rice.p2p.aggregation
Class AggregationImpl

java.lang.Object
  rice.p2p.aggregation.AggregationImpl

All Implemented Interfaces:

Aggregation, Application, VersioningPast, GCPast, Past, DebugCommandHandler

public class AggregationImpl

extends java.lang.Object

implements Past, GCPast, VersioningPast, Aggregation, Application, DebugCommandHandler

Field Summary

protected AggregateList	aggregateList
protected Past	aggregateStore
protected Endpoint	endpoint
protected IdFactory	factory
protected Continuation	flushWait
protected java.lang.String	instance
protected Logger	logger
protected java.util.Vector	monitorIDs
protected Node	node
protected Past	objectStore
protected AggregationPolicy	policy
protected boolean	rebuildInProgress
protected AggregationStatistics	stats
protected java.util.Hashtable	timers
protected StorageManager	waitingList

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

INFINITY_EXPIRATION

Constructor Summary

AggregationImpl(Node node, Past aggregateStore, Past objectStore, StorageManager waitingList, java.lang.String configFileName, IdFactory factory, java.lang.String instance)

AggregationImpl(Node node, Past aggregateStore, Past objectStore, StorageManager waitingList, java.lang.String configFileName, IdFactory factory, java.lang.String instance, AggregationPolicy policy)

Method Summary

void	deliver(Id id, Message message) This method is called on the application at the destination node for the given id.
void	fetch(PastContentHandle handle, Continuation command) Retrieves the object associated with a given content handle.
void	flush(Continuation command) Creates aggregates from all objects in the local object cache.
void	flush(Id id, Continuation command) Creates an aggregate that includes the most current object with the specified key.
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.
Past	getAggregateStore()
Environment	getEnvironment()
java.io.Serializable	getHandle() Fetches the handle object.
java.lang.String	getInstance()
NodeHandle	getLocalNodeHandle() get the nodeHandle of the local Past node
int	getNumObjectsWaiting()
Past	getObjectStore()
int	getReplicationFactor() Returns the number of replicas used in this Past
AggregationStatistics	getStatistics()
java.lang.String	handleDebugCommand(java.lang.String command)
void	insert(PastContent obj, Continuation command) Inserts an object with the given ID into this instance of Past.
void	insert(PastContent obj, long lifetime, Continuation command) Inserts an object with the given ID into this instance of Past.
void	lookup(Id id, boolean cache, Continuation command) Retrieves the object stored in this instance of Past with the given ID.
void	lookup(Id id, Continuation command) Retrieves the object stored in this instance of Past with the given ID.
void	lookup(Id id, long version, Continuation command) Retrieves the object stored in this instance of Past with the given ID and the specified version.
void	lookupHandle(Id id, NodeHandle handle, Continuation command) Retrieves the handle for the given object stored on the requested node.
void	lookupHandles(Id id, int max, Continuation command) Retrieves the handles of up to max replicas of the object stored in this instance of Past with the given ID.
void	lookupHandles(Id id, long version, int max, Continuation command) Retrieves the handles of up to max replicas of the object stored in this instance of Past with the given ID.
void	refresh(Id[] ids, 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[] ids, long[] versions, 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[] ids, long expiration, Continuation command) Updates the objects stored under the provided keys id to expire no earlier than the provided expiration time.
void	reset(Continuation command) Deletes all local state, including the aggregate list and all objects waiting in the local buffer.
void	rollback(Id id, Continuation command) Attempts to retrieve the most recent object that has been inserted by the local node under the specified key.
void	setConsolidationInterval(long consolidationIntervalSec)
void	setConsolidationMinObjectsPerAggregate(int minObjectsInAggregateArg)
void	setConsolidationMinUtilization(double minUtilization)
void	setConsolidationThreshold(long consolidationThresholdSec)
void	setFlushInterval(int flushIntervalSec)
void	setHandle(java.io.Serializable handle, Continuation command) Restores the handle object.
void	setMaxAggregateSize(int maxAggregateSize)
void	setMaxObjectsInAggregate(int maxObjectsInAggregate)
void	setRenewThreshold(int expirationRenewThresholdHrs)
void	update(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

aggregateStore

protected final Past aggregateStore

waitingList

protected final StorageManager waitingList

policy

protected final AggregationPolicy policy

aggregateList

protected final AggregateList aggregateList

endpoint

protected final Endpoint endpoint

objectStore

protected final Past objectStore

instance

protected final java.lang.String instance

factory

protected final IdFactory factory

node

protected final Node node

timers

protected java.util.Hashtable timers

flushWait

protected Continuation flushWait

rebuildInProgress

protected boolean rebuildInProgress

monitorIDs

protected java.util.Vector monitorIDs

stats

protected AggregationStatistics stats

logger

protected Logger logger

Constructor Detail

AggregationImpl

public AggregationImpl(Node node,
                       Past aggregateStore,
                       Past objectStore,
                       StorageManager waitingList,
                       java.lang.String configFileName,
                       IdFactory factory,
                       java.lang.String instance)
                throws java.io.IOException

Throws:

java.io.IOException

AggregationImpl

public AggregationImpl(Node node,
                       Past aggregateStore,
                       Past objectStore,
                       StorageManager waitingList,
                       java.lang.String configFileName,
                       IdFactory factory,
                       java.lang.String instance,
                       AggregationPolicy policy)
                throws java.io.IOException

Throws:

java.io.IOException

Method Detail

handleDebugCommand

public java.lang.String handleDebugCommand(java.lang.String command)

Specified by:

handleDebugCommand in interface DebugCommandHandler

refresh

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

Description copied from interface: GCPast

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

expiration - The time to extend the lifetime to (applies to all keys)

command - Command to be performed when the result is received

refresh

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

Description copied from interface: GCPast

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

expirations - The time to extend the lifetime to

command - Command to be performed when the result is received

refresh

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

Description copied from interface: VersioningPast

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 VersioningPast

command - Command to be performed when the result is received

getHandle

public java.io.Serializable getHandle()

Description copied from interface: Aggregation

Fetches the handle object. This object is important in the event of a failure that causes Aggregation to lose its local metadata cache. When the handle object is later restored via setHandle(), Aggregation can recover all objects that have been aggregated prior to the getHandle() call, except objects that have already expired. Note that this does not include objects that were still in the local buffer when the failure occurred. To prevent data loss, it is recommended to invoke flush() before fetching the handle object.

Specified by:

getHandle in interface Aggregation

Returns:

the current handle object

setHandle

public void setHandle(java.io.Serializable handle,
                      Continuation command)

Description copied from interface: Aggregation

Restores the handle object. This method should always be invoked at startup, using the most current handle object available. When the continuation is invoked, all non-expired objects linked to the handle are accessible from the local node.

Specified by:

setHandle in interface Aggregation

Parameters:

handle - the handle object

command - Command to be performed when the method completes.

insert

public void insert(PastContent obj,
                   Continuation command)

Description copied from interface: GCPast

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

Parameters:

obj - the object to be inserted

command - Command to be performed when the result is received

insert

public void insert(PastContent obj,
                   long lifetime,
                   Continuation command)

Description copied from interface: GCPast

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

lifetime - the time until which the object must be stored

command - Command to be performed when the result is received

lookup

public void lookup(Id id,
                   boolean cache,
                   Continuation command)

Description copied from interface: Past

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. This method also allows applications to specify if the result should be cached locally.

Specified by:

lookup in interface Past

Parameters:

id - the key to be queried

cache - Whether or not the result should be cached

command - Command to be performed when the result is received

lookup

public void lookup(Id id,
                   long version,
                   Continuation command)

Description copied from interface: VersioningPast

Retrieves the object stored in this instance of Past with the given ID and the specified version. Asynchronously returns a PastContent object as the result to the provided Continuation, or a PastException.

Specified by:

lookup in interface VersioningPast

Parameters:

id - the key to be queried

command - Command to be performed when the result is received

lookup

public void lookup(Id id,
                   Continuation command)

Description copied from interface: Past

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. By default, this method attempts to cache the result locally for future use. Applications which do not desire this behavior should use the lookup(id, boolean, command) method.

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(Id id,
                          long version,
                          int max,
                          Continuation command)

Description copied from interface: VersioningPast

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 VersioningPast

Parameters:

id - the key to be queried

version - the requested version

command - Command to be performed when the result is received

lookupHandle

public void lookupHandle(Id id,
                         NodeHandle handle,
                         Continuation command)

Description copied from interface: Past

Retrieves the handle for the given object stored on the requested node. Asynchronously returns a PostContentHandle (or null) to the provided continuation.

Specified by:

lookupHandle in interface Past

Parameters:

id - the key to be queried

handle - The node on which the handle is requested

command - Command to be performed when the result is received

lookupHandles

public void lookupHandles(Id id,
                          int max,
                          Continuation command)

Description copied from interface: Past

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(PastContentHandle handle,
                  Continuation command)

Description copied from interface: Past

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:

handle - the key to be queried

command - Command to be performed when the result is received

flush

public void flush(Id id,
                  Continuation command)

Description copied from interface: Aggregation

Creates an aggregate that includes the most current object with the specified key. When the continuation is invoked, the object is persistent and linked to the current handle object.

Specified by:

flush in interface Aggregation

Parameters:

id - the key of the object to be made persistent.

command - Command to be performed when the method completes.

flush

public void flush(Continuation command)

Description copied from interface: Aggregation

Creates aggregates from all objects in the local object cache. When the continuation is invoked, all objects that were inserted prior to flush() are persistent and linked to the current handle object.

Specified by:

flush in interface Aggregation

Parameters:

command - Command to be performed when the method completes.

rollback

public void rollback(Id id,
                     Continuation command)

Description copied from interface: Aggregation

Attempts to retrieve the most recent object that has been inserted by the local node under the specified key. This is useful when the object has been overwritten by an attacker. This method may fail or return an outdated version of the object if a) the object is not linked to the current handle, or b) the object was never aggregated because of the aggregation policy.

Specified by:

rollback in interface Aggregation

Parameters:

id - the key of the object to be retrieved

command - Command to be performed when the method completes.

reset

public void reset(Continuation command)

Description copied from interface: Aggregation

Deletes all local state, including the aggregate list and all objects waiting in the local buffer. This is useful when the local instance appears to have been corrupted or tampered with. The state can be recovered by invoking setHandle() with an earlier handle object, and by using rollback() on objects that appear to have been overwritten.

Specified by:

reset in interface Aggregation

Parameters:

command - Command to be performed when the method completes.

getLocalNodeHandle

public NodeHandle getLocalNodeHandle()

Description copied from interface: Past

get the nodeHandle of the local Past node

Specified by:

getLocalNodeHandle in interface Past

Returns:

the nodehandle

getReplicationFactor

public int getReplicationFactor()

Description copied from interface: Past

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(RouteMessage message)

Description copied from interface: Application

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

update

public void update(NodeHandle handle,
                   boolean joined)

Description copied from interface: Application

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

deliver

public void deliver(Id id,
                    Message message)

Description copied from interface: Application

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

setFlushInterval

public void setFlushInterval(int flushIntervalSec)

setMaxAggregateSize

public void setMaxAggregateSize(int maxAggregateSize)

setMaxObjectsInAggregate

public void setMaxObjectsInAggregate(int maxObjectsInAggregate)

setRenewThreshold

public void setRenewThreshold(int expirationRenewThresholdHrs)

setConsolidationInterval

public void setConsolidationInterval(long consolidationIntervalSec)

setConsolidationThreshold

public void setConsolidationThreshold(long consolidationThresholdSec)

setConsolidationMinObjectsPerAggregate

public void setConsolidationMinObjectsPerAggregate(int minObjectsInAggregateArg)

setConsolidationMinUtilization

public void setConsolidationMinUtilization(double minUtilization)

getAggregateStore

public Past getAggregateStore()

getObjectStore

public Past getObjectStore()

getNumObjectsWaiting

public int getNumObjectsWaiting()

getStatistics

public AggregationStatistics getStatistics()

getInstance

public java.lang.String getInstance()

Specified by:

getInstance in interface Past

Returns:

getEnvironment

public Environment getEnvironment()

Specified by:

getEnvironment in interface Past