/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.epl.agg.access;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.epl.expression.core.ExprEvaluatorContext;
/**
* Base interface for providing access-aggregations, i.e. aggregations that mirror a data window
* but group by the group-by clause and that do not mirror the data windows sorting policy.
*/
public interface AggregationState {
/**
* Enter an event.
*
* @param eventsPerStream all events in all streams, typically implementations pick the relevant stream's events to add
* @param exprEvaluatorContext expression eval context
*/
void applyEnter(EventBean[] eventsPerStream, ExprEvaluatorContext exprEvaluatorContext);
/**
* Remove an event.
*
* @param eventsPerStream all events in all streams, typically implementations pick the relevant stream's events to remove
* @param exprEvaluatorContext expression eval context
*/
void applyLeave(EventBean[] eventsPerStream, ExprEvaluatorContext exprEvaluatorContext);
/**
* Clear all events in the group.
*/
public void clear();
}