/*
***************************************************************************************
* 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.view.internal;
import com.espertech.esper.client.EventBean;
import com.espertech.esper.client.EventType;
import com.espertech.esper.collection.FlushedEventBuffer;
import com.espertech.esper.view.ViewSupport;
import java.util.Iterator;
/**
* A view that acts as an adapter between views and update listeners.
* The view can be added to a parent view. When the parent view publishes data, the view will forward the
* data to the UpdateListener implementation that has been supplied. If no UpdateListener has been supplied,
* then the view will cache the last data published by the parent view.
*/
public final class BufferView extends ViewSupport {
private final int streamId;
private BufferObserver observer;
private FlushedEventBuffer newDataBuffer = new FlushedEventBuffer();
private FlushedEventBuffer oldDataBuffer = new FlushedEventBuffer();
/**
* Ctor.
*
* @param streamId - number of the stream for which the view buffers the generated events.
*/
public BufferView(int streamId) {
this.streamId = streamId;
}
/**
* Set the observer for indicating new and old data.
*
* @param observer to indicate new and old events
*/
public void setObserver(BufferObserver observer) {
this.observer = observer;
}
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);
observer.newData(streamId, newDataBuffer, oldDataBuffer);
}
/**
* Returns the buffer for new data.
*
* @return new data buffer
*/
public FlushedEventBuffer getNewDataBuffer() {
return newDataBuffer;
}
}