/**************************************************************************************
* 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.pattern.guard;
import com.espertech.esper.client.EPException;
import com.espertech.esper.epl.expression.ExprNode;
import com.espertech.esper.epl.expression.ExprTimePeriod;
import com.espertech.esper.pattern.*;
import com.espertech.esper.util.JavaClassHelper;
import com.espertech.esper.util.MetaDefItem;
import java.io.Serializable;
import java.util.List;
/**
* Factory for {@link TimerWithinGuard} instances.
*/
public class TimerWithinGuardFactory implements GuardFactory, MetaDefItem, Serializable
{
private static final long serialVersionUID = -1026320055174163611L;
/**
* Number of milliseconds.
*/
protected ExprNode millisecondsExpr;
/**
* For converting matched-events maps to events-per-stream.
*/
protected transient MatchedEventConvertor convertor;
public void setGuardParameters(List<ExprNode> parameters, MatchedEventConvertor convertor) throws GuardParameterException
{
String errorMessage = "Timer-within guard requires a single numeric or time period parameter";
if (parameters.size() != 1)
{
throw new GuardParameterException(errorMessage);
}
if (!JavaClassHelper.isNumeric(parameters.get(0).getExprEvaluator().getType()))
{
throw new GuardParameterException(errorMessage);
}
this.convertor = convertor;
this.millisecondsExpr = parameters.get(0);
}
protected long computeMilliseconds(MatchedEventMap beginState, PatternAgentInstanceContext context) {
if (millisecondsExpr instanceof ExprTimePeriod) {
ExprTimePeriod timePeriod = (ExprTimePeriod) millisecondsExpr;
return timePeriod.nonconstEvaluator().deltaMillisecondsUseEngineTime(convertor.convert(beginState), context.getAgentInstanceContext());
}
else {
Object millisecondVal = PatternExpressionUtil.evaluate("Timer-within guard", beginState, millisecondsExpr, convertor, context.getAgentInstanceContext());
if (millisecondVal == null) {
throw new EPException("Timer-within guard expression returned a null-value");
}
Number param = (Number) millisecondVal;
return Math.round(1000d * param.doubleValue());
}
}
public Guard makeGuard(PatternAgentInstanceContext context, MatchedEventMap matchedEventMap, Quitable quitable, EvalStateNodeNumber stateNodeId, Object guardState)
{
return new TimerWithinGuard(computeMilliseconds(matchedEventMap, context), quitable);
}
}