/// A wrapper around the various hop representations.
///
-/// Used to construct a [`PathBuildingHop`] and to estimate [`EffectiveCapacity`].
+/// Can be used to examine the properties of a hop,
+/// potentially to decide whether to include it in a route.
#[derive(Clone, Debug)]
-enum CandidateRouteHop<'a> {
+pub enum CandidateRouteHop<'a> {
/// A hop from the payer, where the outbound liquidity is known.
FirstHop {
+ /// Channel details of the first hop
+ /// [`ChannelDetails::get_outbound_payment_scid`] is assumed
+ /// to always return `Some(scid)`
+ /// this assumption is checked in [`find_route`] method.
details: &'a ChannelDetails,
+ /// The node id of the payer.
+ ///
+ /// Can be accessed via `source` method.
+ node_id: NodeId
},
- /// A hop found in the [`ReadOnlyNetworkGraph`], where the channel capacity may be unknown.
+ /// A hop found in the [`ReadOnlyNetworkGraph`],
+ /// where the channel capacity may be unknown.
PublicHop {
+ /// channel info of the hop.
info: DirectedChannelInfo<'a>,
+ /// short_channel_id of the channel.
short_channel_id: u64,
},
- /// A hop to the payee found in the BOLT 11 payment invoice, though not necessarily a direct
+ /// A hop to the payee found in the BOLT 11 payment invoice,
+ /// though not necessarily a direct
/// channel.
PrivateHop {
+ /// Hint provides information about a private hop,
+ /// needed while routing through a private
+ /// channel.
hint: &'a RouteHintHop,
+ /// Node id of the next hop in route.
+ target_node_id: NodeId
},
- /// The payee's identity is concealed behind blinded paths provided in a BOLT 12 invoice.
+ /// The payee's identity is concealed behind
+ /// blinded paths provided in a BOLT 12 invoice.
Blinded {
+ /// Hint provides information about a blinded hop,
+ /// needed while routing through a blinded path.
+ /// `BlindedPayInfo` provides information needed about the
+ /// payment while routing through a blinded path.
+ /// `BlindedPath` is the blinded path to the destination.
hint: &'a (BlindedPayInfo, BlindedPath),
+ /// Index of the hint in the original list of blinded hints.
+ /// Provided to uniquely identify a hop as we are
+ /// route building.
hint_idx: usize,
},
- /// Similar to [`Self::Blinded`], but the path here has 1 blinded hop. `BlindedPayInfo` provided
- /// for 1-hop blinded paths is ignored because it is meant to apply to the hops *between* the
- /// introduction node and the destination. Useful for tracking that we need to include a blinded
+ /// Similar to [`Self::Blinded`], but the path here
+ /// has 1 blinded hop. `BlindedPayInfo` provided
+ /// for 1-hop blinded paths is ignored
+ /// because it is meant to apply to the hops *between* the
+ /// introduction node and the destination.
+ /// Useful for tracking that we need to include a blinded
/// path at the end of our [`Route`].
OneHopBlinded {
+ /// Hint provides information about a single blinded hop,
+ /// needed while routing through a one hop blinded path.
+ /// `BlindedPayInfo` is ignored here.
+ /// `BlindedPath` is the blinded path to the destination.
hint: &'a (BlindedPayInfo, BlindedPath),
+ /// Index of the hint in the original list of blinded hints.
+ /// Provided to uniquely identify a hop as we are route building.
hint_idx: usize,
},
}
impl<'a> CandidateRouteHop<'a> {
fn short_channel_id(&self) -> Option<u64> {
match self {
- CandidateRouteHop::FirstHop { details } => Some(details.get_outbound_payment_scid().unwrap()),
+ CandidateRouteHop::FirstHop { details, .. } => Some(details.get_outbound_payment_scid().unwrap()),
CandidateRouteHop::PublicHop { short_channel_id, .. } => Some(*short_channel_id),
- CandidateRouteHop::PrivateHop { hint } => Some(hint.short_channel_id),
+ CandidateRouteHop::PrivateHop { hint, .. } => Some(hint.short_channel_id),
CandidateRouteHop::Blinded { .. } => None,
CandidateRouteHop::OneHopBlinded { .. } => None,
}
// NOTE: This may alloc memory so avoid calling it in a hot code path.
fn features(&self) -> ChannelFeatures {
match self {
- CandidateRouteHop::FirstHop { details } => details.counterparty.features.to_context(),
+ CandidateRouteHop::FirstHop { details, .. } => details.counterparty.features.to_context(),
CandidateRouteHop::PublicHop { info, .. } => info.channel().features.clone(),
CandidateRouteHop::PrivateHop { .. } => ChannelFeatures::empty(),
CandidateRouteHop::Blinded { .. } => ChannelFeatures::empty(),
match self {
CandidateRouteHop::FirstHop { .. } => 0,
CandidateRouteHop::PublicHop { info, .. } => info.direction().cltv_expiry_delta as u32,
- CandidateRouteHop::PrivateHop { hint } => hint.cltv_expiry_delta as u32,
+ CandidateRouteHop::PrivateHop { hint, .. } => hint.cltv_expiry_delta as u32,
CandidateRouteHop::Blinded { hint, .. } => hint.0.cltv_expiry_delta as u32,
CandidateRouteHop::OneHopBlinded { .. } => 0,
}
fn htlc_minimum_msat(&self) -> u64 {
match self {
- CandidateRouteHop::FirstHop { details } => details.next_outbound_htlc_minimum_msat,
+ CandidateRouteHop::FirstHop { details, .. } => details.next_outbound_htlc_minimum_msat,
CandidateRouteHop::PublicHop { info, .. } => info.direction().htlc_minimum_msat,
- CandidateRouteHop::PrivateHop { hint } => hint.htlc_minimum_msat.unwrap_or(0),
+ CandidateRouteHop::PrivateHop { hint, .. } => hint.htlc_minimum_msat.unwrap_or(0),
CandidateRouteHop::Blinded { hint, .. } => hint.0.htlc_minimum_msat,
CandidateRouteHop::OneHopBlinded { .. } => 0,
}
base_msat: 0, proportional_millionths: 0,
},
CandidateRouteHop::PublicHop { info, .. } => info.direction().fees,
- CandidateRouteHop::PrivateHop { hint } => hint.fees,
+ CandidateRouteHop::PrivateHop { hint, .. } => hint.fees,
CandidateRouteHop::Blinded { hint, .. } => {
RoutingFees {
base_msat: hint.0.fee_base_msat,
fn effective_capacity(&self) -> EffectiveCapacity {
match self {
- CandidateRouteHop::FirstHop { details } => EffectiveCapacity::ExactLiquidity {
+ CandidateRouteHop::FirstHop { details, .. } => EffectiveCapacity::ExactLiquidity {
liquidity_msat: details.next_outbound_htlc_limit_msat,
},
CandidateRouteHop::PublicHop { info, .. } => info.effective_capacity(),
- CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }} =>
+ CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: Some(max), .. }, .. } =>
EffectiveCapacity::HintMaxHTLC { amount_msat: *max },
- CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }} =>
+ CandidateRouteHop::PrivateHop { hint: RouteHintHop { htlc_maximum_msat: None, .. }, .. } =>
EffectiveCapacity::Infinite,
CandidateRouteHop::Blinded { hint, .. } =>
EffectiveCapacity::HintMaxHTLC { amount_msat: hint.0.htlc_maximum_msat },
}
}
- fn id(&self, channel_direction: bool /* src_node_id < target_node_id */) -> CandidateHopId {
+ /// Returns the id of this hop.
+ /// For `Blinded` and `OneHopBlinded` we return `CandidateHopId::Blinded` with `hint_idx` because we don't know the channel id.
+ /// For any other option we return `CandidateHopId::Clear` because we know the channel id and the direction.
+ pub fn id(&self) -> CandidateHopId {
match self {
CandidateRouteHop::Blinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
CandidateRouteHop::OneHopBlinded { hint_idx, .. } => CandidateHopId::Blinded(*hint_idx),
- _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), channel_direction)),
+ _ => CandidateHopId::Clear((self.short_channel_id().unwrap(), self.source() < self.target().unwrap())),
}
}
fn blinded_path(&self) -> Option<&'a BlindedPath> {
_ => None,
}
}
+ /// Returns the source node id of current hop.
+ ///
+ /// Source node id refers to the hop forwarding the payment.
+ ///
+ /// For `FirstHop` we return payer's node id.
+ pub fn source(&self) -> NodeId {
+ match self {
+ CandidateRouteHop::FirstHop { node_id, .. } => *node_id,
+ CandidateRouteHop::PublicHop { info, .. } => *info.source(),
+ CandidateRouteHop::PrivateHop { hint, .. } => hint.src_node_id.into(),
+ CandidateRouteHop::Blinded { hint, .. } => hint.1.introduction_node_id.into(),
+ CandidateRouteHop::OneHopBlinded { hint, .. } => hint.1.introduction_node_id.into()
+ }
+ }
+ /// Returns the target node id of this hop, if known.
+ ///
+ /// Target node id refers to the hop receiving the payment.
+ ///
+ /// For `Blinded` and `OneHopBlinded` we return `None` because next hop is blinded.
+ pub fn target(&self) -> Option<NodeId> {
+ match self {
+ CandidateRouteHop::FirstHop { details, .. } => Some(details.counterparty.node_id.into()),
+ CandidateRouteHop::PublicHop { info, .. } => Some(*info.target()),
+ CandidateRouteHop::PrivateHop { target_node_id, .. } => Some(*target_node_id),
+ CandidateRouteHop::Blinded { .. } => None,
+ CandidateRouteHop::OneHopBlinded { .. } => None,
+ }
+ }
}
+/// A wrapper around the various hop id representations.
+///
+/// `CandidateHopId::Clear` is used to identify a hop with a known short channel id and direction.
+/// `CandidateHopId::Blinded` is used to identify a blinded hop `hint_idx`.
#[derive(Clone, Copy, Eq, Hash, Ord, PartialOrd, PartialEq)]
-enum CandidateHopId {
+pub enum CandidateHopId {
/// Contains (scid, src_node_id < target_node_id)
Clear((u64, bool)),
/// Index of the blinded route hint in [`Payee::Blinded::route_hints`].
let mut num_ignored_htlc_minimum_msat_limit: u32 = 0;
macro_rules! add_entry {
- // Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
+ // Adds entry which goes from $candidate.source() to $candidate.target() over the $candidate hop.
// $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
// since that value has to be transferred over this channel.
// Returns the contribution amount of $candidate if the channel caused an update to `targets`.
- ( $candidate: expr, $src_node_id: expr, $dest_node_id: expr, $next_hops_fee_msat: expr,
+ ( $candidate: expr, $next_hops_fee_msat: expr,
$next_hops_value_contribution: expr, $next_hops_path_htlc_minimum_msat: expr,
$next_hops_path_penalty_msat: expr, $next_hops_cltv_delta: expr, $next_hops_path_length: expr ) => { {
// We "return" whether we updated the path at the end, and how much we can route via
// practice these cases should be caught earlier:
// - for regular channels at channel announcement (TODO)
// - for first and last hops early in get_route
- if $src_node_id != $dest_node_id {
+ let src_node_id = $candidate.source();
+ let dest_node_id = $candidate.target().unwrap_or(maybe_dummy_payee_node_id);
+ if src_node_id != dest_node_id {
let scid_opt = $candidate.short_channel_id();
let effective_capacity = $candidate.effective_capacity();
let htlc_maximum_msat = max_htlc_from_capacity(effective_capacity, channel_saturation_pow_half);
// We do this for now, but this is a subject for removal.
if let Some(mut available_value_contribution_msat) = htlc_maximum_msat.checked_sub($next_hops_fee_msat) {
let used_liquidity_msat = used_liquidities
- .get(&$candidate.id($src_node_id < $dest_node_id))
+ .get(&$candidate.id())
.map_or(0, |used_liquidity_msat| {
available_value_contribution_msat = available_value_contribution_msat
.saturating_sub(*used_liquidity_msat);
|scid| payment_params.previously_failed_channels.contains(&scid));
let (should_log_candidate, first_hop_details) = match $candidate {
- CandidateRouteHop::FirstHop { details } => (true, Some(details)),
+ CandidateRouteHop::FirstHop { details, .. } => (true, Some(details)),
CandidateRouteHop::PrivateHop { .. } => (true, None),
CandidateRouteHop::Blinded { .. } => (true, None),
CandidateRouteHop::OneHopBlinded { .. } => (true, None),
);
let path_htlc_minimum_msat = compute_fees_saturating(curr_min, $candidate.fees())
.saturating_add(curr_min);
- let hm_entry = dist.entry($src_node_id);
+ let hm_entry = dist.entry(src_node_id);
let old_entry = hm_entry.or_insert_with(|| {
// If there was previously no known way to access the source node
// (recall it goes payee-to-payer) of short_channel_id, first add a
// semi-dummy record just to compute the fees to reach the source node.
// This will affect our decision on selecting short_channel_id
- // as a way to reach the $dest_node_id.
+ // as a way to reach the $candidate.target() node.
PathBuildingHop {
- node_id: $dest_node_id.clone(),
+ node_id: dest_node_id.clone(),
candidate: $candidate.clone(),
fee_msat: 0,
next_hops_fee_msat: u64::max_value(),
// Ignore hop_use_fee_msat for channel-from-us as we assume all channels-from-us
// will have the same effective-fee
- if $src_node_id != our_node_id {
+ if src_node_id != our_node_id {
// Note that `u64::max_value` means we'll always fail the
// `old_entry.total_fee_msat > total_fee_msat` check below
hop_use_fee_msat = compute_fees_saturating(amount_to_transfer_over_msat, $candidate.fees());
effective_capacity,
};
let channel_penalty_msat = scid_opt.map_or(0,
- |scid| scorer.channel_penalty_msat(scid, &$src_node_id, &$dest_node_id,
+ |scid| scorer.channel_penalty_msat(scid, &src_node_id, &dest_node_id,
channel_usage, score_params));
let path_penalty_msat = $next_hops_path_penalty_msat
.saturating_add(channel_penalty_msat);
let new_graph_node = RouteGraphNode {
- node_id: $src_node_id,
+ node_id: src_node_id,
lowest_fee_to_node: total_fee_msat,
total_cltv_delta: hop_total_cltv_delta,
value_contribution_msat,
path_length_to_node,
};
- // Update the way of reaching $src_node_id with the given short_channel_id (from $dest_node_id),
+ // Update the way of reaching $candidate.source()
+ // with the given short_channel_id (from $candidate.target()),
// if this way is cheaper than the already known
// (considering the cost to "reach" this channel from the route destination,
// the cost of using this channel,
old_entry.next_hops_fee_msat = $next_hops_fee_msat;
old_entry.hop_use_fee_msat = hop_use_fee_msat;
old_entry.total_fee_msat = total_fee_msat;
- old_entry.node_id = $dest_node_id.clone();
+ old_entry.node_id = dest_node_id;
old_entry.candidate = $candidate.clone();
old_entry.fee_msat = 0; // This value will be later filled with hop_use_fee_msat of the following channel
old_entry.path_htlc_minimum_msat = path_htlc_minimum_msat;
if !skip_node {
if let Some(first_channels) = first_hop_targets.get(&$node_id) {
for details in first_channels {
- let candidate = CandidateRouteHop::FirstHop { details };
- add_entry!(candidate, our_node_id, $node_id, $fee_to_target_msat,
+ let candidate = CandidateRouteHop::FirstHop { details, node_id: our_node_id };
+ add_entry!(&candidate, $fee_to_target_msat,
$next_hops_value_contribution,
$next_hops_path_htlc_minimum_msat, $next_hops_path_penalty_msat,
$next_hops_cltv_delta, $next_hops_path_length);
info: directed_channel,
short_channel_id: *chan_id,
};
- add_entry!(candidate, *source, $node_id,
+ add_entry!(&candidate,
$fee_to_target_msat,
$next_hops_value_contribution,
$next_hops_path_htlc_minimum_msat,
// place where it could be added.
payee_node_id_opt.map(|payee| first_hop_targets.get(&payee).map(|first_channels| {
for details in first_channels {
- let candidate = CandidateRouteHop::FirstHop { details };
- let added = add_entry!(candidate, our_node_id, payee, 0, path_value_msat,
+ let candidate = CandidateRouteHop::FirstHop { details, node_id: our_node_id };
+ let added = add_entry!(&candidate, 0, path_value_msat,
0, 0u64, 0, 0).is_some();
log_trace!(logger, "{} direct route to payee via {}",
if added { "Added" } else { "Skipped" }, LoggedCandidateHop(&candidate));
CandidateRouteHop::OneHopBlinded { hint, hint_idx }
} else { CandidateRouteHop::Blinded { hint, hint_idx } };
let mut path_contribution_msat = path_value_msat;
- if let Some(hop_used_msat) = add_entry!(candidate, intro_node_id, maybe_dummy_payee_node_id,
+ if let Some(hop_used_msat) = add_entry!(&candidate,
0, path_contribution_msat, 0, 0_u64, 0, 0)
{
path_contribution_msat = hop_used_msat;
sort_first_hop_channels(first_channels, &used_liquidities, recommended_value_msat,
our_node_pubkey);
for details in first_channels {
- let first_hop_candidate = CandidateRouteHop::FirstHop { details };
+ let first_hop_candidate = CandidateRouteHop::FirstHop { details, node_id: our_node_id};
let blinded_path_fee = match compute_fees(path_contribution_msat, candidate.fees()) {
Some(fee) => fee,
None => continue
};
let path_min = candidate.htlc_minimum_msat().saturating_add(
compute_fees_saturating(candidate.htlc_minimum_msat(), candidate.fees()));
- add_entry!(first_hop_candidate, our_node_id, intro_node_id, blinded_path_fee,
+ add_entry!(&first_hop_candidate, blinded_path_fee,
path_contribution_msat, path_min, 0_u64, candidate.cltv_expiry_delta(),
candidate.blinded_path().map_or(1, |bp| bp.blinded_hops.len() as u8));
}
info,
short_channel_id: hop.short_channel_id,
})
- .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop });
+ .unwrap_or_else(|| CandidateRouteHop::PrivateHop { hint: hop, target_node_id: target });
- if let Some(hop_used_msat) = add_entry!(candidate, source, target,
+ if let Some(hop_used_msat) = add_entry!(&candidate,
aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length)
}
let used_liquidity_msat = used_liquidities
- .get(&candidate.id(source < target)).copied()
+ .get(&candidate.id()).copied()
.unwrap_or(0);
let channel_usage = ChannelUsage {
amount_msat: final_value_msat + aggregate_next_hops_fee_msat,
sort_first_hop_channels(first_channels, &used_liquidities,
recommended_value_msat, our_node_pubkey);
for details in first_channels {
- let first_hop_candidate = CandidateRouteHop::FirstHop { details };
- add_entry!(first_hop_candidate, our_node_id, target,
+ let first_hop_candidate = CandidateRouteHop::FirstHop { details, node_id: our_node_id};
+ add_entry!(&first_hop_candidate,
aggregate_next_hops_fee_msat, aggregate_path_contribution_msat,
aggregate_next_hops_path_htlc_minimum_msat, aggregate_next_hops_path_penalty_msat,
aggregate_next_hops_cltv_delta, aggregate_next_hops_path_length);
sort_first_hop_channels(first_channels, &used_liquidities,
recommended_value_msat, our_node_pubkey);
for details in first_channels {
- let first_hop_candidate = CandidateRouteHop::FirstHop { details };
- add_entry!(first_hop_candidate, our_node_id,
- NodeId::from_pubkey(&hop.src_node_id),
+ let first_hop_candidate = CandidateRouteHop::FirstHop { details, node_id: our_node_id};
+ add_entry!(&first_hop_candidate,
aggregate_next_hops_fee_msat,
aggregate_path_contribution_msat,
aggregate_next_hops_path_htlc_minimum_msat,
// Remember that we used these channels so that we don't rely
// on the same liquidity in future paths.
let mut prevented_redundant_path_selection = false;
- let prev_hop_iter = core::iter::once(&our_node_id)
- .chain(payment_path.hops.iter().map(|(hop, _)| &hop.node_id));
- for (prev_hop, (hop, _)) in prev_hop_iter.zip(payment_path.hops.iter()) {
+ for (hop, _) in payment_path.hops.iter() {
let spent_on_hop_msat = value_contribution_msat + hop.next_hops_fee_msat;
let used_liquidity_msat = used_liquidities
- .entry(hop.candidate.id(*prev_hop < hop.node_id))
+ .entry(hop.candidate.id())
.and_modify(|used_liquidity_msat| *used_liquidity_msat += spent_on_hop_msat)
.or_insert(spent_on_hop_msat);
let hop_capacity = hop.candidate.effective_capacity();
log_trace!(logger,
"Disabling route candidate {} for future path building iterations to avoid duplicates.",
LoggedCandidateHop(victim_candidate));
- *used_liquidities.entry(victim_candidate.id(false)).or_default() = exhausted;
- *used_liquidities.entry(victim_candidate.id(true)).or_default() = exhausted;
+ if let Some(scid) = victim_candidate.short_channel_id() {
+ *used_liquidities.entry(CandidateHopId::Clear((scid, false))).or_default() = exhausted;
+ *used_liquidities.entry(CandidateHopId::Clear((scid, true))).or_default() = exhausted;
+ }
}
// Track the total amount all our collected paths allow to send so that we know
selected_route.sort_unstable_by_key(|path| {
let mut key = [CandidateHopId::Clear((42, true)) ; MAX_PATH_LENGTH_ESTIMATE as usize];
debug_assert!(path.hops.len() <= key.len());
- for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id(true)).zip(key.iter_mut()) {
+ for (scid, key) in path.hops.iter() .map(|h| h.0.candidate.id()).zip(key.iter_mut()) {
*key = scid;
}
key
});
for idx in 0..(selected_route.len() - 1) {
if idx + 1 >= selected_route.len() { break; }
- if iter_equal(selected_route[idx ].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id)),
- selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(true), h.0.node_id))) {
+ if iter_equal(selected_route[idx].hops.iter().map(|h| (h.0.candidate.id(), h.0.node_id)),
+ selected_route[idx + 1].hops.iter().map(|h| (h.0.candidate.id(), h.0.node_id))) {
let new_value = selected_route[idx].get_value_msat() + selected_route[idx + 1].get_value_msat();
selected_route[idx].update_value_and_recompute_fees(new_value);
selected_route.remove(idx + 1);
let mut paths = Vec::new();
for payment_path in selected_route {
let mut hops = Vec::with_capacity(payment_path.hops.len());
- let mut prev_hop_node_id = our_node_id;
for (hop, node_features) in payment_path.hops.iter()
.filter(|(h, _)| h.candidate.short_channel_id().is_some())
{
let maybe_announced_channel = if let CandidateRouteHop::PublicHop { .. } = hop.candidate {
// If we sourced the hop from the graph we're sure the target node is announced.
true
- } else if let CandidateRouteHop::FirstHop { details } = hop.candidate {
+ } else if let CandidateRouteHop::FirstHop { details, .. } = hop.candidate {
// If this is a first hop we also know if it's announced.
details.is_public
} else {
// an alias, in which case we don't take any chances here.
network_graph.node(&hop.node_id).map_or(false, |hop_node|
hop_node.channels.iter().any(|scid| network_graph.channel(*scid)
- .map_or(false, |c| c.as_directed_from(&prev_hop_node_id).is_some()))
+ .map_or(false, |c| c.as_directed_from(&hop.candidate.source()).is_some()))
)
};
cltv_expiry_delta: hop.candidate.cltv_expiry_delta(),
maybe_announced_channel,
});
-
- prev_hop_node_id = hop.node_id;
}
let mut final_cltv_delta = final_cltv_expiry_delta;
let blinded_tail = payment_path.hops.last().and_then(|(h, _)| {
projects / rust-lightning / commitdiff