/**
* 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.flowable;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.exceptions.*;
import io.reactivex.functions.BiPredicate;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.SpscArrayQueue;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.AtomicThrowable;
import io.reactivex.plugins.RxJavaPlugins;
public final class FlowableSequenceEqual<T> extends Flowable<Boolean> {
final Publisher<? extends T> first;
final Publisher<? extends T> second;
final BiPredicate<? super T, ? super T> comparer;
final int prefetch;
public FlowableSequenceEqual(Publisher<? extends T> first, Publisher<? extends T> second,
BiPredicate<? super T, ? super T> comparer, int prefetch) {
this.first = first;
this.second = second;
this.comparer = comparer;
this.prefetch = prefetch;
}
@Override
public void subscribeActual(Subscriber<? super Boolean> s) {
EqualCoordinator<T> parent = new EqualCoordinator<T>(s, prefetch, comparer);
s.onSubscribe(parent);
parent.subscribe(first, second);
}
/**
* Provides callbacks for the EqualSubscribers.
*/
interface EqualCoordinatorHelper {
void drain();
void innerError(Throwable ex);
}
static final class EqualCoordinator<T> extends DeferredScalarSubscription<Boolean>
implements EqualCoordinatorHelper {
private static final long serialVersionUID = -6178010334400373240L;
final BiPredicate<? super T, ? super T> comparer;
final EqualSubscriber<T> first;
final EqualSubscriber<T> second;
final AtomicThrowable error;
final AtomicInteger wip;
T v1;
T v2;
EqualCoordinator(Subscriber<? super Boolean> actual, int prefetch, BiPredicate<? super T, ? super T> comparer) {
super(actual);
this.comparer = comparer;
this.wip = new AtomicInteger();
this.first = new EqualSubscriber<T>(this, prefetch);
this.second = new EqualSubscriber<T>(this, prefetch);
this.error = new AtomicThrowable();
}
void subscribe(Publisher<? extends T> source1, Publisher<? extends T> source2) {
source1.subscribe(first);
source2.subscribe(second);
}
@Override
public void cancel() {
super.cancel();
first.cancel();
second.cancel();
if (wip.getAndIncrement() == 0) {
first.clear();
second.clear();
}
}
void cancelAndClear() {
first.cancel();
first.clear();
second.cancel();
second.clear();
}
@Override
public void drain() {
if (wip.getAndIncrement() != 0) {
return;
}
int missed = 1;
for (;;) {
SimpleQueue<T> q1 = first.queue;
SimpleQueue<T> q2 = second.queue;
if (q1 != null && q2 != null) {
for (;;) {
if (isCancelled()) {
first.clear();
second.clear();
return;
}
Throwable ex = error.get();
if (ex != null) {
cancelAndClear();
actual.onError(error.terminate());
return;
}
boolean d1 = first.done;
T a = v1;
if (a == null) {
try {
a = q1.poll();
} catch (Throwable exc) {
Exceptions.throwIfFatal(exc);
cancelAndClear();
error.addThrowable(exc);
actual.onError(error.terminate());
return;
}
v1 = a;
}
boolean e1 = a == null;
boolean d2 = second.done;
T b = v2;
if (b == null) {
try {
b = q2.poll();
} catch (Throwable exc) {
Exceptions.throwIfFatal(exc);
cancelAndClear();
error.addThrowable(exc);
actual.onError(error.terminate());
return;
}
v2 = b;
}
boolean e2 = b == null;
if (d1 && d2 && e1 && e2) {
complete(true);
return;
}
if ((d1 && d2) && (e1 != e2)) {
cancelAndClear();
complete(false);
return;
}
if (e1 || e2) {
break;
}
boolean c;
try {
c = comparer.test(a, b);
} catch (Throwable exc) {
Exceptions.throwIfFatal(exc);
cancelAndClear();
error.addThrowable(exc);
actual.onError(error.terminate());
return;
}
if (!c) {
cancelAndClear();
complete(false);
return;
}
v1 = null;
v2 = null;
first.request();
second.request();
}
} else {
if (isCancelled()) {
first.clear();
second.clear();
return;
}
Throwable ex = error.get();
if (ex != null) {
cancelAndClear();
actual.onError(error.terminate());
return;
}
}
missed = wip.addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
@Override
public void innerError(Throwable t) {
if (error.addThrowable(t)) {
drain();
} else {
RxJavaPlugins.onError(t);
}
}
}
static final class EqualSubscriber<T>
extends AtomicReference<Subscription>
implements FlowableSubscriber<T> {
private static final long serialVersionUID = 4804128302091633067L;
final EqualCoordinatorHelper parent;
final int prefetch;
final int limit;
long produced;
volatile SimpleQueue<T> queue;
volatile boolean done;
int sourceMode;
EqualSubscriber(EqualCoordinatorHelper parent, int prefetch) {
this.parent = parent;
this.limit = prefetch - (prefetch >> 2);
this.prefetch = prefetch;
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.setOnce(this, s)) {
if (s instanceof QueueSubscription) {
@SuppressWarnings("unchecked")
QueueSubscription<T> qs = (QueueSubscription<T>) s;
int m = qs.requestFusion(QueueSubscription.ANY);
if (m == QueueSubscription.SYNC) {
sourceMode = m;
queue = qs;
done = true;
parent.drain();
return;
}
if (m == QueueSubscription.ASYNC) {
sourceMode = m;
queue = qs;
s.request(prefetch);
return;
}
}
queue = new SpscArrayQueue<T>(prefetch);
s.request(prefetch);
}
}
@Override
public void onNext(T t) {
if (sourceMode == QueueSubscription.NONE) {
if (!queue.offer(t)) {
onError(new MissingBackpressureException());
return;
}
}
parent.drain();
}
@Override
public void onError(Throwable t) {
parent.innerError(t);
}
@Override
public void onComplete() {
done = true;
parent.drain();
}
public void request() {
if (sourceMode != QueueSubscription.SYNC) {
long p = produced + 1;
if (p >= limit) {
produced = 0;
get().request(p);
} else {
produced = p;
}
}
}
public void cancel() {
SubscriptionHelper.cancel(this);
}
void clear() {
SimpleQueue<T> sq = queue;
if (sq != null) {
sq.clear();
}
}
}
}