scala - 如何在 Actor 中停止 Source.tick？

Question

我有一个 Actor ，每 2 秒产生一次 NotUsed .也许它没有任何意义，但它只是为了测试目的。

import akka.NotUsed
import akka.actor.{Actor, ActorLogging, Props}
import akka.stream.{ActorMaterializer, KillSwitches}
import akka.stream.scaladsl.{Keep, Sink, Source}
import com.sweetsoft.FsmSystem.{Add, StartTicker, StopTicker}

import scala.concurrent.duration._

object AddActor {

  def props: Props = Props(new AddActor)

}

final class AddActor extends Actor with ActorLogging {

  implicit val materilizer = ActorMaterializer()

  private val consumer: NotUsed => Unit = _ =>
    context.parent ! Add

  private val runnable = Source.tick(2.second, 2.second, NotUsed)
    .named("Ticker")
    .toMat(Sink.foreach(consumer))(Keep.both)

  override def receive: Receive = {
    case StartTicker =>

      runnable.run()
    case StopTicker =>

  }
}  

当Actor收到消息StopTicker ，然后我想停止流。通过 StartTicker ，然后启动流。

调用run()方法，我会得到物化值Cancellabel但无法在StopTicker 内访问范围。

我该怎么办？

Answer 1

您可以使用 becode/unbecome图案:

final class AddActor extends Actor with ActorLogging {
    import context._

    implicit val materilizer: ActorMaterializer = ActorMaterializer()

    private val consumer: NotUsed => Unit = _ =>
      self ! Add //send Add to self rather than directly to context.parent

    private val runnable = Source.tick(2.second, 2.second, NotUsed)
      .named("Ticker")
      .toMat(Sink.foreach(consumer))(Keep.both)

    override def preStart(): Unit = { //start runnable on actor start
      super.preStart()
      runnable.run()
    }

    val running: Receive = { //when running ignore new StartTicker but handle StopTicker and Add
      case StopTicker =>
        become(paused)

      case Add =>
        context.parent ! Add
    }

    val paused: Receive = { //handle just StartTicker
      case StartTicker =>
        become(running)
    }

    override def receive: Receive = paused //initial receive is paused

}