Package com.linecorp.armeria.common.stream

Interface StreamWriter<T>

Type Parameters:

T - the type of the stream element

All Known Subinterfaces:

HttpRequestWriter, HttpResponseWriter

All Known Implementing Classes:

DefaultHttpRequest, DefaultHttpResponse, DefaultStreamMessage, EventLoopStreamMessage

public interface StreamWriter<T>

Produces the objects to be published by a StreamMessage.

Life cycle of reference-counted objects

When the following methods are given with a ReferenceCounted object, such as ByteBuf and ByteBufHttpData, or the Supplier that provides such an object:

• tryWrite(Object)
• tryWrite(Supplier)
• write(Object)
• write(Supplier)

the object will be released automatically by the stream when it's no longer in use, such as when:

• The method returns false or raises an exception.
• The Subscriber of the stream consumes it.
• The stream is cancelled, aborted or failed.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the StreamMessage successfully.
void	close(Throwable cause)	Closes the StreamMessage exceptionally.
default void	close(T obj)	Writes the given object and closes the stream successfully.
boolean	isOpen()	Returns true if the StreamMessage is open.
CompletableFuture<Void>	onDemand(Runnable task)	Performs the specified task when there are enough demands from the Subscriber.
default boolean	tryWrite(Supplier<? extends T> o)	Writes the specified object Supplier to the StreamMessage.
boolean	tryWrite(T o)	Writes the specified object to the StreamMessage.
default void	write(Supplier<? extends T> o)	Writes the specified object Supplier to the StreamMessage.
default void	write(T o)	Writes the specified object to the StreamMessage.

Method Detail

isOpen

boolean isOpen()

Returns true if the StreamMessage is open.

write

default void write(T o)

Writes the specified object to the StreamMessage. The written object will be transferred to the Subscriber.

Throws:

ClosedPublisherException - if the stream was already closed

IllegalArgumentException - if the publication of the specified object has been rejected

See Also:

Life cycle of reference-counted objects

write

default void write(Supplier<? extends T> o)

Writes the specified object Supplier to the StreamMessage. The object provided by the Supplier will be transferred to the Subscriber.

Throws:

ClosedPublisherException - if the stream was already closed.

See Also:

Life cycle of reference-counted objects

tryWrite

@CheckReturnValue
boolean tryWrite(T o)

Writes the specified object to the StreamMessage. The written object will be transferred to the Subscriber.

Returns:

true if the specified object has been scheduled for publication. false if the stream has been closed already.

Throws:

IllegalArgumentException - if the publication of the specified object has been rejected

See Also:

Life cycle of reference-counted objects

tryWrite

@CheckReturnValue
default boolean tryWrite(Supplier<? extends T> o)

Writes the specified object Supplier to the StreamMessage. The object provided by the Supplier will be transferred to the Subscriber.

Returns:

true if the specified object has been scheduled for publication. false if the stream has been closed already.

See Also:

Life cycle of reference-counted objects

onDemand

CompletableFuture<Void> onDemand(Runnable task)

Performs the specified task when there are enough demands from the Subscriber.

Returns:

the future that completes successfully when the task finishes or exceptionally when the StreamMessage is closed unexpectedly.

close

void close()

Closes the StreamMessage successfully. Subscriber.onComplete() will be invoked to signal that the Subscriber has consumed the stream completely.

close

void close(Throwable cause)

Closes the StreamMessage exceptionally. Subscriber.onError(Throwable) will be invoked to signal that the Subscriber did not consume the stream completely.

close

default void close(T obj)

Writes the given object and closes the stream successfully.