1 /*******************************************************************************
2 * Copyright (c) 2010, 2014 Sonatype, Inc.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Eclipse Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html
7 *
8 * Contributors:
9 * Sonatype, Inc. - initial API and implementation
10 *******************************************************************************/
11 package org.eclipse.aether;
12
13 /**
14 * Caches auxiliary data used during repository access like already processed metadata. The data in the cache is meant
15 * for exclusive consumption by the repository system and is opaque to the cache implementation. <strong>Note:</strong>
16 * Actual cache implementations must be thread-safe.
17 *
18 * @see RepositorySystemSession#getCache()
19 */
20 public interface RepositoryCache
21 {
22
23 /**
24 * Puts the specified data into the cache. It is entirely up to the cache implementation how long this data will be
25 * kept before being purged, i.e. callers must not make any assumptions about the lifetime of cached data.
26 * <p>
27 * <em>Warning:</em> The cache will directly save the provided reference. If the cached data is mutable, i.e. could
28 * be modified after being put into the cache, the caller is responsible for creating a copy of the original data
29 * and store the copy in the cache.
30 *
31 * @param session The repository session during which the cache is accessed, must not be {@code null}.
32 * @param key The key to use for lookup of the data, must not be {@code null}.
33 * @param data The data to store in the cache, may be {@code null}.
34 */
35 void put( RepositorySystemSession session, Object key, Object data );
36
37 /**
38 * Gets the specified data from the cache.
39 * <p>
40 * <em>Warning:</em> The cache will directly return the saved reference. If the cached data is to be modified after
41 * its retrieval, the caller is responsible to create a copy of the returned data and use this instead of the cache
42 * record.
43 *
44 * @param session The repository session during which the cache is accessed, must not be {@code null}.
45 * @param key The key to use for lookup of the data, must not be {@code null}.
46 * @return The requested data or {@code null} if none was present in the cache.
47 */
48 Object get( RepositorySystemSession session, Object key );
49
50 }