io.prestosql.execution.buffer

Interface OutputBuffer

All Known Implementing Classes:

ArbitraryOutputBuffer, BroadcastOutputBuffer, LazyOutputBuffer, PartitionedOutputBuffer

public interface OutputBuffer

Method Summary

Modifier and Type	Method and Description
void	abort(OutputBuffers.OutputBufferId bufferId) Closes the specified output buffer.
void	acknowledge(OutputBuffers.OutputBufferId bufferId, long token) Acknowledges the previously received pages from the output buffer.
void	addStateChangeListener(StateMachine.StateChangeListener<BufferState> stateChangeListener) Add a listener which fires anytime the buffer state changes.
void	destroy() Destroys the buffer, discarding all pages.
void	enqueue(int partition, List<SerializedPage> pages) Adds a split-up page to a specific partition.
void	enqueue(List<SerializedPage> pages) Adds a split-up page to an unpartitioned buffer.
void	fail() Fail the buffer, discarding all pages, but blocking readers.
com.google.common.util.concurrent.ListenableFuture<BufferResult>	get(OutputBuffers.OutputBufferId bufferId, long token, io.airlift.units.DataSize maxSize) Gets pages from the output buffer, and acknowledges all pages received from the last request.
OutputBufferInfo	getInfo() Gets the current state of this buffer.
long	getPeakMemoryUsage()
double	getUtilization() Get the memory utilization percentage.
boolean	isFinished() A buffer is finished once no-more-pages has been set and all buffers have been closed with an abort call.
com.google.common.util.concurrent.ListenableFuture<?>	isFull() Get a future that will be completed when the buffer is not full.
boolean	isOverutilized() Check if the buffer is blocking producers.
void	setNoMorePages() Notify buffer that no more pages will be added.
void	setOutputBuffers(OutputBuffers newOutputBuffers) Updates the buffer configuration.

Method Detail

getInfo

OutputBufferInfo getInfo()

Gets the current state of this buffer. This method is guaranteed to not block or acquire contended locks, but the stats in the info object may be internally inconsistent.

isFinished

boolean isFinished()

A buffer is finished once no-more-pages has been set and all buffers have been closed with an abort call.

getUtilization

double getUtilization()

Get the memory utilization percentage.

isOverutilized

boolean isOverutilized()

Check if the buffer is blocking producers.

addStateChangeListener

void addStateChangeListener(StateMachine.StateChangeListener<BufferState> stateChangeListener)

Add a listener which fires anytime the buffer state changes. Listener is always notified asynchronously using a dedicated notification thread pool so, care should be taken to avoid leaking this when adding a listener in a constructor. Additionally, it is possible notifications are observed out of order due to the asynchronous execution.

setOutputBuffers

void setOutputBuffers(OutputBuffers newOutputBuffers)

Updates the buffer configuration.

get

com.google.common.util.concurrent.ListenableFuture<BufferResult> get(OutputBuffers.OutputBufferId bufferId,
                                                                     long token,
                                                                     io.airlift.units.DataSize maxSize)

Gets pages from the output buffer, and acknowledges all pages received from the last request. The initial token is zero. Subsequent tokens are acquired from the next token field in the BufferResult returned from the previous request. If the buffer result is marked as complete, the client must call abort to acknowledge receipt of the final state.

acknowledge

void acknowledge(OutputBuffers.OutputBufferId bufferId,
                 long token)

Acknowledges the previously received pages from the output buffer.

abort

void abort(OutputBuffers.OutputBufferId bufferId)

Closes the specified output buffer.

isFull

com.google.common.util.concurrent.ListenableFuture<?> isFull()

Get a future that will be completed when the buffer is not full.

enqueue

void enqueue(List<SerializedPage> pages)

Adds a split-up page to an unpartitioned buffer. If no-more-pages has been set, the enqueue page call is ignored. This can happen with limit queries.

enqueue

void enqueue(int partition,
             List<SerializedPage> pages)

Adds a split-up page to a specific partition. If no-more-pages has been set, the enqueue page call is ignored. This can happen with limit queries.

setNoMorePages

void setNoMorePages()

Notify buffer that no more pages will be added. Any future calls to enqueue a page are ignored.

destroy

void destroy()

Destroys the buffer, discarding all pages.

fail

void fail()

Fail the buffer, discarding all pages, but blocking readers. It is expected that readers will be unblocked when the failed query is cleaned up.

getPeakMemoryUsage

long getPeakMemoryUsage()

Returns:

the peak memory usage of this output buffer.