io.reactivex.rxjava3.internal.operators.flowable.FlowableFlatMapSingle Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rxjava Show documentation
Show all versions of rxjava Show documentation
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.rxjava3.internal.operators.flowable;
import java.util.Objects;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.rxjava3.core.*;
import io.reactivex.rxjava3.disposables.*;
import io.reactivex.rxjava3.exceptions.Exceptions;
import io.reactivex.rxjava3.functions.Function;
import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
import io.reactivex.rxjava3.internal.util.*;
import io.reactivex.rxjava3.operators.SpscLinkedArrayQueue;
/**
* Maps upstream values into SingleSources and merges their signals into one sequence.
* @param the source value type
* @param the result value type
*/
public final class FlowableFlatMapSingle extends AbstractFlowableWithUpstream {
final Function> mapper;
final boolean delayErrors;
final int maxConcurrency;
public FlowableFlatMapSingle(Flowable source, Function> mapper,
boolean delayError, int maxConcurrency) {
super(source);
this.mapper = mapper;
this.delayErrors = delayError;
this.maxConcurrency = maxConcurrency;
}
@Override
protected void subscribeActual(Subscriber s) {
source.subscribe(new FlatMapSingleSubscriber<>(s, mapper, delayErrors, maxConcurrency));
}
static final class FlatMapSingleSubscriber
extends AtomicInteger
implements FlowableSubscriber, Subscription {
private static final long serialVersionUID = 8600231336733376951L;
final Subscriber downstream;
final boolean delayErrors;
final int maxConcurrency;
final AtomicLong requested;
final CompositeDisposable set;
final AtomicInteger active;
final AtomicThrowable errors;
final Function> mapper;
final AtomicReference> queue;
Subscription upstream;
volatile boolean cancelled;
FlatMapSingleSubscriber(Subscriber actual,
Function> mapper, boolean delayErrors, int maxConcurrency) {
this.downstream = actual;
this.mapper = mapper;
this.delayErrors = delayErrors;
this.maxConcurrency = maxConcurrency;
this.requested = new AtomicLong();
this.set = new CompositeDisposable();
this.errors = new AtomicThrowable();
this.active = new AtomicInteger(1);
this.queue = new AtomicReference<>();
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.upstream, s)) {
this.upstream = s;
downstream.onSubscribe(this);
int m = maxConcurrency;
if (m == Integer.MAX_VALUE) {
s.request(Long.MAX_VALUE);
} else {
s.request(maxConcurrency);
}
}
}
@Override
public void onNext(T t) {
SingleSource ms;
try {
ms = Objects.requireNonNull(mapper.apply(t), "The mapper returned a null SingleSource");
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
upstream.cancel();
onError(ex);
return;
}
active.getAndIncrement();
InnerObserver inner = new InnerObserver();
if (!cancelled && set.add(inner)) {
ms.subscribe(inner);
}
}
@Override
public void onError(Throwable t) {
active.decrementAndGet();
if (errors.tryAddThrowableOrReport(t)) {
if (!delayErrors) {
set.dispose();
}
drain();
}
}
@Override
public void onComplete() {
active.decrementAndGet();
drain();
}
@Override
public void cancel() {
cancelled = true;
upstream.cancel();
set.dispose();
errors.tryTerminateAndReport();
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
drain();
}
}
void innerSuccess(InnerObserver inner, R value) {
set.delete(inner);
if (get() == 0 && compareAndSet(0, 1)) {
boolean d = active.decrementAndGet() == 0;
if (requested.get() != 0) {
downstream.onNext(value);
SpscLinkedArrayQueue q = queue.get();
if (d && (q == null || q.isEmpty())) {
errors.tryTerminateConsumer(downstream);
return;
}
BackpressureHelper.produced(requested, 1);
if (maxConcurrency != Integer.MAX_VALUE) {
upstream.request(1);
}
} else {
SpscLinkedArrayQueue q = getOrCreateQueue();
synchronized (q) {
q.offer(value);
}
}
if (decrementAndGet() == 0) {
return;
}
} else {
SpscLinkedArrayQueue q = getOrCreateQueue();
synchronized (q) {
q.offer(value);
}
active.decrementAndGet();
if (getAndIncrement() != 0) {
return;
}
}
drainLoop();
}
SpscLinkedArrayQueue getOrCreateQueue() {
SpscLinkedArrayQueue current = queue.get();
if (current != null) {
return current;
}
current = new SpscLinkedArrayQueue<>(Flowable.bufferSize());
if (queue.compareAndSet(null, current)) {
return current;
}
return queue.get();
}
void innerError(InnerObserver inner, Throwable e) {
set.delete(inner);
if (errors.tryAddThrowableOrReport(e)) {
if (!delayErrors) {
upstream.cancel();
set.dispose();
} else {
if (maxConcurrency != Integer.MAX_VALUE) {
upstream.request(1);
}
}
active.decrementAndGet();
drain();
}
}
void drain() {
if (getAndIncrement() == 0) {
drainLoop();
}
}
void clear() {
SpscLinkedArrayQueue q = queue.get();
if (q != null) {
q.clear();
}
}
void drainLoop() {
int missed = 1;
Subscriber a = downstream;
AtomicInteger n = active;
AtomicReference> qr = queue;
for (;;) {
long r = requested.get();
long e = 0L;
while (e != r) {
if (cancelled) {
clear();
return;
}
if (!delayErrors) {
Throwable ex = errors.get();
if (ex != null) {
clear();
errors.tryTerminateConsumer(downstream);
return;
}
}
boolean d = n.get() == 0;
SpscLinkedArrayQueue q = qr.get();
R v = q != null ? q.poll() : null;
boolean empty = v == null;
if (d && empty) {
errors.tryTerminateConsumer(a);
return;
}
if (empty) {
break;
}
a.onNext(v);
e++;
}
if (e == r) {
if (cancelled) {
clear();
return;
}
if (!delayErrors) {
Throwable ex = errors.get();
if (ex != null) {
clear();
errors.tryTerminateConsumer(a);
return;
}
}
boolean d = n.get() == 0;
SpscLinkedArrayQueue q = qr.get();
boolean empty = q == null || q.isEmpty();
if (d && empty) {
errors.tryTerminateConsumer(a);
return;
}
}
if (e != 0L) {
BackpressureHelper.produced(requested, e);
if (maxConcurrency != Integer.MAX_VALUE) {
upstream.request(e);
}
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
final class InnerObserver extends AtomicReference
implements SingleObserver, Disposable {
private static final long serialVersionUID = -502562646270949838L;
@Override
public void onSubscribe(Disposable d) {
DisposableHelper.setOnce(this, d);
}
@Override
public void onSuccess(R value) {
innerSuccess(this, value);
}
@Override
public void onError(Throwable e) {
innerError(this, e);
}
@Override
public boolean isDisposed() {
return DisposableHelper.isDisposed(get());
}
@Override
public void dispose() {
DisposableHelper.dispose(this);
}
}
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy