com.graphhopper.routing

Class DijkstraOneToMany

java.lang.Object

com.graphhopper.routing.AbstractRoutingAlgorithm

com.graphhopper.routing.DijkstraOneToMany

All Implemented Interfaces:

RoutingAlgorithm

public class DijkstraOneToMany
extends AbstractRoutingAlgorithm

A simple dijkstra tuned to perform multiple one to many queries with the same source and different target nodes more efficiently than Dijkstra. Old data structures are cached between requests and potentially reused and the shortest path tree is stored in (large as the graph) arrays instead of hash maps.

Author:

Peter Karich

Field Summary

Fields

Modifier and Type	Field and Description
protected double[]	weights

Fields inherited from class com.graphhopper.routing.AbstractRoutingAlgorithm

edgeExplorer, flagEncoder, graph, inEdgeFilter, maxVisitedNodes, nodeAccess, outEdgeFilter, traversalMode, weighting

Constructor Summary

Constructors

Constructor and Description
DijkstraOneToMany(Graph graph, Weighting weighting, TraversalMode tMode)

Method Summary

Modifier and Type	Method and Description
Path	calcPath(int from, int to) Calculates the best path between the specified nodes.
DijkstraOneToMany	clear() Call clear if you have a different start node and need to clear the cache.
void	close()
Path	extractPath() To be overwritten from extending class.
int	findEndNode(int from, int to)
boolean	finished() To be overwritten from extending class.
String	getMemoryUsageAsString() List currently used memory in MB (approximately)
String	getName()
int	getVisitedNodes() Returns the visited nodes after searching.
double	getWeight(int endNode)
protected boolean	isWeightLimitExceeded()
void	setWeightLimit(double weightLimit)

Methods inherited from class com.graphhopper.routing.AbstractRoutingAlgorithm

accept, calcPaths, checkAlreadyRun, createEmptyPath, isMaxVisitedNodesExceeded, setMaxVisitedNodes, toString

Methods inherited from class java.lang.Object

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

Field Detail

weights

protected double[] weights

Constructor Detail

DijkstraOneToMany

public DijkstraOneToMany(Graph graph,
                         Weighting weighting,
                         TraversalMode tMode)

Method Detail

calcPath

public Path calcPath(int from,
                     int to)

Description copied from interface: RoutingAlgorithm

Calculates the best path between the specified nodes.

Returns:

the path. Call the method found() to make sure that the path is valid.

extractPath

public Path extractPath()

Description copied from class: AbstractRoutingAlgorithm

To be overwritten from extending class. Should we make this available in RoutingAlgorithm interface?

Specified by:

extractPath in class AbstractRoutingAlgorithm

Returns:

true if finished.

clear

public DijkstraOneToMany clear()

Call clear if you have a different start node and need to clear the cache.

getWeight

public double getWeight(int endNode)

findEndNode

public int findEndNode(int from,
                       int to)

finished

public boolean finished()

Description copied from class: AbstractRoutingAlgorithm

To be overwritten from extending class. Should we make this available in RoutingAlgorithm interface?

Specified by:

finished in class AbstractRoutingAlgorithm

Returns:

true if finished.

setWeightLimit

public void setWeightLimit(double weightLimit)

isWeightLimitExceeded

protected boolean isWeightLimitExceeded()

close

public void close()

getVisitedNodes

public int getVisitedNodes()

Description copied from interface: RoutingAlgorithm

Returns the visited nodes after searching. Useful for debugging.

getName

public String getName()

Specified by:

getName in interface RoutingAlgorithm

Overrides:

getName in class AbstractRoutingAlgorithm

Returns:

name of this algorithm

getMemoryUsageAsString

public String getMemoryUsageAsString()

List currently used memory in MB (approximately)