monix.reactive.internal.consumers.ForeachAsyncConsumer.scala Maven / Gradle / Ivy
/*
* Copyright (c) 2014-2020 by The Monix Project Developers.
* See the project homepage at: https://monix.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package monix.reactive.internal.consumers
import monix.execution.{Ack, Callback, Cancelable, Scheduler}
import monix.eval.Task
import monix.execution.Ack.{Continue, Stop}
import monix.execution.cancelables.{AssignableCancelable, SingleAssignCancelable}
import scala.util.control.NonFatal
import monix.reactive.Consumer
import monix.reactive.observers.Subscriber
import scala.concurrent.Future
/** Implementation for [[monix.reactive.Consumer.foreachTask]]. */
private[reactive] final class ForeachAsyncConsumer[A](f: A => Task[Unit]) extends Consumer[A, Unit] {
def createSubscriber(cb: Callback[Throwable, Unit], s: Scheduler): (Subscriber[A], AssignableCancelable) = {
var isDone = false
var lastCancelable = Cancelable.empty
val out = new Subscriber[A] {
implicit val scheduler = s
def onNext(elem: A): Future[Ack] = {
try {
this.synchronized {
if (!isDone) {
val future = f(elem).redeem({e => onError(e); Stop}, _ => Continue).runToFuture
lastCancelable = future
future.syncTryFlatten
} else Stop
}
} catch {
case ex if NonFatal(ex) =>
onError(ex)
Stop
}
}
def onComplete(): Unit =
if (!isDone) {
isDone = true
cb.onSuccess(())
}
def onError(ex: Throwable): Unit =
if (!isDone) {
isDone = true
cb.onError(ex)
}
}
(out, SingleAssignCancelable.plusOne(Cancelable { () =>
out.synchronized {
isDone = true
lastCancelable.cancel()
lastCancelable = Cancelable.empty
}
}))
}
}