streams

Type Members

1. final class Deduplicate[T, U] extends SimpleLinearGraphStage[T]

   

   Only pass on those elements that have not been seen so far.

   Only pass on those elements that have not been seen so far.

   Emits when the element is not a duplicate

   Backpressures when the element is not a duplicate and downstream backpressures

   Completes when upstream completes

   Cancels when downstream cancels

2. case class FlowTimeoutException(msg: String = "Flow timed out!") extends TimeoutException with Product with Serializable

   

   Exception thrown when an element times out.

   Exception thrown when an element times out.

   msg

   Defaults to "Flow timed out!"

3. case class MutableLong(value: Long = 0L) extends Product with Serializable

   

   MutableLong is used to avoid boxing/unboxing and also to avoid java.util.Map#put operation to increment the counters in the registry.

4. final class RetryBidi[In, Out, Context] extends GraphStage[BidiShape[(In, Context), (In, Context), (Try[Out], Context), (Try[Out], Context)]]

   

   A bidi GraphStage that can be joined with flows that produce Try's to add Retry functionality when there are any failures.

   A bidi GraphStage that can be joined with flows that produce Try's to add Retry functionality when there are any failures. When the joined Flow has a failure then based on the provided max retries count, it will retry the failures.

   Emits when a Success is available from joined flow or a failure has been retried the maximum number of retries

   Backpressures when the element is not a failure and downstream backpressures or the retry buffer is full

   Completes when upstream completes

   Cancels when downstream cancels

            upstream      +------+      downstream
         (In, Context) ~> |      | ~> (In, Context)
              In1         | bidi |        Out1
   (Try[Out], Context) <~ |      | <~ (Try[Out], Context)
             Out2         +------+        In2

   In

   the type of elements pulled from the upstream along with the Context

   Out

   the type of the elements that are pushed by the joined Flow along with the Context. This then gets wrapped with a Try and pushed downstream with a Context

   Context

   the type of the context that is carried around along with the elements.

5. final class TimeoutBidiOrdered[In, Out] extends GraphStage[BidiShape[In, In, Out, Try[Out]]]

   

   A bidi GraphStage that is joined with flows to add timeout functionality.

   A bidi GraphStage that is joined with flows to add timeout functionality. This bidi stage is used with flows that guarantee the message ordering.

   Emits when an element is available from the wrapped flow or an element has already timed out

   Backpressures when the downstream backpressures

   Completes when upstream completes

   Cancels when downstream cancels

               +------+
         In ~> |      | ~> In
               | bidi |
   Try[Out] <~ |      | <~ Out
               +------+

   In

   the type of the elements pulled from the upstream and pushed down to joined flow

   Out

   the type of the elements that are pushed to downstream

6. final class TimeoutBidiUnordered[In, Out, Context] extends GraphStage[BidiShape[(In, Context), (In, Context), (Out, Context), (Try[Out], Context)]] with LazyLogging

   

   A bidi GraphStage that is joined with flows to add timeout functionality.

   A bidi GraphStage that is joined with flows to add timeout functionality. This bidi stage is used with flows that do not guarantee the message ordering. So, it requires a context to be carried along with the elements to uniquely identify each element.

   Emits when an element is available from the joined Flow or an element has already timed out

   Backpressures when the downstream backpressures

   Completes when upstream completes

   Cancels when downstream cancels

                          +------+
         (In, Context) ~> |      | ~> (In, Context)
                          | bidi |
   (Try[Out], Context) <~ |      | <~ (Out, Context)
                          +------+

   In

   the type of the elements pulled from the upstream along with the Context

   Out

   the type of the elements that are pushed by the joined Flow along with the Context. This then gets wrapped with a Try and pushed downstream with a Context

   Context

   the type of the context that is carried around along with the elements.

7. abstract class TimeoutGraphStageLogic[In, FromWrapped, Out] extends TimerGraphStageLogic

   

   A bidi GraphStageLogic that is used by TimeoutBidiOrdered and TimeoutBidiUnordered to wrap flows to add timeout functionality.

   A bidi GraphStageLogic that is used by TimeoutBidiOrdered and TimeoutBidiUnordered to wrap flows to add timeout functionality.

   Once an element is pushed from the wrapped flow (from fromWrapped), it first checks if the element is already timed out. If a timeout message has already been sent for that element to downstream, then the element from the wrapped flow is dropped.

   A timer gets scheduled when there is a downstream demand that's not immediately addressed. This is to make sure that a timeout response is sent to the downstream when upstream cannot address the demand on time.

   Timer precision is at best 10ms to avoid unnecessary timer scheduling cycles

          +------+
    In ~> |      | ~> In
          | bidi |
   Out <~ |      | <~ FromWrapped
          +------+

   In

   the type of the elements that gets forwarded to the wrapped flow

   FromWrapped

   the type of the elements that the wrapped flow sends back

   Out

   the type of the elements that are pushed to downstream