View Javadoc

1   package org.apache.jcs.auxiliary;
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  import java.util.Set;
25  
26  import org.apache.jcs.engine.behavior.ICache;
27  import org.apache.jcs.engine.behavior.IElementSerializer;
28  import org.apache.jcs.engine.logging.behavior.ICacheEventLogger;
29  import org.apache.jcs.engine.stats.behavior.IStats;
30  
31  /**
32   * Tag interface for auxiliary caches. Currently this provides no additional methods over what is in
33   * ICache, but I anticipate that will change. For example, there will be a mechanism for determining
34   * the type (disk/lateral/remote) of the auxiliary here -- and the existing getCacheType will be
35   * removed from ICache.
36   */
37  public interface AuxiliaryCache<K extends Serializable, V extends Serializable>
38      extends ICache<K, V>
39  {
40      /**
41       * Gets the set of keys of objects currently in the group
42       * @param group
43       * @return a set of group keys
44       * @throws IOException
45       */
46      Set<K> getGroupKeys( String group )
47          throws IOException;
48  
49      /**
50       * Gets the set of group names currently in the cache
51       * @return a set of group names
52       * @throws IOException
53       */
54      Set<String> getGroupNames()
55          throws IOException;
56  
57      /**
58       * @return the historical and statistical data for a region's auxiliary cache.
59       */
60      IStats getStatistics();
61  
62      /**
63       * This returns the generic attributes for an auxiliary cache. Most implementations will cast
64       * this to a more specific type.
65       * <p>
66       * @return the attributes for the auxiliary cache
67       */
68      AuxiliaryCacheAttributes getAuxiliaryCacheAttributes();
69  
70      /**
71       * Allows you to inject a custom serializer. A good example would be a compressing standard
72       * serializer.
73       * <p>
74       * @param elementSerializer
75       */
76      void setElementSerializer( IElementSerializer elementSerializer );
77  
78      /**
79       * Every Auxiliary must allow for the use of an event logger.
80       * <p>
81       * @param cacheEventLogger
82       */
83      void setCacheEventLogger( ICacheEventLogger cacheEventLogger );
84  }