rice.p2p.past.gc
Class GCPastImpl

java.lang.Object
  rice.p2p.past.PastImpl
      rice.p2p.past.gc.GCPastImpl

All Implemented Interfaces:

Application, GCPast, Past, ReplicationManagerClient

Direct Known Subclasses:

DeliveryPastImpl

public class GCPastImpl

extends PastImpl

implements GCPast

Version:

$Id: GCPastImpl.java 2867 2005-12-20 15:58:51Z jstewart $

Author:

Alan Mislove, Andreas Haeberlen

Nested Class Summary

protected class

GCPastImpl.ReplicaMap

Nested classes/interfaces inherited from class rice.p2p.past.PastImpl

PastImpl.MessageBuilder

Field Summary

int	collected
static long	DEFAULT_EXPIRATION The default expiration, or when objects inserted with no timeout will expire
protected IdFactory	realFactory The real factory, which is not wrapped with a GCIdFactory
int	refreshed

Fields inherited from class rice.p2p.past.PastImpl

backup, endpoint, environment, factory, fetchHandles, inserts, instance, logger, lookups, MESSAGE_TIMEOUT, other, policy, replicaManager, replicationFactor, storage, SUCCESSFUL_INSERT_THRESHOLD, trash

Fields inherited from interface rice.p2p.past.gc.GCPast

INFINITY_EXPIRATION

Constructor Summary

GCPastImpl(Node node, StorageManager manager, Cache backup, int replicas, java.lang.String instance, PastPolicy policy, long collectionInterval, StorageManager trash)
Constructor for GCPast

GCPastImpl(Node node, StorageManager manager, int replicas, java.lang.String instance, PastPolicy policy, long collectionInterval)
Constructor for GCPast

Method Summary

protected void	collect(java.util.SortedMap map, Continuation command) Internal method which collects all of the objects in the given set
void	deliver(Id id, Message message) This method is called on the application at the destination node for the given id.
boolean	exists(Id id) This upcall should return whether or not the given id is currently stored by the client.
void	existsInOverlay(Id id, Continuation command) This upcall should return whether or not the given id is currently stored somewhere in the overlay by the client.
void	fetch(Id id, NodeHandle hint, Continuation command) This upcall is invoked to tell the client to fetch the given id, and to call the given command with the boolean result once the fetch is completed.
boolean	forward(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.
void	insert(PastContent obj, Continuation command) Inserts an object with the given ID into this instance of Past.
void	insert(PastContent obj, long expiration, Continuation command) Inserts an object with the given ID into this instance of Past.
protected void	refresh(GCIdSet ids, Continuation command) Internal method which actually does the refreshing.
void	refresh(Id[] array, long[] expirations, Continuation command) Updates the objects stored under the provided keys id to expire no earlier than the provided expiration time.
void	refresh(Id[] array, long expiration, Continuation command) Updates the objects stored under the provided keys id to expire no earlier than the provided expiration time.
void	reInsert(Id id, Continuation command) Asks a client to reinsert an object it already holds into the overlay
void	remove(Id id, Continuation command) This upcall is to notify the client that the given id can be safely removed from the storage.
IdSet	scan() This upcall should return the set of keys that the application currently stores.
IdSet	scan(IdRange range) This upcall should return the set of keys that the application currently stores in this range.

Methods inherited from class rice.p2p.past.PastImpl

buildReplicationManager, cache, doInsert, fetch, getEndpoint, getEnvironment, getHandles, getInstance, getLocalNodeHandle, getOutstandingMessages, getReplication, getReplicationFactor, getResponseContinuation, getStorageManager, getUID, lookup, lookup, lookupHandle, lookupHandles, sendRequest, sendRequest, sendRequest, update

Methods inherited from class java.lang.Object

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

Methods inherited from interface rice.p2p.past.Past

fetch, getEnvironment, getInstance, getLocalNodeHandle, getReplicationFactor, lookup, lookup, lookupHandle, lookupHandles

Field Detail

DEFAULT_EXPIRATION

public static final long DEFAULT_EXPIRATION

The default expiration, or when objects inserted with no timeout will expire

See Also:

Constant Field Values

realFactory

protected IdFactory realFactory

The real factory, which is not wrapped with a GCIdFactory

collected

public int collected

refreshed

public int refreshed

Constructor Detail

GCPastImpl

public GCPastImpl(Node node,
                  StorageManager manager,
                  int replicas,
                  java.lang.String instance,
                  PastPolicy policy,
                  long collectionInterval)

Constructor for GCPast

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

policy - The policy this past instance should use

collectionInterval - The frequency with which GCPast should collection local expired objects

GCPastImpl

public GCPastImpl(Node node,
                  StorageManager manager,
                  Cache backup,
                  int replicas,
                  java.lang.String instance,
                  PastPolicy policy,
                  long collectionInterval,
                  StorageManager trash)

Constructor for GCPast

Parameters:

node - The node below this Past implementation

manager - The storage manager to be used by Past

backup - The cache used for previously-responsible objects (can be null)

replicas - The number of object replicas

instance - The unique instance name of this Past

trash - The storage manager to place the deleted objects into (if null, they are removed)

policy - The policy this past instance should use

collectionInterval - The frequency with which GCPast should collection local expired objects

Method Detail

insert

public void insert(PastContent obj,
                   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. This method is equivalent to insert(obj, INFINITY_EXPIRATION, command) as it inserts the object with a timeout value of infinity. This is done for simplicity, as well as backwards-compatibility for applications.

Specified by:

insert in interface GCPast

Specified by:

insert in interface Past

Overrides:

insert in class PastImpl

Parameters:

obj - the object to be inserted

command - Command to be performed when the result is received

insert

public void insert(PastContent obj,
                   long expiration,
                   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. The contract for this method is that the provided object will be stored until the provided expiration time. Thus, if the application determines that it is still interested in this object, it must refresh the object via the refresh() method.

Specified by:

insert in interface GCPast

Parameters:

obj - the object to be inserted

expiration - the time until which the object must be stored

command - Command to be performed when the result is received

refresh

public void refresh(Id[] array,
                    long expiration,
                    Continuation command)

Updates the objects stored under the provided keys id to expire no earlier than the provided expiration time. Asyncroniously returns the result to the caller via the provided continuation. The result of this operation is an Object[], which is the same length as the input array of Ids. Each element in the array is either Boolean(true), representing that the refresh succeeded for the cooresponding Id, or an Exception describing why the refresh failed. Specifically, the possible exceptions which can be returned are: ObjectNotFoundException - if no object was found under the given key RefreshFailedException - if the refresh operation failed for any other reason (the getMessage() will describe the failure)

Specified by:

refresh in interface GCPast

Parameters:

id - The keys which to refresh

expiration - The time to extend the lifetime to

command - Command to be performed when the result is received

refresh

public void refresh(Id[] array,
                    long[] expirations,
                    Continuation command)

Updates the objects stored under the provided keys id to expire no earlier than the provided expiration time. Asyncroniously returns the result to the caller via the provided continuation. The result of this operation is an Object[], which is the same length as the input array of Ids. Each element in the array is either Boolean(true), representing that the refresh succeeded for the cooresponding Id, or an Exception describing why the refresh failed. Specifically, the possible exceptions which can be returned are: ObjectNotFoundException - if no object was found under the given key RefreshFailedException - if the refresh operation failed for any other reason (the getMessage() will describe the failure)

Specified by:

refresh in interface GCPast

Parameters:

id - The keys which to refresh

expiration - The time to extend the lifetime to

command - Command to be performed when the result is received

refresh

protected void refresh(GCIdSet ids,
                       Continuation command)

Internal method which actually does the refreshing. Should not be called by external applications.

Parameters:

ids - The ids to refresh

expiration - The time to extend the lifetime until

command - The command to return the result to

forward

public boolean forward(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

Overrides:

forward in class PastImpl

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(Id id,
                    Message message)

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

Specified by:

deliver in interface Application

Overrides:

deliver in class PastImpl

Parameters:

id - The destination id of the message

message - The message being sent

collect

protected void collect(java.util.SortedMap map,
                       Continuation command)

Internal method which collects all of the objects in the given set

Parameters:

set - THe set to collect

command - The command to call once done

fetch

public void fetch(Id id,
                  NodeHandle hint,
                  Continuation command)

This upcall is invoked to tell the client to fetch the given id, and to call the given command with the boolean result once the fetch is completed. The client *MUST* call the command at some point in the future, as the manager waits for the command to return before continuing.

Specified by:

fetch in interface ReplicationManagerClient

Overrides:

fetch in class PastImpl

Parameters:

id - The id to fetch

hint - A hint where to find the key from. This is where the local node heard about the key.

command - The command to return the result to

remove

public void remove(Id id,
                   Continuation command)

This upcall is to notify the client that the given id can be safely removed from the storage. The client may choose to perform advanced behavior, such as caching the object, or may simply delete it.

Specified by:

remove in interface ReplicationManagerClient

Overrides:

remove in class PastImpl

Parameters:

id - The id to remove

scan

public IdSet scan(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 ReplicationManagerClient

Overrides:

scan in class PastImpl

Parameters:

range - the requested range

scan

public IdSet scan()

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

Overrides:

scan in class PastImpl

Parameters:

range - the requested range

exists

public boolean exists(Id id)

This upcall should return whether or not the given id is currently stored by the client.

Specified by:

exists in interface ReplicationManagerClient

Overrides:

exists in class PastImpl

Parameters:

id - The id in question

Returns:

Whether or not the id exists

existsInOverlay

public void existsInOverlay(Id id,
                            Continuation command)

Description copied from interface: ReplicationManagerClient

This upcall should return whether or not the given id is currently stored somewhere in the overlay by the client.

Specified by:

existsInOverlay in interface ReplicationManagerClient

Overrides:

existsInOverlay in class PastImpl

Parameters:

id - The id in question

reInsert

public void reInsert(Id id,
                     Continuation command)

Description copied from interface: ReplicationManagerClient

Asks a client to reinsert an object it already holds into the overlay

Specified by:

reInsert in interface ReplicationManagerClient

Overrides:

reInsert in class PastImpl

Parameters:

id - The id in question