1 package org.apache.jcs.engine.memory.fifo;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.io.IOException;
23 import java.io.Serializable;
24
25 import org.apache.jcs.engine.behavior.ICacheElement;
26 import org.apache.jcs.engine.memory.AbstractDoubleLinkedListMemoryCache;
27 import org.apache.jcs.engine.memory.util.MemoryElementDescriptor;
28
29 /**
30 * The items are spooled in the order they are added. No adjustments to the list are made on get.
31 */
32 public class FIFOMemoryCache<K extends Serializable, V extends Serializable>
33 extends AbstractDoubleLinkedListMemoryCache<K, V>
34 {
35 /** Don't change */
36 private static final long serialVersionUID = 6403738094136424201L;
37
38 /**
39 * Puts an item to the cache. Removes any pre-existing entries of the same key from the linked
40 * list and adds this one first.
41 * <p>
42 * @param ce The cache element, or entry wrapper
43 * @return MemoryElementDescriptor the new node
44 * @exception IOException
45 */
46 @Override
47 protected MemoryElementDescriptor<K, V> adjustListForUpdate( ICacheElement<K, V> ce )
48 throws IOException
49 {
50 return addFirst( ce );
51 }
52
53 /**
54 * Does nothing.
55 * <p>
56 * @param me
57 */
58 @Override
59 protected void adjustListForGet( MemoryElementDescriptor<K, V> me )
60 {
61 // DO NOTHING
62 }
63 }