persistent become

pBecome.scala

case class Message()

class PActor extends PersistentActor with ActorLogging {

  override def persistenceId: String = "test"

  override def receiveRecover: Receive = recovery(0)

  def recovery(count: Int): Receive = {
    case RecoveryCompleted =>
      log.info(s"Currently have: ${count}")
      log.info("Recovery completed!")

    case m: Message =>
      log.info(s"Count: {}", count)
      context.become(recovery(count + 1))
  }

 override def receiveCommand: Receive = {
    case m: Message =>
      persist(m)(_ => log.info("persisted"))
  }


}

object Main extends App {

  val system = ActorSystem("test", ConfigFactory.defaultApplication())

  val ref = system.actorOf(Props(classOf[PActor]))

  (1 to 3).foreach(_ => ref ! Message())
  
}

/* first run
[INFO] [01/18/2017 03:27:10.850] [test-akka.actor.default-dispatcher-4] [akka://test/user/$a] Currently have: 0
[INFO] [01/18/2017 03:27:10.851] [test-akka.actor.default-dispatcher-4] [akka://test/user/$a] Recovery completed!
[INFO] [01/18/2017 03:27:10.939] [test-akka.actor.default-dispatcher-3] [akka://test/user/$a] persisted
[INFO] [01/18/2017 03:27:10.955] [test-akka.actor.default-dispatcher-4] [akka://test/user/$a] persisted
[INFO] [01/18/2017 03:27:10.966] [test-akka.actor.default-dispatcher-2] [akka://test/user/$a] persisted

*/

/* second run
[INFO] [01/18/2017 03:28:16.821] [akka://test/user/$a] Count: 0
[INFO] [01/18/2017 03:28:16.822] [akka://test/user/$a] Count: 0 <----- should print "Count: 1"
[INFO] [01/18/2017 03:28:16.822] [akka://test/user/$a] Count: 0
[INFO] [01/18/2017 03:28:16.824] [akka://test/user/$a] Currently have: 0
[INFO] [01/18/2017 03:28:16.824] [akka://test/user/$a] Recovery completed!
[INFO] [01/18/2017 03:28:16.825] [akka://test/user/$a] Count: 1 <----- should use receiveCommand, but it stayed in receiveRecover
[INFO] [01/18/2017 03:28:16.826] [akka://test/user/$a] Count: 2
[INFO] [01/18/2017 03:28:16.826] [akka://test/user/$a] Count: 3
*/