rice.pastry.pns
Class PNSApplication

java.lang.Object
  rice.pastry.client.PastryAppl
      rice.pastry.pns.PNSApplication

All Implemented Interfaces:

ProximityListener<NodeHandle>, ProximityNeighborSelector

Direct Known Subclasses:

RendezvousPNSApplication

public class PNSApplication
extends PastryAppl
implements ProximityNeighborSelector, ProximityListener<NodeHandle>

Can request LeafSet, RouteRow, Proximity of nodes, implements the PNS algorithm. Flow: call getLeafSet(...) addToWaitingForLeafSet() cancellable.cancel() removeFromWaitingForLeafSet() TODO: Make use the environment's clock for the wait() calls.

Author:

Jeff Hoye

Field Summary

static int	DEFAULT_PROXIMITY
protected Environment	environment
protected java.util.Map<NodeHandle,java.lang.Integer>	pingCache Hashtable which keeps track of temporary ping values, which are only used during the getNearest() method
protected byte	rtBase
protected Timer	timer

Fields inherited from class rice.pastry.client.PastryAppl

address, deserializer, instance, logger, options, receiver, thePastryNode

Constructor Summary

PNSApplication(PastryNode pn)

PNSApplication(PastryNode pn, Logger logger)

Method Summary

protected void	addToWaitingForLeafSet(NodeHandle handle, Continuation<LeafSet,java.lang.Exception> c, Cancellable cancelMeWhenSuccess)
protected void	addToWaitingForRouteRow(NodeHandle handle, int row, Continuation<RouteSet[],java.lang.Exception> c, Cancellable cancelMeWhenSuccess)
boolean	deliverWhenNotReady() We always want to receive messages.
Cancellable	getLeafSet(NodeHandle handle, Continuation<LeafSet,java.lang.Exception> c) This method returns the remote leafset of the provided handle to the caller, in a protocol-dependent fashion.
Cancellable	getNearest(NodeHandle seed, Continuation<java.util.Collection<NodeHandle>,java.lang.Exception> retToMe) This method implements the algorithm in the Pastry locality paper for finding a close node the the current node through iterative leafset and route row requests.
Cancellable	getNearHandles(java.util.Collection<NodeHandle> bootHandles, Continuation<java.util.Collection<NodeHandle>,java.lang.Exception> deliverResultToMe)
protected java.util.List<NodeHandle>	getNearHandlesHelper(java.util.List<NodeHandle> handles) Helper for getNearHandles Can be overridden to select out any handles that shouldn't be returned.
Cancellable	getProximity(NodeHandle handle, Continuation<java.lang.Integer,java.io.IOException> c, int timeout) Non-blocking version, no timeout.
Cancellable	getRouteRow(NodeHandle handle, short row, Continuation<RouteSet[],java.lang.Exception> c) Non-blocking version.
void	messageForAppl(Message msg) Called by pastry when a message arrives for this application.
void	proximityChanged(NodeHandle i, int newProximity, java.util.Map<java.lang.String,java.lang.Object> options)
protected boolean	removeFromWaitingForLeafSet(NodeHandle handle, Continuation<LeafSet,java.lang.Exception> c)
protected boolean	removeFromWaitingForRouteRow(NodeHandle handle, int row, Continuation<RouteSet[],java.lang.Exception> c)
java.util.List<NodeHandle>	sortedProximityCache()

Methods inherited from class rice.pastry.client.PastryAppl

accept, canReceiveSocket, connect, destroy, enrouteMessage, finishReceiveSocket, getAddress, getDeserializer, getLeafSet, getNodeHandle, getNodeId, getRoutingTable, isClosest, leafSetChange, notifyReady, receiveMessage, receiveMessageInternal, register, routeMsg, routeMsg, routeMsgDirect, routeSetChange, setDeserializer

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PROXIMITY

public static final int DEFAULT_PROXIMITY

See Also:

Constant Field Values

pingCache

protected java.util.Map<NodeHandle,java.lang.Integer> pingCache

Hashtable which keeps track of temporary ping values, which are only used during the getNearest() method

rtBase

protected final byte rtBase

environment

protected Environment environment

timer

protected Timer timer

Constructor Detail

PNSApplication

public PNSApplication(PastryNode pn)

PNSApplication

public PNSApplication(PastryNode pn,
                      Logger logger)

Method Detail

deliverWhenNotReady

public boolean deliverWhenNotReady()

We always want to receive messages.

Overrides:

deliverWhenNotReady in class PastryAppl

Returns:

false unless the node is a service

messageForAppl

public void messageForAppl(Message msg)

Description copied from class: PastryAppl

Called by pastry when a message arrives for this application.

Specified by:

messageForAppl in class PastryAppl

Parameters:

msg - the message that is arriving.

getNearHandles

public Cancellable getNearHandles(java.util.Collection<NodeHandle> bootHandles,
                                  Continuation<java.util.Collection<NodeHandle>,java.lang.Exception> deliverResultToMe)

Specified by:

getNearHandles in interface ProximityNeighborSelector

getNearHandlesHelper

protected java.util.List<NodeHandle> getNearHandlesHelper(java.util.List<NodeHandle> handles)

Helper for getNearHandles Can be overridden to select out any handles that shouldn't be returned.

Parameters:

handles -

Returns:

getLeafSet

public Cancellable getLeafSet(NodeHandle handle,
                              Continuation<LeafSet,java.lang.Exception> c)

This method returns the remote leafset of the provided handle to the caller, in a protocol-dependent fashion. Note that this method may block while sending the message across the wire. Non-blocking version.

Parameters:

handle - The node to connect to

c - Continuation to return the LeafSet to

Returns:

Throws:

java.io.IOException

addToWaitingForLeafSet

protected void addToWaitingForLeafSet(NodeHandle handle,
                                      Continuation<LeafSet,java.lang.Exception> c,
                                      Cancellable cancelMeWhenSuccess)

removeFromWaitingForLeafSet

protected boolean removeFromWaitingForLeafSet(NodeHandle handle,
                                              Continuation<LeafSet,java.lang.Exception> c)

getRouteRow

public Cancellable getRouteRow(NodeHandle handle,
                               short row,
                               Continuation<RouteSet[],java.lang.Exception> c)

Non-blocking version.

Parameters:

handle -

row -

c -

Returns:

Throws:

java.io.IOException

addToWaitingForRouteRow

protected void addToWaitingForRouteRow(NodeHandle handle,
                                       int row,
                                       Continuation<RouteSet[],java.lang.Exception> c,
                                       Cancellable cancelMeWhenSuccess)

removeFromWaitingForRouteRow

protected boolean removeFromWaitingForRouteRow(NodeHandle handle,
                                               int row,
                                               Continuation<RouteSet[],java.lang.Exception> c)

getProximity

public Cancellable getProximity(NodeHandle handle,
                                Continuation<java.lang.Integer,java.io.IOException> c,
                                int timeout)

Non-blocking version, no timeout. TODO: Make this fail early if faulty.

Parameters:

handle -

c -

proximityChanged

public void proximityChanged(NodeHandle i,
                             int newProximity,
                             java.util.Map<java.lang.String,java.lang.Object> options)

Specified by:

proximityChanged in interface ProximityListener<NodeHandle>

sortedProximityCache

public java.util.List<NodeHandle> sortedProximityCache()

getNearest

public Cancellable getNearest(NodeHandle seed,
                              Continuation<java.util.Collection<NodeHandle>,java.lang.Exception> retToMe)

This method implements the algorithm in the Pastry locality paper for finding a close node the the current node through iterative leafset and route row requests. The seed node provided is any node in the network which is a member of the pastry ring. This algorithm is designed to work in a protocol-independent manner, using the getResponse(Message) method provided by subclasses.

Parameters:

seed - Any member of the pastry ring

Returns:

A node suitable to boot off of (which is close the this node)