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.util.graph.version;
020
021import org.eclipse.aether.RepositorySystemSession;
022import org.eclipse.aether.artifact.Artifact;
023import org.eclipse.aether.collection.DependencyCollectionContext;
024import org.eclipse.aether.collection.VersionFilter;
025import org.eclipse.aether.util.ConfigUtils;
026
027/**
028 * A version filter that blocks "*-SNAPSHOT" versions if the
029 * {@link org.eclipse.aether.collection.CollectRequest#getRootArtifact() root artifact} of the dependency graph is not a
030 * snapshot. Alternatively, this filter can be forced to always ban snapshot versions by setting the boolean
031 * {@link RepositorySystemSession#getConfigProperties() configuration property} {@link #CONFIG_PROP_ENABLE} to
032 * {@code true}.
033 */
034public final class ContextualSnapshotVersionFilter implements VersionFilter {
035
036    /**
037     * The key in the repository session's {@link RepositorySystemSession#getConfigProperties() configuration
038     * properties} used to store a {@link Boolean} flag whether this filter should be forced to ban snapshots. By
039     * default, snapshots are only filtered if the root artifact is not a snapshot.
040     */
041    public static final String CONFIG_PROP_ENABLE = "aether.snapshotFilter";
042
043    private final SnapshotVersionFilter filter;
044
045    /**
046     * Creates a new instance of this version filter.
047     */
048    public ContextualSnapshotVersionFilter() {
049        filter = new SnapshotVersionFilter();
050    }
051
052    private boolean isEnabled(RepositorySystemSession session) {
053        return ConfigUtils.getBoolean(session, false, CONFIG_PROP_ENABLE);
054    }
055
056    public void filterVersions(VersionFilterContext context) {
057        if (isEnabled(context.getSession())) {
058            filter.filterVersions(context);
059        }
060    }
061
062    public VersionFilter deriveChildFilter(DependencyCollectionContext context) {
063        if (!isEnabled(context.getSession())) {
064            Artifact artifact = context.getArtifact();
065            if (artifact == null) {
066                // no root artifact to test, allow snapshots and recheck once we reach the direct dependencies
067                return this;
068            }
069            if (artifact.isSnapshot()) {
070                // root is a snapshot, allow snapshots all the way down
071                return null;
072            }
073        }
074        // artifact is a non-snapshot or filter explicitly enabled, block snapshots all the way down
075        return filter;
076    }
077
078    @Override
079    public boolean equals(Object obj) {
080        if (this == obj) {
081            return true;
082        } else if (null == obj || !getClass().equals(obj.getClass())) {
083            return false;
084        }
085        return true;
086    }
087
088    @Override
089    public int hashCode() {
090        return getClass().hashCode();
091    }
092}