monix.reactive.internal.operators.DumpObservable.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.operators
import java.io.PrintStream
import scala.util.control.NonFatal
import monix.execution.{Ack, Cancelable}
import monix.reactive.Observable
import monix.reactive.observers.Subscriber
import scala.concurrent.Future
private[reactive] final class DumpObservable[A](source: Observable[A], prefix: String, out: PrintStream)
extends Observable[A] {
def unsafeSubscribeFn(subscriber: Subscriber[A]): Cancelable = {
var pos = 0
val upstream = source.unsafeSubscribeFn(new Subscriber[A] {
implicit val scheduler = subscriber.scheduler
private[this] val downstreamActive = Cancelable { () =>
pos += 1
out.println(s"$pos: $prefix stopped")
}
def onNext(elem: A): Future[Ack] = {
try {
out.println(s"$pos: $prefix --> $elem")
pos += 1
} catch {
case NonFatal(_) => () // ignore
}
subscriber.onNext(elem).syncOnStopOrFailure(_ => downstreamActive.cancel())
}
def onError(ex: Throwable) = {
try {
out.println(s"$pos: $prefix --> $ex")
pos += 1
} catch {
case NonFatal(_) => () // ignore
}
subscriber.onError(ex)
}
def onComplete() = {
try {
out.println(s"$pos: $prefix completed")
pos += 1
} catch {
case NonFatal(_) =>
() // ignore
}
subscriber.onComplete()
}
})
Cancelable { () =>
upstream.cancel()
pos += 1
out.println(s"$pos: $prefix canceled")
}
}
}