#[cfg(not(c_bindings))]
impl<'a, T> WriteableScore<'a> for T where T: LockableScore<'a> + Writeable {}
-/// This is not exported to bindings users
+#[cfg(not(c_bindings))]
impl<'a, T: 'a + Score> LockableScore<'a> for Mutex<T> {
type Score = T;
type Locked = MutexGuard<'a, T>;
}
}
+#[cfg(not(c_bindings))]
impl<'a, T: 'a + Score> LockableScore<'a> for RefCell<T> {
type Score = T;
type Locked = RefMut<'a, T>;
}
}
-#[cfg(c_bindings)]
-/// This is not exported to bindings users
-impl<'a, T: Writeable> Writeable for RefMut<'a, T> {
- fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
- T::write(&**self, writer)
- }
-}
-#[cfg(c_bindings)]
-/// This is not exported to bindings users
-impl<'a, S: Writeable> Writeable for MutexGuard<'a, S> {
- fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
- S::write(&**self, writer)
- }
-}
/// Proposed use of a channel passed as a parameter to [`Score::channel_penalty_msat`].
#[derive(Clone, Copy, Debug, PartialEq)]
pub manual_node_penalties: HashMap<NodeId, u64>,
/// This penalty is applied when `htlc_maximum_msat` is equal to or larger than half of the
- /// channel's capacity, (ie. htlc_maximum_msat ≥ 0.5 * channel_capacity) which makes us
+ /// channel's capacity, (ie. htlc_maximum_msat >= 0.5 * channel_capacity) which makes us
/// prefer nodes with a smaller `htlc_maximum_msat`. We treat such nodes preferentially
/// as this makes balance discovery attacks harder to execute, thereby creating an incentive
/// to restrict `htlc_maximum_msat` and improve privacy.
}
fn decayed_offset_msat(&self, offset_msat: u64) -> u64 {
- self.now.duration_since(*self.last_updated).as_secs()
- .checked_div(self.decay_params.liquidity_offset_half_life.as_secs())
- .and_then(|decays| offset_msat.checked_shr(decays as u32))
- .unwrap_or(0)
+ let half_life = self.decay_params.liquidity_offset_half_life.as_secs();
+ if half_life != 0 {
+ // Decay the offset by the appropriate number of half lives. If half of the next half
+ // life has passed, approximate an additional three-quarter life to help smooth out the
+ // decay.
+ let elapsed_time = self.now.duration_since(*self.last_updated).as_secs();
+ let half_decays = elapsed_time / (half_life / 2);
+ let decays = half_decays / 2;
+ let decayed_offset_msat = offset_msat.checked_shr(decays as u32).unwrap_or(0);
+ if half_decays % 2 == 0 {
+ decayed_offset_msat
+ } else {
+ // 11_585 / 16_384 ~= core::f64::consts::FRAC_1_SQRT_2
+ // 16_384 == 2^14
+ (decayed_offset_msat as u128 * 11_585 / 16_384) as u64
+ }
+ } else {
+ 0
+ }
}
}
scorer.payment_path_failed(&payment_path_for_amount(768), 42);
scorer.payment_path_failed(&payment_path_for_amount(128), 43);
+ // Initial penalties
let usage = ChannelUsage { amount_msat: 128, ..usage };
assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 0);
let usage = ChannelUsage { amount_msat: 256, ..usage };
let usage = ChannelUsage { amount_msat: 896, ..usage };
assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), u64::max_value());
- SinceEpoch::advance(Duration::from_secs(9));
+ // No decay
+ SinceEpoch::advance(Duration::from_secs(4));
let usage = ChannelUsage { amount_msat: 128, ..usage };
assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 0);
let usage = ChannelUsage { amount_msat: 256, ..usage };
let usage = ChannelUsage { amount_msat: 896, ..usage };
assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), u64::max_value());
+ // Half decay (i.e., three-quarter life)
SinceEpoch::advance(Duration::from_secs(1));
+ let usage = ChannelUsage { amount_msat: 128, ..usage };
+ assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 22);
+ let usage = ChannelUsage { amount_msat: 256, ..usage };
+ assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 106);
+ let usage = ChannelUsage { amount_msat: 768, ..usage };
+ assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 916);
+ let usage = ChannelUsage { amount_msat: 896, ..usage };
+ assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), u64::max_value());
+
+ // One decay (i.e., half life)
+ SinceEpoch::advance(Duration::from_secs(5));
let usage = ChannelUsage { amount_msat: 64, ..usage };
assert_eq!(scorer.channel_penalty_msat(42, &source, &target, usage, ¶ms), 0);
let usage = ChannelUsage { amount_msat: 128, ..usage };