- // ...else just increase the previous feerate by 25% (because that's a nice number)
- (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
+ // Our fee estimate has decreased, but our transaction remains unconfirmed after
+ // using our previous fee estimate. This may point to an unreliable fee estimator,
+ // so we choose to bump our previous feerate by 25%, making sure we don't use a
+ // lower feerate or overpay by a large margin by limiting it to 5x the new fee
+ // estimate.
+ let previous_feerate = self.feerate_previous.try_into().unwrap_or(u32::max_value());
+ let mut new_feerate = previous_feerate.saturating_add(previous_feerate / 4);
+ if new_feerate > feerate_estimate * 5 {
+ new_feerate = cmp::max(feerate_estimate * 5, previous_feerate);
+ }
+ new_feerate