X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Frouting%2Frouter.rs;h=0ad307cdf2f17bf1a347b535ebf5009e9a000c14;hb=13a33409b519e57b7d14cd9e440223d3495d55eb;hp=c53e46157d5dc74941bb0dee94886a06f3d5f83f;hpb=bb62420b0f020d539944c8df8799b65a93f7cf7f;p=rust-lightning

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index c53e4615..0ad307cd 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -249,14 +249,12 @@ impl<'a> PaymentPath<'a> {
 	// If the amount transferred by the path is updated, the fees should be adjusted. Any other way
 	// to change fees may result in an inconsistency.
 	//
-	// Sometimes we call this function right after constructing a path which has inconsistent
-	// (in terms of reaching htlc_minimum_msat), so that this function puts the fees in order.
-	// In that case we call it on the "same" amount we initially allocated for this path, and which
-	// could have been reduced on the way. In that case, there is also a risk of exceeding
-	// available_liquidity inside this function, because the function is unaware of this bound.
-	// In our specific recomputation cases where we never increase the value the risk is pretty low.
-	// This function, however, does not support arbitrarily increasing the value being transferred,
-	// and the exception will be triggered.
+	// Sometimes we call this function right after constructing a path which is inconsistent in
+	// that it the value being transferred has decreased while we were doing path finding, leading
+	// to the fees being paid not lining up with the actual limits.
+	//
+	// Note that this function is not aware of the available_liquidity limit, and thus does not
+	// support increasing the value being transferred.
 	fn update_value_and_recompute_fees(&mut self, value_msat: u64) {
 		assert!(value_msat <= self.hops.last().unwrap().0.fee_msat);
 
@@ -478,7 +476,13 @@ pub fn get_route<L: Deref>(our_node_id: &PublicKey, network: &NetworkGraph, paye
 
 	let empty_channel_features = ChannelFeatures::empty();
 
-	let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
+	// The main heap containing all candidate next-hops sorted by their score (max(A* fee,
+	// htlc_minimum)). Ideally this would be a heap which allowed cheap score reduction instead of
+	// adding duplicate entries when we find a better path to a given node.
+	let mut targets = BinaryHeap::new();
+
+	// Map from node_id to information about the best current path to that node, including feerate
+	// information.
 	let mut dist = HashMap::with_capacity(network.get_nodes().len());
 
 	// During routing, if we ignore a path due to an htlc_minimum_msat limit, we set this,
@@ -3847,7 +3851,8 @@ mod tests {
 			});
 		#[cfg(require_route_graph_test)]
 		return Ok(res.expect("Didn't have route graph and was configured to require it"));
-		res
+		#[cfg(not(require_route_graph_test))]
+		return res;
 	}
 
 	pub(super) fn random_init_seed() -> u64 {
@@ -3918,7 +3923,6 @@ mod benches {
 	use super::*;
 	use util::logger::{Logger, Record};
 
-	use std::fs::File;
 	use test::Bencher;
 
 	struct DummyLogger {}