Package com.ibm.asyncutil.flow

Class FlowAdapter

java.lang.Object

com.ibm.asyncutil.flow.FlowAdapter

public class FlowAdapter
extends Object

Adapters to convert between Flow.Publisher and AsyncIterator.

Method Summary

Modifier and Type	Method	Description
static <T> AsyncIterator<T>	toAsyncIterator(Flow.Publisher<? extends T> publisher)	Convert a Flow.Publisher into an AsyncIterator.
static <T> Flow.Publisher<T>	toPublisher(AsyncIterator<? extends T> asyncIterator)	Convert an AsyncIterator into a Flow.Publisher.
static <T> Flow.Publisher<T>	toPublisher(Supplier<AsyncIterator<? extends T>> asyncIteratorSupplier)	Convert a Supplier of AsyncIterators into a Flow.Publisher.

Methods inherited from class java.lang.Object

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

Method Detail

toAsyncIterator

public static <T> AsyncIterator<T> toAsyncIterator(Flow.Publisher<? extends T> publisher)

Convert a Flow.Publisher into an AsyncIterator. Calling a terminal method on a pipeline including the returned iterator will start a subscription on publisher. Elements will be requested as the returned iterator is consumed, and the returned iterator will stop iteration when the publisher finishes or produces an error.

Users of the returned AsyncIterator must call AsyncIterator.close() when they have finished using the iterator so that publisher may clean up any associated resources.

Parameters:

publisher - that will be subscribed to in order to yield elements from the returned iterator

Returns:

An AsyncIterator that will iterate over elements produced via a Flow.Subscription from the given publisher

toPublisher

public static <T> Flow.Publisher<T> toPublisher(AsyncIterator<? extends T> asyncIterator)

Convert an AsyncIterator into a Flow.Publisher. Because AsyncIterators are single consumer, the returned publisher should only be subscribed to once. When asyncIterator is exhausted or returns an exception the iterator will be closed and Flow.Subscriber will be notified accordingly. If the Flow.Subscription is cancelled before iterator is complete, the iterator be closed as well.

Exceptions produced by either iteration or by close will be delivered via Flow.Subscriber.onError(Throwable). If both iteration and close produce exceptions, the exception produced by close will be added as a suppressed exception to the iteration exception.

Parameters:

asyncIterator - used to produce elements published by the returned Flow.Publisher

Returns:

a Flow.Publisher that supports a single subscription that will yield elements from asyncIterator

toPublisher

public static <T> Flow.Publisher<T> toPublisher(Supplier<AsyncIterator<? extends T>> asyncIteratorSupplier)

Convert a Supplier of AsyncIterators into a Flow.Publisher. Because AsyncIterators are single consumer, each subscription of the returned publisher will generate a new AsyncIterator from asyncIteratorSupplier. When a generated AsyncIterator is exhausted or returns an exception the iterator will be closed and Flow.Subscriber will be notified accordingly. If the Flow.Subscription is cancelled before iterator is complete, the iterator be closed as well.

Exceptions produced by either iteration or by close will be delivered via Flow.Subscriber.onError(Throwable). If both iteration and close produce exceptions, the exception produced by close will be added as a suppressed exception to the iteration exception.

Parameters:

asyncIteratorSupplier - used to produce AsyncIterators of elements published by the returned Flow.Publisher

Returns:

a Flow.Publisher that supports multiple subscriptions that will yield elements from AsyncIterators generated from asyncIteratorSupplier