add signal_channel_readiness to ChannelManager api

Author: johncantrell97

lightning/src/ln/channel.rs

@@ -4746,6 +4746,10 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 		self.pending_channel_ready_event_emitted = true;
 	}
 
+	pub(crate) fn unset_requires_manual_readiness_signal(&mut self) {
+		self.requires_manual_readiness_signal = false;
+	}
+
 	/// Tracks the number of ticks elapsed since the previous [`ChannelConfig`] was updated. Once
 	/// [`EXPIRE_PREV_CONFIG_TICKS`] is reached, the previous config is considered expired and will
 	/// no longer be considered when forwarding HTLCs.
@@ -5010,7 +5014,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 		self.channel_update_status = status;
 	}
 
-	fn check_get_channel_ready(&mut self, height: u32) -> (Option<msgs::ChannelReady>, bool) {
+	pub fn check_get_channel_ready(&mut self, height: u32) -> (Option<msgs::ChannelReady>, bool) {
 		// Called:
 		//  * always when a new block/transactions are confirmed with the new height
 		//  * when funding is signed with a height of 0

lightning/src/ln/channelmanager.rs

@@ -4406,6 +4406,42 @@ where
 		Ok(())
 	}
 
+	/// Signals channel readiness after a [`Event::PendingChannelReady`].
+	///
+	/// The `channel_id` parameter indicates which channel should signal readiness,
+	/// and the `counterparty_node_id` parameter is the id of the peer the channel is with.
+	///
+	/// [`Event::PendingChannelReady`]: events::Event::PendingChannelReady
+	pub fn signal_channel_readiness(&self, channel_id: &[u8; 32], counterparty_node_id: &PublicKey) -> Result<(), APIError> {
+		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
+
+		let per_peer_state = self.per_peer_state.read().unwrap();
+		let peer_state_mutex = per_peer_state.get(counterparty_node_id)
+			.ok_or_else(|| APIError::ChannelUnavailable { err: format!("Can't find a peer matching the passed counterparty node_id {}", counterparty_node_id) })?;
+		let mut peer_state_lock = peer_state_mutex.lock().unwrap();
+		let peer_state = &mut *peer_state_lock;
+		let pending_msg_events = &mut peer_state.pending_msg_events;
+		match peer_state.channel_by_id.entry(channel_id.clone()) {
+			hash_map::Entry::Occupied(mut channel) => {
+				let best_block_height = self.best_block.read().unwrap().height();
+				let channel = channel.get_mut();
+				let (channel_ready_opt, _) = channel.check_get_channel_ready(best_block_height);
+				match channel_ready_opt {
+					Some(channel_ready) => {
+						channel.unset_requires_manual_readiness_signal();
+						send_channel_ready!(self, pending_msg_events, channel, channel_ready);
+					}
+					None => return Err(APIError::APIMisuseError { err: "The channel isn't currently in a state where we can signal readiness.".to_owned() })
+				}				
+			}
+			hash_map::Entry::Vacant(_) => {
+				return Err(APIError::ChannelUnavailable { err: format!("Channel with id {} not found for the passed counterparty node_id {}", log_bytes!(*channel_id), counterparty_node_id) });
+			}
+		}
+
+		Ok(())
+	}
+
 	/// Gets the number of peers which match the given filter and do not have any funded, outbound,
 	/// or 0-conf channels.
 	///