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 /*
28 * ====================================================================
29 * Licensed to the Apache Software Foundation (ASF) under one
30 * or more contributor license agreements. See the NOTICE file
31 * distributed with this work for additional information
32 * regarding copyright ownership. The ASF licenses this file
33 * to you under the Apache License, Version 2.0 (the
34 * "License"); you may not use this file except in compliance
35 * with the License. You may obtain a copy of the License at
36 *
37 * http://www.apache.org/licenses/LICENSE-2.0
38 *
39 * Unless required by applicable law or agreed to in writing,
40 * software distributed under the License is distributed on an
41 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
42 * KIND, either express or implied. See the License for the
43 * specific language governing permissions and limitations
44 * under the License.
45 * ====================================================================
46 *
47 * This software consists of voluntary contributions made by many
48 * individuals on behalf of the Apache Software Foundation. For more
49 * information on the Apache Software Foundation, please see
50 * <http://www.apache.org/>.
51 *
52 */package org.apache.hc.client5.http.impl.cache.memcached;
53
54 /**
55 * Since the {@link org.apache.hc.client5.http.cache.HttpCacheStorage} interface
56 * expects to use variant-annotated URLs for its storage keys, but Memcached
57 * has a maximum key size, we need to support mapping storage keys to cache
58 * keys. Clients can implement this interface to change the way the mapping
59 * is done (for example, to add a prefix to all cache keys to provide a form
60 * of memcached namespacing).
61 *
62 * @since 4.1
63 */
64 public interface KeyHashingScheme {
65
66 /** Maps a storage key to a cache key. The storage key is what
67 * the higher-level HTTP cache uses as a key; the cache key is what
68 * we use as a key for talking to memcached.
69 * @param storageKey what the higher-level HTTP cache wants to use
70 * as its key for looking up cache entries
71 * @return a cache key suitable for use with memcached
72 */
73 String hash(String storageKey);
74 }