/**
* Copyright (c) 2002-2011 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.kernel.impl.traversal;
import java.util.Collections;
import java.util.Iterator;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.Path;
import org.neo4j.graphdb.Relationship;
import org.neo4j.graphdb.RelationshipExpander;
import org.neo4j.graphdb.traversal.Evaluation;
import org.neo4j.graphdb.traversal.TraversalBranch;
import org.neo4j.kernel.impl.traversal.TraverserImpl.TraverserIterator;
class TraversalBranchImpl implements TraversalBranch//, Path
{
private final TraversalBranch parent;
private final Node source;
private Iterator<Relationship> relationships;
private final Relationship howIGotHere;
private final int depth;
final TraverserIterator traverser;
private Path path;
private int expandedCount;
private Evaluation evaluation;
/*
* For expansion sources for all nodes except the start node
*/
TraversalBranchImpl( TraverserIterator traverser, TraversalBranch parent, int depth,
Node source, RelationshipExpander expander, Relationship toHere )
{
this.traverser = traverser;
this.parent = parent;
this.source = source;
this.howIGotHere = toHere;
this.depth = depth;
}
@Override
public String toString()
{
return "TraversalBranch[source=" + source + ",howIGotHere=" + howIGotHere + ",depth=" + depth + "]";
}
/*
* For the start node expansion source
*/
TraversalBranchImpl( TraverserIterator traverser, Node source,
RelationshipExpander expander )
{
this.traverser = traverser;
this.parent = null;
this.source = source;
this.howIGotHere = null;
this.depth = 0;
this.evaluation = traverser.description.evaluator.evaluate( position() );
}
protected void expandRelationships( boolean doChecks )
{
boolean okToExpand = !doChecks || evaluation.continues();
relationships = okToExpand ?
traverser.description.expander.expand( source ).iterator() :
Collections.<Relationship>emptyList().iterator();
}
protected boolean hasExpandedRelationships()
{
return relationships != null;
}
public void initialize()
{
evaluation = traverser.description.evaluator.evaluate( position() );
expandRelationships( true );
}
public TraversalBranch next()
{
while ( relationships.hasNext() )
{
Relationship relationship = relationships.next();
if ( relationship.equals( howIGotHere ) )
{
continue;
}
expandedCount++;
Node node = relationship.getOtherNode( source );
TraversalBranch next = new TraversalBranchImpl( traverser, this, depth + 1, node,
traverser.description.expander, relationship );
if ( traverser.okToProceed( next ) )
{
next.initialize();
return next;
}
}
return null;
}
public Path position()
{
return ensurePathInstantiated();
}
private Path ensurePathInstantiated()
{
if ( this.path == null )
{
this.path = new TraversalPath( this );
}
return this.path;
}
public int depth()
{
return depth;
}
public Relationship relationship()
{
return howIGotHere;
}
public Node node()
{
return source;
}
public TraversalBranch parent()
{
return this.parent;
}
public int expanded()
{
return expandedCount;
}
public Evaluation evaluation()
{
return evaluation;
}
// public Node startNode()
// {
// return ensurePathInstantiated().startNode();
// }
//
// public Node endNode()
// {
// return source;
// }
//
// public Relationship lastRelationship()
// {
// return howIGotHere;
// }
//
// public Iterable<Relationship> relationships()
// {
// return ensurePathInstantiated().relationships();
// }
//
// public Iterable<Node> nodes()
// {
// return ensurePathInstantiated().nodes();
// }
//
// public int length()
// {
// return depth;
// }
//
// public Iterator<PropertyContainer> iterator()
// {
// return ensurePathInstantiated().iterator();
// }
}