Trait breez_sdk_core::lightning::chain::Watch
pub trait Watch<ChannelSigner>where
ChannelSigner: WriteableEcdsaChannelSigner,{
// Required methods
fn watch_channel(
&self,
funding_txo: OutPoint,
monitor: ChannelMonitor<ChannelSigner>,
) -> Result<ChannelMonitorUpdateStatus, ()>;
fn update_channel(
&self,
funding_txo: OutPoint,
update: &ChannelMonitorUpdate,
) -> ChannelMonitorUpdateStatus;
fn release_pending_monitor_events(
&self,
) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>;
}
Expand description
The Watch
trait defines behavior for watching on-chain activity pertaining to channels as
blocks are connected and disconnected.
Each channel is associated with a ChannelMonitor
. Implementations of this trait are
responsible for maintaining a set of monitors such that they can be updated as channel state
changes. On each update, all copies of a ChannelMonitor
must be updated and the update
persisted to disk to ensure that the latest ChannelMonitor
state can be reloaded if the
application crashes.
See method documentation and ChannelMonitorUpdateStatus
for specific requirements.
Required Methods§
fn watch_channel(
&self,
funding_txo: OutPoint,
monitor: ChannelMonitor<ChannelSigner>,
) -> Result<ChannelMonitorUpdateStatus, ()>
fn watch_channel( &self, funding_txo: OutPoint, monitor: ChannelMonitor<ChannelSigner>, ) -> Result<ChannelMonitorUpdateStatus, ()>
Watches a channel identified by funding_txo
using monitor
.
Implementations are responsible for watching the chain for the funding transaction along
with any spends of outputs returned by get_outputs_to_watch
. In practice, this means
calling block_connected
and block_disconnected
on the monitor.
A return of Err(())
indicates that the channel should immediately be force-closed without
broadcasting the funding transaction.
If the given funding_txo
has previously been registered via watch_channel
, Err(())
must be returned.
fn update_channel(
&self,
funding_txo: OutPoint,
update: &ChannelMonitorUpdate,
) -> ChannelMonitorUpdateStatus
fn update_channel( &self, funding_txo: OutPoint, update: &ChannelMonitorUpdate, ) -> ChannelMonitorUpdateStatus
Updates a channel identified by funding_txo
by applying update
to its monitor.
Implementations must call ChannelMonitor::update_monitor
with the given update. This
may fail (returning an Err(())
), in which case this should return
ChannelMonitorUpdateStatus::InProgress
(and the update should never complete). This
generally implies the channel has been closed (either by the funding outpoint being spent
on-chain or the ChannelMonitor
having decided to do so and broadcasted a transaction),
and the ChannelManager
state will be updated once it sees the funding spend on-chain.
In general, persistence failures should be retried after returning
ChannelMonitorUpdateStatus::InProgress
and eventually complete. If a failure truly
cannot be retried, the node should shut down immediately after returning
ChannelMonitorUpdateStatus::UnrecoverableError
, see its documentation for more info.
fn release_pending_monitor_events(
&self,
) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>
fn release_pending_monitor_events( &self, ) -> Vec<(OutPoint, Vec<MonitorEvent>, Option<PublicKey>)>
Returns any monitor events since the last call. Subsequent calls must only return new events.
Note that after any block- or transaction-connection calls to a ChannelMonitor
, no
further events may be returned here until the ChannelMonitor
has been fully persisted
to disk.
For details on asynchronous ChannelMonitor
updating and returning
MonitorEvent::Completed
here, see ChannelMonitorUpdateStatus::InProgress
.