Module methanol

Package com.github.mizosoft.methanol.internal.flow

Class AbstractSubscription<T>

java.lang.Object

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

All Implemented Interfaces:

Flow.Subscription

Direct Known Subclasses:

AbstractPollableSubscription

public abstract class AbstractSubscription<T>
extends Object
implements Flow.Subscription

An abstract Flow.Subscription that implements most of the machinery for execution and backpressure control.

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
protected void	abort(boolean flowInterrupted)	Releases resources held by this subscription.
final void	cancel()
protected final void	cancelOnComplete(Flow.Subscriber<? super T> downstream)	Calls downstream's onComplete after cancelling this subscription.
protected final void	cancelOnError(Flow.Subscriber<? super T> downstream, Throwable exception, boolean flowInterrupted)	Calls downstream's onError with the given exception after cancelling this subscription.
protected long	currentDemand()
protected abstract long	emit(Flow.Subscriber<? super T> downstream, long emit)	Emits at most emit items to downstream using submitOnNext(Subscriber, Object) as long as it returns true.
void	fireOrKeepAlive()
void	fireOrKeepAliveOnError(Throwable exception)
void	fireOrKeepAliveOnNext()
protected final boolean	hasPendingErrors()	Returns true if the subscriber is to be completed exceptionally.
protected final boolean	isCancelled()	Returns true if this subscription is cancelled.
final void	request(long n)
protected final boolean	submitOnNext(Flow.Subscriber<? super T> downstream, T item)	Submits given item to the downstream, returning false and cancelling on failure.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractSubscription

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

Method Details

request

public final void request(long n)

Specified by:

request in interface Flow.Subscription

cancel

public final void cancel()

Specified by:

cancel in interface Flow.Subscription

fireOrKeepAlive

public void fireOrKeepAlive()

fireOrKeepAliveOnNext

public void fireOrKeepAliveOnNext()

fireOrKeepAliveOnError

public void fireOrKeepAliveOnError(Throwable exception)

emit

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

Emits at most emit items to downstream using 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 cancelOnComplete(Subscriber).

abort

protected void abort(boolean flowInterrupted)

Releases resources held by this subscription. flowInterrupted tells whether cancellation was due to flow interruption by downstream (e.g. calling cancel() or throwing from onNext or onSubscribe), or due to ending the normal flow of signals (onSubscribe -> onNext* -> (onError | onComplete)).

isCancelled

protected final boolean isCancelled()

Returns true if this subscription is cancelled. false result is immediately outdated. Can be used by implementation to halt producing items in case the subscription was asynchronously cancelled.

hasPendingErrors

protected final boolean hasPendingErrors()

Returns true if the subscriber is to be completed exceptionally. false result is immediately outdated. Can be used by implementation to halt producing items in case the subscription was asynchronously signalled with an error.

cancelOnError

protected final void cancelOnError(Flow.Subscriber<? super T> downstream,
 Throwable exception,
 boolean flowInterrupted)

Calls downstream's onError with the given exception after cancelling this subscription. flowInterrupted tells whether the error interrupted the normal flow of signals.

cancelOnComplete

protected final void cancelOnComplete(Flow.Subscriber<? super T> downstream)

Calls downstream's onComplete after cancelling this subscription.

submitOnNext

protected final boolean submitOnNext(Flow.Subscriber<? super T> downstream,
 T item)

Submits given item to the downstream, returning false and cancelling on failure. false is also returned if the subscription is already cancelled or has pending errors. On such cases, caller should stop emitting items.

currentDemand

protected long currentDemand()