/**************************************************************************************
* 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.named;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.collection.ArrayEventIterator;
import com.espertech.esper.collection.MultiKey;
import com.espertech.esper.collection.UniformPair;
import com.espertech.esper.epl.core.ResultSetProcessor;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;
import com.espertech.esper.event.EventBeanUtility;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;
/**
* View for the on-select statement that handles selecting events from a named window.
*/
public class NamedWindowOnSelectView extends NamedWindowOnExprBaseView
{
private static final Log log = LogFactory.getLog(NamedWindowOnSelectView.class);
private final NamedWindowOnSelectViewFactory parent;
private final ResultSetProcessor resultSetProcessor;
private EventBean[] lastResult;
private Set<MultiKey<EventBean>> oldEvents = new HashSet<MultiKey<EventBean>>();
public NamedWindowOnSelectView(NamedWindowLookupStrategy lookupStrategy, NamedWindowRootViewInstance rootView, ExprEvaluatorContext exprEvaluatorContext, NamedWindowOnSelectViewFactory parent, ResultSetProcessor resultSetProcessor) {
super(lookupStrategy, rootView, exprEvaluatorContext);
this.parent = parent;
this.resultSetProcessor = resultSetProcessor;
}
public void handleMatching(EventBean[] triggerEvents, EventBean[] matchingEvents)
{
EventBean[] newData;
// clear state from prior results
resultSetProcessor.clear();
// build join result
// use linked hash set to retain order of join results for last/first/window to work most intuitively
Set<MultiKey<EventBean>> newEvents = new LinkedHashSet<MultiKey<EventBean>>();
for (int i = 0; i < triggerEvents.length; i++)
{
EventBean triggerEvent = triggerEvents[0];
if (matchingEvents != null)
{
for (int j = 0; j < matchingEvents.length; j++)
{
EventBean[] eventsPerStream = new EventBean[2];
eventsPerStream[0] = matchingEvents[j];
eventsPerStream[1] = triggerEvent;
newEvents.add(new MultiKey<EventBean>(eventsPerStream));
}
}
}
// process matches
UniformPair<EventBean[]> pair = resultSetProcessor.processJoinResult(newEvents, oldEvents, false);
newData = (pair != null ? pair.getFirst() : null);
if (parent.isDistinct())
{
newData = EventBeanUtility.getDistinctByProp(newData, parent.getEventBeanReader());
}
if (parent.getInternalEventRouter() != null)
{
if (newData != null)
{
for (int i = 0; i < newData.length; i++)
{
parent.getInternalEventRouter().route(newData[i], parent.getStatementHandle(), parent.getInternalEventRouteDest(), getExprEvaluatorContext(), parent.isAddToFront());
}
}
}
// The on-select listeners receive the events selected
if ((newData != null) && (newData.length > 0))
{
// And post only if we have listeners/subscribers that need the data
if (parent.getStatementResultService().isMakeNatural() || parent.getStatementResultService().isMakeSynthetic())
{
updateChildren(newData, null);
}
}
lastResult = newData;
// clear state from prior results
resultSetProcessor.clear();
}
public EventType getEventType()
{
if (resultSetProcessor != null)
{
return resultSetProcessor.getResultEventType();
}
else
{
return rootView.getEventType();
}
}
public Iterator<EventBean> iterator()
{
return new ArrayEventIterator(lastResult);
}
}