X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=lightning%2Fsrc%2Frouting%2Frouter.rs;fp=lightning%2Fsrc%2Frouting%2Frouter.rs;h=3419f122e7ddfa907ffde3b44c2ee89f47ca6518;hb=1db53a9d734593860f89e6af87bb9e3f70758809;hp=caba139103249179228738a6aa7bca3c0e54c378;hpb=543c5bfe138aa176a7a6fc38aba8de20d11bbebc;p=rust-lightning

diff --git a/lightning/src/routing/router.rs b/lightning/src/routing/router.rs
index caba1391..3419f122 100644
--- a/lightning/src/routing/router.rs
+++ b/lightning/src/routing/router.rs
@@ -1333,6 +1333,14 @@ impl<'a> fmt::Display for LoggedCandidateHop<'a> {
 				" and blinding point ".fmt(f)?;
 				hint.1.blinding_point.fmt(f)
 			},
+			CandidateRouteHop::FirstHop { .. } => {
+				"first hop with SCID ".fmt(f)?;
+				self.0.short_channel_id().unwrap().fmt(f)
+			},
+			CandidateRouteHop::PrivateHop { .. } => {
+				"route hint with SCID ".fmt(f)?;
+				self.0.short_channel_id().unwrap().fmt(f)
+			},
 			_ => {
 				"SCID ".fmt(f)?;
 				self.0.short_channel_id().unwrap().fmt(f)
@@ -1640,6 +1648,12 @@ where L::Target: Logger {
 	log_trace!(logger, "Building path from {} to payer {} for value {} msat.",
 		LoggedPayeePubkey(payment_params.payee.node_id()), our_node_pubkey, final_value_msat);
 
+	// Remember how many candidates we ignored to allow for some logging afterwards.
+	let mut num_ignored_value_contribution = 0;
+	let mut num_ignored_path_length_limit = 0;
+	let mut num_ignored_cltv_delta_limit = 0;
+	let mut num_ignored_previously_failed = 0;
+
 	macro_rules! add_entry {
 		// Adds entry which goes from $src_node_id to $dest_node_id over the $candidate hop.
 		// $next_hops_fee_msat represents the fees paid for using all the channels *after* this one,
@@ -1714,13 +1728,37 @@ where L::Target: Logger {
 					let payment_failed_on_this_channel = scid_opt.map_or(false,
 						|scid| payment_params.previously_failed_channels.contains(&scid));
 
+					let should_log_candidate = match $candidate {
+						CandidateRouteHop::FirstHop { .. } => true,
+						CandidateRouteHop::PrivateHop { .. } => true,
+						CandidateRouteHop::Blinded { .. } => true,
+						_ => false,
+					};
+
 					// If HTLC minimum is larger than the amount we're going to transfer, we shouldn't
 					// bother considering this channel. If retrying with recommended_value_msat may
 					// allow us to hit the HTLC minimum limit, set htlc_minimum_limit so that we go
 					// around again with a higher amount.
-					if !contributes_sufficient_value || exceeds_max_path_length ||
-						exceeds_cltv_delta_limit || payment_failed_on_this_channel {
-						// Path isn't useful, ignore it and move on.
+					if !contributes_sufficient_value {
+						if should_log_candidate {
+							log_trace!(logger, "Ignoring {} due to insufficient value contribution.", LoggedCandidateHop(&$candidate));
+						}
+						num_ignored_value_contribution += 1;
+					} else if exceeds_max_path_length {
+						if should_log_candidate {
+							log_trace!(logger, "Ignoring {} due to exceeding maximum path length limit.", LoggedCandidateHop(&$candidate));
+						}
+						num_ignored_path_length_limit += 1;
+					} else if exceeds_cltv_delta_limit {
+						if should_log_candidate {
+							log_trace!(logger, "Ignoring {} due to exceeding CLTV delta limit.", LoggedCandidateHop(&$candidate));
+						}
+						num_ignored_cltv_delta_limit += 1;
+					} else if payment_failed_on_this_channel {
+						if should_log_candidate {
+							log_trace!(logger, "Ignoring {} due to a failed previous payment attempt.", LoggedCandidateHop(&$candidate));
+						}
+						num_ignored_previously_failed += 1;
 					} else if may_overpay_to_meet_path_minimum_msat {
 						hit_minimum_limit = true;
 					} else if over_path_minimum_msat {
@@ -2322,6 +2360,12 @@ where L::Target: Logger {
 		}
 	}
 
+	let num_ignored_total = num_ignored_value_contribution + num_ignored_path_length_limit +
+		num_ignored_cltv_delta_limit + num_ignored_previously_failed;
+	if num_ignored_total > 0 {
+		log_trace!(logger, "Ignored {} candidate hops due to insufficient value contribution, {} due to path length limit, {} due to CLTV delta limit, {} due to previous payment failure. Total: {} ignored candidates.", num_ignored_value_contribution, num_ignored_path_length_limit, num_ignored_cltv_delta_limit, num_ignored_previously_failed, num_ignored_total);
+	}
+
 	// Step (5).
 	if payment_paths.len() == 0 {
 		return Err(LightningError{err: "Failed to find a path to the given destination".to_owned(), action: ErrorAction::IgnoreError});