Skip always iterating over all nodes in get_route

[rust-lightning] / src / ln / router.rs

diff --git a/src/ln/router.rs b/src/ln/router.rs
index 10432b9a6d83e915a50551cb90bc1a99d5d512df..063339382ada8cdf97aca90dfac484ec015aea79 100644 (file)
--- a/src/ln/router.rs
+++ b/src/ln/router.rs
@@ -377,17 +377,6 @@ impl Router {
 
                let mut targets = BinaryHeap::new(); //TODO: Do we care about switching to eg Fibbonaci heap?
                let mut dist = HashMap::with_capacity(network.nodes.len());
-               for (key, node) in network.nodes.iter() {
-                       dist.insert(key.clone(), (u64::max_value(),
-                               node.lowest_inbound_channel_fee_base_msat as u64,
-                               node.lowest_inbound_channel_fee_proportional_millionths as u64,
-                               RouteHop {
-                                       pubkey: PublicKey::new(),
-                                       short_channel_id: 0,
-                                       fee_msat: 0,
-                                       cltv_expiry_delta: 0,
-                       }));
-               }
 
                macro_rules! add_entry {
                        // Adds entry which goes from the node pointed to by $directional_info to
@@ -398,7 +387,19 @@ impl Router {
                                if $starting_fee_msat as u64 + final_value_msat > $directional_info.htlc_minimum_msat {
                                        let new_fee = $directional_info.fee_base_msat as u64 + ($starting_fee_msat + final_value_msat) * ($directional_info.fee_proportional_millionths as u64) / 1000000;
                                        let mut total_fee = $starting_fee_msat as u64;
-                                       let old_entry = dist.get_mut(&$directional_info.src_node_id).unwrap();
+                                       let mut hm_entry = dist.entry(&$directional_info.src_node_id);
+                                       let old_entry = hm_entry.or_insert_with(|| {
+                                               let node = network.nodes.get(&$directional_info.src_node_id).unwrap();
+                                               (u64::max_value(),
+                                                       node.lowest_inbound_channel_fee_base_msat as u64,
+                                                       node.lowest_inbound_channel_fee_proportional_millionths as u64,
+                                                       RouteHop {
+                                                               pubkey: PublicKey::new(),
+                                                               short_channel_id: 0,
+                                                               fee_msat: 0,
+                                                               cltv_expiry_delta: 0,
+                                               })
+                                       });
                                        if $directional_info.src_node_id != network.our_node_id {
                                                // Ignore new_fee for channel-from-us as we assume all channels-from-us
                                                // will have the same effective-fee