/**
* Copyright (c) 2016-present, RxJava Contributors.
*
* 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 io.reactivex.internal.operators.mixed;
import java.util.concurrent.atomic.
AtomicReference;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.exceptions.
Exceptions;
import io.reactivex.functions.
Function;
import io.reactivex.internal.disposables.
DisposableHelper;
import io.reactivex.internal.functions.
ObjectHelper;
import io.reactivex.internal.util.*;
import io.reactivex.plugins.
RxJavaPlugins;
/**
* Maps the upstream values into {@link CompletableSource}s, subscribes to the newer one while
* disposing the subscription to the previous {@code CompletableSource}, thus keeping at most one
* active {@code CompletableSource} running.
* <p>History: 2.1.11 - experimental
* @param <T> the upstream value type
* @since 2.2
*/
public final class
ObservableSwitchMapCompletable<T> extends
Completable {
final
Observable<T>
source;
final
Function<? super T, ? extends
CompletableSource>
mapper;
final boolean
delayErrors;
public
ObservableSwitchMapCompletable(
Observable<T>
source,
Function<? super T, ? extends
CompletableSource>
mapper, boolean
delayErrors) {
this.
source =
source;
this.
mapper =
mapper;
this.
delayErrors =
delayErrors;
}
@
Override
protected void
subscribeActual(
CompletableObserver observer) {
if (!
ScalarXMapZHelper.
tryAsCompletable(
source,
mapper,
observer)) {
source.
subscribe(new
SwitchMapCompletableObserver<T>(
observer,
mapper,
delayErrors));
}
}
static final class
SwitchMapCompletableObserver<T> implements
Observer<T>,
Disposable {
final
CompletableObserver downstream;
final
Function<? super T, ? extends
CompletableSource>
mapper;
final boolean
delayErrors;
final
AtomicThrowable errors;
final
AtomicReference<
SwitchMapInnerObserver>
inner;
static final
SwitchMapInnerObserver INNER_DISPOSED = new
SwitchMapInnerObserver(null);
volatile boolean
done;
Disposable upstream;
SwitchMapCompletableObserver(
CompletableObserver downstream,
Function<? super T, ? extends
CompletableSource>
mapper, boolean
delayErrors) {
this.
downstream =
downstream;
this.
mapper =
mapper;
this.
delayErrors =
delayErrors;
this.
errors = new
AtomicThrowable();
this.
inner = new
AtomicReference<
SwitchMapInnerObserver>();
}
@
Override
public void
onSubscribe(
Disposable d) {
if (
DisposableHelper.
validate(
upstream,
d)) {
this.
upstream =
d;
downstream.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
CompletableSource c;
try {
c =
ObjectHelper.
requireNonNull(
mapper.
apply(
t), "The mapper returned a null CompletableSource");
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
upstream.
dispose();
onError(
ex);
return;
}
SwitchMapInnerObserver o = new
SwitchMapInnerObserver(this);
for (;;) {
SwitchMapInnerObserver current =
inner.
get();
if (
current ==
INNER_DISPOSED) {
break;
}
if (
inner.
compareAndSet(
current,
o)) {
if (
current != null) {
current.
dispose();
}
c.
subscribe(
o);
break;
}
}
}
@
Override
public void
onError(
Throwable t) {
if (
errors.
addThrowable(
t)) {
if (
delayErrors) {
onComplete();
} else {
disposeInner();
Throwable ex =
errors.
terminate();
if (
ex !=
ExceptionHelper.
TERMINATED) {
downstream.
onError(
ex);
}
}
} else {
RxJavaPlugins.
onError(
t);
}
}
@
Override
public void
onComplete() {
done = true;
if (
inner.
get() == null) {
Throwable ex =
errors.
terminate();
if (
ex == null) {
downstream.
onComplete();
} else {
downstream.
onError(
ex);
}
}
}
void
disposeInner() {
SwitchMapInnerObserver o =
inner.
getAndSet(
INNER_DISPOSED);
if (
o != null &&
o !=
INNER_DISPOSED) {
o.
dispose();
}
}
@
Override
public void
dispose() {
upstream.
dispose();
disposeInner();
}
@
Override
public boolean
isDisposed() {
return
inner.
get() ==
INNER_DISPOSED;
}
void
innerError(
SwitchMapInnerObserver sender,
Throwable error) {
if (
inner.
compareAndSet(
sender, null)) {
if (
errors.
addThrowable(
error)) {
if (
delayErrors) {
if (
done) {
Throwable ex =
errors.
terminate();
downstream.
onError(
ex);
}
} else {
dispose();
Throwable ex =
errors.
terminate();
if (
ex !=
ExceptionHelper.
TERMINATED) {
downstream.
onError(
ex);
}
}
return;
}
}
RxJavaPlugins.
onError(
error);
}
void
innerComplete(
SwitchMapInnerObserver sender) {
if (
inner.
compareAndSet(
sender, null)) {
if (
done) {
Throwable ex =
errors.
terminate();
if (
ex == null) {
downstream.
onComplete();
} else {
downstream.
onError(
ex);
}
}
}
}
static final class
SwitchMapInnerObserver extends
AtomicReference<
Disposable>
implements
CompletableObserver {
private static final long
serialVersionUID = -8003404460084760287L;
final
SwitchMapCompletableObserver<?>
parent;
SwitchMapInnerObserver(
SwitchMapCompletableObserver<?>
parent) {
this.
parent =
parent;
}
@
Override
public void
onSubscribe(
Disposable d) {
DisposableHelper.
setOnce(this,
d);
}
@
Override
public void
onError(
Throwable e) {
parent.
innerError(this,
e);
}
@
Override
public void
onComplete() {
parent.
innerComplete(this);
}
void
dispose() {
DisposableHelper.
dispose(this);
}
}
}
}