Add ChannelEstablished event

This adds a `ChannelEstablished` event that will be emitted as soon as a new
channel becomes usable, i.e., after both sides have sent `channel_ready`.

Author: tnull

lightning/src/util/events.rs

@@ -505,6 +505,27 @@ pub enum Event {
 		/// transaction.
 		claim_from_onchain_tx: bool,
 	},
+	/// Used to indicate that a previously opened channel with the given `channel_id` is ready to
+	/// be used. This event is emitted either when the funding transaction has been confirmed
+	/// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
+	/// establishment.
+	ChannelEstablished {
+		/// The channel_id of the channel that is ready.
+		channel_id: [u8; 32],
+		/// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
+		/// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
+		/// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
+		/// `user_channel_id` will be 0 for an inbound channel.
+		///
+		/// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+		/// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+		/// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+		user_channel_id: u64,
+		/// The node_id of the channel counterparty.
+		counterparty_node_id: PublicKey,
+		/// The features that this channel will operate with.
+		channel_type: ChannelTypeFeatures,
+	},
 	/// Used to indicate that a previously opened channel with the given `channel_id` is in the
 	/// process of closure.
 	ChannelClosed  {
@@ -753,6 +774,15 @@ impl Writeable for Event {
 					(2, failed_next_destination, required),
 				})
 			},
+			&Event::ChannelEstablished { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
+				27u8.write(writer)?;
+				write_tlv_fields!(writer, {
+					(0, channel_id, required),
+					(1, user_channel_id, required),
+					(2, counterparty_node_id, required),
+					(3, channel_type, required),
+				});
+			},
 			// Note that, going forward, all new events must only write data inside of
 			// `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 			// data via `write_tlv_fields`.
@@ -1033,6 +1063,27 @@ impl MaybeReadable for Event {
 				};
 				f()
 			},
+			27u8 => {
+				let f = || {
+					let mut channel_id = [0; 32];
+					let mut user_channel_id: u64 = 0;
+					let mut counterparty_node_id_opt = None;
+					let mut channel_type_opt = None;
+					read_tlv_fields!(reader, {
+						(0, channel_id, required),
+						(1, user_channel_id, required),
+						(2, counterparty_node_id_opt, option),
+						(3, channel_type_opt, option),
+					});
+
+					Ok(Some(Event::ChannelEstablished { channel_id,
+						user_channel_id,
+						counterparty_node_id: counterparty_node_id_opt.unwrap(),
+						channel_type: channel_type_opt.unwrap()
+					}))
+				};
+				f()
+			},
 			// Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
 			// Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
 			// reads.