monifu.reactive.internals.operators.flatten.scala Maven / Gradle / Ivy
/*
* Copyright (c) 2014-2015 by its authors. Some rights reserved.
* See the project homepage at: http://www.monifu.org
*
* 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 monifu.reactive.internals.operators
import monifu.concurrent.cancelables.{BooleanCancelable, RefCountCancelable}
import monifu.reactive.Ack.{Cancel, Continue}
import monifu.reactive.exceptions.CompositeException
import monifu.reactive.internals._
import monifu.reactive.observers.{BufferedSubscriber, SynchronousObserver}
import monifu.reactive._
import scala.collection.mutable
import scala.concurrent.Promise
private[reactive] object flatten {
/**
* Implementation for [[Observable.concat]].
*/
def concat[T,U](source: Observable[T], delayErrors: Boolean)
(implicit ev: T <:< Observable[U]): Observable[U] = {
Observable.create[U] { subscriber =>
implicit val s = subscriber.scheduler
val observerU = subscriber.observer
source.onSubscribe(new Observer[T] {
private[this] val errors = if (delayErrors)
mutable.ArrayBuffer.empty[Throwable] else null
private[this] val refCount = RefCountCancelable {
if (delayErrors && errors.nonEmpty)
observerU.onError(CompositeException(errors))
else
observerU.onComplete()
}
def onNext(childObservable: T) = {
val upstreamPromise = Promise[Ack]()
val refID = refCount.acquire()
childObservable.onSubscribe(new Observer[U] {
def onNext(elem: U) = {
observerU.onNext(elem)
.ifCancelTryCanceling(upstreamPromise)
}
def onError(ex: Throwable): Unit = {
if (delayErrors) {
errors += ex
onComplete()
}
else {
// error happened, so signaling both the main thread that it should stop
// and the downstream consumer of the error
upstreamPromise.trySuccess(Cancel)
observerU.onError(ex)
}
}
def onComplete(): Unit = {
// NOTE: we aren't sending this onComplete signal downstream to our observerU
// instead we are just instructing upstream to send the next observable
upstreamPromise.trySuccess(Continue)
refID.cancel()
}
})
upstreamPromise.future
}
def onError(ex: Throwable) = {
if (delayErrors) {
errors += ex
onComplete()
}
else {
// oops, error happened on main thread, piping that
// along should cancel everything
observerU.onError(ex)
}
}
def onComplete() = {
refCount.cancel()
}
})
}
}
/**
* Implementation for [[Observable.merge]].
*/
def merge[T,U](source: Observable[T])
(overflowStrategy: OverflowStrategy, onOverflow: Long => U, delayErrors: Boolean)
(implicit ev: T <:< Observable[U]): Observable[U] = {
Observable.create { subscriber =>
implicit val s = subscriber.scheduler
val buffer = BufferedSubscriber(subscriber.observer, overflowStrategy, onOverflow)
val observerU = buffer.observer
source.onSubscribe(new SynchronousObserver[T] {
private[this] val streamActivity =
BooleanCancelable()
private[this] val errors = if (delayErrors)
mutable.ArrayBuffer.empty[Throwable] else null
private[this] val refCount = RefCountCancelable {
if (delayErrors)
errors.synchronized {
if (errors.nonEmpty)
observerU.onError(CompositeException(errors))
else
observerU.onComplete()
}
else
observerU.onComplete()
}
def onNext(childObservable: T) = {
val refID = refCount.acquire()
childObservable.onSubscribe(new Observer[U] {
def onNext(elem: U) = {
if (streamActivity.isCanceled)
Cancel
else
observerU.onNext(elem)
.ifCanceledDoCancel(streamActivity)
}
def onError(ex: Throwable): Unit = {
if (delayErrors) errors.synchronized {
errors += ex
refID.cancel()
}
else {
streamActivity.cancel()
observerU.onError(ex)
}
}
def onComplete(): Unit = {
// NOTE: we aren't sending this onComplete signal downstream to our observerU
// we will eventually do that after all of them are complete
refID.cancel()
}
})
if (streamActivity.isCanceled)
Cancel
else
Continue
}
def onError(ex: Throwable) = {
if (delayErrors) errors.synchronized {
errors += ex
refCount.cancel()
}
else {
// oops, error happened on main thread,
// piping that along should cancel everything
observerU.onError(ex)
}
}
def onComplete() = {
refCount.cancel()
}
})
}
}
}