/**
* 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.Callable;
import java.util.concurrent.atomic.AtomicInteger;
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 FlowableConcatMap<T, R> extends AbstractFlowableWithUpstream<T, R> {
final Function<? super T, ? extends Publisher<? extends R>> mapper;
final int prefetch;
final ErrorMode errorMode;
public FlowableConcatMap(Flowable<T> source,
Function<? super T, ? extends Publisher<? extends R>> mapper,
int prefetch, ErrorMode errorMode) {
super(source);
this.mapper = mapper;
this.prefetch = prefetch;
this.errorMode = errorMode;
}
public static <T, R> Subscriber<T> subscribe(Subscriber<? super R> s, Function<? super T, ? extends Publisher<? extends R>> mapper,
int prefetch, ErrorMode errorMode) {
switch (errorMode) {
case BOUNDARY:
return new ConcatMapDelayed<T, R>(s, mapper, prefetch, false);
case END:
return new ConcatMapDelayed<T, R>(s, mapper, prefetch, true);
default:
return new ConcatMapImmediate<T, R>(s, mapper, prefetch);
}
}
@Override
protected void subscribeActual(Subscriber<? super R> s) {
if (FlowableScalarXMap.tryScalarXMapSubscribe(source, s, mapper)) {
return;
}
source.subscribe(subscribe(s, mapper, prefetch, errorMode));
}
abstract static class BaseConcatMapSubscriber<T, R>
extends AtomicInteger
implements FlowableSubscriber<T>, ConcatMapSupport<R>, Subscription {
private static final long serialVersionUID = -3511336836796789179L;
final ConcatMapInner<R> inner;
final Function<? super T, ? extends Publisher<? extends R>> mapper;
final int prefetch;
final int limit;
Subscription s;
int consumed;
SimpleQueue<T> queue;
volatile boolean done;
volatile boolean cancelled;
final AtomicThrowable errors;
volatile boolean active;
int sourceMode;
BaseConcatMapSubscriber(
Function<? super T, ? extends Publisher<? extends R>> mapper,
int prefetch) {
this.mapper = mapper;
this.prefetch = prefetch;
this.limit = prefetch - (prefetch >> 2);
this.inner = new ConcatMapInner<R>(this);
this.errors = new AtomicThrowable();
}
@Override
public final void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.s, s)) {
this.s = s;
if (s instanceof QueueSubscription) {
@SuppressWarnings("unchecked") QueueSubscription<T> f = (QueueSubscription<T>)s;
int m = f.requestFusion(QueueSubscription.ANY);
if (m == QueueSubscription.SYNC) {
sourceMode = m;
queue = f;
done = true;
subscribeActual();
drain();
return;
}
if (m == QueueSubscription.ASYNC) {
sourceMode = m;
queue = f;
subscribeActual();
s.request(prefetch);
return;
}
}
queue = new SpscArrayQueue<T>(prefetch);
subscribeActual();
s.request(prefetch);
}
}
abstract void drain();
abstract void subscribeActual();
@Override
public final void onNext(T t) {
if (sourceMode != QueueSubscription.ASYNC) {
if (!queue.offer(t)) {
s.cancel();
onError(new IllegalStateException("Queue full?!"));
return;
}
}
drain();
}
@Override
public final void onComplete() {
done = true;
drain();
}
@Override
public final void innerComplete() {
active = false;
drain();
}
}
static final class ConcatMapImmediate<T, R>
extends BaseConcatMapSubscriber<T, R> {
private static final long serialVersionUID = 7898995095634264146L;
final Subscriber<? super R> actual;
final AtomicInteger wip;
ConcatMapImmediate(Subscriber<? super R> actual,
Function<? super T, ? extends Publisher<? extends R>> mapper,
int prefetch) {
super(mapper, prefetch);
this.actual = actual;
this.wip = new AtomicInteger();
}
@Override
void subscribeActual() {
actual.onSubscribe(this);
}
@Override
public void onError(Throwable t) {
if (errors.addThrowable(t)) {
inner.cancel();
if (getAndIncrement() == 0) {
actual.onError(errors.terminate());
}
} else {
RxJavaPlugins.onError(t);
}
}
@Override
public void innerNext(R value) {
if (get() == 0 && compareAndSet(0, 1)) {
actual.onNext(value);
if (compareAndSet(1, 0)) {
return;
}
actual.onError(errors.terminate());
}
}
@Override
public void innerError(Throwable e) {
if (errors.addThrowable(e)) {
s.cancel();
if (getAndIncrement() == 0) {
actual.onError(errors.terminate());
}
} else {
RxJavaPlugins.onError(e);
}
}
@Override
public void request(long n) {
inner.request(n);
}
@Override
public void cancel() {
if (!cancelled) {
cancelled = true;
inner.cancel();
s.cancel();
}
}
@Override
void drain() {
if (wip.getAndIncrement() == 0) {
for (;;) {
if (cancelled) {
return;
}
if (!active) {
boolean d = done;
T v;
try {
v = queue.poll();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
boolean empty = v == null;
if (d && empty) {
actual.onComplete();
return;
}
if (!empty) {
Publisher<? extends R> p;
try {
p = ObjectHelper.requireNonNull(mapper.apply(v), "The mapper returned a null Publisher");
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
if (sourceMode != QueueSubscription.SYNC) {
int c = consumed + 1;
if (c == limit) {
consumed = 0;
s.request(c);
} else {
consumed = c;
}
}
if (p instanceof Callable) {
@SuppressWarnings("unchecked")
Callable<R> callable = (Callable<R>) p;
R vr;
try {
vr = callable.call();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
if (vr == null) {
continue;
}
if (inner.isUnbounded()) {
if (get() == 0 && compareAndSet(0, 1)) {
actual.onNext(vr);
if (!compareAndSet(1, 0)) {
actual.onError(errors.terminate());
return;
}
}
continue;
} else {
active = true;
inner.setSubscription(new WeakScalarSubscription<R>(vr, inner));
}
} else {
active = true;
p.subscribe(inner);
}
}
}
if (wip.decrementAndGet() == 0) {
break;
}
}
}
}
}
static final class WeakScalarSubscription<T> implements Subscription {
final Subscriber<? super T> actual;
final T value;
boolean once;
WeakScalarSubscription(T value, Subscriber<? super T> actual) {
this.value = value;
this.actual = actual;
}
@Override
public void request(long n) {
if (n > 0 && !once) {
once = true;
Subscriber<? super T> a = actual;
a.onNext(value);
a.onComplete();
}
}
@Override
public void cancel() {
}
}
static final class ConcatMapDelayed<T, R>
extends BaseConcatMapSubscriber<T, R> {
private static final long serialVersionUID = -2945777694260521066L;
final Subscriber<? super R> actual;
final boolean veryEnd;
ConcatMapDelayed(Subscriber<? super R> actual,
Function<? super T, ? extends Publisher<? extends R>> mapper,
int prefetch, boolean veryEnd) {
super(mapper, prefetch);
this.actual = actual;
this.veryEnd = veryEnd;
}
@Override
void subscribeActual() {
actual.onSubscribe(this);
}
@Override
public void onError(Throwable t) {
if (errors.addThrowable(t)) {
done = true;
drain();
} else {
RxJavaPlugins.onError(t);
}
}
@Override
public void innerNext(R value) {
actual.onNext(value);
}
@Override
public void innerError(Throwable e) {
if (errors.addThrowable(e)) {
if (!veryEnd) {
s.cancel();
done = true;
}
active = false;
drain();
} else {
RxJavaPlugins.onError(e);
}
}
@Override
public void request(long n) {
inner.request(n);
}
@Override
public void cancel() {
if (!cancelled) {
cancelled = true;
inner.cancel();
s.cancel();
}
}
@Override
void drain() {
if (getAndIncrement() == 0) {
for (;;) {
if (cancelled) {
return;
}
if (!active) {
boolean d = done;
if (d && !veryEnd) {
Throwable ex = errors.get();
if (ex != null) {
actual.onError(errors.terminate());
return;
}
}
T v;
try {
v = queue.poll();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
boolean empty = v == null;
if (d && empty) {
Throwable ex = errors.terminate();
if (ex != null) {
actual.onError(ex);
} else {
actual.onComplete();
}
return;
}
if (!empty) {
Publisher<? extends R> p;
try {
p = ObjectHelper.requireNonNull(mapper.apply(v), "The mapper returned a null Publisher");
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
if (sourceMode != QueueSubscription.SYNC) {
int c = consumed + 1;
if (c == limit) {
consumed = 0;
s.request(c);
} else {
consumed = c;
}
}
if (p instanceof Callable) {
@SuppressWarnings("unchecked")
Callable<R> supplier = (Callable<R>) p;
R vr;
try {
vr = supplier.call();
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
s.cancel();
errors.addThrowable(e);
actual.onError(errors.terminate());
return;
}
if (vr == null) {
continue;
}
if (inner.isUnbounded()) {
actual.onNext(vr);
continue;
} else {
active = true;
inner.setSubscription(new WeakScalarSubscription<R>(vr, inner));
}
} else {
active = true;
p.subscribe(inner);
}
}
}
if (decrementAndGet() == 0) {
break;
}
}
}
}
}
interface ConcatMapSupport<T> {
void innerNext(T value);
void innerComplete();
void innerError(Throwable e);
}
static final class ConcatMapInner<R>
extends SubscriptionArbiter
implements FlowableSubscriber<R> {
private static final long serialVersionUID = 897683679971470653L;
final ConcatMapSupport<R> parent;
long produced;
ConcatMapInner(ConcatMapSupport<R> parent) {
this.parent = parent;
}
@Override
public void onSubscribe(Subscription s) {
setSubscription(s);
}
@Override
public void onNext(R t) {
produced++;
parent.innerNext(t);
}
@Override
public void onError(Throwable t) {
long p = produced;
if (p != 0L) {
produced = 0L;
produced(p);
}
parent.innerError(t);
}
@Override
public void onComplete() {
long p = produced;
if (p != 0L) {
produced = 0L;
produced(p);
}
parent.innerComplete();
}
}
}