001package org.eclipse.aether.internal.impl.synccontext.named;
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 org.eclipse.aether.RepositorySystemSession;
023import org.eclipse.aether.artifact.Artifact;
024import org.eclipse.aether.metadata.Metadata;
025import org.eclipse.aether.util.ChecksumUtils;
026import org.eclipse.aether.util.ConfigUtils;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030import javax.inject.Inject;
031import javax.inject.Named;
032import javax.inject.Singleton;
033import java.io.File;
034import java.net.InetAddress;
035import java.net.UnknownHostException;
036import java.nio.charset.StandardCharsets;
037import java.util.Collection;
038import java.util.Collections;
039import java.util.Map;
040import java.util.Objects;
041
042import static java.util.stream.Collectors.toList;
043
044/**
045 * Discriminating {@link NameMapper}, that wraps another {@link NameMapper} and adds a "discriminator" as prefix, that
046 * makes lock names unique including the hostname and local repository (by default). The discriminator may be passed
047 * in via {@link RepositorySystemSession} or is automatically calculated based on the local hostname and repository
048 * path. The implementation retains order of collection elements as it got it from
049 * {@link NameMapper#nameLocks(RepositorySystemSession, Collection, Collection)} method.
050 * <p>
051 * The default setup wraps {@link GAVNameMapper}, but manually may be created any instance needed.
052 */
053@Singleton
054@Named( DiscriminatingNameMapper.NAME )
055public class DiscriminatingNameMapper implements NameMapper
056{
057    public static final String NAME = "discriminating";
058
059    /**
060     * Configuration property to pass in discriminator
061     */
062    private static final String CONFIG_PROP_DISCRIMINATOR = "aether.syncContext.named.discriminating.discriminator";
063
064    /**
065     * Configuration property to pass in hostname
066     */
067    private static final String CONFIG_PROP_HOSTNAME = "aether.syncContext.named.discriminating.hostname";
068
069    private static final String DEFAULT_DISCRIMINATOR_DIGEST = "da39a3ee5e6b4b0d3255bfef95601890afd80709";
070
071    private static final String DEFAULT_HOSTNAME = "localhost";
072
073    private static final Logger LOGGER = LoggerFactory.getLogger( DiscriminatingNameMapper.class );
074
075    private final NameMapper nameMapper;
076
077    private final String hostname;
078
079    @Inject
080    public DiscriminatingNameMapper( @Named( GAVNameMapper.NAME ) final NameMapper nameMapper )
081    {
082        this.nameMapper = Objects.requireNonNull( nameMapper );
083        this.hostname = getHostname();
084    }
085
086    @Override
087    public Collection<String> nameLocks( final RepositorySystemSession session,
088                                         final Collection<? extends Artifact> artifacts,
089                                         final Collection<? extends Metadata> metadatas )
090    {
091        String discriminator = createDiscriminator( session );
092        return nameMapper.nameLocks( session, artifacts, metadatas ).stream().map( s -> discriminator + ":" + s )
093                         .collect( toList() );
094    }
095
096    private String getHostname()
097    {
098        try
099        {
100            return InetAddress.getLocalHost().getHostName();
101        }
102        catch ( UnknownHostException e )
103        {
104            LOGGER.warn( "Failed to get hostname, using '{}'", DEFAULT_HOSTNAME, e );
105            return DEFAULT_HOSTNAME;
106        }
107    }
108
109    private String createDiscriminator( final RepositorySystemSession session )
110    {
111        String discriminator = ConfigUtils.getString( session, null, CONFIG_PROP_DISCRIMINATOR );
112
113        if ( discriminator == null || discriminator.isEmpty() )
114        {
115            String hostname = ConfigUtils.getString( session, this.hostname, CONFIG_PROP_HOSTNAME );
116            File basedir = session.getLocalRepository().getBasedir();
117            discriminator = hostname + ":" + basedir;
118            try
119            {
120                Map<String, Object> checksums = ChecksumUtils
121                        .calc( discriminator.getBytes( StandardCharsets.UTF_8 ), Collections.singletonList( "SHA-1" ) );
122                Object checksum = checksums.get( "SHA-1" );
123
124                if ( checksum instanceof Exception )
125                {
126                    throw (Exception) checksum;
127                }
128
129                return String.valueOf( checksum );
130            }
131            catch ( Exception e )
132            {
133                LOGGER.warn( "Failed to calculate discriminator digest, using '{}'", DEFAULT_DISCRIMINATOR_DIGEST, e );
134                return DEFAULT_DISCRIMINATOR_DIGEST;
135            }
136        }
137        return discriminator;
138    }
139}