monitor_pending_forwards: Vec<(PendingHTLCInfo, u64)>,
monitor_pending_failures: Vec<(HTLCSource, PaymentHash, HTLCFailReason)>,
- // pending_update_fee is filled when sending and receiving update_fee
- // For outbound channel, feerate_per_kw is updated with the value from
- // pending_update_fee when revoke_and_ack is received
+ // pending_update_fee is filled when sending and receiving update_fee.
//
- // For inbound channel, feerate_per_kw is updated when it receives
- // commitment_signed and revoke_and_ack is generated
- // The pending value is kept when another pair of update_fee and commitment_signed
- // is received during AwaitingRemoteRevoke and relieved when the expected
- // revoke_and_ack is received and new commitment_signed is generated to be
- // sent to the funder. Otherwise, the pending value is removed when receiving
- // commitment_signed.
+ // Because it follows the same commitment flow as HTLCs, `FeeUpdateState` is either `Outbound`
+ // or matches a subset of the `InboundHTLCOutput` variants. It is then updated/used when
+ // generating new commitment transactions with exactly the same criteria as inbound/outbound
+ // HTLCs with similar state.
pending_update_fee: Option<(u32, FeeUpdateState)>,
- // update_fee() during ChannelState::AwaitingRemoteRevoke is hold in
- // holdina_cell_update_fee then moved to pending_udpate_fee when revoke_and_ack
- // is received. holding_cell_update_fee is updated when there are additional
- // update_fee() during ChannelState::AwaitingRemoteRevoke.
+ // If a `send_update_fee()` call is made with ChannelState::AwaitingRemoteRevoke set, we place
+ // it here instead of `pending_update_fee` in the same way as we place outbound HTLC updates in
+ // `holding_cell_htlc_updates` instead of `pending_outbound_htlcs`. It is released into
+ // `pending_update_fee` with the same criteria as outbound HTLC updates but can be updated by
+ // further `send_update_fee` calls, dropping the previous holding cell update entirely.
holding_cell_update_fee: Option<u32>,
next_holder_htlc_id: u64,
next_counterparty_htlc_id: u64,
// more dust balance if the feerate increases when we have several HTLCs pending
// which are near the dust limit.
let mut feerate_per_kw = self.feerate_per_kw;
+ // If there's a pending update fee, use it to ensure we aren't under-estimating
+ // potential feerate updates coming soon.
if let Some((feerate, _)) = self.pending_update_fee {
feerate_per_kw = cmp::max(feerate_per_kw, feerate);
}
if self.is_outbound() {
self.pending_update_fee.map(|(a, _)| a).write(writer)?;
} else if let Some((feerate, FeeUpdateState::AwaitingRemoteRevokeToAnnounce)) = self.pending_update_fee {
- // As for inbound HTLCs, if the update was only announced and never committed, drop it.
Some(feerate).write(writer)?;
} else {
+ // As for inbound HTLCs, if the update was only announced and never committed in a
+ // commitment_signed, drop it.
None::<u32>.write(writer)?;
}
self.holding_cell_update_fee.write(writer)?;