org.eclipse.aether.util.graph.visitor.CloningDependencyVisitor Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of spring-cloud-contract-shade Show documentation
Show all versions of spring-cloud-contract-shade Show documentation
Spring Cloud Contract Shaded Dependencies
/*******************************************************************************
* Copyright (c) 2010, 2013 Sonatype, Inc.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Sonatype, Inc. - initial API and implementation
*******************************************************************************/
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 clones;
private final Stack parents;
private DependencyNode root;
/**
* Creates a new visitor that clones the visited nodes.
*/
public CloningDependencyVisitor()
{
parents = new Stack();
clones = new IdentityHashMap( 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;
}
}