org.activemq.store.vm
Class VMPersistenceAdapter

java.lang.Object
  org.activemq.store.vm.VMPersistenceAdapter

All Implemented Interfaces:

Service, PersistenceAdapter

public class VMPersistenceAdapter
extends Object
implements PersistenceAdapter

Version:

$Revision: 1.1.1.1 $

Constructor Summary

VMPersistenceAdapter()

Method Summary

void	beginTransaction() This method starts a transaction on the persistent storage - which is nothing to do with JMS or XA transactions - its purely a mechanism to perform multiple writes to a persistent store in 1 transaction as a performance optimisation.
void	commitTransaction() Commit a persistence transaction
MessageStore	createQueueMessageStore(String destinationName) Factory method to create a new queue message store with the given destination name
TopicMessageStore	createTopicMessageStore(String destinationName) Factory method to create a new topic message store with the given destination name
TransactionStore	createTransactionStore() Factory method to create a new persistent prepared transaction store for XA recovery
boolean	deadLetterAlreadySent(long seq, boolean useLocking) Verifies if a dead letter has already been sent for a message
Map	getInitialDestinations() Returns a map, indexed by String name, of all the Destination objects active on startup.
static VMPersistenceAdapter	newInstance(File file)
void	rollbackTransaction() Rollback a persistence transaction
void	start() Called to start the service
void	stop() Called to shutdown the service

Methods inherited from class java.lang.Object

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

Constructor Detail

VMPersistenceAdapter

public VMPersistenceAdapter()

Method Detail

getInitialDestinations

public Map getInitialDestinations()

Description copied from interface: PersistenceAdapter

Returns a map, indexed by String name, of all the Destination objects active on startup.

Specified by:

getInitialDestinations in interface PersistenceAdapter

Returns:

newInstance

public static VMPersistenceAdapter newInstance(File file)

createQueueMessageStore

public MessageStore createQueueMessageStore(String destinationName)
                                     throws JMSException

Description copied from interface: PersistenceAdapter

Factory method to create a new queue message store with the given destination name

Specified by:

createQueueMessageStore in interface PersistenceAdapter

Throws:

JMSException

createTopicMessageStore

public TopicMessageStore createTopicMessageStore(String destinationName)
                                          throws JMSException

Description copied from interface: PersistenceAdapter

Factory method to create a new topic message store with the given destination name

Specified by:

createTopicMessageStore in interface PersistenceAdapter

Throws:

JMSException

createTransactionStore

public TransactionStore createTransactionStore()
                                        throws JMSException

Description copied from interface: PersistenceAdapter

Factory method to create a new persistent prepared transaction store for XA recovery

Specified by:

createTransactionStore in interface PersistenceAdapter

Throws:

JMSException

beginTransaction

public void beginTransaction()

Description copied from interface: PersistenceAdapter

This method starts a transaction on the persistent storage - which is nothing to do with JMS or XA transactions - its purely a mechanism to perform multiple writes to a persistent store in 1 transaction as a performance optimisation.

Typically one transaction will require one disk synchronization point and so for real high performance its usually faster to perform many writes within the same transaction to minimise latency caused by disk synchronization. This is especially true when using tools like Berkeley Db or embedded JDBC servers.

Specified by:

beginTransaction in interface PersistenceAdapter

commitTransaction

public void commitTransaction()

Description copied from interface: PersistenceAdapter

Commit a persistence transaction

Specified by:

commitTransaction in interface PersistenceAdapter

See Also:

PersistenceAdapter.beginTransaction()

rollbackTransaction

public void rollbackTransaction()

Description copied from interface: PersistenceAdapter

Rollback a persistence transaction

Specified by:

rollbackTransaction in interface PersistenceAdapter

See Also:

PersistenceAdapter.beginTransaction()

start

public void start()
           throws JMSException

Description copied from interface: Service

Called to start the service

Specified by:

start in interface Service

Throws:

JMSException

stop

public void stop()
          throws JMSException

Description copied from interface: Service

Called to shutdown the service

Specified by:

stop in interface Service

Throws:

JMSException

deadLetterAlreadySent

public boolean deadLetterAlreadySent(long seq,
                                     boolean useLocking)

Verifies if a dead letter has already been sent for a message

Specified by:

deadLetterAlreadySent in interface PersistenceAdapter

Parameters:

seq -

useLocking - to prevent concurrency/dups

Returns: