monix.reactive.internal.builders.PipeThroughSelectorObservable.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.builders
import monix.execution.{Ack, Cancelable}
import monix.execution.cancelables.SingleAssignCancelable
import scala.util.control.NonFatal
import monix.reactive.observers.Subscriber
import monix.reactive.{Observable, Pipe}
import scala.concurrent.Future
private[reactive] final class PipeThroughSelectorObservable[A, B, C](
source: Observable[A],
pipe: Pipe[A, B],
f: Observable[B] => Observable[C])
extends Observable[C] {
def unsafeSubscribeFn(out: Subscriber[C]): Cancelable = {
import out.scheduler
var streamErrors = true
val upstream = SingleAssignCancelable()
try {
val connectable = source.multicast(pipe)
val observable = f(connectable)
streamErrors = false
val downstream = observable.unsafeSubscribeFn(new Subscriber[C] {
implicit val scheduler = out.scheduler
def onError(ex: Throwable) = out.onError(ex)
def onComplete() = out.onComplete()
def onNext(elem: C): Future[Ack] = {
// Treating STOP event
out.onNext(elem).syncOnStopOrFailure(_ => upstream.cancel())
}
})
upstream := connectable.connect()
Cancelable { () =>
upstream.cancel()
downstream.cancel()
}
} catch {
case ex if NonFatal(ex) =>
upstream.cancel()
if (streamErrors) out.onError(ex)
else out.scheduler.reportFailure(ex)
Cancelable.empty
}
}
}