/* ********************************************************************** **
** Copyright notice **
** **
** (c) 2005-2006 RSSOwl Development Team **
** http://www.rssowl.org/ **
** **
** All rights reserved **
** **
** This program and the accompanying materials are made available under **
** the terms of the Eclipse Public License v1.0 which accompanies this **
** distribution, and is available at: **
** http://www.rssowl.org/legal/epl-v10.html **
** **
** A copy is found in the file epl-v10.html and important notices to the **
** license from the team is found in the textfile LICENSE.txt distributed **
** in this package. **
** **
** This copyright notice MUST APPEAR in all copies of the file! **
** **
** Contributors: **
** RSSOwl Development Team - initial API and implementation **
** **
** ********************************************************************** */
package org.rssowl.core.util;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* The <code>BatchedBuffer</code> can be used to batch certain types of
* Objects for later processing. The type of Object is identified by the generic
* <code>T</code>.
*
* @author bpasero
* @param <T> The type that will be buffered
*/
public class BatchedBuffer<T> {
private int fBatchInterval;
private List<T> fBuffer;
private Job fBufferProcessor;
private Receiver<T> fReceiver;
/**
* @param <T> The type that will be received from the
* <code>BatchedBuffer</code>
*/
public interface Receiver<T> {
/**
* Asks the implementor to process the given Set of Objects. This method
* will be called after <code>batchInterval</code> millies.
*
* @param objects A Set of Objects that have been added during
* <code>batchInterval</code>.
*/
void receive(Set<T> objects);
}
/**
* @param receiver An instance of <code>Receiver</code> to process the
* elements of this buffer after <code>batchInterval</code> millies.
* @param batchInterval The interval in millies before types get processed.
*/
public BatchedBuffer(Receiver<T> receiver, int batchInterval) {
fReceiver = receiver;
fBatchInterval = batchInterval;
fBuffer = new ArrayList<T>();
fBufferProcessor = createBufferProcessor();
}
/**
* Adds all Objects of the given Collection to this Buffer. The Buffer will be
* cleared after <code>batchInterval</code> millies by calling the
* <code>receive(Set)</code> method.
*
* @param objects The Collection of Objects to add into this Buffer.
*/
public void addAll(Collection<T> objects) {
if (objects.isEmpty())
return;
synchronized (fBuffer) {
/* New Batch */
if (fBuffer.isEmpty()) {
fBuffer.addAll(objects);
fBufferProcessor.schedule(fBatchInterval);
}
/* Existing Batch */
else {
fBuffer.addAll(objects);
}
}
}
/* Creates a Job to process the contents of the Buffer */
private Job createBufferProcessor() {
Job job = new Job("Batched Buffer Processor") {
@Override
protected IStatus run(IProgressMonitor monitor) {
synchronized (fBuffer) {
fReceiver.receive(new HashSet<T>(fBuffer));
fBuffer.clear();
}
return Status.OK_STATUS;
}
};
job.setSystem(true);
job.setUser(false);
return job;
}
}