reactor.core.publisher

Class Operators.MonoSubscriber<I,O>

java.lang.Object

reactor.core.publisher.Operators.MonoSubscriber<I,O>

Type Parameters:

I - The upstream sequence type

O - The downstream sequence type

All Implemented Interfaces:

Iterable<O>, Collection<O>, Queue<O>, Subscription, Fuseable, Fuseable.QueueSubscription<O>

Enclosing class:

Operators

public static class Operators.MonoSubscriber<I,O>
extends Object
implements Fuseable, Fuseable.QueueSubscription<O>

A Subscriber/Subscription barrier that holds a single value at most and properly gates asynchronous behaviors resulting from concurrent request or cancel and onXXX signals.

Nested Class Summary

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

Scannable.Attr<T>

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

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

Field Summary

Fields

Modifier and Type	Field and Description
protected CoreSubscriber<? super O>	actual
protected O	value The value stored by this Mono operator.

Fields inherited from interface reactor.core.Scannable

OPERATOR_NAME_UNRELATED_WORDS_PATTERN

Fields inherited from interface reactor.core.Fuseable

ANY, ASYNC, NONE, SYNC, THREAD_BARRIER

Fields inherited from interface reactor.core.Fuseable.QueueSubscription

NOT_SUPPORTED_MESSAGE

Constructor Summary

Constructors

Constructor and Description
MonoSubscriber(CoreSubscriber<? super O> actual)

Method Summary

Modifier and Type	Method and Description
CoreSubscriber<? super O>	actual()
void	cancel()
void	clear()
void	complete(O v) Tries to emit the value and complete the underlying subscriber or stores the value away until there is a request for it.
default Context	currentContext() Request a Context from dependent components which can include downstream operators during subscribing or a terminal Subscriber.
protected void	discard(O v) Discard the given value, generally this.value field.
boolean	isCancelled() Returns true if this Subscription has been cancelled.
boolean	isEmpty()
void	onComplete()
void	onError(Throwable t)
void	onNext(I t)
void	onSubscribe(Subscription s) Implementors should initialize any state used by Subscriber.onNext(Object) before calling Subscription.request(long).
O	poll()
void	request(long n)
int	requestFusion(int mode) 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.
void	setValue(O value) Set the value internally, without impacting request tracking state.
int	size()

Methods inherited from class java.lang.Object

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

Methods inherited from interface reactor.core.Scannable

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

Methods inherited from interface reactor.core.Fuseable

fusionModeName, fusionModeName

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

Field Detail

actual

protected final CoreSubscriber<? super O> actual

value

@Nullable
protected O value

The value stored by this Mono operator. Strongly prefer using setValue(Object) rather than direct writes to this field, when possible.

Constructor Detail

MonoSubscriber

public MonoSubscriber(CoreSubscriber<? super O> actual)

Method Detail

cancel

public void cancel()

Specified by:

cancel in interface Subscription

scanUnsafe

@Nullable
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.

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.

clear

public final void clear()

Specified by:

clear in interface Collection<O>

complete

public final void complete(@Nullable
                           O v)

Tries to emit the value and complete the underlying subscriber or stores the value away until there is a request for it.

Make sure this method is called at most once

Parameters:

v - the value to emit

discard

protected void discard(@Nullable
                       O v)

Discard the given value, generally this.value field. Lets derived subscriber with further knowledge about the possible types of the value discard such values in a specific way. Note that fields should generally be nulled out along the discard call.

Parameters:

v - the value to discard

actual

public final CoreSubscriber<? super O> actual()

isCancelled

public final boolean isCancelled()

Returns true if this Subscription has been cancelled.

Returns:

true if this Subscription has been cancelled

isEmpty

public final boolean isEmpty()

Specified by:

isEmpty in interface Collection<O>

onComplete

public void onComplete()

onError

public void onError(Throwable t)

onNext

public void onNext(I 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.

poll

@Nullable
public final O poll()

Specified by:

poll in interface Queue<O>

request

public void request(long n)

Specified by:

request in interface Subscription

requestFusion

public int requestFusion(int mode)

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<O>

Parameters:

mode - the mode requested by the intermediate operator

Returns:

the actual fusion mode activated

setValue

public void setValue(@Nullable
                     O value)

Set the value internally, without impacting request tracking state. This however discards the provided value when detecting a cancellation.

Parameters:

value - the new value.

See Also:

complete(Object)

size

public int size()

Specified by:

size in interface Collection<O>

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.

Returns:

a resolved context or Context.empty()