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Reactive Extensions for Java
/**
* 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.Arrays;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.functions.Function;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.SpscArrayQueue;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.internal.util.*;
import io.reactivex.plugins.RxJavaPlugins;
public final class FlowableZip extends Flowable {
final Publisher[] sources;
final Iterable> sourcesIterable;
final Function zipper;
final int bufferSize;
final boolean delayError;
public FlowableZip(Publisher[] sources,
Iterable> sourcesIterable,
Function zipper,
int bufferSize,
boolean delayError) {
this.sources = sources;
this.sourcesIterable = sourcesIterable;
this.zipper = zipper;
this.bufferSize = bufferSize;
this.delayError = delayError;
}
@Override
@SuppressWarnings("unchecked")
public void subscribeActual(Subscriber s) {
Publisher[] sources = this.sources;
int count = 0;
if (sources == null) {
sources = new Publisher[8];
for (Publisher p : sourcesIterable) {
if (count == sources.length) {
Publisher[] b = new Publisher[count + (count >> 2)];
System.arraycopy(sources, 0, b, 0, count);
sources = b;
}
sources[count++] = p;
}
} else {
count = sources.length;
}
if (count == 0) {
EmptySubscription.complete(s);
return;
}
ZipCoordinator coordinator = new ZipCoordinator(s, zipper, count, bufferSize, delayError);
s.onSubscribe(coordinator);
coordinator.subscribe(sources, count);
}
static final class ZipCoordinator
extends AtomicInteger
implements Subscription {
private static final long serialVersionUID = -2434867452883857743L;
final Subscriber downstream;
final ZipSubscriber[] subscribers;
final Function zipper;
final AtomicLong requested;
final AtomicThrowable errors;
final boolean delayErrors;
volatile boolean cancelled;
final Object[] current;
ZipCoordinator(Subscriber actual,
Function zipper, int n, int prefetch, boolean delayErrors) {
this.downstream = actual;
this.zipper = zipper;
this.delayErrors = delayErrors;
@SuppressWarnings("unchecked")
ZipSubscriber[] a = new ZipSubscriber[n];
for (int i = 0; i < n; i++) {
a[i] = new ZipSubscriber(this, prefetch);
}
this.current = new Object[n];
this.subscribers = a;
this.requested = new AtomicLong();
this.errors = new AtomicThrowable();
}
void subscribe(Publisher[] sources, int n) {
ZipSubscriber[] a = subscribers;
for (int i = 0; i < n; i++) {
if (cancelled || (!delayErrors && errors.get() != null)) {
return;
}
sources[i].subscribe(a[i]);
}
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
drain();
}
}
@Override
public void cancel() {
if (!cancelled) {
cancelled = true;
cancelAll();
}
}
void error(ZipSubscriber inner, Throwable e) {
if (errors.addThrowable(e)) {
inner.done = true;
drain();
} else {
RxJavaPlugins.onError(e);
}
}
void cancelAll() {
for (ZipSubscriber s : subscribers) {
s.cancel();
}
}
void drain() {
if (getAndIncrement() != 0) {
return;
}
final Subscriber a = downstream;
final ZipSubscriber[] qs = subscribers;
final int n = qs.length;
Object[] values = current;
int missed = 1;
for (;;) {
long r = requested.get();
long e = 0L;
while (r != e) {
if (cancelled) {
return;
}
if (!delayErrors && errors.get() != null) {
cancelAll();
a.onError(errors.terminate());
return;
}
boolean empty = false;
for (int j = 0; j < n; j++) {
ZipSubscriber inner = qs[j];
if (values[j] == null) {
try {
boolean d = inner.done;
SimpleQueue q = inner.queue;
T v = q != null ? q.poll() : null;
boolean sourceEmpty = v == null;
if (d && sourceEmpty) {
cancelAll();
Throwable ex = errors.get();
if (ex != null) {
a.onError(errors.terminate());
} else {
a.onComplete();
}
return;
}
if (!sourceEmpty) {
values[j] = v;
} else {
empty = true;
}
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
errors.addThrowable(ex);
if (!delayErrors) {
cancelAll();
a.onError(errors.terminate());
return;
}
empty = true;
}
}
}
if (empty) {
break;
}
R v;
try {
v = ObjectHelper.requireNonNull(zipper.apply(values.clone()), "The zipper returned a null value");
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
cancelAll();
errors.addThrowable(ex);
a.onError(errors.terminate());
return;
}
a.onNext(v);
e++;
Arrays.fill(values, null);
}
if (r == e) {
if (cancelled) {
return;
}
if (!delayErrors && errors.get() != null) {
cancelAll();
a.onError(errors.terminate());
return;
}
for (int j = 0; j < n; j++) {
ZipSubscriber inner = qs[j];
if (values[j] == null) {
try {
boolean d = inner.done;
SimpleQueue q = inner.queue;
T v = q != null ? q.poll() : null;
boolean empty = v == null;
if (d && empty) {
cancelAll();
Throwable ex = errors.get();
if (ex != null) {
a.onError(errors.terminate());
} else {
a.onComplete();
}
return;
}
if (!empty) {
values[j] = v;
}
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
errors.addThrowable(ex);
if (!delayErrors) {
cancelAll();
a.onError(errors.terminate());
return;
}
}
}
}
}
if (e != 0L) {
for (ZipSubscriber inner : qs) {
inner.request(e);
}
if (r != Long.MAX_VALUE) {
requested.addAndGet(-e);
}
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
}
static final class ZipSubscriber extends AtomicReference implements FlowableSubscriber, Subscription {
private static final long serialVersionUID = -4627193790118206028L;
final ZipCoordinator parent;
final int prefetch;
final int limit;
SimpleQueue queue;
long produced;
volatile boolean done;
int sourceMode;
ZipSubscriber(ZipCoordinator parent, int prefetch) {
this.parent = parent;
this.prefetch = prefetch;
this.limit = prefetch - (prefetch >> 2);
}
@SuppressWarnings("unchecked")
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.setOnce(this, s)) {
if (s instanceof QueueSubscription) {
QueueSubscription f = (QueueSubscription) s;
int m = f.requestFusion(QueueSubscription.ANY | QueueSubscription.BOUNDARY);
if (m == QueueSubscription.SYNC) {
sourceMode = m;
queue = f;
done = true;
parent.drain();
return;
}
if (m == QueueSubscription.ASYNC) {
sourceMode = m;
queue = f;
s.request(prefetch);
return;
}
}
queue = new SpscArrayQueue(prefetch);
s.request(prefetch);
}
}
@Override
public void onNext(T t) {
if (sourceMode != QueueSubscription.ASYNC) {
queue.offer(t);
}
parent.drain();
}
@Override
public void onError(Throwable t) {
parent.error(this, t);
}
@Override
public void onComplete() {
done = true;
parent.drain();
}
@Override
public void cancel() {
SubscriptionHelper.cancel(this);
}
@Override
public void request(long n) {
if (sourceMode != QueueSubscription.SYNC) {
long p = produced + n;
if (p >= limit) {
produced = 0L;
get().request(p);
} else {
produced = p;
}
}
}
}
}