namespace org { namespace ldk { namespace enums {/** * An enum representing the status of a channel monitor update persistence. */ public enum ChannelMonitorUpdateStatus { /** * The update has been durably persisted and all copies of the relevant [`ChannelMonitor`] * have been updated. * * This includes performing any `fsync()` calls required to ensure the update is guaranteed to * be available on restart even if the application crashes. */ LDKChannelMonitorUpdateStatus_Completed, /** * 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) which failed * have been successfully applied, a [`MonitorEvent::Completed`] can be used to restore the * channel to an operational state. * * Note that a given [`ChannelManager`] will *never* re-generate a [`ChannelMonitorUpdate`]. * If you return this error you must ensure that it is written to disk safely before writing * the latest [`ChannelManager`] state, or you should return [`PermanentFailure`] instead. * * Even when a channel has been \"frozen\", updates to the [`ChannelMonitor`] can continue to * occur (e.g. if an inbound HTLC which we forwarded was claimed upstream, resulting in us * attempting to claim it on this channel) and those updates must still be persisted. * * No updates to the channel will be made which could invalidate other [`ChannelMonitor`]s * until a [`MonitorEvent::Completed`] is provided, even if you return no error on a later * monitor update for the same channel. * * 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 [`InProgress`] until the remote copies could be updated. * * [`PermanentFailure`]: ChannelMonitorUpdateStatus::PermanentFailure * [`InProgress`]: ChannelMonitorUpdateStatus::InProgress * [`ChannelManager`]: crate::ln::channelmanager::ChannelManager */ LDKChannelMonitorUpdateStatus_InProgress, /** * Used to indicate no further channel monitor updates will be allowed (likely a disk failure * or a remote copy of this [`ChannelMonitor`] is no longer reachable and thus not updatable). * * When this is returned, [`ChannelManager`] will force-close the channel but *not* broadcast * our current commitment transaction. This avoids a dangerous case where a local disk failure * (e.g. the Linux-default remounting of the disk as read-only) causes [`PermanentFailure`]s * for all monitor updates. If we were to broadcast our latest commitment transaction and then * restart, we could end up reading a previous [`ChannelMonitor`] and [`ChannelManager`], * revoking our now-broadcasted state before seeing it confirm and losing all our funds. * * Note that this is somewhat of a tradeoff - if the disk is really gone and we may have lost * the data permanently, we really should broadcast immediately. If the data can be recovered * with manual intervention, we'd rather close the channel, rejecting future updates to it, * and broadcast the latest state only if we have HTLCs to claim which are timing out (which * we do as long as blocks are connected). * * In order to broadcast the latest local commitment transaction, you'll need to call * [`ChannelMonitor::get_latest_holder_commitment_txn`] and broadcast the resulting * transactions once you've safely ensured no further channel updates can be generated by your * [`ChannelManager`]. * * Note that at least one final [`ChannelMonitorUpdate`] may still be provided, which must * still be processed by a running [`ChannelMonitor`]. This final update will mark the * [`ChannelMonitor`] as finalized, ensuring no further updates (e.g. revocation of the latest * commitment transaction) are allowed. * * Note that even if you return a [`PermanentFailure`] due to unavailability of secondary * [`ChannelMonitor`] copies, you should still make an attempt to store the update where * possible to ensure you can claim HTLC outputs on the latest commitment transaction * broadcasted later. * * 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. * * [`PermanentFailure`]: ChannelMonitorUpdateStatus::PermanentFailure * [`ChannelManager`]: crate::ln::channelmanager::ChannelManager */ LDKChannelMonitorUpdateStatus_PermanentFailure, }} } }