org.apache.druid.frame.processor

Class FrameProcessorExecutor

java.lang.Object

org.apache.druid.frame.processor.FrameProcessorExecutor

public class FrameProcessorExecutor
extends Object

Manages execution of FrameProcessor in an ExecutorService. If you want single threaded execution, use Execs.singleThreaded(). It is not a good idea to use this with a same-thread executor like Execs.directExecutor(), because it will lead to deep call stacks.

Constructor Summary

Constructors

Constructor and Description
FrameProcessorExecutor(com.google.common.util.concurrent.ListeningExecutorService exec)

Method Summary

Modifier and Type	Method and Description
void	cancel(String cancellationId) Cancels all processors associated with a given cancellationId.
com.google.common.util.concurrent.ListeningExecutorService	getExecutorService() Returns the underlying executor service used by this executor.
<T,ResultType> com.google.common.util.concurrent.ListenableFuture<ResultType>	runAllFully(Sequence<? extends FrameProcessor<T>> processors, ResultType initialResult, BiFunction<ResultType,T,ResultType> accumulateFn, int maxOutstandingProcessors, Bouncer bouncer, String cancellationId) Runs a sequence of processors and returns a future that resolves when execution is complete.
<T> com.google.common.util.concurrent.ListenableFuture<T>	runFully(FrameProcessor<T> processor, String cancellationId) Runs a processor until it is done, and returns a future that resolves when execution is complete.

Methods inherited from class java.lang.Object

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

Constructor Detail

FrameProcessorExecutor

public FrameProcessorExecutor(com.google.common.util.concurrent.ListeningExecutorService exec)

Method Detail

getExecutorService

public com.google.common.util.concurrent.ListeningExecutorService getExecutorService()

Returns the underlying executor service used by this executor.

runFully

public <T> com.google.common.util.concurrent.ListenableFuture<T> runFully(FrameProcessor<T> processor,
                                                                          @Nullable
                                                                          String cancellationId)

Runs a processor until it is done, and returns a future that resolves when execution is complete. If "cancellationId" is provided, it can be used with the cancel(String) method to cancel all processors currently running with the same cancellationId.

runAllFully

public <T,ResultType> com.google.common.util.concurrent.ListenableFuture<ResultType> runAllFully(Sequence<? extends FrameProcessor<T>> processors,
                                                                                                 ResultType initialResult,
                                                                                                 BiFunction<ResultType,T,ResultType> accumulateFn,
                                                                                                 int maxOutstandingProcessors,
                                                                                                 Bouncer bouncer,
                                                                                                 @Nullable
                                                                                                 String cancellationId)

Runs a sequence of processors and returns a future that resolves when execution is complete. Returns a value accumulated using the provided accumulateFn.

Parameters:

processors - sequence of processors to run

initialResult - initial value for result accumulation. If there are no processors at all, this is returned.

accumulateFn - result accumulator. Applied in a critical section, so it should be something that executes quickly. It gets initialResult for the initial accumulation.

maxOutstandingProcessors - maximum number of processors to run at once

bouncer - additional limiter on outstanding processors, beyond maxOutstandingProcessors. Useful when there is some finite resource being shared against multiple different calls to this method.

cancellationId - optional cancellation id for runFully(org.apache.druid.frame.processor.FrameProcessor<T>, java.lang.String).

cancel

public void cancel(String cancellationId)
            throws InterruptedException

Cancels all processors associated with a given cancellationId. Waits for the processors to exit before returning.

Throws:

InterruptedException