/* Soot - a J*va Optimization Framework
* Copyright (C) 2003 Ondrej Lhotak
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
package soot.util.queue;
/** A queue of Object's. One can add objects to the queue, and they are
* later read by a QueueReader. One can create arbitrary numbers of
* QueueReader's for a queue, and each one receives all the Object's that
* are added. Only objects that have not been read by all the QueueReader's
* are kept. A QueueReader only receives the Object's added to the queue
* <b>after</b> the QueueReader was created.
* @author Ondrej Lhotak
*/
@SuppressWarnings("unchecked")
public final class ChunkedQueue<E>
{
static Object NULL_CONST = new Object();
private static final int LENGTH = 60;
private Object[] q;
private int index;
public ChunkedQueue() {
q = new Object[LENGTH];
index = 0;
}
/** Add an object to the queue. */
public void add( E o ) {
if( o == null ) o = (E)NULL_CONST;
if( index == LENGTH - 1 ) {
Object[] temp = new Object[LENGTH];
q[index] = temp;
q = temp;
index = 0;
}
q[index++] = o;
}
/** Create reader which will read objects from the queue. */
public QueueReader<E> reader() {
return new QueueReader<E>( (E[])q, index );
}
}