1 package org.apache.commons.jcs.access.behavior;
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 org.apache.commons.jcs.access.exception.CacheException;
23 import org.apache.commons.jcs.engine.behavior.ICompositeCacheAttributes;
24 import org.apache.commons.jcs.engine.behavior.IElementAttributes;
25 import org.apache.commons.jcs.engine.stats.behavior.ICacheStats;
26
27 /**
28 * ICacheAccessManagement defines the methods for cache management, cleanup and shutdown.
29 */
30 public interface ICacheAccessManagement
31 {
32 /**
33 * Dispose this region. Flushes objects to and closes auxiliary caches. This is a shutdown
34 * command!
35 * <p>
36 * To simply remove all elements from the region use clear().
37 */
38 void dispose();
39
40 /**
41 * Removes all of the elements from a region.
42 * <p>
43 * @throws CacheException
44 */
45 void clear() throws CacheException;
46
47 /**
48 * GetElementAttributes will return an attribute object describing the current attributes
49 * associated with the object name. If no name parameter is available, the attributes for the
50 * region will be returned. The name object must override the Object.equals and Object.hashCode
51 * methods.
52 * <p>
53 * @return The elementAttributes value
54 * @throws CacheException
55 */
56 IElementAttributes getDefaultElementAttributes()
57 throws CacheException;
58
59 /**
60 * This method is does not reset the attributes for items already in the cache. It could
61 * potentially do this for items in memory, and maybe on disk (which would be slow) but not
62 * remote items. Rather than have unpredictable behavior, this method just sets the default
63 * attributes. Items subsequently put into the cache will use these defaults if they do not
64 * specify specific attributes.
65 * <p>
66 * @param attr the default attributes.
67 * @throws CacheException if something goes wrong.
68 */
69 void setDefaultElementAttributes( IElementAttributes attr ) throws CacheException;
70
71 /**
72 * Gets the ICompositeCacheAttributes of the cache region
73 * <p>
74 * @return ICompositeCacheAttributes
75 */
76 ICompositeCacheAttributes getCacheAttributes();
77
78 /**
79 * Sets the ICompositeCacheAttributes of the cache region
80 * <p>
81 * @param cattr The new ICompositeCacheAttribute value
82 */
83 void setCacheAttributes( ICompositeCacheAttributes cattr );
84
85 /**
86 * This instructs the memory cache to remove the <i>numberToFree</i> according to its eviction
87 * policy. For example, the LRUMemoryCache will remove the <i>numberToFree</i> least recently
88 * used items. These will be spooled to disk if a disk auxiliary is available.
89 * <p>
90 * @param numberToFree
91 * @return the number that were removed. if you ask to free 5, but there are only 3, you will
92 * get 3.
93 * @throws CacheException
94 */
95 int freeMemoryElements( int numberToFree )
96 throws CacheException;
97
98 /**
99 * This returns the ICacheStats object with information on this region and its auxiliaries.
100 * <p>
101 * This data can be formatted as needed.
102 * <p>
103 * @return ICacheStats
104 */
105 ICacheStats getStatistics();
106
107 /**
108 * @return A String version of the stats.
109 */
110 String getStats();
111 }