Package org.apache.pekko.stream.scaladsl

Interface SourceQueue<T>

All Known Subinterfaces:
SourceQueueWithComplete<T>
public interface SourceQueue<T>
This trait allows to have a queue as a data source for some stream.

  • Method Summary

    Modifier and Type
    Method
    Description
    scala.concurrent.Future<QueueOfferResult>
    offer(T elem)
    Offers an element to a stream and returns a Future that: - completes with Enqueued if the element is consumed by a stream - completes with Dropped when the stream dropped the offered element - completes with QueueClosed when the stream is completed whilst the Future is active - completes with Failure(f) in case of failure to enqueue element from upstream - fails when stream is already completed
    scala.concurrent.Future<Done>
    watchCompletion()
    Returns a Future that will be completed if this operator completes, or will be failed when the operator faces an internal failure.

  • Method Details

    • offer

      scala.concurrent.Future<QueueOfferResult> offer(T elem)
      Offers an element to a stream and returns a Future that: - completes with Enqueued if the element is consumed by a stream - completes with Dropped when the stream dropped the offered element - completes with QueueClosed when the stream is completed whilst the Future is active - completes with Failure(f) in case of failure to enqueue element from upstream - fails when stream is already completed

      Additionally when using the backpressure overflowStrategy: - If the buffer is full the Future won't be completed until there is space in the buffer - Calling offer before the Future is completed, in this case it will return a failed Future

      Parameters:
      elem - element to send to a stream

    • watchCompletion

      scala.concurrent.Future<Done> watchCompletion()
      Returns a Future that will be completed if this operator completes, or will be failed when the operator faces an internal failure.

      Note that this only means the elements have been passed downstream, not that downstream has successfully processed them.