1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
7 // You may not use this file except in accordance with one or both of these
10 //! Events are returned from various bits in the library which indicate some action must be taken
13 //! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
14 //! future, as well as generate and broadcast funding transactions handle payment preimages and a
17 use chain::keysinterface::SpendableOutputDescriptor;
19 use ln::msgs::DecodeError;
20 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
21 use routing::network_graph::NetworkUpdate;
22 use util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, VecReadWrapper, VecWriteWrapper};
23 use routing::router::{PaymentPathRetry, RouteHop};
25 use bitcoin::blockdata::script::Script;
26 use bitcoin::hashes::Hash;
27 use bitcoin::hashes::sha256::Hash as Sha256;
28 use bitcoin::secp256k1::key::PublicKey;
32 use core::time::Duration;
34 use bitcoin::Transaction;
36 /// Some information provided on receipt of payment depends on whether the payment received is a
37 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
38 #[derive(Clone, Debug)]
39 pub enum PaymentPurpose {
40 /// Information for receiving a payment that we generated an invoice for.
42 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
43 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
44 /// [`ChannelManager::claim_funds`].
46 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
47 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
48 payment_preimage: Option<PaymentPreimage>,
49 /// The "payment secret". This authenticates the sender to the recipient, preventing a
50 /// number of deanonymization attacks during the routing process.
51 /// It is provided here for your reference, however its accuracy is enforced directly by
52 /// [`ChannelManager`] using the values you previously provided to
53 /// [`ChannelManager::create_inbound_payment`] or
54 /// [`ChannelManager::create_inbound_payment_for_hash`].
56 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
57 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
58 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
59 payment_secret: PaymentSecret,
60 /// This is the `user_payment_id` which was provided to
61 /// [`ChannelManager::create_inbound_payment_for_hash`] or
62 /// [`ChannelManager::create_inbound_payment`]. It has no meaning inside of LDK and is
63 /// simply copied here. It may be used to correlate PaymentReceived events with invoice
64 /// metadata stored elsewhere.
66 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
67 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
70 /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
71 /// (the payee) providing a preimage.
72 SpontaneousPayment(PaymentPreimage),
75 #[derive(Clone, Debug, PartialEq)]
76 /// The reason the channel was closed. See individual variants more details.
77 pub enum ClosureReason {
78 /// Closure generated from receiving a peer error message.
80 /// Our counterparty may have broadcasted their latest commitment state, and we have
82 CounterpartyForceClosed {
83 /// The error which the peer sent us.
85 /// The string should be sanitized before it is used (e.g emitted to logs
86 /// or printed to stdout). Otherwise, a well crafted error message may exploit
87 /// a security vulnerability in the terminal emulator or the logging subsystem.
90 /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
92 /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
94 /// The channel was closed after negotiating a cooperative close and we've now broadcasted
95 /// the cooperative close transaction. Note the shutdown may have been initiated by us.
96 //TODO: split between CounterpartyInitiated/LocallyInitiated
98 /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
99 /// commitment transaction came from our counterparty, but it may also have come from
100 /// a copy of our own `ChannelMonitor`.
101 CommitmentTxConfirmed,
102 /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
104 /// A developer-readable error message which we generated.
107 /// The `PeerManager` informed us that we've disconnected from the peer. We close channels
108 /// if the `PeerManager` informed us that it is unlikely we'll be able to connect to the
109 /// peer again in the future or if the peer disconnected before we finished negotiating
110 /// the channel open. The first case may be caused by incompatible features which our
111 /// counterparty, or we, require.
112 //TODO: split between PeerUnconnectable/PeerDisconnected ?
114 /// Closure generated from `ChannelManager::read` if the ChannelMonitor is newer than
115 /// the ChannelManager deserialized.
116 OutdatedChannelManager
119 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
120 (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
121 (2, HolderForceClosed) => {},
122 (6, CommitmentTxConfirmed) => {},
123 (4, CooperativeClosure) => {},
124 (8, ProcessingError) => { (1, err, required) },
125 (10, DisconnectedPeer) => {},
126 (12, OutdatedChannelManager) => {},
129 /// An Event which you should probably take some action in response to.
131 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
132 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
133 /// written as it makes no sense to respond to it after reconnecting to peers).
134 #[derive(Clone, Debug)]
136 /// Used to indicate that the client should generate a funding transaction with the given
137 /// parameters and then call ChannelManager::funding_transaction_generated.
138 /// Generated in ChannelManager message handling.
139 /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
140 /// counterparty can steal your funds!
141 FundingGenerationReady {
142 /// The random channel_id we picked which you'll need to pass into
143 /// ChannelManager::funding_transaction_generated.
144 temporary_channel_id: [u8; 32],
145 /// The value, in satoshis, that the output should have.
146 channel_value_satoshis: u64,
147 /// The script which should be used in the transaction output.
148 output_script: Script,
149 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or 0 for
150 /// an inbound channel.
152 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
153 user_channel_id: u64,
155 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
156 /// [`ChannelManager::claim_funds`] to get it....
157 /// Note that if the preimage is not known, you should call
158 /// [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
159 /// network congestion.
160 /// If you fail to call either [`ChannelManager::claim_funds`] or
161 /// [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
162 /// automatically failed.
164 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
165 /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
167 /// The hash for which the preimage should be handed to the ChannelManager.
168 payment_hash: PaymentHash,
169 /// The value, in thousandths of a satoshi, that this payment is for.
171 /// Information for claiming this received payment, based on whether the purpose of the
172 /// payment is to pay an invoice or to send a spontaneous payment.
173 purpose: PaymentPurpose,
175 /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
176 /// and we got back the payment preimage for it).
178 /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
179 /// event. In this situation, you SHOULD treat this payment as having succeeded.
181 /// The preimage to the hash given to ChannelManager::send_payment.
182 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
183 /// store it somehow!
184 payment_preimage: PaymentPreimage,
185 /// The hash which was given to [`ChannelManager::send_payment`].
187 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
188 payment_hash: PaymentHash,
190 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
191 /// something. You may wish to retry with a different route.
193 /// The hash which was given to ChannelManager::send_payment.
194 payment_hash: PaymentHash,
195 /// Indicates the payment was rejected for some reason by the recipient. This implies that
196 /// the payment has failed, not just the route in question. If this is not set, you may
197 /// retry the payment via a different route.
198 rejected_by_dest: bool,
199 /// Any failure information conveyed via the Onion return packet by a node along the failed
202 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
203 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
205 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
206 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
207 network_update: Option<NetworkUpdate>,
208 /// For both single-path and multi-path payments, this is set if all paths of the payment have
209 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
210 /// larger MPP payment were still in flight when this event was generated.
211 all_paths_failed: bool,
212 /// The payment path that failed.
214 /// The channel responsible for the failed payment path.
216 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
217 /// retried. May be `None` for older [`Event`] serializations.
218 short_channel_id: Option<u64>,
219 /// Parameters needed to re-compute a [`Route`] for retrying the failed path.
221 /// See [`get_retry_route`] for details.
223 /// [`Route`]: crate::routing::router::Route
224 /// [`get_retry_route`]: crate::routing::router::get_retry_route
225 retry: Option<PaymentPathRetry>,
227 error_code: Option<u16>,
229 error_data: Option<Vec<u8>>,
231 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
232 /// time in the future.
233 PendingHTLCsForwardable {
234 /// The minimum amount of time that should be waited prior to calling
235 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
236 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
237 /// now + 5*time_forwardable).
238 time_forwardable: Duration,
240 /// Used to indicate that an output which you should know how to spend was confirmed on chain
241 /// and is now spendable.
242 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
243 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
244 /// somewhere and spend them when you create on-chain transactions.
246 /// The outputs which you should store as spendable by you.
247 outputs: Vec<SpendableOutputDescriptor>,
249 /// This event is generated when a payment has been successfully forwarded through us and a
250 /// forwarding fee earned.
252 /// The fee, in milli-satoshis, which was earned as a result of the payment.
254 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
255 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
256 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
257 /// claimed the full value in millisatoshis from the source. In this case,
258 /// `claim_from_onchain_tx` will be set.
260 /// If the channel which sent us the payment has been force-closed, we will claim the funds
261 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
262 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
263 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
265 fee_earned_msat: Option<u64>,
266 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
268 claim_from_onchain_tx: bool,
270 /// Used to indicate that a channel with the given `channel_id` is in the process of closure.
272 /// The channel_id of the channel which has been closed. Note that on-chain transactions
273 /// resolving the channel are likely still awaiting confirmation.
274 channel_id: [u8; 32],
275 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or 0 for
276 /// an inbound channel. This will always be zero for objects serialized with LDK versions
277 /// prior to 0.0.102.
279 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
280 user_channel_id: u64,
281 /// The reason the channel was closed.
282 reason: ClosureReason
284 /// Used to indicate to the user that they can abandon the funding transaction and recycle the
285 /// inputs for another purpose.
287 /// The channel_id of the channel which has been closed.
288 channel_id: [u8; 32],
289 /// The full transaction received from the user
290 transaction: Transaction
294 impl Writeable for Event {
295 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
297 &Event::FundingGenerationReady { .. } => {
299 // We never write out FundingGenerationReady events as, upon disconnection, peers
300 // drop any channels which have not yet exchanged funding_signed.
302 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
304 let mut payment_secret = None;
305 let mut user_payment_id = None;
306 let payment_preimage;
308 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
309 payment_secret = Some(secret);
310 payment_preimage = *preimage;
311 user_payment_id = Some(id);
313 PaymentPurpose::SpontaneousPayment(preimage) => {
314 payment_preimage = Some(*preimage);
317 write_tlv_fields!(writer, {
318 (0, payment_hash, required),
319 (2, payment_secret, option),
321 (6, user_payment_id, option),
322 (8, payment_preimage, option),
325 &Event::PaymentSent { ref payment_preimage, ref payment_hash} => {
327 write_tlv_fields!(writer, {
328 (0, payment_preimage, required),
329 (1, payment_hash, required),
332 &Event::PaymentPathFailed {
333 ref payment_hash, ref rejected_by_dest, ref network_update,
334 ref all_paths_failed, ref path, ref short_channel_id, ref retry,
342 error_code.write(writer)?;
344 error_data.write(writer)?;
345 write_tlv_fields!(writer, {
346 (0, payment_hash, required),
347 (1, network_update, option),
348 (2, rejected_by_dest, required),
349 (3, all_paths_failed, required),
351 (7, short_channel_id, option),
355 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
357 // Note that we now ignore these on the read end as we'll re-generate them in
358 // ChannelManager, we write them here only for backwards compatibility.
360 &Event::SpendableOutputs { ref outputs } => {
362 write_tlv_fields!(writer, {
363 (0, VecWriteWrapper(outputs), required),
366 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
368 write_tlv_fields!(writer, {
369 (0, fee_earned_msat, option),
370 (2, claim_from_onchain_tx, required),
373 &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
375 write_tlv_fields!(writer, {
376 (0, channel_id, required),
377 (1, user_channel_id, required),
378 (2, reason, required)
381 &Event::DiscardFunding { ref channel_id, ref transaction } => {
383 write_tlv_fields!(writer, {
384 (0, channel_id, required),
385 (2, transaction, required)
388 // Note that, going forward, all new events must only write data inside of
389 // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
390 // data via `write_tlv_fields`.
395 impl MaybeReadable for Event {
396 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
397 match Readable::read(reader)? {
398 // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
399 // unlike all other events, thus we return immediately here.
403 let mut payment_hash = PaymentHash([0; 32]);
404 let mut payment_preimage = None;
405 let mut payment_secret = None;
407 let mut user_payment_id = None;
408 read_tlv_fields!(reader, {
409 (0, payment_hash, required),
410 (2, payment_secret, option),
412 (6, user_payment_id, option),
413 (8, payment_preimage, option),
415 let purpose = match payment_secret {
416 Some(secret) => PaymentPurpose::InvoicePayment {
418 payment_secret: secret,
419 user_payment_id: if let Some(id) = user_payment_id {
421 } else { return Err(msgs::DecodeError::InvalidValue) }
423 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
424 None => return Err(msgs::DecodeError::InvalidValue),
426 Ok(Some(Event::PaymentReceived {
436 let mut payment_preimage = PaymentPreimage([0; 32]);
437 let mut payment_hash = None;
438 read_tlv_fields!(reader, {
439 (0, payment_preimage, required),
440 (1, payment_hash, option),
442 if payment_hash.is_none() {
443 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
445 Ok(Some(Event::PaymentSent {
447 payment_hash: payment_hash.unwrap(),
455 let error_code = Readable::read(reader)?;
457 let error_data = Readable::read(reader)?;
458 let mut payment_hash = PaymentHash([0; 32]);
459 let mut rejected_by_dest = false;
460 let mut network_update = None;
461 let mut all_paths_failed = Some(true);
462 let mut path: Option<Vec<RouteHop>> = Some(vec![]);
463 let mut short_channel_id = None;
464 let mut retry = None;
465 read_tlv_fields!(reader, {
466 (0, payment_hash, required),
467 (1, network_update, ignorable),
468 (2, rejected_by_dest, required),
469 (3, all_paths_failed, option),
471 (7, short_channel_id, option),
474 Ok(Some(Event::PaymentPathFailed {
478 all_paths_failed: all_paths_failed.unwrap(),
493 let mut outputs = VecReadWrapper(Vec::new());
494 read_tlv_fields!(reader, {
495 (0, outputs, required),
497 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
503 let mut fee_earned_msat = None;
504 let mut claim_from_onchain_tx = false;
505 read_tlv_fields!(reader, {
506 (0, fee_earned_msat, option),
507 (2, claim_from_onchain_tx, required),
509 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
515 let mut channel_id = [0; 32];
516 let mut reason = None;
517 let mut user_channel_id_opt = None;
518 read_tlv_fields!(reader, {
519 (0, channel_id, required),
520 (1, user_channel_id_opt, option),
521 (2, reason, ignorable),
523 if reason.is_none() { return Ok(None); }
524 let user_channel_id = if let Some(id) = user_channel_id_opt { id } else { 0 };
525 Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: reason.unwrap() }))
531 let mut channel_id = [0; 32];
532 let mut transaction = Transaction{ version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
533 read_tlv_fields!(reader, {
534 (0, channel_id, required),
535 (2, transaction, required),
537 Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
541 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
542 // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
545 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
546 // which prefixes the whole thing with a length BigSize. Because the event is
547 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
548 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
549 // exactly the number of bytes specified, ignoring them entirely.
550 let tlv_len: BigSize = Readable::read(reader)?;
551 FixedLengthReader::new(reader, tlv_len.0)
552 .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
555 _ => Err(msgs::DecodeError::InvalidValue)
560 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
561 /// broadcast to most peers).
562 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
563 #[derive(Clone, Debug)]
564 pub enum MessageSendEvent {
565 /// Used to indicate that we've accepted a channel open and should send the accept_channel
566 /// message provided to the given peer.
568 /// The node_id of the node which should receive this message
570 /// The message which should be sent.
571 msg: msgs::AcceptChannel,
573 /// Used to indicate that we've initiated a channel open and should send the open_channel
574 /// message provided to the given peer.
576 /// The node_id of the node which should receive this message
578 /// The message which should be sent.
579 msg: msgs::OpenChannel,
581 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
583 /// The node_id of the node which should receive this message
585 /// The message which should be sent.
586 msg: msgs::FundingCreated,
588 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
590 /// The node_id of the node which should receive this message
592 /// The message which should be sent.
593 msg: msgs::FundingSigned,
595 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
597 /// The node_id of the node which should receive these message(s)
599 /// The funding_locked message which should be sent.
600 msg: msgs::FundingLocked,
602 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
603 SendAnnouncementSignatures {
604 /// The node_id of the node which should receive these message(s)
606 /// The announcement_signatures message which should be sent.
607 msg: msgs::AnnouncementSignatures,
609 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
610 /// message should be sent to the peer with the given node_id.
612 /// The node_id of the node which should receive these message(s)
614 /// The update messages which should be sent. ALL messages in the struct should be sent!
615 updates: msgs::CommitmentUpdate,
617 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
619 /// The node_id of the node which should receive this message
621 /// The message which should be sent.
622 msg: msgs::RevokeAndACK,
624 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
626 /// The node_id of the node which should receive this message
628 /// The message which should be sent.
629 msg: msgs::ClosingSigned,
631 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
633 /// The node_id of the node which should receive this message
635 /// The message which should be sent.
638 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
639 SendChannelReestablish {
640 /// The node_id of the node which should receive this message
642 /// The message which should be sent.
643 msg: msgs::ChannelReestablish,
645 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
646 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
648 /// Note that after doing so, you very likely (unless you did so very recently) want to call
649 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
650 /// This ensures that any nodes which see our channel_announcement also have a relevant
651 /// node_announcement, including relevant feature flags which may be important for routing
652 /// through or to us.
653 BroadcastChannelAnnouncement {
654 /// The channel_announcement which should be sent.
655 msg: msgs::ChannelAnnouncement,
656 /// The followup channel_update which should be sent.
657 update_msg: msgs::ChannelUpdate,
659 /// Used to indicate that a node_announcement should be broadcast to all peers.
660 BroadcastNodeAnnouncement {
661 /// The node_announcement which should be sent.
662 msg: msgs::NodeAnnouncement,
664 /// Used to indicate that a channel_update should be broadcast to all peers.
665 BroadcastChannelUpdate {
666 /// The channel_update which should be sent.
667 msg: msgs::ChannelUpdate,
669 /// Used to indicate that a channel_update should be sent to a single peer.
670 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
671 /// private channel and we shouldn't be informing all of our peers of channel parameters.
673 /// The node_id of the node which should receive this message
675 /// The channel_update which should be sent.
676 msg: msgs::ChannelUpdate,
678 /// Broadcast an error downstream to be handled
680 /// The node_id of the node which should receive this message
682 /// The action which should be taken.
683 action: msgs::ErrorAction
685 /// Query a peer for channels with funding transaction UTXOs in a block range.
686 SendChannelRangeQuery {
687 /// The node_id of this message recipient
689 /// The query_channel_range which should be sent.
690 msg: msgs::QueryChannelRange,
692 /// Request routing gossip messages from a peer for a list of channels identified by
693 /// their short_channel_ids.
695 /// The node_id of this message recipient
697 /// The query_short_channel_ids which should be sent.
698 msg: msgs::QueryShortChannelIds,
700 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
701 /// emitted during processing of the query.
702 SendReplyChannelRange {
703 /// The node_id of this message recipient
705 /// The reply_channel_range which should be sent.
706 msg: msgs::ReplyChannelRange,
710 /// A trait indicating an object may generate message send events
711 pub trait MessageSendEventsProvider {
712 /// Gets the list of pending events which were generated by previous actions, clearing the list
714 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
717 /// A trait indicating an object may generate events.
719 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
723 /// See [`process_pending_events`] for requirements around event processing.
725 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
726 /// event since the last invocation. The handler must either act upon the event immediately
727 /// or preserve it for later handling.
729 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
730 /// consult the provider's documentation on the implication of processing events and how a handler
731 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
732 /// [`ChainMonitor::process_pending_events`]).
734 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
737 /// [`process_pending_events`]: Self::process_pending_events
738 /// [`handle_event`]: EventHandler::handle_event
739 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
740 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
741 pub trait EventsProvider {
742 /// Processes any events generated since the last call using the given event handler.
744 /// Subsequent calls must only process new events. However, handlers must be capable of handling
745 /// duplicate events across process restarts. This may occur if the provider was recovered from
746 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
747 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
750 /// A trait implemented for objects handling events from [`EventsProvider`].
751 pub trait EventHandler {
752 /// Handles the given [`Event`].
754 /// See [`EventsProvider`] for details that must be considered when implementing this method.
755 fn handle_event(&self, event: &Event);
758 impl<F> EventHandler for F where F: Fn(&Event) {
759 fn handle_event(&self, event: &Event) {