1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27 package org.apache.http.impl.client.cache.memcached;
28
29 import org.apache.http.client.cache.HttpCacheEntry;
30
31 /**
32 * Provides for serialization and deserialization of higher-level
33 * {@link HttpCacheEntry} objects into byte arrays suitable for
34 * storage in memcached. Clients wishing to change the serialization
35 * mechanism from the provided defaults should implement this
36 * interface as well as {@link MemcachedCacheEntryFactory}.
37 */
38 public interface MemcachedCacheEntry {
39
40 /**
41 * Returns a serialized representation of the current cache entry.
42 */
43 byte[] toByteArray();
44
45 /**
46 * Returns the storage key associated with this entry. May return
47 * {@code null} if this is an "unset" instance waiting to be
48 * {@link #set(byte[])} with a serialized representation.
49 */
50 String getStorageKey();
51
52 /**
53 * Returns the {@link HttpCacheEntry} associated with this entry.
54 * May return {@code null} if this is an "unset" instance
55 * waiting to be {@link #set(byte[])} with a serialized
56 * representation.
57 */
58 HttpCacheEntry getHttpCacheEntry();
59
60 /**
61 * Given a serialized representation of a {@link MemcachedCacheEntry},
62 * attempt to reconstitute the storage key and {@link HttpCacheEntry}
63 * represented therein. After a successful call to this method, this
64 * object should return updated (as appropriate) values for
65 * {@link #getStorageKey()} and {@link #getHttpCacheEntry()}. This
66 * should be viewed as an atomic operation on the
67 * {@code MemcachedCacheEntry}.
68 *
69 * @param bytes serialized representation
70 * @throws MemcachedSerializationException if deserialization
71 * fails. In this case, the prior values for {{@link #getStorageKey()}
72 * and {@link #getHttpCacheEntry()} should remain unchanged.
73 */
74 void set(byte[] bytes);
75
76 }