)
}
+const MAX_CHANNEL_HINTS: usize = 3;
+
fn _create_phantom_invoice<ES: Deref, NS: Deref, L: Deref>(
amt_msat: Option<u64>, payment_hash: Option<PaymentHash>, description: InvoiceDescription,
invoice_expiry_delta_secs: u32, phantom_route_hints: Vec<PhantomRouteHints>, entropy_source: ES,
invoice = invoice.amount_milli_satoshis(amt);
}
- for route_hint in select_phantom_hints(amt_msat, phantom_route_hints, logger) {
+
+ for route_hint in select_phantom_hints(amt_msat, phantom_route_hints, logger).take(MAX_CHANNEL_HINTS) {
invoice = invoice.private_route(route_hint);
}
///
/// [`PhantomKeysManager`]: lightning::sign::PhantomKeysManager
fn select_phantom_hints<L: Deref>(amt_msat: Option<u64>, phantom_route_hints: Vec<PhantomRouteHints>,
- logger: L) -> Vec<RouteHint>
+ logger: L) -> impl Iterator<Item = RouteHint>
where
L::Target: Logger,
{
- let mut phantom_hints: Vec<Vec<RouteHint>> = Vec::new();
+ let mut phantom_hints: Vec<_> = Vec::new();
for PhantomRouteHints { channels, phantom_scid, real_node_pubkey } in phantom_route_hints {
log_trace!(logger, "Generating phantom route hints for node {}",
log_pubkey!(real_node_pubkey));
- let mut route_hints = sort_and_filter_channels(channels, amt_msat, &logger);
+ let route_hints = sort_and_filter_channels(channels, amt_msat, &logger);
// If we have any public channel, the route hints from `sort_and_filter_channels` will be
// empty. In that case we create a RouteHint on which we will push a single hop with the
// phantom route into the invoice, and let the sender find the path to the `real_node_pubkey`
// node by looking at our public channels.
- if route_hints.is_empty() {
- route_hints.push(RouteHint(vec![]))
- }
- for route_hint in &mut route_hints {
- route_hint.0.push(RouteHintHop {
- src_node_id: real_node_pubkey,
- short_channel_id: phantom_scid,
- fees: RoutingFees {
- base_msat: 0,
- proportional_millionths: 0,
- },
- cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
- htlc_minimum_msat: None,
- htlc_maximum_msat: None,});
- }
+ let empty_route_hints = route_hints.len() == 0;
+ let mut have_pushed_empty = false;
+ let route_hints = route_hints
+ .chain(core::iter::from_fn(move || {
+ if empty_route_hints && !have_pushed_empty {
+ // set flag of having handled the empty route_hints and ensure empty vector
+ // returned only once
+ have_pushed_empty = true;
+ Some(RouteHint(Vec::new()))
+ } else {
+ None
+ }
+ }))
+ .map(move |mut hint| {
+ hint.0.push(RouteHintHop {
+ src_node_id: real_node_pubkey,
+ short_channel_id: phantom_scid,
+ fees: RoutingFees {
+ base_msat: 0,
+ proportional_millionths: 0,
+ },
+ cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
+ htlc_minimum_msat: None,
+ htlc_maximum_msat: None,
+ });
+ hint
+ });
phantom_hints.push(route_hints);
}
// the hints across our real nodes we add one hint from each in turn until no node has any hints
// left (if one node has more hints than any other, these will accumulate at the end of the
// vector).
- let mut invoice_hints: Vec<RouteHint> = Vec::new();
- let mut hint_idx = 0;
-
- loop {
- let mut remaining_hints = false;
-
- for hints in phantom_hints.iter() {
- if invoice_hints.len() == 3 {
- return invoice_hints
- }
-
- if hint_idx < hints.len() {
- invoice_hints.push(hints[hint_idx].clone());
- remaining_hints = true
- }
- }
-
- if !remaining_hints {
- return invoice_hints
- }
-
- hint_idx +=1;
- }
+ rotate_through_iterators(phantom_hints)
}
/// Draw items iteratively from multiple iterators. The items are retrieved by index and
/// * Sorted by lowest inbound capacity if an online channel with the minimum amount requested exists,
/// otherwise sort by highest inbound capacity to give the payment the best chance of succeeding.
fn sort_and_filter_channels<L: Deref>(
- channels: Vec<ChannelDetails>, min_inbound_capacity_msat: Option<u64>, logger: &L
-) -> Vec<RouteHint> where L::Target: Logger {
+ channels: Vec<ChannelDetails>,
+ min_inbound_capacity_msat: Option<u64>,
+ logger: &L,
+) -> impl ExactSizeIterator<Item = RouteHint>
+where
+ L::Target: Logger,
+{
let mut filtered_channels: HashMap<PublicKey, ChannelDetails> = HashMap::new();
let min_inbound_capacity = min_inbound_capacity_msat.unwrap_or(0);
let mut min_capacity_channel_exists = false;
let mut online_min_capacity_channel_exists = false;
let mut has_pub_unconf_chan = false;
+ let route_hint_from_channel = |channel: ChannelDetails| {
+ let forwarding_info = channel.counterparty.forwarding_info.as_ref().unwrap();
+ RouteHint(vec![RouteHintHop {
+ src_node_id: channel.counterparty.node_id,
+ short_channel_id: channel.get_inbound_payment_scid().unwrap(),
+ fees: RoutingFees {
+ base_msat: forwarding_info.fee_base_msat,
+ proportional_millionths: forwarding_info.fee_proportional_millionths,
+ },
+ cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
+ htlc_minimum_msat: channel.inbound_htlc_minimum_msat,
+ htlc_maximum_msat: channel.inbound_htlc_maximum_msat,}])
+ };
+
log_trace!(logger, "Considering {} channels for invoice route hints", channels.len());
for channel in channels.into_iter().filter(|chan| chan.is_channel_ready) {
if channel.get_inbound_payment_scid().is_none() || channel.counterparty.forwarding_info.is_none() {
// look at the public channels instead.
log_trace!(logger, "Not including channels in invoice route hints on account of public channel {}",
log_bytes!(channel.channel_id));
- return vec![]
+ return vec![].into_iter().take(MAX_CHANNEL_HINTS).map(route_hint_from_channel);
}
}
}
}
- let route_hint_from_channel = |channel: ChannelDetails| {
- let forwarding_info = channel.counterparty.forwarding_info.as_ref().unwrap();
- RouteHint(vec![RouteHintHop {
- src_node_id: channel.counterparty.node_id,
- short_channel_id: channel.get_inbound_payment_scid().unwrap(),
- fees: RoutingFees {
- base_msat: forwarding_info.fee_base_msat,
- proportional_millionths: forwarding_info.fee_proportional_millionths,
- },
- cltv_expiry_delta: forwarding_info.cltv_expiry_delta,
- htlc_minimum_msat: channel.inbound_htlc_minimum_msat,
- htlc_maximum_msat: channel.inbound_htlc_maximum_msat,}])
- };
// If all channels are private, prefer to return route hints which have a higher capacity than
// the payment value and where we're currently connected to the channel counterparty.
// Even if we cannot satisfy both goals, always ensure we include *some* hints, preferring
} else {
b.inbound_capacity_msat.cmp(&a.inbound_capacity_msat)
}});
- eligible_channels.into_iter().take(3).map(route_hint_from_channel).collect::<Vec<RouteHint>>()
+
+ eligible_channels.into_iter().take(MAX_CHANNEL_HINTS).map(route_hint_from_channel)
}
/// prefer_current_channel chooses a channel to use for route hints between a currently selected and candidate
projects / rust-lightning / commitdiff