1 package org.eclipse.aether;
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 /**
23 * Caches auxiliary data used during repository access like already processed metadata. The data in the cache is meant
24 * for exclusive consumption by the repository system and is opaque to the cache implementation. <strong>Note:</strong>
25 * Actual cache implementations must be thread-safe.
26 *
27 * @see RepositorySystemSession#getCache()
28 */
29 public interface RepositoryCache
30 {
31
32 /**
33 * Puts the specified data into the cache. It is entirely up to the cache implementation how long this data will be
34 * kept before being purged, i.e. callers must not make any assumptions about the lifetime of cached data.
35 * <p>
36 * <em>Warning:</em> The cache will directly save the provided reference. If the cached data is mutable, i.e. could
37 * be modified after being put into the cache, the caller is responsible for creating a copy of the original data
38 * and store the copy in the cache.
39 *
40 * @param session The repository session during which the cache is accessed, must not be {@code null}.
41 * @param key The key to use for lookup of the data, must not be {@code null}.
42 * @param data The data to store in the cache, may be {@code null}.
43 */
44 void put( RepositorySystemSession session, Object key, Object data );
45
46 /**
47 * Gets the specified data from the cache.
48 * <p>
49 * <em>Warning:</em> The cache will directly return the saved reference. If the cached data is to be modified after
50 * its retrieval, the caller is responsible to create a copy of the returned data and use this instead of the cache
51 * record.
52 *
53 * @param session The repository session during which the cache is accessed, must not be {@code null}.
54 * @param key The key to use for lookup of the data, must not be {@code null}.
55 * @return The requested data or {@code null} if none was present in the cache.
56 */
57 Object get( RepositorySystemSession session, Object key );
58
59 }