SingleStreamDispatchView.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.view.internal;

import java.util.Iterator;

import com.espertech.esper.view.ViewSupport;
import com.espertech.esper.client.EventType;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.collection.FlushedEventBuffer;
import com.espertech.esper.core.service.EPStatementDispatch;
import com.espertech.esper.epl.expression.ExprEvaluatorContext;

/**
 * View to dispatch for a single stream (no join).
 */
public final class SingleStreamDispatchView extends ViewSupport implements EPStatementDispatch
{
    private boolean hasData = false;
    private FlushedEventBuffer newDataBuffer = new FlushedEventBuffer();
    private FlushedEventBuffer oldDataBuffer = new FlushedEventBuffer();

    /**
     * Ctor.
     */
    public SingleStreamDispatchView()
    {
    }

    public final EventType getEventType()
    {
        return parent.getEventType();
    }

    public final Iterator<EventBean> iterator()
    {
        return parent.iterator();
    }

    public final void update(EventBean[] newData, EventBean[] oldData)
    {
        newDataBuffer.add(newData);
        oldDataBuffer.add(oldData);
        hasData = true;
    }

    public void execute(ExprEvaluatorContext exprEvaluatorContext)
    {
        if (hasData) {
            hasData = false;
            this.updateChildren(newDataBuffer.getAndFlush(), oldDataBuffer.getAndFlush());
        }
    }
}