001package org.apache.maven.project;
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.Collections;
023import java.util.HashMap;
024import java.util.List;
025import java.util.Map;
026
027import org.codehaus.plexus.classworlds.realm.ClassRealm;
028import org.codehaus.plexus.component.annotations.Component;
029import org.eclipse.aether.graph.DependencyFilter;
030
031/**
032 * Default project realm cache implementation. Assumes cached data does not change.
033 */
034@Component( role = ProjectRealmCache.class )
035public class DefaultProjectRealmCache
036    implements ProjectRealmCache
037{
038
039    private static class CacheKey
040    {
041
042        private final List<? extends ClassRealm> extensionRealms;
043
044        private final int hashCode;
045
046        public CacheKey( List<? extends ClassRealm> extensionRealms )
047        {
048            this.extensionRealms = ( extensionRealms != null ) ? extensionRealms : Collections.<ClassRealm> emptyList();
049
050            this.hashCode = this.extensionRealms.hashCode();
051        }
052
053        @Override
054        public int hashCode()
055        {
056            return hashCode;
057        }
058
059        @Override
060        public boolean equals( Object o )
061        {
062            if ( o == this )
063            {
064                return true;
065            }
066
067            if ( !( o instanceof CacheKey ) )
068            {
069                return false;
070            }
071
072            CacheKey other = (CacheKey) o;
073
074            return extensionRealms.equals( other.extensionRealms );
075        }
076
077    }
078
079    private final Map<CacheKey, CacheRecord> cache = new HashMap<CacheKey, CacheRecord>();
080
081    public CacheRecord get( List<? extends ClassRealm> extensionRealms )
082    {
083        return cache.get( new CacheKey( extensionRealms ) );
084    }
085
086    public CacheRecord put( List<? extends ClassRealm> extensionRealms, ClassRealm projectRealm,
087                            DependencyFilter extensionArtifactFilter )
088    {
089        if ( projectRealm == null )
090        {
091            throw new NullPointerException();
092        }
093
094        CacheKey key = new CacheKey( extensionRealms );
095
096        if ( cache.containsKey( key ) )
097        {
098            throw new IllegalStateException( "Duplicate project realm for extensions " + extensionRealms );
099        }
100
101        CacheRecord record = new CacheRecord( projectRealm, extensionArtifactFilter );
102
103        cache.put( key, record );
104
105        return record;
106    }
107
108    public void flush()
109    {
110        cache.clear();
111    }
112
113    public void register( MavenProject project, CacheRecord record )
114    {
115        // default cache does not track record usage
116    }
117
118}