Package com.ibm.websphere.objectgrid.plugins

These are the interfaces for adding plugins to the Grid core framework.

See:
Description

Interface Summary

BackingMapLifecycleListener	Listener for BackingMap life cycle events.
BackingMapLifecycleListener.LifecycleEvent	The LifecycleEvent describes the situation that caused a change in the lifecycle of the BackingMap.
BackingMapPlugin	BackingMap plug-ins implement this interface to be invoked when the plug-in should be initialized and destroyed.
BeanFactory	Implement this interface to allow bean factories like Spring or Google guice to be integrated.
CacheEntry	This interface represents a cache entry in an ObjectGrid map.
Destroyable	Java bean plug-ins can implement this interface to allow destroying the plug-in after it's state has been set.
EventListener	The EventListener interface is the base interface used to indicate that an implementing class can accept certain ObjectGrid or BackingMap events.
EvictionEventCallback	An instance of EvictionEventCallback is passed into the Evictor at initialization time.
Evictor	Data contained in a BackingMap are evicted when the map is full.
EvictorData	This interface is optionally used by an implementator of the Evictor interface.
ExceptionMapper	The ExceptionMapper interface allows users to plug in specific exception mapping functionality.
Initializable	Java bean plug-ins can implement this interface to allow initializing the plug-in after it's state has been set.
Loader	Data in a map sometimes are backed up by a "database".
LogElement	LogElements are the individual entries within a LogSequence.
LogSequence	LogSequence is the ordered list of changes performed against a given map for a given transaction.
LogSequenceFilter	This interface can be used to filter a LogSequence.
MapEventListener	This callback interface is implemented by the application when it wants to receive events about a Map such as the eviction of a map entry.
ObjectGridEventGroup	This is a set of single method interfaces for fine grained events delivered for an ObjectGrid.
ObjectGridEventGroup.ShardEvents	These events are fired when a shard is made a primary shard and when the shard is demoted from a primary.
ObjectGridEventGroup.ShardLifecycle	These events are fired when an ObjectGrid shard is initialized and destroyed.
ObjectGridEventGroup.TransactionEvents	These events are called every single transaction.
ObjectGridEventListener	This interface is used to create an implementation of an event listener for an ObjectGrid.
ObjectGridLifecycleListener	Listener for ObjectGrid life cycle events.
ObjectGridLifecycleListener.LifecycleEvent	The LifecycleEvent describes the situation that caused a change in the lifecycle of the ObjectGrid.
ObjectGridPlugin	ObjectGrid plug-ins implement this interface to be invoked when the plug-in should be initialized and destroyed.
ObjectTransformer	Deprecated. This plug-in is deprecated in version 7.1.1.
OptimisticCallback	Deprecated. This plug-in is deprecated in version 7.1.1.
PartitionableKey	This interface is used to identify keys that want to use their own partitioning algorithm.
ReplicaPreloadController	A Map Loader should also implement this interface in the following circumstances.
ReplicationMapListener	Deprecated. The client replicated map function is deprecated in version 8.6.
RetryableLoader	This interface represents a loader which is capable of handling a retry (redo) update from ObjectGrid runtime.
RollbackEvictor	This interface is optionally implemented by an Evictor plugin.
TransactionCallback	Calling methods on a Session will send corresponding events to the TransactionCallback.
TransactionCallback.BeforeCommit	The BeforeCommit optional mix-in interface for the TransactionCallback plug-in interface allows plug-ins to be notified at the beginning of a Session.commit().
TransactionCallback.BeforeCommit.TransactionContext	The TransactionContext identifies various information that's available to the beforeCommit() method.
ValueProxyInfo	This interface can be used by value objects to inform a BackingMap or Loader which attribute(s) have been dirtied.

Class Summary

DistributionMode	This class is used to define the "distribution" mode when the serialize() method on the LogSequenceTransformer interface is used.
EvictorData.SpecialEvictorData	Special value class used for representing the key not being found in the BackingMap.
Loader.SpecialValue	Special value class used for representing the key not being found in the Loader.
LogElement.Type	The Type class is used to represent a LogElement type.
LogSequenceTransformer	This class is used to serialize and de-serialize LogSequences.
ReplicaPreloadController.Status	This class is used as an enumerator for the Map preload status.

Enum Summary

BackingMapLifecycleListener.State	The state of a BackingMap's life cycle.
ObjectGridLifecycleListener.State	The state of a ObjectGrid's life cycle.

Exception Summary

CacheEntryException	This exception indicates an error occurred during a cache entry operation.
LifecycleFailedException	Thrown when there is a fatal problem invoking a BackingMapLifecycleListener or ObjectGridLifecycleListener.
LoaderException	This exception is the base exception for any exceptions encountered by a Loader.
OptimisticCollisionException	This exception is thrown when optimistic locking strategy is used and more than one update transaction collides on the same map entry of a ObjectGrid instance.
TransactionCallbackException	This exception is thrown when a method call to TransactionCallback fails.

Package com.ibm.websphere.objectgrid.plugins Description

These are the interfaces for adding plugins to the Grid core framework.

Overview

These plugins can be added into ObjectGrid in several ways such as xml configuration, programmatically adding, or using annotation.

Annotation based callbacks

ObjectGrid when running on Java 5 will start to use an annotated method callback system. This means that objects can be registered as callbacks or listeners. The methods on the object must be annotated as to be invoked for a certain event. Unannotated methods are not invoked. The name of the method is unimportant. The method arguments and return type must be the same as expected for the callback method.

Why?

Usually, callbacks are specified using an interface. This works well but results in a possible performance loss as all methods on the interface will be invoked by the ObjectGrid even though the application is only interested in a single event. This wastes precious resources. Another issue is when we need to add a new event. Adding a new method to an existing interface breaks back wards compatibility. We can make a new interface extending the old one with the new methods but this is also undesirable as soon there are many interfaces in the hierarchy as new events are added. The annotation system allows the application to only mark methods to be called avoiding the first problem and if new event types are added they have no impact on existing callback objects. Newer applications can add a method and annotate it with the new event annotation to receive the event.