(Duration::from_secs(10));
- assert_eq!(deserialized_scorer.channel_penalty_msat(42, &source, &target, usage), 1_128);
- }
-
- #[test]
- fn charges_per_1024th_penalty() {
- let scorer = Scorer::new(ScoringParameters {
- base_penalty_msat: 0,
- failure_penalty_msat: 0,
- failure_penalty_half_life: Duration::from_secs(0),
- overuse_penalty_start_1024th: 256,
- overuse_penalty_msat_per_1024th: 100,
- });
- let source = source_node_id();
- let target = target_node_id();
-
- let usage = ChannelUsage {
- amount_msat: 1_000,
- inflight_htlc_msat: 0,
- effective_capacity: EffectiveCapacity::Total { capacity_msat: 1_024_000 },
- };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
-
- let usage = ChannelUsage { amount_msat: 256_999, ..usage };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 0);
-
- let usage = ChannelUsage { amount_msat: 257_000, ..usage };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 100);
-
- let usage = ChannelUsage { amount_msat: 258_000, ..usage };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 200);
-
- let usage = ChannelUsage { amount_msat: 512_000, ..usage };
- assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage), 256 * 100);
- }
-
// `ProbabilisticScorer` tests
/// A probabilistic scorer for testing with time that can be manually advanced.