org.apache.pulsar.shade.org.reactivestreams.Subscription Maven / Gradle / Ivy
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* *
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* It can only be used once by a single {@link Subscriber}.
*
* It is used to both signal desire for data and cancel demand (and allow resource cleanup).
*
*/
public interface Subscription {
/**
* No events will be sent by a {@link Publisher} until demand is signaled via this method.
*
* It can be called however often and whenever needed—but if the outstanding cumulative demand ever becomes Long.MAX_VALUE or more,
* it may be treated by the {@link Publisher} as "effectively unbounded".
*
* Whatever has been requested can be sent by the {@link Publisher} so only signal demand for what can be safely handled.
*
* A {@link Publisher} can send less than is requested if the stream ends but
* then must emit either {@link Subscriber#onError(Throwable)} or {@link Subscriber#onComplete()}.
*
* @param n the strictly positive number of elements to requests to the upstream {@link Publisher}
*/
public void request(long n);
/**
* Request the {@link Publisher} to stop sending data and clean up resources.
*
* Data may still be sent to meet previously signalled demand after calling cancel.
*/
public void cancel();
}