akka.pattern.PromiseRef.scala Maven / Gradle / Ivy
/*
* Copyright (C) 2009-2019 Lightbend Inc.
*/
package akka.pattern
import akka.actor._
import akka.util.Timeout
import scala.concurrent.{ Future, Promise }
/**
* A combination of a Future and an ActorRef associated with it, which points
* to an actor performing a task which will eventually resolve the Future.
*/
trait FutureRef[T] {
/**
* ActorRef associated with this FutureRef.
*/
def ref: ActorRef
/**
* Future associated with this FutureRef.
*/
def future: Future[T]
}
/**
* A combination of a Promise and an ActorRef associated with it, which points
* to an actor performing a task which will eventually resolve the Promise.
*/
trait PromiseRef[T] { this: FutureRef[T] =>
/**
* ActorRef associated with this PromiseRef.
*/
def ref: ActorRef
/**
* Promise associated with this PromiseRef.
*/
def promise: Promise[T]
/**
* Future containing the value of the Promise associated with this PromiseRef.
*/
final def future = promise.future
/**
* Converts this PromiseRef to FutureRef, effectively narrowing it's API.
*/
def toFutureRef: FutureRef[T]
}
object PromiseRef {
/**
* Wraps an ActorRef and a Promise into a PromiseRef.
*/
private[akka] def wrap[T](actorRef: ActorRef, promise: Promise[T]): PromiseRef[T] = {
new PromiseRefImpl(actorRef, promise)
}
/**
* Constructs a new PromiseRef which will be completed with the first message sent to it.
*
* {{{
* // enables transparent use of PromiseRef as ActorRef and Promise
* import PromiseRef.Implicits._
*
* val promiseRef = PromiseRef(system, 5.seconds)
* promiseRef ! "message"
* promiseRef.onComplete(println) // prints "message"
* }}}
*/
def apply(system: ActorSystem, timeout: Timeout): PromiseRef[Any] = {
val provider = system.asInstanceOf[ExtendedActorSystem].provider
AskPromiseRef(provider, timeout)
}
/**
* Constructs a new PromiseRef which will be completed with the first message sent to it.
*
* {{{
* // enables transparent use of PromiseRef as ActorRef and Promise
* import PromiseRef.Implicits._
*
* // requires an implicit ActorSystem in scope
* val promiseRef = PromiseRef(5.seconds)
* promiseRef ! "message"
* promiseRef.future.onComplete(println) // prints "message"
* }}}
*/
def apply(timeout: Timeout)(implicit system: ActorSystem): PromiseRef[Any] = {
PromiseRef(system, timeout)
}
}
object FutureRef {
/**
* Wraps an ActorRef and a Future into a FutureRef.
*/
private[akka] def wrap[T](actorRef: ActorRef, future: Future[T]): FutureRef[T] = {
new FutureRefImpl(actorRef, future)
}
/**
* Constructs a new FutureRef which will be completed with the first message sent to it.
*
* {{{
* // enables transparent use of FutureRef as ActorRef and Future
* import FutureRef.Implicits._
*
* val futureRef = FutureRef(system, 5.seconds)
* futureRef ! "message"
* futureRef.onComplete(println) // prints "message"
* }}}
*/
def apply(system: ActorSystem, timeout: Timeout): FutureRef[Any] = {
PromiseRef(system, timeout).toFutureRef
}
/**
* Constructs a new PromiseRef which will be completed with the first message sent to it.
*
* {{{
* // enables transparent use of FutureRef as ActorRef and Promise
* import FutureRef.Implicits._
*
* // requires an implicit ActorSystem in scope
* val futureRef = FutureRef(5.seconds)
* futureRef ! "message"
* futureRef.onComplete(println) // prints "message"
* }}}
*/
def apply(timeout: Timeout)(implicit system: ActorSystem): FutureRef[Any] = {
FutureRef(system, timeout)
}
}
private[akka] class PromiseRefImpl[T](val ref: ActorRef, val promise: Promise[T])
extends PromiseRef[T]
with FutureRef[T] {
def toFutureRef: FutureRef[T] = this
}
private[akka] final class FutureRefImpl[T](val ref: ActorRef, val future: Future[T]) extends FutureRef[T]
private[akka] final class AskPromiseRef private (promiseActorRef: PromiseActorRef)
extends PromiseRefImpl[Any](promiseActorRef, promiseActorRef.result)
private[akka] object AskPromiseRef {
def apply(provider: ActorRefProvider, timeout: Timeout): AskPromiseRef = {
if (timeout.duration.length > 0) {
val promiseActorRef = PromiseActorRef(provider, timeout, "unknown", "unknown", provider.deadLetters)
new AskPromiseRef(promiseActorRef)
} else {
throw new IllegalArgumentException(s"Timeout length must not be negative, was: $timeout")
}
}
}
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