rice.pastry.dist
Class DistCoalesedNodeHandle

java.lang.Object
  java.util.Observable
      rice.p2p.commonapi.NodeHandle
          rice.pastry.NodeHandle
              rice.pastry.dist.DistNodeHandle
                  rice.pastry.dist.DistCoalesedNodeHandle

All Implemented Interfaces:

LocalNodeI, MessageReceiver, java.util.Observer, java.io.Serializable

public abstract class DistCoalesedNodeHandle

extends DistNodeHandle

Abstract class for handles to "real" remote nodes. This class abstracts out the node handle verification which is necessary in the "real" pastry protocols, since NodeHandles are sent across the wire.

Version:

$Id: DistCoalesedNodeHandle.java,v 1.5 2005/03/11 00:58:01 jeffh Exp $

Author:

Alan Mislove

See Also:

Serialized Form

Field Summary

static int	DEFAULT_DISTANCE DESCRIBE THE FIELD
protected boolean	isInPool DESCRIBE THE FIELD
protected boolean	isLocal DESCRIBE THE FIELD
protected int	status DESCRIBE THE FIELD

Fields inherited from class rice.pastry.dist.DistNodeHandle

address, epoch, nodeId

Fields inherited from class rice.pastry.NodeHandle

LIVENESS_ALIVE, LIVENESS_DEAD, LIVENESS_SUSPECTED, localnode

Fields inherited from class rice.p2p.commonapi.NodeHandle

DECLARED_DEAD, DECLARED_LIVE, PROXIMITY_CHANGED

Fields inherited from interface rice.pastry.LocalNodeI

pending

Constructor Summary

DistCoalesedNodeHandle(NodeId nodeId, java.net.InetSocketAddress address)
Constructor

Method Summary

void	addObserver(java.util.Observer o) Adds a feature to the Observer attribute of the DistCoalesedNodeHandle object
void	afterSetLocalNode() Method called from LocalNode after localnode is set to non-null.
protected void	clearChanged() DESCRIBE THE METHOD
int	countObservers() DESCRIBE THE METHOD
protected void	debug(java.lang.String s) Prints out nicely formatted debug messages.
void	deleteObserver(java.util.Observer o) DESCRIBE THE METHOD
void	deleteObservers() DESCRIBE THE METHOD
boolean	equals(java.lang.Object obj) Equivalence relation for nodehandles.
boolean	getIsInPool() Returns whether or not this node handle is the one in the node handle pool.
int	getLiveness() Returns the last known liveness information about the Pastry node associated with this handle.
boolean	hasChanged() DESCRIBE THE METHOD
int	hashCode() Hash codes for node handles.
void	markAlive() Marks this handle as alive (if dead earlier), and reset distance to infinity.
void	markDead() Mark this handle as dead (if alive earlier), and reset distance to infinity.
void	notifyObservers() DESCRIBE THE METHOD
void	notifyObservers(java.lang.Object arg) DESCRIBE THE METHOD
boolean	ping() Ping the node.
protected abstract boolean	pingImpl() Ping the node.
int	proximity() Returns the last known proximity information about the Pastry node associated with this handle.
void	receiveMessage(Message message) Called to send a message to the node corresponding to this handle.
protected abstract void	receiveMessageImpl(Message message) Called to send a message to the node corresponding to this handle.
protected void	setChanged() Sets the Changed attribute of the DistCoalesedNodeHandle object
void	setIsInPool(boolean iip) Sets whether or not this node handle is in the node handle pool.
protected void	setProximity(int value) Method which is designed to be called by subclassses whenever there is a change in the distance metric.
java.lang.String	toString() Returns a String representation of this DistNodeHandle.
protected abstract java.lang.String	toStringImpl() Returns a String representation of this DistNodeHandle.
void	update(java.util.Observable o, java.lang.Object obj) DESCRIBE THE METHOD

Methods inherited from class rice.pastry.dist.DistNodeHandle

getAddress, getEpoch, getNodeId

Methods inherited from class rice.pastry.NodeHandle

assertLocalNode, bootstrap, checkLiveness, getId, getLocalNode, isAlive, setLocalNode

Methods inherited from class java.lang.Object

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

Field Detail

isInPool

protected transient boolean isInPool

DESCRIBE THE FIELD

status

protected transient int status

DESCRIBE THE FIELD

isLocal

protected transient boolean isLocal

DESCRIBE THE FIELD

DEFAULT_DISTANCE

public static int DEFAULT_DISTANCE

DESCRIBE THE FIELD

Constructor Detail

DistCoalesedNodeHandle

public DistCoalesedNodeHandle(NodeId nodeId,
                              java.net.InetSocketAddress address)

Constructor

Parameters:

nodeId - This node handle's node Id.

address - DESCRIBE THE PARAMETER

Method Detail

getLiveness

public final int getLiveness()

Returns the last known liveness information about the Pastry node associated with this handle. Invoking this method does not cause network activity. This method is designed to be called by clients using the node handle, and is provided in order to ensure that the right node handle is being talked to.

Specified by:

getLiveness in class NodeHandle

Returns:

true if the node is alive, false otherwise.

getIsInPool

public boolean getIsInPool()

Returns whether or not this node handle is the one in the node handle pool.

Returns:

Whether or not this node handle is in the pool.

setProximity

protected final void setProximity(int value)

Method which is designed to be called by subclassses whenever there is a change in the distance metric. This is done in order to abstract out the notification of the observers of a distance metric change.

Parameters:

value - The new distance value

setIsInPool

public void setIsInPool(boolean iip)

Sets whether or not this node handle is in the node handle pool.

Parameters:

iip - Whether or not this node handle is in the node handle pool.

setChanged

protected void setChanged()

Sets the Changed attribute of the DistCoalesedNodeHandle object

afterSetLocalNode

public void afterSetLocalNode()

Method called from LocalNode after localnode is set to non-null. Updates the isLocal and alive variables.

Overrides:

afterSetLocalNode in class NodeHandle

markAlive

public final void markAlive()

Marks this handle as alive (if dead earlier), and reset distance to infinity. If node is already marked as alive, this does nothing.

markDead

public final void markDead()

Mark this handle as dead (if alive earlier), and reset distance to infinity. If node is already marked as deas, this method does nothing.

proximity

public final int proximity()

Returns the last known proximity information about the Pastry node associated with this handle. Invoking this method does not cause network activity. This method is designed to be called by clients using the node handle, and is provided in order to ensure that the right node handle is being talked to. Smaller values imply greater proximity. The exact nature and interpretation of the proximity metric implementation-specific.

Specified by:

proximity in class NodeHandle

Returns:

the proximity metric value

ping

public final boolean ping()

Ping the node. Refreshes the cached liveness status and proximity value of the Pastry node associated with this. Invoking this method causes network activity. This method is designed to be called by clients using the node handle, and is provided in order to ensure that the right node handle is being talked to.

Specified by:

ping in class NodeHandle

Returns:

true if node is currently alive.

pingImpl

protected abstract boolean pingImpl()

Ping the node. Refreshes the cached liveness status and proximity value of the Pastry node associated with this. Invoking this method causes network activity. This method is to be run by the node handle which is in the NodeHandlePool.

Returns:

true if node is currently alive.

receiveMessage

public final void receiveMessage(Message message)

Called to send a message to the node corresponding to this handle. This method is designed to be called by clients using the node handle, and is provided in order to ensure that the right node handle is being talked to.

Parameters:

message - DESCRIBE THE PARAMETER

receiveMessageImpl

protected abstract void receiveMessageImpl(Message message)

Called to send a message to the node corresponding to this handle. This method is to be run by the node handle which is in the NodeHandlePool.

Parameters:

message - DESCRIBE THE PARAMETER

toString

public final java.lang.String toString()

Returns a String representation of this DistNodeHandle. This method is designed to be called by clients using the node handle, and is provided in order to ensure that the right node handle is being talked to.

Specified by:

toString in class DistNodeHandle

Returns:

A String representation of the node handle.

toStringImpl

protected abstract java.lang.String toStringImpl()

Returns a String representation of this DistNodeHandle. This method is to be run by the node handle which is in the NodeHandlePool.

Returns:

A String representation of the node handle.

equals

public boolean equals(java.lang.Object obj)

Equivalence relation for nodehandles. They are equal if and only if their corresponding NodeIds are equal.

Specified by:

equals in class DistNodeHandle

Parameters:

obj - the other nodehandle .

Returns:

true if they are equal, false otherwise.

hashCode

public int hashCode()

Hash codes for node handles. It is the hashcode of their corresponding NodeId's.

Specified by:

hashCode in class DistNodeHandle

Returns:

a hash code.

debug

protected void debug(java.lang.String s)

Prints out nicely formatted debug messages.

Parameters:

s - The message to print.

addObserver

public void addObserver(java.util.Observer o)

Adds a feature to the Observer attribute of the DistCoalesedNodeHandle object

Parameters:

o - The feature to be added to the Observer attribute

countObservers

public int countObservers()

DESCRIBE THE METHOD

Returns:

DESCRIBE THE RETURN VALUE

deleteObserver

public void deleteObserver(java.util.Observer o)

DESCRIBE THE METHOD

Parameters:

o - DESCRIBE THE PARAMETER

deleteObservers

public void deleteObservers()

DESCRIBE THE METHOD

hasChanged

public boolean hasChanged()

DESCRIBE THE METHOD

Returns:

DESCRIBE THE RETURN VALUE

notifyObservers

public void notifyObservers()

DESCRIBE THE METHOD

notifyObservers

public void notifyObservers(java.lang.Object arg)

DESCRIBE THE METHOD

Parameters:

arg - DESCRIBE THE PARAMETER

clearChanged

protected void clearChanged()

DESCRIBE THE METHOD

update

public void update(java.util.Observable o,
                   java.lang.Object obj)

DESCRIBE THE METHOD

Parameters:

o - DESCRIBE THE PARAMETER

obj - DESCRIBE THE PARAMETER