Package reactor.core.publisher

Interface FluxSink<T>

Type Parameters:

T - the value type

public interface FluxSink<T>

Wrapper API around a downstream Subscriber for emitting any number of next signals followed by zero or one onError/onComplete.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static enum	FluxSink.OverflowStrategy	Enumeration for backpressure handling.

Method Summary

Modifier and Type	Method	Description
void	complete()	Terminate the sequence successfully, generating an onComplete signal.
default ContextView	contextView()	Return the current subscriber's context as a ContextView for inspection.
Context	currentContext()	Deprecated. To be removed in 3.6.0 at the earliest.
void	error(Throwable e)	Fail the sequence, generating an onError signal.
boolean	isCancelled()	Returns true if the downstream cancelled the sequence.
FluxSink<T>	next(T t)	Emit a non-null element, generating an onNext signal.
FluxSink<T>	onCancel(Disposable d)	Attach a Disposable as a callback for when this FluxSink is cancelled.
FluxSink<T>	onDispose(Disposable d)	Attach a Disposable as a callback for when this FluxSink is effectively disposed, that is it cannot be used anymore.
FluxSink<T>	onRequest(LongConsumer consumer)	Attaches a LongConsumer to this FluxSink that will be notified of any request to this sink.
long	requestedFromDownstream()	The current outstanding request amount.

Method Details

next

FluxSink<T> next(T t)

Emit a non-null element, generating an onNext signal.

Might throw an unchecked exception in case of a fatal error downstream which cannot be propagated to any asynchronous handler (aka a bubbling exception).

Parameters:

t - the value to emit, not null

Returns:

this sink for chaining further signals

complete

void complete()

Terminate the sequence successfully, generating an onComplete signal.

See Also:

• Subscriber.onComplete()

error

void error(Throwable e)

Fail the sequence, generating an onError signal.

Parameters:

e - the exception to signal, not null

See Also:

• Subscriber.onError(Throwable)

currentContext

@Deprecated
Context currentContext()

Deprecated.

To be removed in 3.6.0 at the earliest. Prefer using #contextView() instead.

Return the current subscriber Context.

Context can be enriched via Flux.contextWrite(Function) operator or directly by a child subscriber overriding CoreSubscriber.currentContext()

contextView

default ContextView contextView()

Return the current subscriber's context as a ContextView for inspection.

Context can be enriched downstream via Flux.contextWrite(Function) operator or directly by a child subscriber overriding CoreSubscriber.currentContext().

Returns:

the current subscriber ContextView.

requestedFromDownstream

long requestedFromDownstream()

The current outstanding request amount.

Returns:

the current outstanding request amount

isCancelled

boolean isCancelled()

Returns true if the downstream cancelled the sequence.

Returns:

true if the downstream cancelled the sequence

onRequest

FluxSink<T> onRequest(LongConsumer consumer)

Attaches a LongConsumer to this FluxSink that will be notified of any request to this sink.

For push/pull sinks created using Flux.create(java.util.function.Consumer) or Flux.create(java.util.function.Consumer, FluxSink.OverflowStrategy), the consumer is invoked for every request to enable a hybrid backpressure-enabled push/pull model.

Note: in case of multiple Subscription.request(long) happening concurrently to this method, the first consumer invocation may process accumulated demand instead of being called multiple times.

When bridging with asynchronous listener-based APIs, the onRequest callback may be used to request more data from source if required and to manage backpressure by delivering data to sink only when requests are pending.

For push-only sinks created using Flux.push(java.util.function.Consumer) or Flux.push(java.util.function.Consumer, FluxSink.OverflowStrategy), the consumer is invoked with an initial request of Long.MAX_VALUE when this method is invoked.

Parameters:

consumer - the consumer to invoke on each request

Returns:

FluxSink with a consumer that is notified of requests

onCancel

FluxSink<T> onCancel(Disposable d)

Attach a Disposable as a callback for when this FluxSink is cancelled. At most one callback can be registered, and subsequent calls to this method will result in the immediate disposal of the extraneous Disposable.

The callback is only relevant when the downstream Subscription is cancelled.

Parameters:

d - the Disposable to use as a callback

Returns:

the FluxSink with a cancellation callback

See Also:

• onDispose(Disposable) for a callback that covers cancellation AND terminal signals

onDispose

FluxSink<T> onDispose(Disposable d)

Attach a Disposable as a callback for when this FluxSink is effectively disposed, that is it cannot be used anymore. This includes both having played terminal signals (onComplete, onError) and having been cancelled (see onCancel(Disposable)). At most one callback can be registered, and subsequent calls to this method will result in the immediate disposal of the extraneous Disposable.

Note that the "dispose" term is used from the perspective of the sink. Not to be confused with Flux.subscribe()'s Disposable.dispose() method, which maps to disposing the Subscription (effectively, a Subscription.cancel() signal).

Parameters:

d - the Disposable to use as a callback

Returns:

the FluxSink with a callback invoked on any terminal signal or on cancellation

See Also:

• onCancel(Disposable) for a cancellation-only callback