Package org.jgrapht.graph

Class DirectedAcyclicGraph.VisitedHashSetImpl

java.lang.Object

org.jgrapht.graph.DirectedAcyclicGraph.VisitedHashSetImpl

All Implemented Interfaces:

java.io.Serializable, DirectedAcyclicGraph.VisitedStrategy, DirectedAcyclicGraph.VisitedStrategyFactory

Enclosing class:

DirectedAcyclicGraph<V,E>

protected static class DirectedAcyclicGraph.VisitedHashSetImpl
extends java.lang.Object
implements DirectedAcyclicGraph.VisitedStrategy, DirectedAcyclicGraph.VisitedStrategyFactory

A visited strategy using a HashSet.

This implementation doesn't seem to perform as well, though I can imagine circumstances where it should shine (lots and lots of vertices). It also should have the lowest memory footprint as it only uses storage for indices that have been visited.

Author:

Peter Giles

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
VisitedHashSetImpl()	Constructor

Method Summary

Modifier and Type	Method	Description
void	clearVisited(int index)	Clear the visited state of the given topological index.
boolean	getVisited(int index)	Get if the given topological index has been visited.
DirectedAcyclicGraph.VisitedStrategy	getVisitedStrategy(DirectedAcyclicGraph.Region affectedRegion)	Create a new instance of DirectedAcyclicGraph.VisitedStrategy.
void	setVisited(int index)	Mark the given topological index as visited.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

VisitedHashSetImpl

public VisitedHashSetImpl()

Constructor

Method Detail

getVisitedStrategy

public DirectedAcyclicGraph.VisitedStrategy getVisitedStrategy(DirectedAcyclicGraph.Region affectedRegion)

Description copied from interface: DirectedAcyclicGraph.VisitedStrategyFactory

Create a new instance of DirectedAcyclicGraph.VisitedStrategy.

Specified by:

getVisitedStrategy in interface DirectedAcyclicGraph.VisitedStrategyFactory

Parameters:

affectedRegion - the affected region

Returns:

a new instance of DirectedAcyclicGraph.VisitedStrategy for the affected region

setVisited

public void setVisited(int index)

Description copied from interface: DirectedAcyclicGraph.VisitedStrategy

Mark the given topological index as visited.

Specified by:

setVisited in interface DirectedAcyclicGraph.VisitedStrategy

Parameters:

index - the topological index

getVisited

public boolean getVisited(int index)

Description copied from interface: DirectedAcyclicGraph.VisitedStrategy

Get if the given topological index has been visited.

Specified by:

getVisited in interface DirectedAcyclicGraph.VisitedStrategy

Parameters:

index - the topological index

Returns:

true if the given topological index has been visited, false otherwise

clearVisited

public void clearVisited(int index)
                  throws java.lang.UnsupportedOperationException

Description copied from interface: DirectedAcyclicGraph.VisitedStrategy

Clear the visited state of the given topological index.

Specified by:

clearVisited in interface DirectedAcyclicGraph.VisitedStrategy

Parameters:

index - the index

Throws:

java.lang.UnsupportedOperationException - if the implementation doesn't support (or doesn't need) clearance. For example, if the factory creates a new instance every time, it is a waste of cycles to reset the state after the search of the Affected Region is done, so an UnsupportedOperationException *should* be thrown.