/**
* 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.completable;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.exceptions.*;
import io.reactivex.internal.disposables.
DisposableHelper;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.*;
import io.reactivex.internal.subscriptions.
SubscriptionHelper;
import io.reactivex.plugins.
RxJavaPlugins;
public final class
CompletableConcat extends
Completable {
final
Publisher<? extends
CompletableSource>
sources;
final int
prefetch;
public
CompletableConcat(
Publisher<? extends
CompletableSource>
sources, int
prefetch) {
this.
sources =
sources;
this.
prefetch =
prefetch;
}
@
Override
public void
subscribeActual(
CompletableObserver observer) {
sources.
subscribe(new
CompletableConcatSubscriber(
observer,
prefetch));
}
static final class
CompletableConcatSubscriber
extends
AtomicInteger
implements
FlowableSubscriber<
CompletableSource>,
Disposable {
private static final long
serialVersionUID = 9032184911934499404L;
final
CompletableObserver downstream;
final int
prefetch;
final int
limit;
final
ConcatInnerObserver inner;
final
AtomicBoolean once;
int
sourceFused;
int
consumed;
SimpleQueue<
CompletableSource>
queue;
Subscription upstream;
volatile boolean
done;
volatile boolean
active;
CompletableConcatSubscriber(
CompletableObserver actual, int
prefetch) {
this.
downstream =
actual;
this.
prefetch =
prefetch;
this.
inner = new
ConcatInnerObserver(this);
this.
once = new
AtomicBoolean();
this.
limit =
prefetch - (
prefetch >> 2);
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
SubscriptionHelper.
validate(this.
upstream,
s)) {
this.
upstream =
s;
long
r =
prefetch ==
Integer.
MAX_VALUE ?
Long.
MAX_VALUE :
prefetch;
if (
s instanceof
QueueSubscription) {
@
SuppressWarnings("unchecked")
QueueSubscription<
CompletableSource>
qs = (
QueueSubscription<
CompletableSource>)
s;
int
m =
qs.
requestFusion(
QueueSubscription.
ANY);
if (
m ==
QueueSubscription.
SYNC) {
sourceFused =
m;
queue =
qs;
done = true;
downstream.
onSubscribe(this);
drain();
return;
}
if (
m ==
QueueSubscription.
ASYNC) {
sourceFused =
m;
queue =
qs;
downstream.
onSubscribe(this);
s.
request(
r);
return;
}
}
if (
prefetch ==
Integer.
MAX_VALUE) {
queue = new
SpscLinkedArrayQueue<
CompletableSource>(
Flowable.
bufferSize());
} else {
queue = new
SpscArrayQueue<
CompletableSource>(
prefetch);
}
downstream.
onSubscribe(this);
s.
request(
r);
}
}
@
Override
public void
onNext(
CompletableSource t) {
if (
sourceFused ==
QueueSubscription.
NONE) {
if (!
queue.
offer(
t)) {
onError(new
MissingBackpressureException());
return;
}
}
drain();
}
@
Override
public void
onError(
Throwable t) {
if (
once.
compareAndSet(false, true)) {
DisposableHelper.
dispose(
inner);
downstream.
onError(
t);
} else {
RxJavaPlugins.
onError(
t);
}
}
@
Override
public void
onComplete() {
done = true;
drain();
}
@
Override
public void
dispose() {
upstream.
cancel();
DisposableHelper.
dispose(
inner);
}
@
Override
public boolean
isDisposed() {
return
DisposableHelper.
isDisposed(
inner.
get());
}
void
drain() {
if (
getAndIncrement() != 0) {
return;
}
for (;;) {
if (
isDisposed()) {
return;
}
if (!
active) {
boolean
d =
done;
CompletableSource cs;
try {
cs =
queue.
poll();
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
innerError(
ex);
return;
}
boolean
empty =
cs == null;
if (
d &&
empty) {
if (
once.
compareAndSet(false, true)) {
downstream.
onComplete();
}
return;
}
if (!
empty) {
active = true;
cs.
subscribe(
inner);
request();
}
}
if (
decrementAndGet() == 0) {
break;
}
}
}
void
request() {
if (
sourceFused !=
QueueSubscription.
SYNC) {
int
p =
consumed + 1;
if (
p ==
limit) {
consumed = 0;
upstream.
request(
p);
} else {
consumed =
p;
}
}
}
void
innerError(
Throwable e) {
if (
once.
compareAndSet(false, true)) {
upstream.
cancel();
downstream.
onError(
e);
} else {
RxJavaPlugins.
onError(
e);
}
}
void
innerComplete() {
active = false;
drain();
}
static final class
ConcatInnerObserver extends
AtomicReference<
Disposable> implements
CompletableObserver {
private static final long
serialVersionUID = -5454794857847146511L;
final
CompletableConcatSubscriber parent;
ConcatInnerObserver(
CompletableConcatSubscriber parent) {
this.
parent =
parent;
}
@
Override
public void
onSubscribe(
Disposable d) {
DisposableHelper.
replace(this,
d);
}
@
Override
public void
onError(
Throwable e) {
parent.
innerError(
e);
}
@
Override
public void
onComplete() {
parent.
innerComplete();
}
}
}
}