*
* # Requirements
*
- * See [`process_pending_events`] for requirements around event processing.
- *
* When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
- * event since the last invocation. The handler must either act upon the event immediately
- * or preserve it for later handling.
+ * event since the last invocation.
+ *
+ * In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
+ * and replay any unhandled events on startup. An [`Event`] is considered handled when
+ * [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
+ * relevant changes to disk *before* returning.
+ *
+ * Further, because an application may crash between an [`Event`] being handled and the
+ * implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
+ * effect, [`Event`]s may be replayed.
*
* Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
* consult the provider's documentation on the implication of processing events and how a handler
/**
* Processes any events generated since the last call using the given event handler.
*
- * Subsequent calls must only process new events. However, handlers must be capable of handling
- * duplicate events across process restarts. This may occur if the provider was recovered from
- * an old state (i.e., it hadn't been successfully persisted after processing pending events).
+ * See the trait-level documentation for requirements.
*/
void process_pending_events(EventHandler handler);
}
/**
* Processes any events generated since the last call using the given event handler.
*
- * Subsequent calls must only process new events. However, handlers must be capable of handling
- * duplicate events across process restarts. This may occur if the provider was recovered from
- * an old state (i.e., it hadn't been successfully persisted after processing pending events).
+ * See the trait-level documentation for requirements.
*/
public void process_pending_events(EventHandler handler) {
bindings.EventsProvider_process_pending_events(this.ptr, handler == null ? 0 : handler.ptr);