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;
28
29 import java.io.IOException;
30
31 import org.apache.http.annotation.Contract;
32 import org.apache.http.annotation.ThreadingBehavior;
33 import org.apache.http.client.cache.HttpCacheEntry;
34 import org.apache.http.client.cache.HttpCacheStorage;
35 import org.apache.http.client.cache.HttpCacheUpdateCallback;
36
37 /**
38 * Basic {@link HttpCacheStorage} implementation backed by an instance of
39 * {@link java.util.LinkedHashMap}. In other words, cache entries and
40 * the cached response bodies are held in-memory. This cache does NOT
41 * deallocate resources associated with the cache entries; it is intended
42 * for use with {@link HeapResource} and similar. This is the default cache
43 * storage backend used by {@link CachingHttpClients}.
44 *
45 * @since 4.1
46 */
47 @Contract(threading = ThreadingBehavior.SAFE)
48 public class BasicHttpCacheStorage implements HttpCacheStorage {
49
50 private final CacheMap entries;
51
52 public BasicHttpCacheStorage(final CacheConfig config) {
53 super();
54 this.entries = new CacheMap(config.getMaxCacheEntries());
55 }
56
57 /**
58 * Places a HttpCacheEntry in the cache
59 *
60 * @param url
61 * Url to use as the cache key
62 * @param entry
63 * HttpCacheEntry to place in the cache
64 */
65 @Override
66 public synchronized void putEntry(final String url, final HttpCacheEntry entry) throws IOException {
67 entries.put(url, entry);
68 }
69
70 /**
71 * Gets an entry from the cache, if it exists
72 *
73 * @param url
74 * Url that is the cache key
75 * @return HttpCacheEntry if one exists, or null for cache miss
76 */
77 @Override
78 public synchronized HttpCacheEntry getEntry(final String url) throws IOException {
79 return entries.get(url);
80 }
81
82 /**
83 * Removes a HttpCacheEntry from the cache
84 *
85 * @param url
86 * Url that is the cache key
87 */
88 @Override
89 public synchronized void removeEntry(final String url) throws IOException {
90 entries.remove(url);
91 }
92
93 @Override
94 public synchronized void updateEntry(
95 final String url,
96 final HttpCacheUpdateCallback callback) throws IOException {
97 final HttpCacheEntry existingEntry = entries.get(url);
98 entries.put(url, callback.update(existingEntry));
99 }
100
101 }