org.geotools.graph.structure.opt

Class OptNode

Object

OptGraphable

OptNode

All Implemented Interfaces:

Serializable, Graphable, Node

Direct Known Subclasses:

OptXYNode

public class OptNode
extends OptGraphable
implements Node

Optimized implementation of Node. The following optimizations reduce space and improve performance.

• Edge adjacency list stored as array of predetermined size.
• Removing support for removing edges from the nodes ajdacency list.
• The related component iterator iterates over the underlying edge array of the node instread of a newly created collection.

Using an optimized node requires that the degree of the node be known before the node is built.

Author:

Justin Deoliveira, Refractions Research Inc, jdeolive@refractions.net

See Also:

Node, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	OptNode.RelatedIterator An iterator used to iterate over related nodes.

Constructor Summary

Constructors

Constructor and Description
OptNode() Constructs a new OptimizedNode.
OptNode(int degree) Constructs a new Optimized Node with a known degree.

Method Summary

Modifier and Type	Method and Description
void	add(Edge e) Adds an edge to the adjacency list of the node.
int	getDegree() Returns the degree of the node.
Edge	getEdge(Node other) Returns an edge in the adjacency list of the node that is adjacent to another specified node.
Edge[]	getEdgeArray() Returns the edge adjacency list of the node as an array.
List<Edge>	getEdges() Returns the edge adjacency list of the node.
List<Edge>	getEdges(Node other) Returns a collection of edges in the adjacency list of the node that are adjacent to another specified node.
Iterator<Node>	getRelated() This iterator iterates over the underlying edge array of the node.
void	remove(Edge e) Not supported.
void	setDegree(int degree) Sets the degree of the node.

Methods inherited from class OptGraphable

getCount, getID, getObject, isVisited, setCount, setID, setObject, setVisited

Methods inherited from class Object

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

Methods inherited from interface Graphable

getCount, getID, getObject, isVisited, setCount, setID, setObject, setVisited

Constructor Detail

OptNode

public OptNode()

Constructs a new OptimizedNode. This constructor does not build the adjacency array for the node.

OptNode

public OptNode(int degree)

Constructs a new Optimized Node with a known degree.

Parameters:

degree - The degree of the node.

Method Detail

add

public void add(Edge e)

Description copied from interface: Node

Adds an edge to the adjacency list of the node.

Specified by:

add in interface Node

Parameters:

e - Adjacent edge to add.

See Also:

Node.add(Edge)

remove

public void remove(Edge e)

Not supported.

Specified by:

remove in interface Node

Parameters:

e - Adjacent edge to remove.

See Also:

Node.remove(Edge)

getEdge

public Edge getEdge(Node other)

Description copied from interface: Node

Returns an edge in the adjacency list of the node that is adjacent to another specified node.

Note: It is possible for two nodes to share multiple edges between them. In this case, getEdges(Node other) can be used to obtain a complete list.

Specified by:

getEdge in interface Node

Parameters:

other - The other node that the desired edge to return is adjacent to.

Returns:

The first edge that is found to be adjacent to the specified node.

See Also:

Node.getEdge(Node)

getEdges

public List<Edge> getEdges(Node other)

Description copied from interface: Node

Returns a collection of edges in the adjacency list of the node that are adjacent to another specified node.

Specified by:

getEdges in interface Node

Parameters:

other - The other node that the desired edges to return are adjacent to.

Returns:

List of all edges that are found to be adjacent to the specified node.

See Also:

Node.getEdges(Node)

getEdgeArray

public Edge[] getEdgeArray()

Returns the edge adjacency list of the node as an array.

Returns:

An array containing edges adjacent to the node.

getEdges

public List<Edge> getEdges()

Description copied from interface: Node

Returns the edge adjacency list of the node.

Specified by:

getEdges in interface Node

Returns:

A list containing all edges that are adjacent to the node.

See Also:

Node.getEdges()

setDegree

public void setDegree(int degree)

Sets the degree of the node. This method build the edge adjacency array for the node.

Parameters:

degree - The degree of the node / size of edge adjacency array.

getDegree

public int getDegree()

Description copied from interface: Node

Returns the degree of the node. The degree of a node is defined as the number of edges that are adjacent to the node.

Specified by:

getDegree in interface Node

Returns:

int Degree of node.

See Also:

Node.getDegree()

getRelated

public Iterator<Node> getRelated()

This iterator iterates over the underlying edge array of the node.

Specified by:

getRelated in interface Graphable

Returns:

Iterator An iterator over other components of the graph that are related to the component.

See Also:

Graphable.getRelated()