bamboo.vivaldi
Class SpecialVC

java.lang.Object
  bamboo.vivaldi.VirtualCoordinate
      bamboo.vivaldi.SpecialVC

All Implemented Interfaces:

ostore.util.QuickSerializable

public class SpecialVC
extends VirtualCoordinate
implements ostore.util.QuickSerializable

A virtual coordinate class where coordinates are modeled by a position on a plane, and a height away from it.

Version:

$Id: SpecialVC.java,v 1.3 2004/03/10 20:39:43 czerwin Exp $

Author:

Steven E. Czerwinski

Field Summary

Fields inherited from class bamboo.vivaldi.VirtualCoordinate

_coordinate, _delta

Constructor Summary

SpecialVC()

SpecialVC(ostore.util.InputBuffer buffer)

Method Summary

double[]	displacement(VirtualCoordinate destination) Returns a unit vector in the direction towards the remote coordinate.
double	distance(VirtualCoordinate destination) Calculates the distance between this coordinate to the given destination.
protected int	getDimensions() Returns the number of dimensions to use for this version of the virtual coordinates.
void	update(VirtualCoordinate remote_coord, double latency) Update this coordinate's position with the given latency sample.

Methods inherited from class bamboo.vivaldi.VirtualCoordinate

equals, getCoordinates, random_displacement, random_displacement, random_displacement, serialize, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface ostore.util.QuickSerializable

serialize

Constructor Detail

SpecialVC

public SpecialVC()

SpecialVC

public SpecialVC(ostore.util.InputBuffer buffer)
          throws ostore.util.QSException

Throws:

ostore.util.QSException

Method Detail

getDimensions

protected int getDimensions()

Description copied from class: VirtualCoordinate

Returns the number of dimensions to use for this version of the virtual coordinates.

Overrides:

getDimensions in class VirtualCoordinate

distance

public double distance(VirtualCoordinate destination)

Calculates the distance between this coordinate to the given destination. This will be an estimate of the one-way network latencies between the two nodes in milliseconds.

Overrides:

distance in class VirtualCoordinate

Parameters:

destination - The coordinate to compare this object against.

Returns:

The distance between the coordinates, as expressed by one-way network latency in milliseconds.

displacement

public double[] displacement(VirtualCoordinate destination)

Description copied from class: VirtualCoordinate

Returns a unit vector in the direction towards the remote coordinate. If the coordinates are the same, null is returned since you cannot produce a unit vector.

Overrides:

displacement in class VirtualCoordinate

Parameters:

destination - The remote coordinate.

Returns:

A unit vector in the direction towards the remote, or null if the coords are the same.

update

public void update(VirtualCoordinate remote_coord,
                   double latency)

Update this coordinate's position with the given latency sample.

Overrides:

update in class VirtualCoordinate

Parameters:

remote_coord - The node's coordinate used to get the latency sample.

latency - The measured network latency (one-way, in milliseconds) to the remote node.