/*
***************************************************************************************
* 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.join.exec.base;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.epl.expression.core.ExprEvaluatorContext;
import com.espertech.esper.epl.join.rep.Cursor;
import com.espertech.esper.epl.lookup.LookupStrategyDesc;
import java.util.Set;
/**
* Strategy for looking up, in some sort of table or index, an event, potentially based on the
* events properties, and returning a set of matched events.
*/
public interface JoinExecTableLookupStrategy {
/**
* Returns matched events for a event to look up for. Never returns an empty result set,
* always returns null to indicate no results.
*
* @param theEvent to look up
* @param cursor the path in the query that the lookup took
* @param exprEvaluatorContext expression evaluation context
* @return set of matching events, or null if none matching
*/
public Set<EventBean> lookup(EventBean theEvent, Cursor cursor, ExprEvaluatorContext exprEvaluatorContext);
public LookupStrategyDesc getStrategyDesc();
}