1 package org.sonatype.aether.collection;
2
3 /*******************************************************************************
4 * Copyright (c) 2010-2011 Sonatype, Inc.
5 * All rights reserved. This program and the accompanying materials
6 * are made available under the terms of the Eclipse Public License v1.0
7 * which accompanies this distribution, and is available at
8 * http://www.eclipse.org/legal/epl-v10.html
9 *******************************************************************************/
10
11 import org.sonatype.aether.graph.Dependency;
12
13 /**
14 * Decides whether the dependencies of a dependency node should be traversed as well. <em>Note:</em> For the sake of
15 * good performance during dependency collection, implementations should provide a semantic
16 * {@link Object#equals(Object) equals()} method.
17 *
18 * @author Benjamin Bentmann
19 * @see org.sonatype.aether.RepositorySystemSession#getDependencyTraverser()
20 * @see org.sonatype.aether.RepositorySystem#collectDependencies(org.sonatype.aether.RepositorySystemSession,
21 * CollectRequest)
22 */
23 public interface DependencyTraverser
24 {
25
26 /**
27 * Decides whether the dependencies of the specified dependency should be traversed.
28 *
29 * @param dependency The dependency to check, must not be {@code null}.
30 * @return {@code true} if the dependency graph builder should recurse into the specified dependency and process its
31 * dependencies, {@code false} otherwise.
32 */
33 boolean traverseDependency( Dependency dependency );
34
35 /**
36 * Derives a dependency traverser that will be used to decide whether the transitive dependencies of the dependency
37 * given in the collection context shall be traversed. When calculating the child traverser, implementors are
38 * strongly advised to simply return the current instance if nothing changed to help save memory.
39 *
40 * @param context The dependency collection context, must not be {@code null}.
41 * @return The dependency traverser for the target node, must not be {@code null}.
42 */
43 DependencyTraverser deriveChildTraverser( DependencyCollectionContext context );
44
45 }