001package org.apache.commons.jcs.engine.memory.fifo; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import java.io.IOException; 023 024import org.apache.commons.jcs.engine.behavior.ICacheElement; 025import org.apache.commons.jcs.engine.memory.AbstractDoubleLinkedListMemoryCache; 026import org.apache.commons.jcs.engine.memory.util.MemoryElementDescriptor; 027 028/** 029 * The items are spooled in the order they are added. No adjustments to the list are made on get. 030 */ 031public class FIFOMemoryCache<K, V> 032 extends AbstractDoubleLinkedListMemoryCache<K, V> 033{ 034 /** 035 * Puts an item to the cache. Removes any pre-existing entries of the same key from the linked 036 * list and adds this one first. 037 * <p> 038 * @param ce The cache element, or entry wrapper 039 * @return MemoryElementDescriptor the new node 040 * @throws IOException 041 */ 042 @Override 043 protected MemoryElementDescriptor<K, V> adjustListForUpdate( ICacheElement<K, V> ce ) 044 throws IOException 045 { 046 return addFirst( ce ); 047 } 048 049 /** 050 * Does nothing. 051 * <p> 052 * @param me 053 */ 054 @Override 055 protected void adjustListForGet( MemoryElementDescriptor<K, V> me ) 056 { 057 // DO NOTHING 058 } 059}