Package com.linecorp.armeria.common.stream

Class EmptyFixedStreamMessage<T>

java.lang.Object

com.linecorp.armeria.common.stream.EmptyFixedStreamMessage<T>

All Implemented Interfaces:

StreamMessage<T>, org.reactivestreams.Publisher<T>

@UnstableApi
public class EmptyFixedStreamMessage<T>
extends Object

A FixedStreamMessage that publishes no objects, just a close event.

Constructor Summary

Constructors

Constructor	Description
EmptyFixedStreamMessage()

Method Summary

Modifier and Type	Method	Description
void	abort()	Closes this stream with AbortedStreamException and prevents further subscription.
void	abort(Throwable cause)	Closes this stream with the specified Throwable and prevents further subscription.
CompletableFuture<List<T>>	drainAll(EventExecutor executor)	Subscribes to this StreamMessage and retrieves all elements from it.
CompletableFuture<List<T>>	drainAll(EventExecutor executor, SubscriptionOption... options)	Subscribes to this StreamMessage and retrieves all elements from it.
boolean	isEmpty()	Returns true if this stream has been closed and did not publish any elements.
boolean	isOpen()	Returns true if this stream is not closed yet.
protected void	onRemoval(T obj)	Invoked after an element is removed from the StreamMessage and before Subscriber.onNext(Object) is invoked.
void	subscribe(org.reactivestreams.Subscriber<? super T> subscriber, EventExecutor executor)	Requests to start streaming data to the specified Subscriber.
void	subscribe(org.reactivestreams.Subscriber<? super T> subscriber, EventExecutor executor, SubscriptionOption... options)	Requests to start streaming data to the specified Subscriber.
CompletableFuture<Void>	whenComplete()	Returns a CompletableFuture that completes when this stream is complete, either successfully or exceptionally, including cancellation and abortion.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.linecorp.armeria.common.stream.StreamMessage

defaultSubscriberExecutor, drainAll, drainAll, isComplete, subscribe, subscribe, toDuplicator, toDuplicator

Constructor Details

EmptyFixedStreamMessage

public EmptyFixedStreamMessage()

Method Details

isEmpty

public final boolean isEmpty()

Description copied from interface: StreamMessage

Returns true if this stream has been closed and did not publish any elements. Note that this method will not return true when the stream is open even if it has not published anything so far, because it may publish something later.

isOpen

public final boolean isOpen()

Description copied from interface: StreamMessage

Returns true if this stream is not closed yet. Note that a stream may not be complete even if it's closed; a stream is complete when it's fully consumed by a Subscriber.

abort

public final void abort()

Description copied from interface: StreamMessage

Closes this stream with AbortedStreamException and prevents further subscription. A Subscriber that attempts to subscribe to an aborted stream will be notified with an AbortedStreamException via Subscriber.onError(Throwable). Calling this method on a closed or aborted stream has no effect.

abort

public final void abort(Throwable cause)

Description copied from interface: StreamMessage

Closes this stream with the specified Throwable and prevents further subscription. A Subscriber that attempts to subscribe to an aborted stream will be notified with the specified Throwable via Subscriber.onError(Throwable). Calling this method on a closed or aborted stream has no effect.

subscribe

public final void subscribe(org.reactivestreams.Subscriber<? super T> subscriber, EventExecutor executor)

Description copied from interface: StreamMessage

Requests to start streaming data to the specified Subscriber. If there is a problem subscribing, Subscriber.onError(Throwable) will be invoked with one of the following exceptions:

• IllegalStateException if other Subscriber subscribed to this stream already.
• AbortedStreamException if this stream has been aborted.
• CancelledSubscriptionException if this stream has been cancelled and SubscriptionOption.NOTIFY_CANCELLATION is specified when subscribed.
• Other exceptions that occurred due to an error while retrieving the elements.

Specified by:

subscribe in interface StreamMessage<T>

executor - the executor to subscribe

subscribe

public final void subscribe(org.reactivestreams.Subscriber<? super T> subscriber, EventExecutor executor, SubscriptionOption... options)

Description copied from interface: StreamMessage

Requests to start streaming data to the specified Subscriber. If there is a problem subscribing, Subscriber.onError(Throwable) will be invoked with one of the following exceptions:

• IllegalStateException if other Subscriber subscribed to this stream already.
• AbortedStreamException if this stream has been aborted.
• CancelledSubscriptionException if this stream has been cancelled and SubscriptionOption.NOTIFY_CANCELLATION is specified when subscribed.
• Other exceptions that occurred due to an error while retrieving the elements.

Specified by:

subscribe in interface StreamMessage<T>

executor - the executor to subscribe

options - SubscriptionOptions to subscribe with

drainAll

public final CompletableFuture<List<T>> drainAll(EventExecutor executor)

Description copied from interface: StreamMessage

Subscribes to this StreamMessage and retrieves all elements from it. The returned CompletableFuture may be completed exceptionally with the following exceptions:

• IllegalStateException if other Subscriber subscribed to this stream already.
• AbortedStreamException if this stream has been aborted.
• Other exceptions that occurred due to an error while retrieving the elements.

Specified by:

drainAll in interface StreamMessage<T>

Parameters:

executor - the executor to retrieve all elements

Returns:

the CompletableFuture which will be completed with the list of the elements retrieved.

drainAll

public final CompletableFuture<List<T>> drainAll(EventExecutor executor, SubscriptionOption... options)

Description copied from interface: StreamMessage

Subscribes to this StreamMessage and retrieves all elements from it. The returned CompletableFuture may be completed exceptionally with the following exceptions:

• IllegalStateException if other Subscriber subscribed to this stream already.
• AbortedStreamException if this stream has been aborted.
• Other exceptions that occurred due to an error while retrieving the elements.

Specified by:

drainAll in interface StreamMessage<T>

Parameters:

executor - the executor to retrieve all elements

options - SubscriptionOptions to subscribe with. Note that SubscriptionOption.NOTIFY_CANCELLATION is ineffective because there's no cancelling while draining all elements.

Returns:

the CompletableFuture which will be completed with the list of the elements retrieved.

whenComplete

public final CompletableFuture<Void> whenComplete()

Description copied from interface: StreamMessage

Returns a CompletableFuture that completes when this stream is complete, either successfully or exceptionally, including cancellation and abortion.

A StreamMessage is complete (or 'fully consumed') when:

• the Subscriber consumes all elements and Subscriber.onComplete() is invoked,
• an error occurred and Subscriber.onError(Throwable) is invoked,
• the Subscription has been cancelled or
• StreamMessage.abort() has been requested.

Specified by:

whenComplete in interface StreamMessage<T>

onRemoval

protected void onRemoval(T obj)

Invoked after an element is removed from the StreamMessage and before Subscriber.onNext(Object) is invoked.

Parameters:

obj - the removed element