Class AbstractPollableSubscription<T>

java.lang.Object

com.github.mizosoft.methanol.internal.flow.AbstractSubscription<T>

com.github.mizosoft.methanol.internal.flow.AbstractPollableSubscription<T>

All Implemented Interfaces:

Flow.Subscription

Direct Known Subclasses:

AbstractQueueSubscription

public abstract class AbstractPollableSubscription<T>
extends AbstractSubscription<T>

A subscription that emits items from a pollable source. This class's abstract methods are called serially, and implementations may assume they're being called from a single thread.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractPollableSubscription(Flow.Subscriber<? super T> downstream, Executor executor)

Method Summary

Modifier and Type	Method	Description
protected long	emit(Flow.Subscriber<? super T> downstream, long emit)	Emits at most emit items to downstream using AbstractSubscription.submitOnNext(Subscriber, Object) as long as it returns true.
protected abstract boolean	isComplete()	Returns true if downstream is to be completed.
protected abstract @Nullable T	poll()	Returns the next item, or null if no items are available.

Methods inherited from class AbstractSubscription

abort, cancel, cancelOnComplete, cancelOnError, currentDemand, fireOrKeepAlive, fireOrKeepAliveOnError, fireOrKeepAliveOnNext, hasPendingErrors, isCancelled, request, submitOnNext

Methods inherited from class Object

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

Constructor Details

AbstractPollableSubscription

protected AbstractPollableSubscription(Flow.Subscriber<? super T> downstream,
 Executor executor)

Method Details

poll

protected abstract @Nullable T poll()

Returns the next item, or null if no items are available.

isComplete

protected abstract boolean isComplete()

Returns true if downstream is to be completed. Implementation must ensure true isn't returned unless the subscription knows it won't produce any more items AND there aren't any present items expected to be polled.

emit

protected long emit(Flow.Subscriber<? super T> downstream,
 long emit)

Description copied from class: AbstractSubscription

Emits at most emit items to downstream using AbstractSubscription.submitOnNext(Subscriber, Object) as long as it returns true. The actual number of emitted items is returned, may be 0 in case of cancellation or if no items are emitted, perhaps due to lack thereof, or if emit itself is zero. If the underlying source is finished, the subscriber is completed with AbstractSubscription.cancelOnComplete(Subscriber).

Specified by:

emit in class AbstractSubscription<T>