org.argeo.slc.repo/src/org/eclipse/aether/RepositoryCache.java

   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 }