Rice Pastry API

rice.pastry
Class PastryNode

java.lang.Object
  extended byjava.util.Observable
      extended byrice.pastry.PastryNode
All Implemented Interfaces:
MessageReceiver, Node
Direct Known Subclasses:
DirectPastryNode, DistPastryNode

public abstract class PastryNode
extends java.util.Observable
implements MessageReceiver, Node

A Pastry node is single entity in the pastry network.

Version:
$Id: PastryNode.java,v 1.55 2005/08/12 14:28:59 jeffh Exp $
Author:
Andrew Ladd

Field Summary
protected  java.util.Vector apps
          DESCRIBE THE FIELD
protected  NodeHandle localhandle
          DESCRIBE THE FIELD
protected  NodeId myNodeId
          DESCRIBE THE FIELD
protected  java.util.WeakHashMap nodeHandleSet
          This hash map helps us coalesce the nodeHandles so that there is only one reference of each maps NodeHandle -> WeakReference(NodeHandle)
 
Constructor Summary
protected PastryNode(NodeId id, Environment e)
          Constructor, with NodeId.
 
Method Summary
 void addLeafSetObserver(java.util.Observer o)
          Add a leaf set observer to the Pastry node.
 void addRouteSetObserver(java.util.Observer o)
          Add a route set observer to the Pastry node.
 void deleteLeafSetObserver(java.util.Observer o)
          Delete a leaf set observer from the Pastry node.
 void deleteRouteSetObserver(java.util.Observer o)
          Delete a route set observer from the Pastry node.
 void destroy()
          Method which kills a PastryNode.
 Environment getEnvironment()
          Gets the Environment attribute of the PastryNode object
 Id getId()
          Returns the Id of this node
 IdFactory getIdFactory()
          Returns a factory for Ids specific to this node's protocol.
 LeafSet getLeafSet()
          Gets the LeafSet attribute of the PastryNode object
 NodeHandle getLocalHandle()
          Gets the LocalHandle attribute of the PastryNode object
 NodeHandle getLocalNodeHandle()
          Gets the LocalNodeHandle attribute of the PastryNode object
 LocalNodeI getLocalNodeI(LocalNodeI lni)
          Gets the LocalNodeI attribute of the PastryNode object
 MessageDispatch getMessageDispatch()
          FOR TESTING ONLY - DO NOT USE!
 NodeId getNodeId()
          Gets the NodeId attribute of the PastryNode object
 RoutingTable getRoutingTable()
          Gets the RoutingTable attribute of the PastryNode object
abstract  void initiateJoin(NodeHandle bootstrap)
          Overridden by derived classes to initiate the join process
 boolean isClosest(NodeId key)
          Called by the layered Pastry application to check if the local pastry node is the one that is currently closest to the object key id.
 boolean isReady()
          Gets the Ready attribute of the PastryNode object
abstract  void nodeIsReady()
          Overridden by derived classes, and invoked when the node has joined successfully.
 void nodeIsReady(boolean state)
          Overridden by derived classes, and invoked when the node has joined successfully.
 void process(Executable task, Continuation command)
          Schedules a job for processing on the dedicated processing thread, should one exist.
 void receiveMessage(Message msg)
          message receiver interface.
 void registerApp(PastryAppl app)
          Registers an application with this pastry node.
 Endpoint registerApplication(Application application, int port)
          This returns a Endpoint specific to the given application and instance name to the application, which the application can then use in order to send an receive messages.
 Endpoint registerApplication(Application application, java.lang.String instance)
          This returns a VirtualizedNode specific to the given application and instance name to the application, which the application can then use in order to send an receive messages.
 void registerReceiver(Credentials cred, Address address, MessageReceiver receiver)
          Registers a message receiver with this Pastry node.
abstract  ScheduledMessage scheduleMsg(Message msg, long delay)
          Schedule the specified message to be sent to the local node after a specified delay.
abstract  ScheduledMessage scheduleMsg(Message msg, long delay, long period)
          Schedule the specified message for repeated fixed-delay delivery to the local node, beginning after the specified delay.
abstract  ScheduledMessage scheduleMsgAtFixedRate(Message msg, long delay, long period)
          Schedule the specified message for repeated fixed-rate delivery to the local node, beginning after the specified delay.
 void setElements(NodeHandle lh, PastrySecurityManager sm, MessageDispatch md, LeafSet ls, RoutingTable rt)
          Combined accessor method for various members of PastryNode.
 void setMessageDispatch(MessageDispatch md)
          Sets the MessageDispatch attribute of the PastryNode object
 void setReady()
          Sets the Ready attribute of the PastryNode object
 void setReady(boolean r)
          Sets the Ready attribute of the PastryNode object
 java.lang.String toString()
          DESCRIBE THE METHOD
 
Methods inherited from class java.util.Observable
addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

myNodeId

protected NodeId myNodeId
DESCRIBE THE FIELD


localhandle

protected NodeHandle localhandle
DESCRIBE THE FIELD


apps

protected java.util.Vector apps
DESCRIBE THE FIELD


nodeHandleSet

protected java.util.WeakHashMap nodeHandleSet
This hash map helps us coalesce the nodeHandles so that there is only one reference of each maps NodeHandle -> WeakReference(NodeHandle)

Constructor Detail

PastryNode

protected PastryNode(NodeId id,
                     Environment e)
Constructor, with NodeId. Need to set the node's ID before this node is inserted as localHandle.localNode.

Parameters:
id - DESCRIBE THE PARAMETER
e - DESCRIBE THE PARAMETER
Method Detail

getLocalNodeI

public LocalNodeI getLocalNodeI(LocalNodeI lni)
Gets the LocalNodeI attribute of the PastryNode object

Parameters:
lni - DESCRIBE THE PARAMETER
Returns:
The LocalNodeI value

getLocalNodeHandle

public NodeHandle getLocalNodeHandle()
Gets the LocalNodeHandle attribute of the PastryNode object

Specified by:
getLocalNodeHandle in interface Node
Returns:
The LocalNodeHandle value

getEnvironment

public Environment getEnvironment()
Gets the Environment attribute of the PastryNode object

Specified by:
getEnvironment in interface Node
Returns:
The Environment value

getLocalHandle

public NodeHandle getLocalHandle()
Gets the LocalHandle attribute of the PastryNode object

Returns:
The LocalHandle value

getNodeId

public NodeId getNodeId()
Gets the NodeId attribute of the PastryNode object

Returns:
The NodeId value

isReady

public boolean isReady()
Gets the Ready attribute of the PastryNode object

Returns:
The Ready value

getMessageDispatch

public MessageDispatch getMessageDispatch()
FOR TESTING ONLY - DO NOT USE!

Returns:
The MessageDispatch value

isClosest

public boolean isClosest(NodeId key)
Called by the layered Pastry application to check if the local pastry node is the one that is currently closest to the object key id.

Parameters:
key - the object key id
Returns:
true if the local node is currently the closest to the key.

getLeafSet

public LeafSet getLeafSet()
Gets the LeafSet attribute of the PastryNode object

Returns:
The LeafSet value

getRoutingTable

public RoutingTable getRoutingTable()
Gets the RoutingTable attribute of the PastryNode object

Returns:
The RoutingTable value

getId

public Id getId()
Returns the Id of this node

Specified by:
getId in interface Node
Returns:
This node's Id

getIdFactory

public IdFactory getIdFactory()
Returns a factory for Ids specific to this node's protocol.

Specified by:
getIdFactory in interface Node
Returns:
A factory for creating Ids.

setElements

public void setElements(NodeHandle lh,
                        PastrySecurityManager sm,
                        MessageDispatch md,
                        LeafSet ls,
                        RoutingTable rt)
Combined accessor method for various members of PastryNode. These are generated by node factories, and assigned here. Other elements specific to the wire protocol are assigned via methods set{RMI,Direct}Elements in the respective derived classes.

Parameters:
lh - Node handle corresponding to this node.
sm - Security manager.
md - Message dispatcher.
ls - Leaf set.
rt - Routing table.

setMessageDispatch

public void setMessageDispatch(MessageDispatch md)
Sets the MessageDispatch attribute of the PastryNode object

Parameters:
md - The new MessageDispatch value

setReady

public void setReady()
Sets the Ready attribute of the PastryNode object


setReady

public void setReady(boolean r)
Sets the Ready attribute of the PastryNode object

Parameters:
r - The new Ready value

nodeIsReady

public abstract void nodeIsReady()
Overridden by derived classes, and invoked when the node has joined successfully. This one is for backwards compatability. It will soon be deprecated.


nodeIsReady

public void nodeIsReady(boolean state)
Overridden by derived classes, and invoked when the node has joined successfully. This should probably be abstract, but maybe in a later version.

Parameters:
state - true when the node is ready, false when not

initiateJoin

public abstract void initiateJoin(NodeHandle bootstrap)
Overridden by derived classes to initiate the join process

Parameters:
bootstrap - Node handle to bootstrap with.

addLeafSetObserver

public void addLeafSetObserver(java.util.Observer o)
Add a leaf set observer to the Pastry node.

Parameters:
o - the observer.

deleteLeafSetObserver

public void deleteLeafSetObserver(java.util.Observer o)
Delete a leaf set observer from the Pastry node.

Parameters:
o - the observer.

addRouteSetObserver

public void addRouteSetObserver(java.util.Observer o)
Add a route set observer to the Pastry node.

Parameters:
o - the observer.

deleteRouteSetObserver

public void deleteRouteSetObserver(java.util.Observer o)
Delete a route set observer from the Pastry node.

Parameters:
o - the observer.

receiveMessage

public void receiveMessage(Message msg)
message receiver interface. synchronized so that the external message processing thread and the leafset/route maintenance thread won't interfere with application messages.

Specified by:
receiveMessage in interface MessageReceiver
Parameters:
msg - DESCRIBE THE PARAMETER

registerReceiver

public void registerReceiver(Credentials cred,
                             Address address,
                             MessageReceiver receiver)
Registers a message receiver with this Pastry node.

Parameters:
cred - the credentials.
address - the address that the receiver will be at.
receiver - the message receiver.

registerApp

public void registerApp(PastryAppl app)
Registers an application with this pastry node.

Parameters:
app - the application

scheduleMsg

public abstract ScheduledMessage scheduleMsg(Message msg,
                                             long delay)
Schedule the specified message to be sent to the local node after a specified delay. Useful to provide timeouts.

Parameters:
msg - a message that will be delivered to the local node after the specified delay
delay - time in milliseconds before message is to be delivered
Returns:
the scheduled event object; can be used to cancel the message

scheduleMsg

public abstract ScheduledMessage scheduleMsg(Message msg,
                                             long delay,
                                             long period)
Schedule the specified message for repeated fixed-delay delivery to the local node, beginning after the specified delay. Subsequent executions take place at approximately regular intervals separated by the specified period. Useful to initiate periodic tasks.

Parameters:
msg - a message that will be delivered to the local node after the specified delay
delay - time in milliseconds before message is to be delivered
period - time in milliseconds between successive message deliveries
Returns:
the scheduled event object; can be used to cancel the message

scheduleMsgAtFixedRate

public abstract ScheduledMessage scheduleMsgAtFixedRate(Message msg,
                                                        long delay,
                                                        long period)
Schedule the specified message for repeated fixed-rate delivery to the local node, beginning after the specified delay. Subsequent executions take place at approximately regular intervals, separated by the specified period.

Parameters:
msg - a message that will be delivered to the local node after the specified delay
delay - time in milliseconds before message is to be delivered
period - time in milliseconds between successive message deliveries
Returns:
the scheduled event object; can be used to cancel the message

toString

public java.lang.String toString()
DESCRIBE THE METHOD

Returns:
DESCRIBE THE RETURN VALUE

registerApplication

public Endpoint registerApplication(Application application,
                                    java.lang.String instance)
This returns a VirtualizedNode specific to the given application and instance name to the application, which the application can then use in order to send an receive messages.

Specified by:
registerApplication in interface Node
Parameters:
application - The Application
instance - An identifier for a given instance
Returns:
The endpoint specific to this applicationk, which can be used for message sending/receiving.

registerApplication

public Endpoint registerApplication(Application application,
                                    int port)
This returns a Endpoint specific to the given application and instance name to the application, which the application can then use in order to send an receive messages. This method allows advanced developers to specify which "port" on the node they wish their application to register as. This "port" determines which of the applications on top of the node should receive an incoming message.

Specified by:
registerApplication in interface Node
Parameters:
application - The Application
port - The port to use
Returns:
The endpoint specific to this applicationk, which can be used for message sending/receiving.

process

public void process(Executable task,
                    Continuation command)
Schedules a job for processing on the dedicated processing thread, should one exist. CPU intensive jobs, such as encryption, erasure encoding, or bloom filter creation should never be done in the context of the underlying node's thread, and should only be done via this method.

Parameters:
task - The task to run on the processing thread
command - The command to return the result to once it's done

destroy

public void destroy()
Method which kills a PastryNode. Note, this doesn't implicitly kill the environment. Make sure to call super.destroy() !!!


Rice Pastry API

Copyright © 2001-2005 - Rice Pastry.


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