| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.eclipse.aether.util.graph.visitor; |
| |
| import java.util.function.Consumer; |
| |
| import org.eclipse.aether.ConfigurationProperties; |
| import org.eclipse.aether.graph.DependencyNode; |
| |
| /** |
| * Processes dependency graph by traversing the graph in postorder. This visitor visits each node exactly once |
| * regardless how many paths within the dependency graph lead to the node such that the resulting node sequence is |
| * free of duplicates. |
| * |
| * @since 2.0.0 |
| * |
| * @see NodeListGenerator |
| */ |
| public final class PostorderDependencyNodeConsumerVisitor extends AbstractDependencyNodeConsumerVisitor { |
| |
| public static final String NAME = ConfigurationProperties.REPOSITORY_SYSTEM_DEPENDENCY_VISITOR_POSTORDER; |
| |
| private final Stack<Boolean> visits; |
| |
| /** |
| * Creates a new postorder list generator. |
| */ |
| public PostorderDependencyNodeConsumerVisitor(Consumer<DependencyNode> nodeConsumer) { |
| super(nodeConsumer); |
| visits = new Stack<>(); |
| } |
| |
| @Override |
| public boolean visitEnter(DependencyNode node) { |
| boolean visited = !setVisited(node); |
| visits.push(visited); |
| return !visited; |
| } |
| |
| @Override |
| public boolean visitLeave(DependencyNode node) { |
| Boolean visited = visits.pop(); |
| if (visited) { |
| return true; |
| } |
| nodeConsumer.accept(node); |
| return true; |
| } |
| } |