com.espertech.esper.client
Interface StatementAwareUpdateListener

All Known Implementing Classes:

EPStatementSource.EmitterCollectorUpdateListener, EPStatementSource.EmitterUpdateListener

public interface StatementAwareUpdateListener

Defines an interface to notify of new and old events.

Also see UpdateListener for update listeners that only require event delivery.

Method Summary

void	update(EventBean[] newEvents, EventBean[] oldEvents, EPStatement statement, EPServiceProvider epServiceProvider) Notify that new events are available or old events are removed.

Method Detail

update

void update(EventBean[] newEvents,
            EventBean[] oldEvents,
            EPStatement statement,
            EPServiceProvider epServiceProvider)

Notify that new events are available or old events are removed.

If the call to update contains new (inserted) events, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted events, then the first argument will be empty and the second will be non-empty.

Either the newEvents or oldEvents will be non-null. This method won't be called with both arguments being null (unless using output rate limiting or force-output options), but either one could be null. The same is true for zero-length arrays. Either newEvents or oldEvents will be non-empty. If both are non-empty, then the update is a modification notification.

Parameters:

newEvents - is any new events. This will be null or empty if the update is for old events only.

oldEvents - is any old events. This will be null or empty if the update is for new events only.

statement - is the statement producing the result

epServiceProvider - is the engine instance that provided the administrative API that created the statement which produces the result