001package org.apache.maven.execution;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.List;
023
024import org.apache.maven.project.MavenProject;
025
026/**
027 * Describes the inter-dependencies between projects in the reactor.
028 * 
029 * @author Benjamin Bentmann
030 */
031public interface ProjectDependencyGraph
032{
033
034    /**
035     * Gets all projects in their intended build order, i.e. after topologically sorting the projects according to their
036     * inter-dependencies.
037     * 
038     * @return The projects in the build order, never {@code null}.
039     */
040    List<MavenProject> getSortedProjects();
041
042    /**
043     * Gets the downstream projects of the specified project. A downstream project is a project that directly or
044     * indirectly depends on the given project.
045     * 
046     * @param project The project whose downstream projects should be retrieved, must not be {@code null}.
047     * @param transitive A flag whether to retrieve all direct and indirect downstream projects or just the immediate
048     *            downstream projects.
049     * @return The downstream projects in the build order, never {@code null}.
050     */
051    List<MavenProject> getDownstreamProjects( MavenProject project, boolean transitive );
052
053    /**
054     * Gets the upstream projects of the specified project. An upstream project is a project that directly or indirectly
055     * is a prerequisite of the given project.
056     * 
057     * @param project The project whose upstream projects should be retrieved, must not be {@code null}.
058     * @param transitive A flag whether to retrieve all direct and indirect upstream projects or just the immediate
059     *            upstream projects.
060     * @return The upstream projects in the build order, never {@code null}.
061     */
062    List<MavenProject> getUpstreamProjects( MavenProject project, boolean transitive );
063
064}