rice.p2p.past
Class PastImpl

java.lang.Object
  |
  +--rice.p2p.past.PastImpl

All Implemented Interfaces:

Application, Past, RMClient

public class PastImpl

extends java.lang.Object

implements Past, Application, RMClient

Version:

$Id: PastImpl.java,v 1.19 2003/10/22 03:14:00 amislove Exp $

Author:

Alan Mislove, Ansley Post, Peter Druschel

Field Summary

protected rice.p2p.commonapi.Endpoint	endpoint
protected rice.p2p.commonapi.IdFactory	factory
protected java.util.logging.Logger	log
static int	MESSAGE_TIMEOUT
protected rice.p2p.commonapi.IdSet	pending
protected rice.rm.RM	replicaManager
protected int	replicationFactor
protected rice.persistence.StorageManager	storage

Constructor Summary

PastImpl(rice.p2p.commonapi.Node node, rice.persistence.StorageManager manager, int replicas, java.lang.String instance)
Constructor for Past

Method Summary

void	deliver(rice.p2p.commonapi.Id id, rice.p2p.commonapi.Message message) This method is called on the application at the destination node for the given id.
void	fetch(rice.pastry.IdSet keySet) This upcall is invoked to notify the application that is should fetch the cooresponding keys in this set, since the node is now responsible for these keys also.
void	fetch(rice.p2p.past.PastContentHandle handle, rice.Continuation command) Retrieves the object associated with a given content handle.
boolean	forward(rice.p2p.commonapi.RouteMessage message) This method is invoked on applications when the underlying node is about to forward the given message with the provided target to the specified next hop.
rice.p2p.commonapi.NodeHandle	getLocalNodeHandle() get the nodeHandle of the local Past node
rice.rm.RM	getReplicaManager() Returns the replica manager for this Past instance.
int	getReplicationFactor() Returns the number of replicas used in this Past
rice.persistence.StorageManager	getStorageManager() Returns this Past's storage manager.
void	insert(rice.p2p.past.PastContent obj, rice.Continuation command) Inserts an object with the given ID into this instance of Past.
void	isResponsible(rice.pastry.IdRange range) This upcall is to notify the application of the range of keys for which it is responsible.
void	lookup(rice.p2p.commonapi.Id id, rice.Continuation command) Retrieves the object stored in this instance of Past with the given ID.
void	lookupHandles(rice.p2p.commonapi.Id id, int max, rice.Continuation command) Retrieves the handles of up to max replicas of the object stored in this instance of Past with the given ID.
void	rmIsReady(rice.rm.RM rm) This upcall is simply to denote that the underlying replica manager (rm) is ready.
rice.p2p.commonapi.IdSet	scan(rice.p2p.commonapi.IdRange range) Return the ids of objects stored in this instance of Past on the *local* node, with ids in a given range.
rice.pastry.IdSet	scan(rice.pastry.IdRange range) This upcall should return the set of keys that the application currently stores in this range.
void	update(rice.p2p.commonapi.NodeHandle handle, boolean joined) This method is invoked to inform the application that the given node has either joined or left the neighbor set of the local node, as the set would be returned by the neighborSet call.

Methods inherited from class java.lang.Object

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

Field Detail

MESSAGE_TIMEOUT

public static int MESSAGE_TIMEOUT

endpoint

protected rice.p2p.commonapi.Endpoint endpoint

storage

protected rice.persistence.StorageManager storage

replicationFactor

protected int replicationFactor

replicaManager

protected rice.rm.RM replicaManager

factory

protected rice.p2p.commonapi.IdFactory factory

pending

protected rice.p2p.commonapi.IdSet pending

log

protected java.util.logging.Logger log

Constructor Detail

PastImpl

public PastImpl(rice.p2p.commonapi.Node node,
                rice.persistence.StorageManager manager,
                int replicas,
                java.lang.String instance)

Constructor for Past

Parameters:

node - The node below this Past implementation

manager - The storage manager to be used by Past

replicas - The number of object replicas

instance - The unique instance name of this Past

Method Detail

insert

public void insert(rice.p2p.past.PastContent obj,
                   rice.Continuation command)

Inserts an object with the given ID into this instance of Past. Asynchronously returns a PastException to command, if the operation was unsuccessful. If the operation was successful, a Boolean[] is returned representing the responses from each of the replicas which inserted the object.

Specified by:

insert in interface Past

Parameters:

obj - the object to be inserted

command - Command to be performed when the result is received

lookup

public void lookup(rice.p2p.commonapi.Id id,
                   rice.Continuation command)

Retrieves the object stored in this instance of Past with the given ID. Asynchronously returns a PastContent object as the result to the provided Continuation, or a PastException. This method is provided for convenience; its effect is identical to a lookupHandles() and a subsequent fetch() to the handle that is nearest in the network. The client must authenticate the object. In case of failure, an alternate replica of the object can be obtained via lookupHandles() and fetch(). This method is not safe if the object is immutable and storage nodes are not trusted. In this case, clients should used the lookUpHandles method to obtains the handles of all primary replicas and determine which replica is fresh in an application-specific manner.

Specified by:

lookup in interface Past

Parameters:

id - the key to be queried

command - Command to be performed when the result is received

lookupHandles

public void lookupHandles(rice.p2p.commonapi.Id id,
                          int max,
                          rice.Continuation command)

Retrieves the handles of up to max replicas of the object stored in this instance of Past with the given ID. Asynchronously returns an array of PastContentHandles as the result to the provided Continuation, or a PastException. Each replica handle is obtained from a different primary storage root for the the given key. If max exceeds the replication factor r of this Past instance, only r replicas are returned. This method will return a PastContentHandle[] array containing all of the handles.

Specified by:

lookupHandles in interface Past

Parameters:

id - the key to be queried

max - the maximal number of replicas requested

command - Command to be performed when the result is received

fetch

public void fetch(rice.p2p.past.PastContentHandle handle,
                  rice.Continuation command)

Retrieves the object associated with a given content handle. Asynchronously returns a PastContent object as the result to the provided Continuation, or a PastException. The client must authenticate the object. In case of failure, an alternate replica can be obtained using a different handle obtained via lookupHandles().

Specified by:

fetch in interface Past

Parameters:

command - Command to be performed when the result is received

handle - the key to be queried

scan

public rice.p2p.commonapi.IdSet scan(rice.p2p.commonapi.IdRange range)

Return the ids of objects stored in this instance of Past on the *local* node, with ids in a given range. The IdSet returned contains the Ids of the stored objects.

Specified by:

scan in interface Past

Parameters:

range - The range to query

Returns:

The set of ids

getLocalNodeHandle

public rice.p2p.commonapi.NodeHandle getLocalNodeHandle()

get the nodeHandle of the local Past node

Specified by:

getLocalNodeHandle in interface Past

Returns:

the nodehandle

getReplicationFactor

public int getReplicationFactor()

Returns the number of replicas used in this Past

Specified by:

getReplicationFactor in interface Past

Returns:

the number of replicas for each object

forward

public boolean forward(rice.p2p.commonapi.RouteMessage message)

This method is invoked on applications when the underlying node is about to forward the given message with the provided target to the specified next hop. Applications can change the contents of the message, specify a different nextHop (through re-routing), or completely terminate the message.

Specified by:

forward in interface Application

Parameters:

message - The message being sent, containing an internal message along with a destination key and nodeHandle next hop.

Returns:

Whether or not to forward the message further

deliver

public void deliver(rice.p2p.commonapi.Id id,
                    rice.p2p.commonapi.Message message)

This method is called on the application at the destination node for the given id.

Specified by:

deliver in interface Application

Parameters:

id - The destination id of the message

message - The message being sent

update

public void update(rice.p2p.commonapi.NodeHandle handle,
                   boolean joined)

This method is invoked to inform the application that the given node has either joined or left the neighbor set of the local node, as the set would be returned by the neighborSet call.

Specified by:

update in interface Application

Parameters:

handle - The handle that has joined/left

joined - Whether the node has joined or left

fetch

public void fetch(rice.pastry.IdSet keySet)

This upcall is invoked to notify the application that is should fetch the cooresponding keys in this set, since the node is now responsible for these keys also.

Specified by:

fetch in interface RMClient

Parameters:

keySet - set containing the keys that needs to be fetched

rmIsReady

public void rmIsReady(rice.rm.RM rm)

This upcall is simply to denote that the underlying replica manager (rm) is ready. The 'rm' should henceforth be used by this RMClient to issue the downcalls on the RM interface.

Specified by:

rmIsReady in interface RMClient

Parameters:

rm - the instance of the Replica Manager

isResponsible

public void isResponsible(rice.pastry.IdRange range)

This upcall is to notify the application of the range of keys for which it is responsible. The application might choose to react to call by calling a scan(complement of this range) to the persistance manager and get the keys for which it is not responsible and call delete on the persistance manager for those objects.

Specified by:

isResponsible in interface RMClient

Parameters:

range - the range of keys for which the local node is currently responsible

scan

public rice.pastry.IdSet scan(rice.pastry.IdRange range)

This upcall should return the set of keys that the application currently stores in this range. Should return a empty IdSet (not null), in the case that no keys belong to this range.

Specified by:

scan in interface RMClient

Parameters:

range - the requested range

getReplicaManager

public rice.rm.RM getReplicaManager()

Returns the replica manager for this Past instance. Should *ONLY* be used for testing. Messing with this will cause unknown behavior.

Returns:

This Past's replica manager

getStorageManager

public rice.persistence.StorageManager getStorageManager()

Returns this Past's storage manager.

Returns:

This Past's storage manager.