| /* |
| * 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.IdentityHashMap; |
| import java.util.Map; |
| |
| import org.eclipse.aether.graph.DefaultDependencyNode; |
| import org.eclipse.aether.graph.DependencyNode; |
| import org.eclipse.aether.graph.DependencyVisitor; |
| |
| /** |
| * A dependency visitor that constructs a clone of the visited dependency graph. If such a visitor is passed into a |
| * {@link FilteringDependencyVisitor}, a sub graph can be created. This class creates shallow clones of the visited |
| * dependency nodes (via {@link DefaultDependencyNode#DefaultDependencyNode(DependencyNode)}) but clients can create a |
| * subclass and override {@link #clone(DependencyNode)} to alter the clone process. |
| */ |
| public class CloningDependencyVisitor |
| implements DependencyVisitor |
| { |
| |
| private final Map<DependencyNode, DependencyNode> clones; |
| |
| private final Stack<DependencyNode> parents; |
| |
| private DependencyNode root; |
| |
| /** |
| * Creates a new visitor that clones the visited nodes. |
| */ |
| public CloningDependencyVisitor() |
| { |
| parents = new Stack<DependencyNode>(); |
| clones = new IdentityHashMap<DependencyNode, DependencyNode>( 256 ); |
| } |
| |
| /** |
| * Gets the root node of the cloned dependency graph. |
| * |
| * @return The root node of the cloned dependency graph or {@code null}. |
| */ |
| public final DependencyNode getRootNode() |
| { |
| return root; |
| } |
| |
| /** |
| * Creates a clone of the specified node. |
| * |
| * @param node The node to clone, must not be {@code null}. |
| * @return The cloned node, never {@code null}. |
| */ |
| protected DependencyNode clone( DependencyNode node ) |
| { |
| DefaultDependencyNode clone = new DefaultDependencyNode( node ); |
| return clone; |
| } |
| |
| public final boolean visitEnter( DependencyNode node ) |
| { |
| boolean recurse = true; |
| |
| DependencyNode clone = clones.get( node ); |
| if ( clone == null ) |
| { |
| clone = clone( node ); |
| clones.put( node, clone ); |
| } |
| else |
| { |
| recurse = false; |
| } |
| |
| DependencyNode parent = parents.peek(); |
| |
| if ( parent == null ) |
| { |
| root = clone; |
| } |
| else |
| { |
| parent.getChildren().add( clone ); |
| } |
| |
| parents.push( clone ); |
| |
| return recurse; |
| } |
| |
| public final boolean visitLeave( DependencyNode node ) |
| { |
| parents.pop(); |
| |
| return true; |
| } |
| |
| } |