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::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 value passed in to ChannelManager::create_channel
150 user_channel_id: u64,
152 /// Indicates we've received money! Just gotta dig out that payment preimage and feed it to
153 /// [`ChannelManager::claim_funds`] to get it....
154 /// Note that if the preimage is not known, you should call
155 /// [`ChannelManager::fail_htlc_backwards`] to free up resources for this HTLC and avoid
156 /// network congestion.
157 /// If you fail to call either [`ChannelManager::claim_funds`] or
158 /// [`ChannelManager::fail_htlc_backwards`] within the HTLC's timeout, the HTLC will be
159 /// automatically failed.
161 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
162 /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
164 /// The hash for which the preimage should be handed to the ChannelManager.
165 payment_hash: PaymentHash,
166 /// The value, in thousandths of a satoshi, that this payment is for.
168 /// Information for claiming this received payment, based on whether the purpose of the
169 /// payment is to pay an invoice or to send a spontaneous payment.
170 purpose: PaymentPurpose,
172 /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
173 /// and we got back the payment preimage for it).
175 /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
176 /// event. In this situation, you SHOULD treat this payment as having succeeded.
178 /// The preimage to the hash given to ChannelManager::send_payment.
179 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
180 /// store it somehow!
181 payment_preimage: PaymentPreimage,
182 /// The hash which was given to [`ChannelManager::send_payment`].
184 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
185 payment_hash: PaymentHash,
187 /// Indicates an outbound payment we made failed. Probably some intermediary node dropped
188 /// something. You may wish to retry with a different route.
190 /// The hash which was given to ChannelManager::send_payment.
191 payment_hash: PaymentHash,
192 /// Indicates the payment was rejected for some reason by the recipient. This implies that
193 /// the payment has failed, not just the route in question. If this is not set, you may
194 /// retry the payment via a different route.
195 rejected_by_dest: bool,
196 /// Any failure information conveyed via the Onion return packet by a node along the failed
199 /// Should be applied to the [`NetworkGraph`] so that routing decisions can take into
200 /// account the update. [`NetGraphMsgHandler`] is capable of doing this.
202 /// [`NetworkGraph`]: crate::routing::network_graph::NetworkGraph
203 /// [`NetGraphMsgHandler`]: crate::routing::network_graph::NetGraphMsgHandler
204 network_update: Option<NetworkUpdate>,
205 /// For both single-path and multi-path payments, this is set if all paths of the payment have
206 /// failed. This will be set to false if (1) this is an MPP payment and (2) other parts of the
207 /// larger MPP payment were still in flight when this event was generated.
208 all_paths_failed: bool,
209 /// The payment path that failed.
211 /// The channel responsible for the failed payment path.
213 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
214 /// retried. May be `None` for older [`Event`] serializations.
215 short_channel_id: Option<u64>,
217 error_code: Option<u16>,
219 error_data: Option<Vec<u8>>,
221 /// Used to indicate that ChannelManager::process_pending_htlc_forwards should be called at a
222 /// time in the future.
223 PendingHTLCsForwardable {
224 /// The minimum amount of time that should be waited prior to calling
225 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
226 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
227 /// now + 5*time_forwardable).
228 time_forwardable: Duration,
230 /// Used to indicate that an output which you should know how to spend was confirmed on chain
231 /// and is now spendable.
232 /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
233 /// counterparty spending them due to some kind of timeout. Thus, you need to store them
234 /// somewhere and spend them when you create on-chain transactions.
236 /// The outputs which you should store as spendable by you.
237 outputs: Vec<SpendableOutputDescriptor>,
239 /// This event is generated when a payment has been successfully forwarded through us and a
240 /// forwarding fee earned.
242 /// The fee, in milli-satoshis, which was earned as a result of the payment.
244 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
245 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
246 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
247 /// claimed the full value in millisatoshis from the source. In this case,
248 /// `claim_from_onchain_tx` will be set.
250 /// If the channel which sent us the payment has been force-closed, we will claim the funds
251 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
252 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
253 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
255 fee_earned_msat: Option<u64>,
256 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
258 claim_from_onchain_tx: bool,
260 /// Used to indicate that a channel with the given `channel_id` is in the process of closure.
262 /// The channel_id of the channel which has been closed. Note that on-chain transactions
263 /// resolving the channel are likely still awaiting confirmation.
264 channel_id: [u8; 32],
265 /// The reason the channel was closed.
266 reason: ClosureReason
268 /// Used to indicate to the user that they can abandon the funding transaction and recycle the
269 /// inputs for another purpose.
271 /// The channel_id of the channel which has been closed.
272 channel_id: [u8; 32],
273 /// The full transaction received from the user
274 transaction: Transaction
278 impl Writeable for Event {
279 fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
281 &Event::FundingGenerationReady { .. } => {
283 // We never write out FundingGenerationReady events as, upon disconnection, peers
284 // drop any channels which have not yet exchanged funding_signed.
286 &Event::PaymentReceived { ref payment_hash, ref amt, ref purpose } => {
288 let mut payment_secret = None;
289 let mut user_payment_id = None;
290 let payment_preimage;
292 PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret, user_payment_id: id } => {
293 payment_secret = Some(secret);
294 payment_preimage = *preimage;
295 user_payment_id = Some(id);
297 PaymentPurpose::SpontaneousPayment(preimage) => {
298 payment_preimage = Some(*preimage);
301 write_tlv_fields!(writer, {
302 (0, payment_hash, required),
303 (2, payment_secret, option),
305 (6, user_payment_id, option),
306 (8, payment_preimage, option),
309 &Event::PaymentSent { ref payment_preimage, ref payment_hash} => {
311 write_tlv_fields!(writer, {
312 (0, payment_preimage, required),
313 (1, payment_hash, required),
316 &Event::PaymentPathFailed { ref payment_hash, ref rejected_by_dest, ref network_update,
317 ref all_paths_failed, ref path, ref short_channel_id,
325 error_code.write(writer)?;
327 error_data.write(writer)?;
328 write_tlv_fields!(writer, {
329 (0, payment_hash, required),
330 (1, network_update, option),
331 (2, rejected_by_dest, required),
332 (3, all_paths_failed, required),
334 (7, short_channel_id, option),
337 &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
339 // Note that we now ignore these on the read end as we'll re-generate them in
340 // ChannelManager, we write them here only for backwards compatibility.
342 &Event::SpendableOutputs { ref outputs } => {
344 write_tlv_fields!(writer, {
345 (0, VecWriteWrapper(outputs), required),
348 &Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx } => {
350 write_tlv_fields!(writer, {
351 (0, fee_earned_msat, option),
352 (2, claim_from_onchain_tx, required),
355 &Event::ChannelClosed { ref channel_id, ref reason } => {
357 write_tlv_fields!(writer, {
358 (0, channel_id, required),
359 (2, reason, required)
362 &Event::DiscardFunding { ref channel_id, ref transaction } => {
364 write_tlv_fields!(writer, {
365 (0, channel_id, required),
366 (2, transaction, required)
369 // Note that, going forward, all new events must only write data inside of
370 // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
371 // data via `write_tlv_fields`.
376 impl MaybeReadable for Event {
377 fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
378 match Readable::read(reader)? {
379 // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
380 // unlike all other events, thus we return immediately here.
384 let mut payment_hash = PaymentHash([0; 32]);
385 let mut payment_preimage = None;
386 let mut payment_secret = None;
388 let mut user_payment_id = None;
389 read_tlv_fields!(reader, {
390 (0, payment_hash, required),
391 (2, payment_secret, option),
393 (6, user_payment_id, option),
394 (8, payment_preimage, option),
396 let purpose = match payment_secret {
397 Some(secret) => PaymentPurpose::InvoicePayment {
399 payment_secret: secret,
400 user_payment_id: if let Some(id) = user_payment_id {
402 } else { return Err(msgs::DecodeError::InvalidValue) }
404 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
405 None => return Err(msgs::DecodeError::InvalidValue),
407 Ok(Some(Event::PaymentReceived {
417 let mut payment_preimage = PaymentPreimage([0; 32]);
418 let mut payment_hash = None;
419 read_tlv_fields!(reader, {
420 (0, payment_preimage, required),
421 (1, payment_hash, option),
423 if payment_hash.is_none() {
424 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
426 Ok(Some(Event::PaymentSent {
428 payment_hash: payment_hash.unwrap(),
436 let error_code = Readable::read(reader)?;
438 let error_data = Readable::read(reader)?;
439 let mut payment_hash = PaymentHash([0; 32]);
440 let mut rejected_by_dest = false;
441 let mut network_update = None;
442 let mut all_paths_failed = Some(true);
443 let mut path: Option<Vec<RouteHop>> = Some(vec![]);
444 let mut short_channel_id = None;
445 read_tlv_fields!(reader, {
446 (0, payment_hash, required),
447 (1, network_update, ignorable),
448 (2, rejected_by_dest, required),
449 (3, all_paths_failed, option),
451 (7, short_channel_id, ignorable),
453 Ok(Some(Event::PaymentPathFailed {
457 all_paths_failed: all_paths_failed.unwrap(),
471 let mut outputs = VecReadWrapper(Vec::new());
472 read_tlv_fields!(reader, {
473 (0, outputs, required),
475 Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
481 let mut fee_earned_msat = None;
482 let mut claim_from_onchain_tx = false;
483 read_tlv_fields!(reader, {
484 (0, fee_earned_msat, option),
485 (2, claim_from_onchain_tx, required),
487 Ok(Some(Event::PaymentForwarded { fee_earned_msat, claim_from_onchain_tx }))
493 let mut channel_id = [0; 32];
494 let mut reason = None;
495 read_tlv_fields!(reader, {
496 (0, channel_id, required),
497 (2, reason, ignorable),
499 if reason.is_none() { return Ok(None); }
500 Ok(Some(Event::ChannelClosed { channel_id, reason: reason.unwrap() }))
506 let mut channel_id = [0; 32];
507 let mut transaction = Transaction{ version: 2, lock_time: 0, input: Vec::new(), output: Vec::new() };
508 read_tlv_fields!(reader, {
509 (0, channel_id, required),
510 (2, transaction, required),
512 Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
516 // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
517 // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
520 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
521 // which prefixes the whole thing with a length BigSize. Because the event is
522 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
523 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
524 // exactly the number of bytes specified, ignoring them entirely.
525 let tlv_len: BigSize = Readable::read(reader)?;
526 FixedLengthReader::new(reader, tlv_len.0)
527 .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
530 _ => Err(msgs::DecodeError::InvalidValue)
535 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
536 /// broadcast to most peers).
537 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
538 #[derive(Clone, Debug)]
539 pub enum MessageSendEvent {
540 /// Used to indicate that we've accepted a channel open and should send the accept_channel
541 /// message provided to the given peer.
543 /// The node_id of the node which should receive this message
545 /// The message which should be sent.
546 msg: msgs::AcceptChannel,
548 /// Used to indicate that we've initiated a channel open and should send the open_channel
549 /// message provided to the given peer.
551 /// The node_id of the node which should receive this message
553 /// The message which should be sent.
554 msg: msgs::OpenChannel,
556 /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
558 /// The node_id of the node which should receive this message
560 /// The message which should be sent.
561 msg: msgs::FundingCreated,
563 /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
565 /// The node_id of the node which should receive this message
567 /// The message which should be sent.
568 msg: msgs::FundingSigned,
570 /// Used to indicate that a funding_locked message should be sent to the peer with the given node_id.
572 /// The node_id of the node which should receive these message(s)
574 /// The funding_locked message which should be sent.
575 msg: msgs::FundingLocked,
577 /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
578 SendAnnouncementSignatures {
579 /// The node_id of the node which should receive these message(s)
581 /// The announcement_signatures message which should be sent.
582 msg: msgs::AnnouncementSignatures,
584 /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
585 /// message should be sent to the peer with the given node_id.
587 /// The node_id of the node which should receive these message(s)
589 /// The update messages which should be sent. ALL messages in the struct should be sent!
590 updates: msgs::CommitmentUpdate,
592 /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
594 /// The node_id of the node which should receive this message
596 /// The message which should be sent.
597 msg: msgs::RevokeAndACK,
599 /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
601 /// The node_id of the node which should receive this message
603 /// The message which should be sent.
604 msg: msgs::ClosingSigned,
606 /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
608 /// The node_id of the node which should receive this message
610 /// The message which should be sent.
613 /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
614 SendChannelReestablish {
615 /// The node_id of the node which should receive this message
617 /// The message which should be sent.
618 msg: msgs::ChannelReestablish,
620 /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
621 /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
623 /// Note that after doing so, you very likely (unless you did so very recently) want to call
624 /// ChannelManager::broadcast_node_announcement to trigger a BroadcastNodeAnnouncement event.
625 /// This ensures that any nodes which see our channel_announcement also have a relevant
626 /// node_announcement, including relevant feature flags which may be important for routing
627 /// through or to us.
628 BroadcastChannelAnnouncement {
629 /// The channel_announcement which should be sent.
630 msg: msgs::ChannelAnnouncement,
631 /// The followup channel_update which should be sent.
632 update_msg: msgs::ChannelUpdate,
634 /// Used to indicate that a node_announcement should be broadcast to all peers.
635 BroadcastNodeAnnouncement {
636 /// The node_announcement which should be sent.
637 msg: msgs::NodeAnnouncement,
639 /// Used to indicate that a channel_update should be broadcast to all peers.
640 BroadcastChannelUpdate {
641 /// The channel_update which should be sent.
642 msg: msgs::ChannelUpdate,
644 /// Used to indicate that a channel_update should be sent to a single peer.
645 /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
646 /// private channel and we shouldn't be informing all of our peers of channel parameters.
648 /// The node_id of the node which should receive this message
650 /// The channel_update which should be sent.
651 msg: msgs::ChannelUpdate,
653 /// Broadcast an error downstream to be handled
655 /// The node_id of the node which should receive this message
657 /// The action which should be taken.
658 action: msgs::ErrorAction
660 /// Query a peer for channels with funding transaction UTXOs in a block range.
661 SendChannelRangeQuery {
662 /// The node_id of this message recipient
664 /// The query_channel_range which should be sent.
665 msg: msgs::QueryChannelRange,
667 /// Request routing gossip messages from a peer for a list of channels identified by
668 /// their short_channel_ids.
670 /// The node_id of this message recipient
672 /// The query_short_channel_ids which should be sent.
673 msg: msgs::QueryShortChannelIds,
675 /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
676 /// emitted during processing of the query.
677 SendReplyChannelRange {
678 /// The node_id of this message recipient
680 /// The reply_channel_range which should be sent.
681 msg: msgs::ReplyChannelRange,
685 /// A trait indicating an object may generate message send events
686 pub trait MessageSendEventsProvider {
687 /// Gets the list of pending events which were generated by previous actions, clearing the list
689 fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
692 /// A trait indicating an object may generate events.
694 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
698 /// See [`process_pending_events`] for requirements around event processing.
700 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
701 /// event since the last invocation. The handler must either act upon the event immediately
702 /// or preserve it for later handling.
704 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
705 /// consult the provider's documentation on the implication of processing events and how a handler
706 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
707 /// [`ChainMonitor::process_pending_events`]).
709 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
712 /// [`process_pending_events`]: Self::process_pending_events
713 /// [`handle_event`]: EventHandler::handle_event
714 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
715 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
716 pub trait EventsProvider {
717 /// Processes any events generated since the last call using the given event handler.
719 /// Subsequent calls must only process new events. However, handlers must be capable of handling
720 /// duplicate events across process restarts. This may occur if the provider was recovered from
721 /// an old state (i.e., it hadn't been successfully persisted after processing pending events).
722 fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
725 /// A trait implemented for objects handling events from [`EventsProvider`].
726 pub trait EventHandler {
727 /// Handles the given [`Event`].
729 /// See [`EventsProvider`] for details that must be considered when implementing this method.
730 fn handle_event(&self, event: &Event);
733 impl<F> EventHandler for F where F: Fn(&Event) {
734 fn handle_event(&self, event: &Event) {