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.transformer;
020
021/**
022 * A collection of keys used by the dependency graph transformers when exchanging information via the graph
023 * transformation context.
024 *
025 * @see org.eclipse.aether.collection.DependencyGraphTransformationContext#get(Object)
026 */
027public final class TransformationContextKeys {
028
029    /**
030     * The key in the graph transformation context where a {@code Map<DependencyNode, Object>} is stored which maps
031     * dependency nodes to their conflict ids. All nodes that map to an equal conflict id belong to the same group of
032     * conflicting dependencies. Note that the map keys use reference equality.
033     *
034     * @see ConflictMarker
035     */
036    public static final Object CONFLICT_IDS = "conflictIds";
037
038    /**
039     * The key in the graph transformation context where a {@code List<Object>} is stored that denotes a topological
040     * sorting of the conflict ids.
041     *
042     * @see ConflictIdSorter
043     */
044    public static final Object SORTED_CONFLICT_IDS = "sortedConflictIds";
045
046    /**
047     * The key in the graph transformation context where a {@code Collection<Collection<Object>>} is stored that denotes
048     * cycles among conflict ids. Each element in the outer collection denotes one cycle, i.e. if the collection is
049     * empty, the conflict ids have no cyclic dependencies.
050     *
051     * @see ConflictIdSorter
052     */
053    public static final Object CYCLIC_CONFLICT_IDS = "cyclicConflictIds";
054
055    /**
056     * The key in the graph transformation context where a {@code Map<String, Object>} is stored that can be used to
057     * include some runtime/performance stats in the debug log. If this map is not present, no stats should be recorded.
058     */
059    public static final Object STATS = "stats";
060
061    private TransformationContextKeys() {
062        // hide constructor
063    }
064}