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Reactive Extensions for Java
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/**
* 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.observable;
import io.reactivex.internal.functions.ObjectHelper;
import java.util.Arrays;
import java.util.concurrent.atomic.*;
import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.Exceptions;
import io.reactivex.functions.Function;
import io.reactivex.internal.disposables.*;
import io.reactivex.internal.queue.SpscLinkedArrayQueue;
public final class ObservableZip extends Observable {
final ObservableSource[] sources;
final Iterable> sourcesIterable;
final Function zipper;
final int bufferSize;
final boolean delayError;
public ObservableZip(ObservableSource[] 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(Observer observer) {
ObservableSource[] sources = this.sources;
int count = 0;
if (sources == null) {
sources = new ObservableSource[8];
for (ObservableSource p : sourcesIterable) {
if (count == sources.length) {
ObservableSource[] b = new ObservableSource[count + (count >> 2)];
System.arraycopy(sources, 0, b, 0, count);
sources = b;
}
sources[count++] = p;
}
} else {
count = sources.length;
}
if (count == 0) {
EmptyDisposable.complete(observer);
return;
}
ZipCoordinator zc = new ZipCoordinator(observer, zipper, count, delayError);
zc.subscribe(sources, bufferSize);
}
static final class ZipCoordinator extends AtomicInteger implements Disposable {
private static final long serialVersionUID = 2983708048395377667L;
final Observer downstream;
final Function zipper;
final ZipObserver[] observers;
final T[] row;
final boolean delayError;
volatile boolean cancelled;
@SuppressWarnings("unchecked")
ZipCoordinator(Observer actual,
Function zipper,
int count, boolean delayError) {
this.downstream = actual;
this.zipper = zipper;
this.observers = new ZipObserver[count];
this.row = (T[])new Object[count];
this.delayError = delayError;
}
public void subscribe(ObservableSource[] sources, int bufferSize) {
ZipObserver[] s = observers;
int len = s.length;
for (int i = 0; i < len; i++) {
s[i] = new ZipObserver(this, bufferSize);
}
// this makes sure the contents of the observers array is visible
this.lazySet(0);
downstream.onSubscribe(this);
for (int i = 0; i < len; i++) {
if (cancelled) {
return;
}
sources[i].subscribe(s[i]);
}
}
@Override
public void dispose() {
if (!cancelled) {
cancelled = true;
cancelSources();
if (getAndIncrement() == 0) {
clear();
}
}
}
@Override
public boolean isDisposed() {
return cancelled;
}
void cancel() {
clear();
cancelSources();
}
void cancelSources() {
for (ZipObserver zs : observers) {
zs.dispose();
}
}
void clear() {
for (ZipObserver zs : observers) {
zs.queue.clear();
}
}
public void drain() {
if (getAndIncrement() != 0) {
return;
}
int missing = 1;
final ZipObserver[] zs = observers;
final Observer a = downstream;
final T[] os = row;
final boolean delayError = this.delayError;
for (;;) {
for (;;) {
int i = 0;
int emptyCount = 0;
for (ZipObserver z : zs) {
if (os[i] == null) {
boolean d = z.done;
T v = z.queue.poll();
boolean empty = v == null;
if (checkTerminated(d, empty, a, delayError, z)) {
return;
}
if (!empty) {
os[i] = v;
} else {
emptyCount++;
}
} else {
if (z.done && !delayError) {
Throwable ex = z.error;
if (ex != null) {
cancelled = true;
cancel();
a.onError(ex);
return;
}
}
}
i++;
}
if (emptyCount != 0) {
break;
}
R v;
try {
v = ObjectHelper.requireNonNull(zipper.apply(os.clone()), "The zipper returned a null value");
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
cancel();
a.onError(ex);
return;
}
a.onNext(v);
Arrays.fill(os, null);
}
missing = addAndGet(-missing);
if (missing == 0) {
return;
}
}
}
boolean checkTerminated(boolean d, boolean empty, Observer a, boolean delayError, ZipObserver source) {
if (cancelled) {
cancel();
return true;
}
if (d) {
if (delayError) {
if (empty) {
Throwable e = source.error;
cancelled = true;
cancel();
if (e != null) {
a.onError(e);
} else {
a.onComplete();
}
return true;
}
} else {
Throwable e = source.error;
if (e != null) {
cancelled = true;
cancel();
a.onError(e);
return true;
} else
if (empty) {
cancelled = true;
cancel();
a.onComplete();
return true;
}
}
}
return false;
}
}
static final class ZipObserver implements Observer {
final ZipCoordinator parent;
final SpscLinkedArrayQueue queue;
volatile boolean done;
Throwable error;
final AtomicReference upstream = new AtomicReference();
ZipObserver(ZipCoordinator parent, int bufferSize) {
this.parent = parent;
this.queue = new SpscLinkedArrayQueue(bufferSize);
}
@Override
public void onSubscribe(Disposable d) {
DisposableHelper.setOnce(this.upstream, d);
}
@Override
public void onNext(T t) {
queue.offer(t);
parent.drain();
}
@Override
public void onError(Throwable t) {
error = t;
done = true;
parent.drain();
}
@Override
public void onComplete() {
done = true;
parent.drain();
}
public void dispose() {
DisposableHelper.dispose(upstream);
}
}
}