Add EventCompletionAction::InboundPaymentClaimedChannelMonitorUpdate

When an Event::PaymentClaimed is processed by the user, we need to track that
so we don't keep regenerating the event redundantly on startup. Here we add an
event completion action for that.

Note that this action will only be generated for closed channels -- if the
channel is open, the inbound payment is pruned automatically when the HTLC is
no longer present in any unrevoked commitment transaction, which stops the
redundant event regeneration.

Similar to EventCompletionAction::ReleasePaymentCompleteChannelMonitorUpdate,
but for inbound payments.

Actual generation and handling of this completion action is added in an
upcoming commit.

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -1475,6 +1475,21 @@ impl_writeable_tlv_based!(PaymentCompleteUpdate, {
 	(7, htlc_id, required),
 });
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct InboundPaymentClaimedUpdate {
+	pub counterparty_node_id: PublicKey,
+	pub channel_funding_outpoint: OutPoint,
+	pub channel_id: ChannelId,
+	pub payment_hash: PaymentHash,
+}
+
+impl_writeable_tlv_based!(InboundPaymentClaimedUpdate, {
+	(1, counterparty_node_id, required),
+	(3, channel_funding_outpoint, required),
+	(5, channel_id, required),
+	(7, payment_hash, required),
+});
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) enum EventCompletionAction {
 	ReleaseRAAChannelMonitorUpdate {
@@ -1489,6 +1504,12 @@ pub(crate) enum EventCompletionAction {
 	/// fully-resolved in the [`ChannelMonitor`], which we do via this action.
 	/// Note that this action will be dropped on downgrade to LDK prior to 0.2!
 	ReleasePaymentCompleteChannelMonitorUpdate(PaymentCompleteUpdate),
+
+	/// When a payment's resolution is communicated to the downstream logic via
+	/// [`Event::PaymentClaimed`], we may want to mark the payment as fully-resolved in the
+	/// [`ChannelMonitor`], which we do via this action.
+	/// Note that this action will be dropped on downgrade to LDK prior to 0.3!
+	InboundPaymentClaimedChannelMonitorUpdate(InboundPaymentClaimedUpdate),
 }
 impl_writeable_tlv_based_enum!(EventCompletionAction,
 	(0, ReleaseRAAChannelMonitorUpdate) => {
@@ -1500,8 +1521,9 @@ impl_writeable_tlv_based_enum!(EventCompletionAction,
 			}
 			ChannelId::v1_from_funding_outpoint(channel_funding_outpoint.unwrap())
 		})),
-	}
+	},
 	{1, ReleasePaymentCompleteChannelMonitorUpdate} => (),
+	{3, InboundPaymentClaimedChannelMonitorUpdate} => (),
 );
 
 /// The source argument which is passed to [`ChannelManager::claim_mpp_part`].
@@ -14818,6 +14840,7 @@ impl<
 						update_step,
 					);
 				},
+				EventCompletionAction::InboundPaymentClaimedChannelMonitorUpdate(_) => {},
 			}
 		}
 	}