co.cask.cdap.data2.queue

Class ForwardingQueueConsumer

java.lang.Object

co.cask.cdap.data2.queue.ForwardingQueueConsumer

All Implemented Interfaces:

QueueConsumer, co.cask.tephra.TransactionAware, Closeable, AutoCloseable

public abstract class ForwardingQueueConsumer
extends Object
implements QueueConsumer, co.cask.tephra.TransactionAware

A TransactionAware QueueConsumer that forwards all queue operations to another QueueConsumer and optionally forward transaction operations if the target QueueConsumer is also TransactionAware.

Field Summary

Fields

Modifier and Type	Field and Description
protected QueueConsumer	consumer
protected co.cask.tephra.TransactionAware	txAware

Constructor Summary

Constructors

Constructor and Description
ForwardingQueueConsumer(QueueConsumer consumer)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	commitTx()
DequeueResult<byte[]>	dequeue() Dequeue an entry from the queue.
DequeueResult<byte[]>	dequeue(int maxBatchSize) Dequeue multiple entries from the queue.
ConsumerConfig	getConfig() Returns the configuration of this consumer.
QueueName	getQueueName() Returns the queue name that this consumer is working on.
String	getTransactionAwareName()
Collection<byte[]>	getTxChanges()
void	postTxCommit()
boolean	rollbackTx()
void	startTx(co.cask.tephra.Transaction tx)
void	updateTx(co.cask.tephra.Transaction transaction)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.io.Closeable

close

Field Detail

consumer

protected final QueueConsumer consumer

txAware

protected final co.cask.tephra.TransactionAware txAware

Constructor Detail

ForwardingQueueConsumer

public ForwardingQueueConsumer(QueueConsumer consumer)

Method Detail

getTransactionAwareName

public String getTransactionAwareName()

Specified by:

getTransactionAwareName in interface co.cask.tephra.TransactionAware

getQueueName

public QueueName getQueueName()

Description copied from interface: QueueConsumer

Returns the queue name that this consumer is working on.

Specified by:

getQueueName in interface QueueConsumer

getConfig

public ConsumerConfig getConfig()

Description copied from interface: QueueConsumer

Returns the configuration of this consumer.

Specified by:

getConfig in interface QueueConsumer

dequeue

public DequeueResult<byte[]> dequeue()
                              throws IOException

Description copied from interface: QueueConsumer

Dequeue an entry from the queue.

Specified by:

dequeue in interface QueueConsumer

Returns:

A DequeueResult.

Throws:

IOException

dequeue

public DequeueResult<byte[]> dequeue(int maxBatchSize)
                              throws IOException

Description copied from interface: QueueConsumer

Dequeue multiple entries from the queue. The dequeue result may have less entries than the given maxBatchSize, depending on how many entries in the queue.

Specified by:

dequeue in interface QueueConsumer

Parameters:

maxBatchSize - Maximum number of entries to queue.

Returns:

A DequeueResult.

Throws:

IOException

startTx

public void startTx(co.cask.tephra.Transaction tx)

Specified by:

startTx in interface co.cask.tephra.TransactionAware

updateTx

public void updateTx(co.cask.tephra.Transaction transaction)

Specified by:

updateTx in interface co.cask.tephra.TransactionAware

getTxChanges

public Collection<byte[]> getTxChanges()

Specified by:

getTxChanges in interface co.cask.tephra.TransactionAware

commitTx

public boolean commitTx()
                 throws Exception

Specified by:

commitTx in interface co.cask.tephra.TransactionAware

Throws:

Exception

postTxCommit

public void postTxCommit()

Specified by:

postTxCommit in interface co.cask.tephra.TransactionAware

rollbackTx

public boolean rollbackTx()
                   throws Exception

Specified by:

rollbackTx in interface co.cask.tephra.TransactionAware

Throws:

Exception