- match compute_fees(amount_to_transfer_over_msat, $candidate.fees()) {
- // max_value means we'll always fail
- // the old_entry.total_fee_msat > total_fee_msat check
- None => total_fee_msat = u64::max_value(),
- Some(fee_msat) => {
- hop_use_fee_msat = fee_msat;
- total_fee_msat += hop_use_fee_msat;
- // When calculating the lowest inbound fees to a node, we
- // calculate fees here not based on the actual value we think
- // will flow over this channel, but on the minimum value that
- // we'll accept flowing over it. The minimum accepted value
- // is a constant through each path collection run, ensuring
- // consistent basis. Otherwise we may later find a
- // different path to the source node that is more expensive,
- // but which we consider to be cheaper because we are capacity
- // constrained and the relative fee becomes lower.
- match compute_fees(minimal_value_contribution_msat, old_entry.src_lowest_inbound_fees)
- .map(|a| a.checked_add(total_fee_msat)) {
- Some(Some(v)) => {
- total_fee_msat = v;
- },
- _ => {
- total_fee_msat = u64::max_value();
- }
- };
- }
- }
+ // 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());
+ total_fee_msat = total_fee_msat.saturating_add(hop_use_fee_msat);