com.github.mizool.core.concurrent

Class BufferedStreamAdapter<F,V>

java.lang.Object

com.github.mizool.core.concurrent.BufferedStreamAdapter<F,V>

public final class BufferedStreamAdapter<F,V>
extends Object

Buffers a stream of futures and provides the results as a new stream.

Futures are collected as fast as possible without the sum of concurrently running futures and available results exceeding bufferSize.

The new stream contains the results in the completion order of the futures. It blocks while no results are available and there are still futures to wait for.

Exceptional completion of futures

When one or more of the futures inside the stream complete exceptionally, the new stream will throw that exception when an attempt is made to consume the next result. The exception is thrown as is (i.e. not wrapped in ExecutionException as with Future.get()). Basically, the new stream behaves as if all computations were performed in a synchronous manner.

Exceptions thrown by the original stream

If the original stream throws an exception instead of producing a future, the new stream will behave the same way as with exceptional completion of futures: the exception will be thrown when an attempt is made to consume the next result.

Usage examples

 Stream<Completable<V>> completables;
 Stream<V> values = BufferedStreamAdapter.completable().adapt(completables, bufferSize, executorService);

 Stream<ListenableFuture<V>> listenables;
 Stream<V> values = BufferedStreamAdapter.listenable().adapt(listenables, bufferSize, executorService);

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BufferedStreamAdapter.Completable
static class	BufferedStreamAdapter.Listenable

Method Summary

Modifier and Type	Method and Description
static <E> Stream<E>	adapt(Stream<com.google.common.util.concurrent.ListenableFuture<E>> futures, int bufferSize, ExecutorService executorService) Deprecated. Use listenable() and BufferedStreamAdapter.Listenable.adapt(Stream, int, ExecutorService) instead.
static BufferedStreamAdapter.Completable	completable()
static BufferedStreamAdapter.Listenable	listenable()

Methods inherited from class java.lang.Object

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

Method Detail

listenable

public static BufferedStreamAdapter.Listenable listenable()

completable

public static BufferedStreamAdapter.Completable completable()

adapt

@Deprecated
public static <E> Stream<E> adapt(Stream<com.google.common.util.concurrent.ListenableFuture<E>> futures,
                                              int bufferSize,
                                              ExecutorService executorService)

Deprecated. Use listenable() and BufferedStreamAdapter.Listenable.adapt(Stream, int, ExecutorService) instead.