/**************************************************************************************
* 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.collection;
import com.espertech.esper.client.EventBean;
import java.util.ArrayDeque;
/**
* Simple collection that exposes a limited add-and-get interface and that is optimized towards holding
* a single event, but can hold multiple events. If more then one event is added, the
* class allocates a linked list for additional events.
*/
public class OneEventCollection
{
private EventBean firstEvent;
private ArrayDeque<EventBean> additionalEvents;
/**
* Add an event to the collection.
* @param theEvent is the event to add
*/
public void add(EventBean theEvent)
{
if (theEvent == null)
{
throw new IllegalArgumentException("Null event not allowed");
}
if (firstEvent == null)
{
firstEvent = theEvent;
return;
}
if (additionalEvents == null)
{
additionalEvents = new ArrayDeque<EventBean>();
}
additionalEvents.add(theEvent);
}
/**
* Returns true if the collection is empty.
* @return true if empty, false if not
*/
public boolean isEmpty()
{
return firstEvent == null;
}
/**
* Returns an array holding the collected events.
* @return event array
*/
public EventBean[] toArray()
{
if (firstEvent == null)
{
return new EventBean[0];
}
if (additionalEvents == null)
{
return new EventBean[] {firstEvent};
}
EventBean[] events = new EventBean[1 + additionalEvents.size()];
events[0] = firstEvent;
int count = 1;
for (EventBean theEvent : additionalEvents)
{
events[count] = theEvent;
count++;
}
return events;
}
public void add(EventBean[] events) {
for (EventBean theEvent : events) {
add(theEvent);
}
}
}