001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.eclipse.aether.internal.impl.filter;
020
021import javax.inject.Inject;
022import javax.inject.Named;
023import javax.inject.Singleton;
024
025import java.util.Collections;
026import java.util.HashMap;
027import java.util.Map;
028import java.util.stream.Collectors;
029
030import org.eclipse.aether.Keys;
031import org.eclipse.aether.RepositorySystemSession;
032import org.eclipse.aether.artifact.Artifact;
033import org.eclipse.aether.impl.RemoteRepositoryFilterManager;
034import org.eclipse.aether.metadata.Metadata;
035import org.eclipse.aether.repository.RemoteRepository;
036import org.eclipse.aether.spi.connector.filter.RemoteRepositoryFilter;
037import org.eclipse.aether.spi.connector.filter.RemoteRepositoryFilterSource;
038
039import static java.util.Objects.requireNonNull;
040
041/**
042 * Default implementation of {@link RemoteRepositoryFilterManager}, it always returns a {@link RemoteRepositoryFilter}
043 * instance, even if no filter sources enabled/registered (then "always allow" instance).
044 * <p>
045 * The created {@link RemoteRepositoryFilter} instance is created once per session and cached.
046 *
047 * @since 1.9.0
048 */
049@Singleton
050@Named
051public final class DefaultRemoteRepositoryFilterManager implements RemoteRepositoryFilterManager {
052    private final Map<String, RemoteRepositoryFilterSource> sources;
053
054    @Inject
055    public DefaultRemoteRepositoryFilterManager(Map<String, RemoteRepositoryFilterSource> sources) {
056        this.sources = requireNonNull(sources);
057    }
058
059    @Override
060    public RemoteRepositoryFilter getRemoteRepositoryFilter(RepositorySystemSession session) {
061        // use session specific key to distinguish between "derived" sessions
062        Object sessionDiscriminator;
063        if (session instanceof RepositorySystemSession.CloseableSession) {
064            sessionDiscriminator = ((RepositorySystemSession.CloseableSession) session).sessionId();
065        } else {
066            sessionDiscriminator = System.identityHashCode(session);
067        }
068        return (RemoteRepositoryFilter) session.getData()
069                .computeIfAbsent(Keys.of(DefaultRemoteRepositoryFilterManager.class, sessionDiscriminator), () -> {
070                    HashMap<String, RemoteRepositoryFilter> filters = new HashMap<>();
071                    for (Map.Entry<String, RemoteRepositoryFilterSource> entry : sources.entrySet()) {
072                        RemoteRepositoryFilter filter = entry.getValue().getRemoteRepositoryFilter(session);
073                        if (filter != null) {
074                            filters.put(entry.getKey(), filter);
075                        }
076                    }
077                    if (!filters.isEmpty()) {
078                        return new Participants(filters);
079                    } else {
080                        return null;
081                    }
082                });
083    }
084
085    /**
086     * {@link RemoteRepositoryFilter} instance when there are participant filters present. It evaluates into result
087     * using {@link Consensus}.
088     */
089    private static class Participants implements RemoteRepositoryFilter {
090        private final Map<String, RemoteRepositoryFilter> participants;
091
092        private Participants(Map<String, RemoteRepositoryFilter> participants) {
093            this.participants = Collections.unmodifiableMap(participants);
094        }
095
096        @Override
097        public RemoteRepositoryFilter.Result acceptArtifact(RemoteRepository remoteRepository, Artifact artifact) {
098            return new Consensus(participants.entrySet().stream()
099                    .collect(Collectors.toMap(
100                            Map.Entry::getKey, e -> e.getValue().acceptArtifact(remoteRepository, artifact))));
101        }
102
103        @Override
104        public RemoteRepositoryFilter.Result acceptMetadata(RemoteRepository remoteRepository, Metadata metadata) {
105            return new Consensus(participants.entrySet().stream()
106                    .collect(Collectors.toMap(
107                            Map.Entry::getKey, e -> e.getValue().acceptMetadata(remoteRepository, metadata))));
108        }
109    }
110
111    /**
112     * {@link RemoteRepositoryFilter.Result} based on "consensus". All participant have to "accept" to make this
113     * instance "accept".
114     */
115    private static class Consensus implements RemoteRepositoryFilter.Result {
116        private final boolean accepted;
117
118        private final String reasoning;
119
120        Consensus(Map<String, RemoteRepositoryFilter.Result> results) {
121            this.accepted = results.values().stream().allMatch(RemoteRepositoryFilter.Result::isAccepted);
122            this.reasoning = results.values().stream()
123                    .filter(r -> !r.isAccepted())
124                    .map(RemoteRepositoryFilter.Result::reasoning)
125                    .collect(Collectors.joining("; "));
126        }
127
128        @Override
129        public boolean isAccepted() {
130            return accepted;
131        }
132
133        @Override
134        public String reasoning() {
135            return reasoning;
136        }
137    }
138}