001package org.apache.maven.plugin;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.List;
023
024import org.apache.maven.project.ExtensionDescriptor;
025import org.apache.maven.project.MavenProject;
026import org.codehaus.plexus.classworlds.realm.ClassRealm;
027import org.eclipse.aether.artifact.Artifact;
028
029/**
030 * Caches extension class realms. <strong>Warning:</strong> This is an internal utility interface that is only public
031 * for technical reasons, it is not part of the public API. In particular, this interface can be changed or deleted
032 * without prior notice.
033 * 
034 * @author Igor Fedorenko
035 * @author Benjamin Bentmann
036 */
037public interface ExtensionRealmCache
038{
039    /**
040     * A cache key.
041     */
042    interface Key
043    {
044        // marker interface for cache keys
045    }
046
047    static class CacheRecord
048    {
049
050        public final ClassRealm realm;
051
052        public final ExtensionDescriptor desciptor;
053
054        public CacheRecord( ClassRealm realm, ExtensionDescriptor descriptor )
055        {
056            this.realm = realm;
057            this.desciptor = descriptor;
058        }
059
060    }
061
062    Key createKey( List<? extends Artifact> extensionArtifacts );
063
064    CacheRecord get( Key key );
065
066    CacheRecord put( Key key, ClassRealm extensionRealm, ExtensionDescriptor extensionDescriptor );
067
068    void flush();
069
070    /**
071     * Registers the specified cache record for usage with the given project. Integrators can use the information
072     * collected from this method in combination with a custom cache implementation to dispose unused records from the
073     * cache.
074     * 
075     * @param project The project that employs the plugin realm, must not be {@code null}.
076     * @param record The cache record being used for the project, must not be {@code null}.
077     */
078    void register( MavenProject project, Key key, CacheRecord record );
079
080}