org.apache.nifi.io.nio.consumer

Class AbstractStreamConsumer

java.lang.Object

org.apache.nifi.io.nio.consumer.AbstractStreamConsumer

All Implemented Interfaces:

StreamConsumer

public abstract class AbstractStreamConsumer
extends Object
implements StreamConsumer

Field Summary

Fields

Modifier and Type	Field and Description
private BufferPool	bufferPool
private AtomicBoolean	consumerEnded
private BlockingQueue<ByteBuffer>	filledBuffers
private AtomicBoolean	streamEnded
private String	uniqueId

Constructor Summary

Constructors

Constructor and Description
AbstractStreamConsumer(String id)

Method Summary

Modifier and Type	Method and Description
void	addFilledBuffer(ByteBuffer buffer) Will be called by the thread that produces byte buffers with available data to be processed.
boolean	equals(Object obj)
String	getId() Uniquely identifies the consumer
int	hashCode()
boolean	isConsumerFinished() If true signals the consumer is done consuming data and will not process any more buffers.
protected void	onConsumerDone() Convenience method that is called when the consumer is done processing based on being told the signal is end of stream and has processed all given buffers.
void	process() Will be called by the thread that executes the consumption of data.
protected abstract void	processBuffer(ByteBuffer buffer)
void	setReturnBufferQueue(BufferPool returnQueue) Will be called once just after construction.
void	signalEndOfStream() Called once the end of the input stream is detected
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

uniqueId

private final String uniqueId

bufferPool

private BufferPool bufferPool

filledBuffers

private final BlockingQueue<ByteBuffer> filledBuffers

streamEnded

private final AtomicBoolean streamEnded

consumerEnded

private final AtomicBoolean consumerEnded

Constructor Detail

AbstractStreamConsumer

public AbstractStreamConsumer(String id)

Method Detail

setReturnBufferQueue

public final void setReturnBufferQueue(BufferPool returnQueue)

Description copied from interface: StreamConsumer

Will be called once just after construction. It provides the queue to which processed and emptied and cleared buffers must be returned. For each time addFilledBuffer is called there should be an associated add to this given queue. If not, buffers will run out and all stream processing will halt. READ THIS!!!

Specified by:

setReturnBufferQueue in interface StreamConsumer

Parameters:

returnQueue - pool of buffers to use

addFilledBuffer

public final void addFilledBuffer(ByteBuffer buffer)

Description copied from interface: StreamConsumer

Will be called by the thread that produces byte buffers with available data to be processed. If the consumer is finished this should simply return the given buffer to the return buffer queue (after it is cleared)

Specified by:

addFilledBuffer in interface StreamConsumer

Parameters:

buffer - filled buffer

process

public final void process()
                   throws IOException

Description copied from interface: StreamConsumer

Will be called by the thread that executes the consumption of data. May be called many times though once isConsumerFinished returns true this method will likely do nothing.

Specified by:

process in interface StreamConsumer

Throws:

IOException - if there is an issue processing

processBuffer

protected abstract void processBuffer(ByteBuffer buffer)
                               throws IOException

Throws:

IOException

signalEndOfStream

public final void signalEndOfStream()

Description copied from interface: StreamConsumer

Called once the end of the input stream is detected

Specified by:

signalEndOfStream in interface StreamConsumer

onConsumerDone

protected void onConsumerDone()

Convenience method that is called when the consumer is done processing based on being told the signal is end of stream and has processed all given buffers.

isConsumerFinished

public final boolean isConsumerFinished()

Description copied from interface: StreamConsumer

If true signals the consumer is done consuming data and will not process any more buffers.

Specified by:

isConsumerFinished in interface StreamConsumer

Returns:

true if finished

getId

public final String getId()

Description copied from interface: StreamConsumer

Uniquely identifies the consumer

Specified by:

getId in interface StreamConsumer

Returns:

identifier of consumer

equals

public final boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public final int hashCode()

Overrides:

hashCode in class Object

toString

public final String toString()

Overrides:

toString in class Object