org.eclipse.jdt.internal.core.util.ICacheEnumeration Maven / Gradle / Ivy

/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 * 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.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.util;

import java.util.Enumeration;

/**
 * The ICacheEnumeration is used to iterate over both the keys
 * and values in an LRUCache.  The getValue() method returns the
 * value of the last key to be retrieved using nextElement().
 * The nextElement() method must be called before the
 * getValue() method.
 *
 * The iteration can be made efficient by making use of the fact that values in
 * the cache (instances of LRUCacheEntry), know their key.  For this reason,
 * Hashtable lookups don't have to be made at each step of the iteration.
 *
 * Modifications to the cache must not be performed while using the
 * enumeration.  Doing so will lead to an illegal state.
 *
 * @see LRUCache
 */
@SuppressWarnings("rawtypes")
public interface ICacheEnumeration extends Enumeration {
	/**
	 * Returns the value of the previously accessed key in the enumeration.
	 * Must be called after a call to nextElement().
	 *
	 * @return Value of current cache entry
	 */
	public Object getValue();
}