export enum ChannelMonitorUpdateErr {
- LDKChannelMonitorUpdateErr_TemporaryFailure,
- LDKChannelMonitorUpdateErr_PermanentFailure,
+ /**
+ * Used to indicate a temporary failure (eg connection to a watchtower or remote backup of
+our state failed, but is expected to succeed at some point in the future).
+
+Such a failure will \"freeze\" a channel, preventing us from revoking old states or
+submitting new commitment transactions to the counterparty. Once the update(s) that failed
+have been successfully applied, a [`MonitorEvent::UpdateCompleted`] event should be returned
+via [`Watch::release_pending_monitor_events`] which will then restore the channel to an
+operational state.
+
+Note that a given ChannelManager will *never* re-generate a given ChannelMonitorUpdate. If
+you return a TemporaryFailure you must ensure that it is written to disk safely before
+writing out the latest ChannelManager state.
+
+Even when a channel has been \"frozen\" updates to the ChannelMonitor can continue to occur
+(eg if an inbound HTLC which we forwarded was claimed upstream resulting in us attempting
+to claim it on this channel) and those updates must be applied wherever they can be. At
+least one such updated ChannelMonitor must be persisted otherwise PermanentFailure should
+be returned to get things on-chain ASAP using only the in-memory copy. Obviously updates to
+the channel which would invalidate previous ChannelMonitors are not made when a channel has
+been \"frozen\".
+
+Note that even if updates made after TemporaryFailure succeed you must still provide a
+[`MonitorEvent::UpdateCompleted`] to ensure you have the latest monitor and re-enable
+normal channel operation. Note that this is normally generated through a call to
+[`ChainMonitor::channel_monitor_updated`].
+
+Note that the update being processed here will not be replayed for you when you return a
+[`MonitorEvent::UpdateCompleted`] event via [`Watch::release_pending_monitor_events`], so
+you must store the update itself on your own local disk prior to returning a
+TemporaryFailure. You may, of course, employ a journaling approach, storing only the
+ChannelMonitorUpdate on disk without updating the monitor itself, replaying the journal at
+reload-time.
+
+For deployments where a copy of ChannelMonitors and other local state are backed up in a
+remote location (with local copies persisted immediately), it is anticipated that all
+updates will return TemporaryFailure until the remote copies could be updated.
+
+[`ChainMonitor::channel_monitor_updated`]: chainmonitor::ChainMonitor::channel_monitor_updated
+ */
+LDKChannelMonitorUpdateErr_TemporaryFailure,
+ /**
+ * Used to indicate no further channel monitor updates will be allowed (eg we've moved on to a
+different watchtower and cannot update with all watchtowers that were previously informed
+of this channel).
+
+At reception of this error, ChannelManager will force-close the channel and return at
+least a final ChannelMonitorUpdate::ChannelForceClosed which must be delivered to at
+least one ChannelMonitor copy. Revocation secret MUST NOT be released and offchain channel
+update must be rejected.
+
+This failure may also signal a failure to update the local persisted copy of one of
+the channel monitor instance.
+
+Note that even when you fail a holder commitment transaction update, you must store the
+update to ensure you can claim from it in case of a duplicate copy of this ChannelMonitor
+broadcasts it (e.g distributed channel-monitor deployment)
+
+In case of distributed watchtowers deployment, the new version must be written to disk, as
+state may have been stored but rejected due to a block forcing a commitment broadcast. This
+storage is used to claim outputs of rejected state confirmed onchain by another watchtower,
+lagging behind on block processing.
+ */
+LDKChannelMonitorUpdateErr_PermanentFailure,
}
projects / ldk-java / blobdiff