001    /*--------------------------------------------------------------------------+
002    $Id: LRUStraightCacheBase.java 26268 2010-02-18 10:44:30Z juergens $
003    |                                                                          |
004    | Copyright 2005-2010 Technische Universitaet Muenchen                     |
005    |                                                                          |
006    | Licensed under the Apache License, Version 2.0 (the "License");          |
007    | you may not use this file except in compliance with the License.         |
008    | You may obtain a copy of the License at                                  |
009    |                                                                          |
010    |    http://www.apache.org/licenses/LICENSE-2.0                            |
011    |                                                                          |
012    | Unless required by applicable law or agreed to in writing, software      |
013    | distributed under the License is distributed on an "AS IS" BASIS,        |
014    | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
015    | See the License for the specific language governing permissions and      |
016    | limitations under the License.                                           |
017    +--------------------------------------------------------------------------*/
018    package edu.tum.cs.commons.cache;
019    
020    import edu.tum.cs.commons.error.NeverThrownRuntimeException;
021    
022    /**
023     * This a special base class for last recently used (LRU) caches that work with
024     * identifiers that are suitable as hash keys.
025     * 
026     * @author Florian Deissenboeck
027     * @author $Author: juergens $
028     * 
029     * @version $Rev: 26268 $
030     * @levd.rating GREEN Hash: BDFF6A27A0F84128189790591C459DE8
031     * 
032     * @param <I>
033     *            the index type of the cache
034     * @param <E>
035     *            the type stored in the cache
036     * @param <X>
037     *            the type of exception thrown by the {@link #obtainItem(Object)}
038     *            method. Use the {@link NeverThrownRuntimeException} if no
039     *            exception will be thrown.
040     */
041    public abstract class LRUStraightCacheBase<I, E, X extends Exception> extends
042                    LRUCacheBase<I, I, E, X> {
043    
044            /** Constructor. */
045            public LRUStraightCacheBase(int maxSize) {
046                    super(maxSize);
047            }
048    
049            /**
050             * This method simply returns the identifier.
051             */
052            @Override
053            protected I getHashKey(I identifier) {
054                    return identifier;
055            }
056    
057    }