tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/internal/utils/QueueTest.java

package org.eclipse.core.tests.internal.utils;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */

import java.util.Enumeration;

import junit.framework.*;
import org.eclipse.core.internal.utils.Queue;

public class QueueTest extends TestCase {
public QueueTest() {
	super(null);
}
public QueueTest(String name) {
	super(name);
}
public static Test suite() {
	return new TestSuite(QueueTest.class);
}
public void testElements() {
	/* add elements without removing */
	Queue queue = new Queue(5, false);
	for (int i = 0; i < 10; i++)
		queue.add(String.valueOf(i));

	/* assert elements are correct */
	Enumeration elements = queue.elements();
	for (int i = 0; i < 10; i++)
		assertTrue("1.0", elements.nextElement().equals(String.valueOf(i)));

	/* add and remove elements */
	queue = new Queue(5, false);
	for (int i = 0; i < 5; i++)
		queue.add(String.valueOf(i));
	for (int i = 0; i < 4; i++)
		queue.remove();
	for (int i = 0; i < 10; i++)
		queue.add(String.valueOf(i));

	/* assert elements are correct */
	elements = queue.elements();
	for (int i = 4; i < 5; i++)
		assertTrue("2.0", elements.nextElement().equals(String.valueOf(i)));
	for (int i = 0; i < 10; i++)
		assertTrue("2.1", elements.nextElement().equals(String.valueOf(i)));
}
public void testGrow() {
	/* add elements without removing */
	Queue queue = new Queue(5, false);
	for (int i = 0; i < 10; i++)
		queue.add(String.valueOf(i));
	assertTrue("1.0", queue.size() == 10);

	/* add and remove elements */
	queue = new Queue(5, false);
	for (int i = 0; i < 5; i++)
		queue.add(String.valueOf(i));
	for (int i = 0; i < 4; i++)
		queue.remove();
	for (int i = 0; i < 10; i++) {
		queue.add(String.valueOf(i));
	}
	assertTrue("2.0", queue.size() == 11);
}
public void testRemoveTail() {
	/* head < tail */
	Queue queue = new Queue(10, false);
	for (int i = 0; i < 8; i++)
		queue.add(String.valueOf(i));
	assertTrue("1.0", queue.peekTail().equals("7"));
	assertTrue("1.1", queue.removeTail().equals("7"));
	assertTrue("1.2", queue.peekTail().equals("6"));

	/* head > tail */
	queue = new Queue(5, false);
	for (int i = 0; i < 5; i++)
		queue.add(String.valueOf(i));
	for (int i = 0; i < 4; i++)
		queue.remove();
	for (int i = 0; i < 10; i++) {
		queue.add(String.valueOf(i));
	}
	assertTrue("2.0", queue.peekTail().equals("9"));
	assertTrue("2.1", queue.removeTail().equals("9"));
	assertTrue("2.2", queue.peekTail().equals("8"));
}
public void testReusableElements() {
	/**/
	class ReusableObject {
		int value;
	};

	/* add elements */
	Queue queue = new Queue(10, true);
	for (int i = 0; i < 9; i++) {
		ReusableObject o = new ReusableObject();
		o.value = i;
		queue.add(o);
	}

	/* remove elements */
	for (int i = 0; i < 9; i++)
		queue.remove();
	
	/* add one more element to avoid null */
	queue.add(new ReusableObject());

	/* add again reusing the elements */
	for (int i = 0; i < 9; i++) {
		ReusableObject o = (ReusableObject) queue.getNextAvailableObject();
		assertTrue("1.0", o != null);
		o.value = i;
		queue.add(o);
	}
}
}