From fc35aa745a49d7eb92d448203a5a86542d81f33b Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Mon, 16 Aug 2021 17:47:36 +0000 Subject: [PATCH] Update docs for pending_update_fee and holding_cell_update_fee The docs were left stale after the logic was updated in #985 as pointed out in post-merge review. --- lightning/src/ln/channel.rs | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index a0071d54..77783775 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -424,22 +424,18 @@ pub(super) struct Channel { 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, next_holder_htlc_id: u64, next_counterparty_htlc_id: u64, -- 2.30.2