reactor.core.publisher

Class UnicastProcessor<T>

java.lang.Object

reactor.core.publisher.Flux<OUT>

reactor.core.publisher.FluxProcessor<T,T>

reactor.core.publisher.UnicastProcessor<T>

Type Parameters:

T - the input and output type

All Implemented Interfaces:

Iterable<T>, Collection<T>, Queue<T>, Processor<T,T>, Publisher<T>, Subscriber<T>, Subscription, CorePublisher<T>, CoreSubscriber<T>, Disposable, Fuseable, Fuseable.QueueSubscription<T>, Scannable

public final class UnicastProcessor<T>
extends FluxProcessor<T,T>
implements Fuseable.QueueSubscription<T>, Fuseable

A Processor implementation that takes a custom queue and allows only a single subscriber. UnicastProcessor allows multiplexing of the events which means that it supports multiple producers and only one consumer. However, it should be noticed that multi-producer case is only valid if appropriate Queue is provided. Otherwise, it could break Reactive Streams Spec if Publishers publish on different threads.

Note: UnicastProcessor does not respect the actual subscriber's demand as it is described in Reactive Streams Spec. However, UnicastProcessor embraces configurable Queue internally which allows enabling backpressure support and preventing of consumer's overwhelming. Hence, interaction model between producers and UnicastProcessor will be PUSH only. In opposite, interaction model between UnicastProcessor and consumer will be PUSH-PULL as defined in Reactive Streams Spec. In the case when upstream's signals overflow the bound of internal Queue, UnicastProcessor will fail with signaling onError( Exceptions.OverflowException).

Note: The implementation keeps the order of signals. That means that in case of terminal signal (completion or error signals) it will be postponed until all of the previous signals has been consumed.

Nested Class Summary

Nested classes/interfaces inherited from interface reactor.core.Fuseable

Fuseable.ConditionalSubscriber<T>, Fuseable.QueueSubscription<T>, Fuseable.ScalarCallable<T>, Fuseable.SynchronousSubscription<T>

Nested classes/interfaces inherited from interface reactor.core.Scannable

Scannable.Attr<T>

Nested classes/interfaces inherited from interface reactor.core.Disposable

Disposable.Composite, Disposable.Swap

Field Summary

Fields inherited from interface reactor.core.Fuseable.QueueSubscription

NOT_SUPPORTED_MESSAGE

Fields inherited from interface reactor.core.Fuseable

ANY, ASYNC, NONE, SYNC, THREAD_BARRIER

Fields inherited from interface reactor.core.Scannable

OPERATOR_NAME_UNRELATED_WORDS_PATTERN

Constructor Summary

Constructors

Constructor and Description
UnicastProcessor(Queue<T> queue)
UnicastProcessor(Queue<T> queue, Consumer<? super T> onOverflow, Disposable onTerminate)
UnicastProcessor(Queue<T> queue, Disposable onTerminate)

Method Summary

Modifier and Type	Method and Description
CoreSubscriber<? super T>	actual()
void	cancel()
void	clear()
static <E> UnicastProcessor<E>	create() Create a new UnicastProcessor that will buffer on an internal queue in an unbounded fashion.
static <E> UnicastProcessor<E>	create(Queue<E> queue) Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.
static <E> UnicastProcessor<E>	create(Queue<E> queue, Consumer<? super E> onOverflow, Disposable endcallback) Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.
static <E> UnicastProcessor<E>	create(Queue<E> queue, Disposable endcallback) Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.
Context	currentContext() Request a Context from dependent components which can include downstream operators during subscribing or a terminal Subscriber.
long	downstreamCount() Return the number of active Subscriber or -1 if untracked.
int	getBufferSize() Return the processor buffer capacity if any or Integer.MAX_VALUE
Throwable	getError() Current error if any, default to null
int	getPrefetch() The prefetch configuration of the Flux
boolean	hasDownstreams() Return true if any Subscriber is actively subscribed
boolean	isDisposed() Optionally return true when the resource or task is disposed.
boolean	isEmpty()
boolean	isTerminated() Has this upstream finished or "completed" / "failed" ?
void	onComplete()
void	onError(Throwable t)
void	onNext(T t)
void	onSubscribe(Subscription s) Implementors should initialize any state used by Subscriber.onNext(Object) before calling Subscription.request(long).
T	poll()
void	request(long n)
int	requestFusion(int requestedMode) Request a specific fusion mode from this QueueSubscription.
Object	scanUnsafe(Scannable.Attr key) This method is used internally by components to define their key-value mappings in a single place.
int	size()
default String	stepName() Return a meaningful String representation of this Scannable in its chain of Scannable.parents() and Scannable.actuals().
void	subscribe(CoreSubscriber<? super T> actual) An internal Publisher.subscribe(Subscriber) that will bypass Hooks.onLastOperator(Function) pointcut.

Methods inherited from class reactor.core.publisher.FluxProcessor

dispose, hasCompleted, hasError, inners, isSerialized, serialize, serializeAlways, sink, sink, switchOnNext, wrap

Methods inherited from class reactor.core.publisher.Flux

all, any, as, blockFirst, blockFirst, blockLast, blockLast, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, buffer, bufferTimeout, bufferTimeout, bufferTimeout, bufferTimeout, bufferUntil, bufferUntil, bufferUntilChanged, bufferUntilChanged, bufferUntilChanged, bufferWhen, bufferWhen, bufferWhile, cache, cache, cache, cache, cache, cache, cancelOn, cast, checkpoint, checkpoint, checkpoint, collect, collect, collectList, collectMap, collectMap, collectMap, collectMultimap, collectMultimap, collectMultimap, collectSortedList, collectSortedList, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, combineLatest, concat, concat, concat, concat, concatDelayError, concatDelayError, concatDelayError, concatDelayError, concatMap, concatMap, concatMapDelayError, concatMapDelayError, concatMapDelayError, concatMapIterable, concatMapIterable, concatWith, concatWithValues, count, create, create, defaultIfEmpty, defer, deferWithContext, delayElements, delayElements, delaySequence, delaySequence, delaySubscription, delaySubscription, delaySubscription, delayUntil, dematerialize, distinct, distinct, distinct, distinct, distinctUntilChanged, distinctUntilChanged, distinctUntilChanged, doAfterTerminate, doFinally, doFirst, doOnCancel, doOnComplete, doOnDiscard, doOnEach, doOnError, doOnError, doOnError, doOnNext, doOnRequest, doOnSubscribe, doOnTerminate, elapsed, elapsed, elementAt, elementAt, empty, error, error, error, expand, expand, expandDeep, expandDeep, filter, filterWhen, filterWhen, first, first, flatMap, flatMap, flatMap, flatMap, flatMapDelayError, flatMapIterable, flatMapIterable, flatMapSequential, flatMapSequential, flatMapSequential, flatMapSequentialDelayError, from, fromArray, fromIterable, fromStream, fromStream, generate, generate, generate, groupBy, groupBy, groupBy, groupBy, groupJoin, handle, hasElement, hasElements, hide, ignoreElements, index, index, interval, interval, interval, interval, join, just, just, last, last, limitRate, limitRate, limitRequest, log, log, log, log, log, log, map, materialize, merge, merge, merge, merge, merge, merge, mergeDelayError, mergeOrdered, mergeOrdered, mergeOrdered, mergeOrderedWith, mergeSequential, mergeSequential, mergeSequential, mergeSequential, mergeSequential, mergeSequential, mergeSequentialDelayError, mergeSequentialDelayError, mergeSequentialDelayError, mergeWith, metrics, name, never, next, ofType, onAssembly, onAssembly, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureBuffer, onBackpressureDrop, onBackpressureDrop, onBackpressureError, onBackpressureLatest, onErrorContinue, onErrorContinue, onErrorContinue, onErrorMap, onErrorMap, onErrorMap, onErrorResume, onErrorResume, onErrorResume, onErrorReturn, onErrorReturn, onErrorReturn, onErrorStop, onTerminateDetach, or, parallel, parallel, parallel, publish, publish, publish, publish, publishNext, publishOn, publishOn, publishOn, push, push, range, reduce, reduce, reduceWith, repeat, repeat, repeat, repeat, repeatWhen, replay, replay, replay, replay, replay, replay, retry, retry, retryWhen, sample, sample, sampleFirst, sampleFirst, sampleTimeout, sampleTimeout, scan, scan, scanWith, share, single, single, singleOrEmpty, skip, skip, skip, skipLast, skipUntil, skipUntilOther, skipWhile, sort, sort, startWith, startWith, startWith, subscribe, subscribe, subscribe, subscribe, subscribe, subscribe, subscribe, subscribeOn, subscribeOn, subscriberContext, subscriberContext, subscribeWith, switchIfEmpty, switchMap, switchMap, switchOnFirst, switchOnFirst, switchOnNext, switchOnNext, tag, take, take, take, takeLast, takeUntil, takeUntilOther, takeWhile, then, then, thenEmpty, thenMany, timeout, timeout, timeout, timeout, timeout, timeout, timeout, timestamp, timestamp, toIterable, toIterable, toIterable, toStream, toStream, toString, transform, transformDeferred, using, using, usingWhen, usingWhen, window, window, window, window, window, window, window, windowTimeout, windowTimeout, windowUntil, windowUntil, windowUntil, windowUntilChanged, windowUntilChanged, windowUntilChanged, windowWhen, windowWhile, windowWhile, withLatestFrom, zip, zip, zip, zip, zip, zip, zip, zip, zip, zip, zip, zip, zip, zipWith, zipWith, zipWith, zipWith, zipWithIterable, zipWithIterable

Methods inherited from class java.lang.Object

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

Methods inherited from interface reactor.core.Fuseable.QueueSubscription

add, addAll, contains, containsAll, element, iterator, offer, peek, remove, remove, removeAll, retainAll, toArray, toArray

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface reactor.core.Scannable

actuals, from, inners, isScanAvailable, name, parents, scan, scanOrDefault, steps, tags

Methods inherited from interface org.reactivestreams.Publisher

subscribe

Constructor Detail

UnicastProcessor

public UnicastProcessor(Queue<T> queue)

UnicastProcessor

public UnicastProcessor(Queue<T> queue,
                        Consumer<? super T> onOverflow,
                        Disposable onTerminate)

UnicastProcessor

public UnicastProcessor(Queue<T> queue,
                        Disposable onTerminate)

Method Detail

actual

public CoreSubscriber<? super T> actual()

cancel

public void cancel()

Specified by:

cancel in interface Subscription

clear

public void clear()

Specified by:

clear in interface Collection<T>

create

public static <E> UnicastProcessor<E> create()

Create a new UnicastProcessor that will buffer on an internal queue in an unbounded fashion.

Type Parameters:

E - the relayed type

Returns:

a unicast FluxProcessor

create

public static <E> UnicastProcessor<E> create(Queue<E> queue)

Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.

Type Parameters:

E - the relayed type

Parameters:

queue - the buffering queue

Returns:

a unicast FluxProcessor

create

public static <E> UnicastProcessor<E> create(Queue<E> queue,
                                             Consumer<? super E> onOverflow,
                                             Disposable endcallback)

Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.

Type Parameters:

E - the relayed type

Parameters:

queue - the buffering queue

endcallback - called on any terminal signal

onOverflow - called when queue.offer return false and unicastProcessor is about to emit onError.

Returns:

a unicast FluxProcessor

create

public static <E> UnicastProcessor<E> create(Queue<E> queue,
                                             Disposable endcallback)

Create a new UnicastProcessor that will buffer on a provided queue in an unbounded fashion.

Type Parameters:

E - the relayed type

Parameters:

queue - the buffering queue

endcallback - called on any terminal signal

Returns:

a unicast FluxProcessor

currentContext

public Context currentContext()

Description copied from interface: CoreSubscriber

Request a Context from dependent components which can include downstream operators during subscribing or a terminal Subscriber.

Specified by:

currentContext in interface CoreSubscriber<T>

Overrides:

currentContext in class FluxProcessor<T,T>

Returns:

a resolved context or Context.empty()

downstreamCount

public long downstreamCount()

Description copied from class: FluxProcessor

Return the number of active Subscriber or -1 if untracked.

Overrides:

downstreamCount in class FluxProcessor<T,T>

Returns:

the number of active Subscriber or -1 if untracked

getBufferSize

public int getBufferSize()

Description copied from class: FluxProcessor

Return the processor buffer capacity if any or Integer.MAX_VALUE

Overrides:

getBufferSize in class FluxProcessor<T,T>

Returns:

processor buffer capacity if any or Integer.MAX_VALUE

getError

@Nullable
public Throwable getError()

Description copied from class: FluxProcessor

Current error if any, default to null

Overrides:

getError in class FluxProcessor<T,T>

Returns:

Current error if any, default to null

getPrefetch

public int getPrefetch()

Description copied from class: Flux

The prefetch configuration of the Flux

Overrides:

getPrefetch in class Flux<T>

Returns:

the prefetch configuration of the Flux, -1 if unspecified

hasDownstreams

public boolean hasDownstreams()

Description copied from class: FluxProcessor

Return true if any Subscriber is actively subscribed

Overrides:

hasDownstreams in class FluxProcessor<T,T>

Returns:

true if any Subscriber is actively subscribed

isDisposed

public boolean isDisposed()

Description copied from interface: Disposable

Optionally return true when the resource or task is disposed.

Implementations are not required to track disposition and as such may never return true even when disposed. However, they MUST only return true when there's a guarantee the resource or task is disposed.

Specified by:

isDisposed in interface Disposable

Returns:

true when there's a guarantee the resource or task is disposed.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<T>

isTerminated

public boolean isTerminated()

Description copied from class: FluxProcessor

Has this upstream finished or "completed" / "failed" ?

Overrides:

isTerminated in class FluxProcessor<T,T>

Returns:

has this upstream finished or "completed" / "failed" ?

onComplete

public void onComplete()

Specified by:

onComplete in interface Subscriber<T>

onError

public void onError(Throwable t)

Specified by:

onError in interface Subscriber<T>

onNext

public void onNext(T t)

Specified by:

onNext in interface Subscriber<T>

onSubscribe

public void onSubscribe(Subscription s)

Description copied from interface: CoreSubscriber

Implementors should initialize any state used by Subscriber.onNext(Object) before calling Subscription.request(long). Should further onNext related state modification occur, thread-safety will be required.

Note that an invalid request <= 0 will not produce an onError and will simply be ignored or reported through a debug-enabled Logger.

Specified by:

onSubscribe in interface Subscriber<T>

Specified by:

onSubscribe in interface CoreSubscriber<T>

poll

@Nullable
public T poll()

Specified by:

poll in interface Queue<T>

request

public void request(long n)

Specified by:

request in interface Subscription

requestFusion

public int requestFusion(int requestedMode)

Description copied from interface: Fuseable.QueueSubscription

Request a specific fusion mode from this QueueSubscription.

One should request either SYNC, ASYNC or ANY modes (never NONE) and the implementor should return NONE, SYNC or ASYNC (never ANY).

For example, if a source supports only ASYNC fusion but the intermediate operator supports only SYNC fuseable sources, the operator may request SYNC fusion and the source can reject it via NONE, thus the operator can return NONE as well to downstream and the fusion doesn't happen.

Specified by:

requestFusion in interface Fuseable.QueueSubscription<T>

Parameters:

requestedMode - the mode requested by the intermediate operator

Returns:

the actual fusion mode activated

scanUnsafe

public Object scanUnsafe(Scannable.Attr key)

Description copied from interface: Scannable

This method is used internally by components to define their key-value mappings in a single place. Although it is ignoring the generic type of the Scannable.Attr key, implementors should take care to return values of the correct type, and return null if no specific value is available.

For public consumption of attributes, prefer using Scannable.scan(Attr), which will return a typed value and fall back to the key's default if the component didn't define any mapping.

Specified by:

scanUnsafe in interface Scannable

Overrides:

scanUnsafe in class FluxProcessor<T,T>

Parameters:

key - a Scannable.Attr to resolve for the component.

Returns:

the value associated to the key for that specific component, or null if none.

size

public int size()

Specified by:

size in interface Collection<T>

subscribe

public void subscribe(CoreSubscriber<? super T> actual)

Description copied from class: Flux

An internal Publisher.subscribe(Subscriber) that will bypass Hooks.onLastOperator(Function) pointcut.

In addition to behave as expected by Publisher.subscribe(Subscriber) in a controlled manner, it supports direct subscribe-time Context passing.

Specified by:

subscribe in interface CorePublisher<T>

Specified by:

subscribe in class Flux<T>

Parameters:

actual - the Subscriber interested into the published sequence

See Also:

Flux.subscribe(Subscriber)

stepName

public String stepName()

Description copied from interface: Scannable

Return a meaningful String representation of this Scannable in its chain of Scannable.parents() and Scannable.actuals().

Specified by:

stepName in interface Scannable