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.io.File;
023import java.util.ArrayList;
024import java.util.HashMap;
025import java.util.List;
026import java.util.Map;
027
028import org.apache.maven.project.ExtensionDescriptor;
029import org.apache.maven.project.MavenProject;
030import org.codehaus.plexus.classworlds.realm.ClassRealm;
031import org.codehaus.plexus.component.annotations.Component;
032import org.eclipse.aether.artifact.Artifact;
033
034/**
035 * Default extension realm cache implementation. Assumes cached data does not change.
036 */
037@Component( role = ExtensionRealmCache.class )
038public class DefaultExtensionRealmCache
039    implements ExtensionRealmCache
040{
041
042    private static class CacheKey
043    {
044
045        private final List<File> files;
046
047        private final List<Long> timestamps;
048
049        private final List<Long> sizes;
050
051        private final List<String> ids;
052
053        private final int hashCode;
054
055        public CacheKey( List<? extends Artifact> extensionArtifacts )
056        {
057            this.files = new ArrayList<File>( extensionArtifacts.size() );
058            this.timestamps = new ArrayList<Long>( extensionArtifacts.size() );
059            this.sizes = new ArrayList<Long>( extensionArtifacts.size() );
060            this.ids = new ArrayList<String>( extensionArtifacts.size() );
061
062            for ( Artifact artifact : extensionArtifacts )
063            {
064                File file = artifact.getFile();
065                files.add( file );
066                timestamps.add( ( file != null ) ? Long.valueOf( file.lastModified() ) : Long.valueOf( 0 ) );
067                sizes.add( ( file != null ) ? Long.valueOf( file.length() ) : Long.valueOf( 0 ) );
068                ids.add( artifact.getVersion() );
069            }
070
071            this.hashCode =
072                31 * files.hashCode() + 31 * ids.hashCode() + 31 * timestamps.hashCode() + 31 * sizes.hashCode();
073        }
074
075        @Override
076        public int hashCode()
077        {
078            return hashCode;
079        }
080
081        @Override
082        public boolean equals( Object o )
083        {
084            if ( o == this )
085            {
086                return true;
087            }
088
089            if ( !( o instanceof CacheKey ) )
090            {
091                return false;
092            }
093
094            CacheKey other = (CacheKey) o;
095
096            return ids.equals( other.ids ) && files.equals( other.files ) && timestamps.equals( other.timestamps )
097                && sizes.equals( other.sizes );
098        }
099
100    }
101
102    private final Map<CacheKey, CacheRecord> cache = new HashMap<CacheKey, CacheRecord>();
103
104    public CacheRecord get( List<? extends Artifact> extensionArtifacts )
105    {
106        return cache.get( new CacheKey( extensionArtifacts ) );
107    }
108
109    public CacheRecord put( List<? extends Artifact> extensionArtifacts, ClassRealm extensionRealm,
110                            ExtensionDescriptor extensionDescriptor )
111    {
112        if ( extensionRealm == null )
113        {
114            throw new NullPointerException();
115        }
116
117        CacheKey key = new CacheKey( extensionArtifacts );
118
119        if ( cache.containsKey( key ) )
120        {
121            throw new IllegalStateException( "Duplicate extension realm for extension " + extensionArtifacts );
122        }
123
124        CacheRecord record = new CacheRecord( extensionRealm, extensionDescriptor );
125
126        cache.put( key, record );
127
128        return record;
129    }
130
131    public void flush()
132    {
133        cache.clear();
134    }
135
136    public void register( MavenProject project, CacheRecord record )
137    {
138        // default cache does not track extension usage
139    }
140
141}