Track persistent_monitor_events flag in Channel{Monitor,Mgr}

Also add provided_monitor_event_ids tracking in ChannelMonitor,
which is in-memory only.

Author: valentinewallace

lightning/src/chain/channelmonitor.rs

@@ -1291,6 +1291,12 @@ pub(crate) struct ChannelMonitorImpl<Signer: EcdsaChannelSigner> {
 	// we further MUST NOT generate events during block/transaction-disconnection.
 	pending_monitor_events: Vec<(u64, MonitorEvent)>,
 	next_monitor_event_id: u64,
+	/// Tracks which monitor events have already been returned to the caller during this runtime
+	/// session. In-memory only — on restart this is empty, so all unacked events are re-provided.
+	provided_monitor_event_ids: HashSet<u64>,
+	/// When set, monitor events are retained until explicitly acked rather than cleared on read.
+	/// In-memory only.
+	persistent_events_enabled: bool,
 
 	pub(super) pending_events: Vec<Event>,
 	pub(super) is_processing_pending_events: bool,
@@ -1774,6 +1780,7 @@ pub(crate) fn write_chanmon_internal<Signer: EcdsaChannelSigner, W: Writer>(
 		(37, channel_monitor.funding_seen_onchain, required),
 		(39, channel_monitor.next_monitor_event_id, required),
 		(41, monitor_event_ids, required_vec),
+		(43, channel_monitor.persistent_events_enabled, required),
 	});
 
 	Ok(())
@@ -1958,6 +1965,8 @@ impl<Signer: EcdsaChannelSigner> ChannelMonitor<Signer> {
 			payment_preimages: new_hash_map(),
 			pending_monitor_events: Vec::new(),
 			next_monitor_event_id: 0,
+			provided_monitor_event_ids: new_hash_set(),
+			persistent_events_enabled: false,
 			pending_events: Vec::new(),
 			is_processing_pending_events: false,
 
@@ -6563,6 +6572,7 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
 		let mut funding_seen_onchain = RequiredWrapper(None);
 		let mut next_monitor_event_id = RequiredWrapper(None);
 		let mut monitor_event_ids: Option<Vec<u64>> = None;
+		let mut persistent_events_enabled = false;
 		read_tlv_fields!(reader, {
 			(1, funding_spend_confirmed, option),
 			(3, htlcs_resolved_on_chain, optional_vec),
@@ -6587,6 +6597,7 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
 			(37, funding_seen_onchain, (default_value, true)),
 			(39, next_monitor_event_id, (default_value, 0u64)),
 			(41, monitor_event_ids, optional_vec),
+			(43, persistent_events_enabled, (default_value, false)),
 		});
 		// Note that `payment_preimages_with_info` was added (and is always written) in LDK 0.1, so
 		// we can use it to determine if this monitor was last written by LDK 0.1 or later.
@@ -6755,6 +6766,8 @@ impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP
 			payment_preimages,
 			pending_monitor_events,
 			next_monitor_event_id,
+			provided_monitor_event_ids: new_hash_set(),
+			persistent_events_enabled,
 			pending_events,
 			is_processing_pending_events: false,
 

lightning/src/ln/channelmanager.rs

@@ -2994,6 +2994,9 @@ pub struct ChannelManager<
 	/// offer they resolve to to the given one.
 	pub testing_dnssec_proof_offer_resolution_override: Mutex<HashMap<HumanReadableName, Offer>>,
 
+	/// When set, new monitors will have persistent events enabled.
+	persistent_monitor_events: bool,
+
 	#[cfg(test)]
 	pub(super) entropy_source: ES,
 	#[cfg(not(test))]
@@ -3683,6 +3686,8 @@ impl<
 
 			logger,
 
+			persistent_monitor_events: false,
+
 			#[cfg(feature = "_test_utils")]
 			testing_dnssec_proof_offer_resolution_override: Mutex::new(new_hash_map()),
 		}
@@ -18092,6 +18097,7 @@ impl<
 			(17, in_flight_monitor_updates, option),
 			(19, peer_storage_dir, optional_vec),
 			(21, WithoutLength(&self.flow.writeable_async_receive_offer_cache()), required),
+			(23, self.persistent_monitor_events, required),
 		});
 
 		// Remove the SpliceFailed and DiscardFunding events added earlier.
@@ -18185,6 +18191,7 @@ pub(super) struct ChannelManagerData<SP: SignerProvider> {
 	forward_htlcs_legacy: HashMap<u64, Vec<HTLCForwardInfo>>,
 	pending_intercepted_htlcs_legacy: HashMap<InterceptId, PendingAddHTLCInfo>,
 	decode_update_add_htlcs_legacy: HashMap<u64, Vec<msgs::UpdateAddHTLC>>,
+	persistent_monitor_events: bool,
 	// The `ChannelManager` version that was written.
 	version: u8,
 }
@@ -18370,6 +18377,7 @@ impl<'a, ES: EntropySource, SP: SignerProvider, L: Logger>
 		let mut inbound_payment_id_secret = None;
 		let mut peer_storage_dir: Option<Vec<(PublicKey, Vec<u8>)>> = None;
 		let mut async_receive_offer_cache: AsyncReceiveOfferCache = AsyncReceiveOfferCache::new();
+		let mut persistent_monitor_events = false;
 		read_tlv_fields!(reader, {
 			(1, pending_outbound_payments_no_retry, option),
 			(2, pending_intercepted_htlcs_legacy, option),
@@ -18388,6 +18396,7 @@ impl<'a, ES: EntropySource, SP: SignerProvider, L: Logger>
 			(17, in_flight_monitor_updates, option),
 			(19, peer_storage_dir, optional_vec),
 			(21, async_receive_offer_cache, (default_value, async_receive_offer_cache)),
+			(23, persistent_monitor_events, (default_value, false)),
 		});
 
 		// Merge legacy pending_outbound_payments fields into a single HashMap.
@@ -18506,6 +18515,7 @@ impl<'a, ES: EntropySource, SP: SignerProvider, L: Logger>
 			peer_storage_dir: peer_storage_dir.unwrap_or_default(),
 			async_receive_offer_cache,
 			version,
+			persistent_monitor_events,
 		})
 	}
 }
@@ -18807,6 +18817,7 @@ impl<
 			mut in_flight_monitor_updates,
 			peer_storage_dir,
 			async_receive_offer_cache,
+			persistent_monitor_events,
 			version: _version,
 		} = data;
 
@@ -20072,6 +20083,8 @@ impl<
 			logger: args.logger,
 			config: RwLock::new(args.config),
 
+			persistent_monitor_events,
+
 			#[cfg(feature = "_test_utils")]
 			testing_dnssec_proof_offer_resolution_override: Mutex::new(new_hash_map()),
 		};