com.graphhopper.routing.ch

Class PrepareContractionHierarchies

java.lang.Object

com.graphhopper.routing.util.AbstractAlgoPreparation

com.graphhopper.routing.ch.PrepareContractionHierarchies

public class PrepareContractionHierarchies
extends AbstractAlgoPreparation

This class prepares the graph for a bidirectional algorithm supporting contraction hierarchies ie. an algorithm returned by createAlgo.

There are several descriptions of contraction hierarchies available. The following is one of the more detailed: http://web.cs.du.edu/~sturtevant/papers/highlevelpathfinding.pdf

The only difference is that we use two skipped edges instead of one skipped node for faster unpacking.

Author:

Peter Karich

Method Summary

Modifier and Type	Method and Description
void	doSpecificWork()
static PrepareContractionHierarchies	fromGraphHopperStorage(GraphHopperStorage ghStorage, CHConfig chConfig)
CHConfig	getCHConfig()
long	getDijkstraCount()
double	getLazyTime()
double	getNeighborTime()
double	getPeriodTime()
RoutingAlgorithmFactory	getRoutingAlgorithmFactory()
long	getShortcuts()
long	getTotalPrepareTime()
Weighting	getWeighting()
boolean	isEdgeBased()
PrepareContractionHierarchies	setParams(PMap pMap)
String	toString()
PrepareContractionHierarchies	useFixedNodeOrdering(NodeOrderingProvider nodeOrderingProvider) Instead of heuristically determining a node ordering for the graph contraction it is also possible to use a fixed ordering.

Methods inherited from class com.graphhopper.routing.util.AbstractAlgoPreparation

doWork, isPrepared

Methods inherited from class java.lang.Object

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

Method Detail

fromGraphHopperStorage

public static PrepareContractionHierarchies fromGraphHopperStorage(GraphHopperStorage ghStorage,
                                                                   CHConfig chConfig)

setParams

public PrepareContractionHierarchies setParams(PMap pMap)

useFixedNodeOrdering

public PrepareContractionHierarchies useFixedNodeOrdering(NodeOrderingProvider nodeOrderingProvider)

Instead of heuristically determining a node ordering for the graph contraction it is also possible to use a fixed ordering. For example this allows re-using a previously calculated node ordering. This will speed up CH preparation, but might lead to slower queries.

doSpecificWork

public void doSpecificWork()

Specified by:

doSpecificWork in class AbstractAlgoPreparation

isEdgeBased

public boolean isEdgeBased()

getDijkstraCount

public long getDijkstraCount()

getShortcuts

public long getShortcuts()

getLazyTime

public double getLazyTime()

getPeriodTime

public double getPeriodTime()

getNeighborTime

public double getNeighborTime()

getWeighting

public Weighting getWeighting()

getCHConfig

public CHConfig getCHConfig()

getTotalPrepareTime

public long getTotalPrepareTime()

toString

public String toString()

Overrides:

toString in class Object

getRoutingAlgorithmFactory

public RoutingAlgorithmFactory getRoutingAlgorithmFactory()