Copyright (c) 2006, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2006, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.internal.filesystem.local;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.ProgressMonitorWrapper;

This class provides a simulation of progress. This is useful for situations where computing the amount of work to do in advance is too costly. The monitor will accept any number of calls to worked(int), and will scale the actual reported work appropriately so that the progress never quite completes. /**
 * This class provides a simulation of progress. This is useful
 * for situations where computing the amount of work to do in advance
 * is too costly.  The monitor will accept any number of calls to
 * {@link #worked(int)}, and will scale the actual reported work appropriately
 * so that the progress never quite completes.
 */
public class InfiniteProgress extends ProgressMonitorWrapper {
	/*
	 * Fields for progress monitoring algorithm.
	 * Initially, give progress for every 4 resources, double
	 * this value at halfway point, then reset halfway point
	 * to be half of remaining work.  (this gives an infinite
	 * series that converges at total work after an infinite
	 * number of resources).
	 */
	private int totalWork;
	private int currentIncrement = 4;
	private int halfWay;
	private int nextProgress = currentIncrement;
	private int worked = 0;

	protected InfiniteProgress(IProgressMonitor monitor) {
		super(monitor);
	}

	@Override
	public void beginTask(String name, int work) {
		super.beginTask(name, work);
		this.totalWork = work;
		this.halfWay = totalWork / 2;
	}

	@Override
	public void worked(int work) {
		if (--nextProgress <= 0) {
			//we have exhausted the current increment, so report progress
			super.worked(1);
			worked++;
			if (worked >= halfWay) {
				//we have passed the current halfway point, so double the
				//increment and reset the halfway point.
				currentIncrement *= 2;
				halfWay += (totalWork - halfWay) / 2;
			}
			//reset the progress counter to another full increment
			nextProgress = currentIncrement;
		}
	}

}