1 package org.eclipse.aether.collection;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import org.eclipse.aether.graph.Dependency;
23
24 /**
25 * Applies dependency management to the dependencies of a dependency node.
26 * <p>
27 * <strong>Note:</strong> Implementations must be stateless.
28 * <p>
29 * <em>Warning:</em> This hook is called from a hot spot and therefore implementations should pay attention to
30 * performance. Among others, implementations should provide a semantic {@link Object#equals(Object) equals()} method.
31 *
32 * @see org.eclipse.aether.RepositorySystemSession#getDependencyManager()
33 * @see org.eclipse.aether.RepositorySystem#collectDependencies(org.eclipse.aether.RepositorySystemSession,
34 * CollectRequest)
35 */
36 public interface DependencyManager
37 {
38
39 /**
40 * Applies dependency management to the specified dependency.
41 *
42 * @param dependency The dependency to manage, must not be {@code null}.
43 * @return The management update to apply to the dependency or {@code null} if the dependency is not managed at all.
44 */
45 DependencyManagement manageDependency( Dependency dependency );
46
47 /**
48 * Derives a dependency manager for the specified collection context. When calculating the child manager,
49 * implementors are strongly advised to simply return the current instance if nothing changed to help save memory.
50 *
51 * @param context The dependency collection context, must not be {@code null}.
52 * @return The dependency manager for the dependencies of the target node or {@code null} if dependency management
53 * should no longer be applied.
54 */
55 DependencyManager deriveChildManager( DependencyCollectionContext context );
56
57 }