AggSvcGroupByReclaimAgedEvalFuncVariable.java

/**************************************************************************************
 * Copyright (C) 2008 EsperTech, Inc. All rights reserved.                            *
 * http://esper.codehaus.org                                                          *
 * 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.service;

import com.espertech.esper.epl.variable.VariableReader;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Implementation for handling aggregation with grouping by group-keys.
 */
public class AggSvcGroupByReclaimAgedEvalFuncVariable implements AggSvcGroupByReclaimAgedEvalFunc
{
    private static final Log log = LogFactory.getLog(AggSvcGroupByReclaimAgedEvalFuncVariable.class);

    private VariableReader variableReader;

    public AggSvcGroupByReclaimAgedEvalFuncVariable(VariableReader variableReader)
    {
        this.variableReader = variableReader;
    }

    public Double getLongValue()
    {
        Object val = variableReader.getValue();
        if ((val != null) && (val instanceof Number))
        {
            return ((Number) val).doubleValue();
        }
        log.warn("Variable '" + variableReader.getVariableName() + " returned a null value, using last valid value");
        return null;
    }
}