Remove deprecated API usage

This change should enable to use op-rabbit with Akka 2.6 especially Akka
Stream as the akka-streams support module was using deprecated API that
got removed in 2.6

addons/akka-stream/src/main/scala/com/spingo/op_rabbit/stream/MessagePublisherSink.scala

@@ -1,98 +1,99 @@
-package com.spingo.op_rabbit
-package stream
+package com.spingo.op_rabbit.stream
 
-import akka.actor.{ActorRef,Props}
+import com.spingo.op_rabbit._
+import com.spingo.op_rabbit.Message._
+import akka.stream.stage.GraphStage
+import akka.actor.{ActorRef, Props}
 import akka.actor.FSM
 import akka.pattern.ask
 import akka.stream.scaladsl.Sink
-import akka.stream.actor._
 import scala.concurrent.{Future, Promise}
 import scala.concurrent.duration._
 import com.timcharper.acked.AckedSink
-import scala.util.{Try,Success,Failure}
+import scala.util.{Try, Success,Failure}
+import akka.stream._
+import akka.stream.stage.GraphStageLogic
+import akka.stream.stage.GraphStageWithMaterializedValue
+import akka.stream.stage.InHandler
+import akka.stream.scaladsl.Flow
+import akka.util.Timeout
 
-private [stream] object MessagePublisherSinkActor {
-  sealed trait State
-  case object Running extends State
-  case object Stopping extends State
-  case object AllDoneFuturePlease
-}
 
-private class MessagePublisherSinkActor(rabbitControl: ActorRef, timeoutAfter: FiniteDuration, qos: Int) extends ActorSubscriber with FSM[MessagePublisherSinkActor.State, Unit] {
-  import ActorSubscriberMessage._
-  import MessagePublisherSinkActor._
+private class MessagePublisherSink(rabbitControl: ActorRef, timeoutAfter: FiniteDuration, qos: Int) extends GraphStageWithMaterializedValue[SinkShape[(Promise[Unit],Message)], Future[Unit]] {
+  val in = Inlet[(Promise[Unit],Message)]("MessagePublisherSink.in")
 
-  private val queue = scala.collection.mutable.Map.empty[Long, Promise[Unit]]
-  private val completed = Promise[Unit]
+  val shape = SinkShape.of(in)
 
-  startWith(Running, ())
+  override def createLogicAndMaterializedValue(inheritedAttributes: Attributes): (GraphStageLogic, Future[Unit]) = {
+    val completed = Promise[Unit]()
 
-  override val requestStrategy = new MaxInFlightRequestStrategy(max = qos) {
-    override def inFlightInternally: Int = queue.size
-  }
+    val logic = new GraphStageLogic(shape) {
+      private val queue = scala.collection.mutable.Map.empty[Long, Promise[Unit]]
 
-  override def postRestart(reason: Throwable): Unit = {
-    stopWith(Failure(reason))
-    super.postRestart(reason)
-  }
+      // callback to schedule the rabbitControl responses into the stage
+      private val futureCallback = getAsyncCallback[Try[Message.ConfirmResponse]]({ 
+        case Success(Message.Ack(id)) =>
+          queue.remove(id).get.success(())
+          pullIfNeeded()
 
-  private def stopWith(reason: Try[Unit]): Unit = {
-    context stop self
-    completed.tryComplete(reason)
-  }
+        case Success(Message.Nack(id)) =>
+          queue.remove(id).get.failure(new MessageNacked(id))
+          pullIfNeeded()
 
-  when(Running) {
-    case Event(response: Message.ConfirmResponse, _) =>
-      handleResponse(response)
-      stay
+        case Success(Message.Fail(id, exception: Throwable)) =>
+          queue.remove(id).get.failure(exception)
+          pullIfNeeded()
 
-    case Event(OnError(e), _) =>
-      completed.tryFailure(e)
-      goto(Stopping)
+        case Failure(exception) => 
+          // currently fails the stream - maybe better just fail the message - needs additional context
+          fail(exception)
+      })
 
-    case Event(OnComplete, _) =>
-      goto(Stopping)
-  }
+      override def preStart(): Unit =  {
+        // we must ensure we can acknowledge messages even on stream complete
+        setKeepGoing(true)
+        pull(in)
+      }
+
+      setHandler(in, new InHandler {
+        override def onPush(): Unit = {
+          val (promise, msg) = grab(in)
+          queue(msg.id) = promise
 
-  when(Stopping) {
-    case Event(response: Message.ConfirmResponse, _) =>
-      handleResponse(response)
-      if(queue.isEmpty)
-        stop
-      else
-        stay
-  }
+          val eventualResult = rabbitControl.ask(msg)(Timeout(timeoutAfter)).mapTo[ConfirmResponse]
 
-  whenUnhandled {
-    case Event(OnNext((p: Promise[Unit] @unchecked, msg: Message)), _) =>
-      queue(msg.id) = p
-      rabbitControl ! msg
-      stay
+          // TODO: which EC to schedule the callback onto?
+          eventualResult.onComplete(futureCallback.invoke)(materializer.executionContext)
 
-    case Event(MessagePublisherSinkActor.AllDoneFuturePlease,_) =>
-      sender ! completed.future
-      stay
-  }
+          pullIfNeeded()
+        }
 
-  onTransition {
-    case Running -> Stopping if queue.isEmpty  =>
-      stopWith(Success(()))
-  }
+        override def onUpstreamFinish(): Unit = {
+          if (queue.isEmpty) complete()
+        }
 
-  onTermination {
-    case e: StopEvent =>
-      stopWith(Success(()))
-  }
+        override def onUpstreamFailure(ex: Throwable): Unit = {
+          fail(ex)
+        }
+      })
+
+      private def pullIfNeeded(): Unit = {
+        if (isClosed(in) && queue.isEmpty) complete()
+        else if (queue.size < qos && !hasBeenPulled(in)) tryPull(in)
+      }
 
-  private val handleResponse: Message.ConfirmResponse => Unit = {
-    case Message.Ack(id) =>
-      queue.remove(id).get.success(())
+      private def complete(): Unit = {
+        completed.success(())
+        completeStage()
+      }
 
-    case Message.Nack(id) =>
-      queue.remove(id).get.failure(new MessageNacked(id))
+      private def fail(ex: Throwable): Unit = {
+        completed.failure(ex)
+        failStage(ex)
+      }
+    }
 
-    case Message.Fail(id, exception: Throwable) =>
-      queue.remove(id).get.failure(exception)
+    (logic, completed.future)
   }
 }
 
@@ -130,12 +131,6 @@ object MessagePublisherSink {
     @param timeoutAfter The duration for which we'll wait for a message to be acked; note, timeouts and non-acknowledged messages will cause the upstream elements to fail. The sink will not throw an exception.
     */
   def apply(rabbitControl: ActorRef, timeoutAfter: FiniteDuration = 30.seconds, qos: Int = 8): AckedSink[Message, Future[Unit]] = AckedSink {
-    Sink.actorSubscriber[(Promise[Unit], Message)](Props(new MessagePublisherSinkActor(rabbitControl, timeoutAfter, qos))).
-      mapMaterializedValue { subscriber =>
-        implicit val akkaTimeout = akka.util.Timeout(timeoutAfter)
-        implicit val ec = SameThreadExecutionContext
-
-        (subscriber ? MessagePublisherSinkActor.AllDoneFuturePlease).mapTo[Future[Unit]].flatMap(identity)
-      }
+    new MessagePublisherSink(rabbitControl, timeoutAfter, qos)
   }
 }

build.sbt

@@ -2,8 +2,8 @@ import java.util.Properties
 
 val json4sVersion = "3.6.6"
 val circeVersion = "0.12.3"
-val akkaVersion = "2.5.25"
-val playVersion = "2.7.4"
+val akkaVersion = "2.6.6"
+val playVersion = "2.9.0"
 
 val appProperties = {
   val prop = new Properties()