1 package org.sonatype.aether;
2
3 /*******************************************************************************
4 * Copyright (c) 2010-2011 Sonatype, Inc.
5 * All rights reserved. This program and the accompanying materials
6 * are made available under the terms of the Eclipse Public License v1.0
7 * which accompanies this distribution, and is available at
8 * http://www.eclipse.org/legal/epl-v10.html
9 *******************************************************************************/
10
11 /**
12 * Caches auxiliary data used during repository access like already processed metadata. The data in the cache is meant
13 * for exclusive consumption by the repository system and is opaque to the cache implementation. <strong>Note:</strong>
14 * Actual cache implementations must be thread-safe.
15 *
16 * @author Benjamin Bentmann
17 */
18 public interface RepositoryCache
19 {
20
21 /**
22 * Puts the specified data into the cache. It is entirely up to the cache implementation how long this data will be
23 * kept before being purged, i.e. callers must not make any assumptions about the lifetime of cached data.
24 * <strong>Warning:</strong> The cache will directly save the provided reference. If the cached data is mutable,
25 * i.e. could be modified after being put into the cache, the caller is responsible for creating a copy of the
26 * original data and store the copy in the cache.
27 *
28 * @param session The repository session during which the cache is accessed, must not be {@code null}.
29 * @param key The key to use for lookup the data with, must not be {@code null}.
30 * @param data The data to store in the cache, may be {@code null}.
31 */
32 void put( RepositorySystemSession session, Object key, Object data );
33
34 /**
35 * Gets the specified data from the cache. <strong>Warning:</strong> The cache will directly return the saved
36 * reference. If the cached data is to be modified after its retrieval, the caller is responsible to create a copy
37 * of the returned data and use this instead of the cache record.
38 *
39 * @param session The repository session during which the cache is accessed, must not be {@code null}.
40 * @param key The key to use for lookup of the data, must not be {@code null}.
41 * @return The requested data or {@code null} if none was present in the cache.
42 */
43 Object get( RepositorySystemSession session, Object key );
44
45 }