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 //! Structs and impls for receiving messages about the network and storing the topology live here.
12 pub mod network_graph;
16 use routing::network_graph::NodeId;
17 use routing::router::RouteHop;
19 use core::cell::{RefCell, RefMut};
20 use core::ops::DerefMut;
21 use sync::{Mutex, MutexGuard};
23 /// An interface used to score payment channels for path finding.
25 /// Scoring is in terms of fees willing to be paid in order to avoid routing through a channel.
27 /// Returns the fee in msats willing to be paid to avoid routing `send_amt_msat` through the
28 /// given channel in the direction from `source` to `target`.
30 /// The channel's capacity (less any other MPP parts which are also being considered for use in
31 /// the same payment) is given by `channel_capacity_msat`. It may be guessed from various
32 /// sources or assumed from no data at all.
34 /// For hints provided in the invoice, we assume the channel has sufficient capacity to accept
35 /// the invoice's full amount, and provide a `channel_capacity_msat` of `None`. In all other
36 /// cases it is set to `Some`, even if we're guessing at the channel value.
38 /// Your code should be overflow-safe through a `channel_capacity_msat` of 21 million BTC.
39 fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option<u64>, source: &NodeId, target: &NodeId) -> u64;
41 /// Handles updating channel penalties after failing to route through a channel.
42 fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64);
45 /// A scorer that is accessed under a lock.
47 /// Needed so that calls to [`Score::channel_penalty_msat`] in [`find_route`] can be made while
48 /// having shared ownership of a scorer but without requiring internal locking in [`Score`]
49 /// implementations. Internal locking would be detrimental to route finding performance and could
50 /// result in [`Score::channel_penalty_msat`] returning a different value for the same channel.
52 /// [`find_route`]: crate::routing::router::find_route
53 pub trait LockableScore<'a> {
54 /// The locked [`Score`] type.
55 type Locked: 'a + Score;
57 /// Returns the locked scorer.
58 fn lock(&'a self) -> Self::Locked;
61 impl<'a, T: 'a + Score> LockableScore<'a> for Mutex<T> {
62 type Locked = MutexGuard<'a, T>;
64 fn lock(&'a self) -> MutexGuard<'a, T> {
65 Mutex::lock(self).unwrap()
69 impl<'a, T: 'a + Score> LockableScore<'a> for RefCell<T> {
70 type Locked = RefMut<'a, T>;
72 fn lock(&'a self) -> RefMut<'a, T> {
77 impl<S: Score, T: DerefMut<Target=S>> Score for T {
78 fn channel_penalty_msat(&self, short_channel_id: u64, send_amt_msat: u64, channel_capacity_msat: Option<u64>, source: &NodeId, target: &NodeId) -> u64 {
79 self.deref().channel_penalty_msat(short_channel_id, send_amt_msat, channel_capacity_msat, source, target)
82 fn payment_path_failed(&mut self, path: &[&RouteHop], short_channel_id: u64) {
83 self.deref_mut().payment_path_failed(path, short_channel_id)