io.reactivex.internal.operators.flowable.FlowableFlatMap 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.internal.operators.flowable;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.*;
import org.reactivestreams.*;
import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.*;
import io.reactivex.functions.Function;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.*;
import io.reactivex.internal.subscriptions.SubscriptionHelper;
import io.reactivex.internal.util.*;
import io.reactivex.plugins.RxJavaPlugins;
public final class FlowableFlatMap extends AbstractFlowableWithUpstream {
final Function> mapper;
final boolean delayErrors;
final int maxConcurrency;
final int bufferSize;
public FlowableFlatMap(Flowable source,
Function> mapper,
boolean delayErrors, int maxConcurrency, int bufferSize) {
super(source);
this.mapper = mapper;
this.delayErrors = delayErrors;
this.maxConcurrency = maxConcurrency;
this.bufferSize = bufferSize;
}
@Override
protected void subscribeActual(Subscriber s) {
if (FlowableScalarXMap.tryScalarXMapSubscribe(source, s, mapper)) {
return;
}
source.subscribe(subscribe(s, mapper, delayErrors, maxConcurrency, bufferSize));
}
public static FlowableSubscriber subscribe(Subscriber s,
Function> mapper,
boolean delayErrors, int maxConcurrency, int bufferSize) {
return new MergeSubscriber(s, mapper, delayErrors, maxConcurrency, bufferSize);
}
static final class MergeSubscriber extends AtomicInteger implements FlowableSubscriber, Subscription {
private static final long serialVersionUID = -2117620485640801370L;
final Subscriber downstream;
final Function> mapper;
final boolean delayErrors;
final int maxConcurrency;
final int bufferSize;
volatile SimplePlainQueue queue;
volatile boolean done;
final AtomicThrowable errs = new AtomicThrowable();
volatile boolean cancelled;
final AtomicReference[]> subscribers = new AtomicReference[]>();
static final InnerSubscriber[] EMPTY = new InnerSubscriber[0];
static final InnerSubscriber[] CANCELLED = new InnerSubscriber[0];
final AtomicLong requested = new AtomicLong();
Subscription upstream;
long uniqueId;
long lastId;
int lastIndex;
int scalarEmitted;
final int scalarLimit;
MergeSubscriber(Subscriber actual, Function> mapper,
boolean delayErrors, int maxConcurrency, int bufferSize) {
this.downstream = actual;
this.mapper = mapper;
this.delayErrors = delayErrors;
this.maxConcurrency = maxConcurrency;
this.bufferSize = bufferSize;
this.scalarLimit = Math.max(1, maxConcurrency >> 1);
subscribers.lazySet(EMPTY);
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.validate(this.upstream, s)) {
this.upstream = s;
downstream.onSubscribe(this);
if (!cancelled) {
if (maxConcurrency == Integer.MAX_VALUE) {
s.request(Long.MAX_VALUE);
} else {
s.request(maxConcurrency);
}
}
}
}
@SuppressWarnings("unchecked")
@Override
public void onNext(T t) {
// safeguard against misbehaving sources
if (done) {
return;
}
Publisher p;
try {
p = ObjectHelper.requireNonNull(mapper.apply(t), "The mapper returned a null Publisher");
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
upstream.cancel();
onError(e);
return;
}
if (p instanceof Callable) {
U u;
try {
u = ((Callable)p).call();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
errs.addThrowable(ex);
drain();
return;
}
if (u != null) {
tryEmitScalar(u);
} else {
if (maxConcurrency != Integer.MAX_VALUE && !cancelled
&& ++scalarEmitted == scalarLimit) {
scalarEmitted = 0;
upstream.request(scalarLimit);
}
}
} else {
InnerSubscriber inner = new InnerSubscriber(this, uniqueId++);
if (addInner(inner)) {
p.subscribe(inner);
}
}
}
boolean addInner(InnerSubscriber inner) {
for (;;) {
InnerSubscriber[] a = subscribers.get();
if (a == CANCELLED) {
inner.dispose();
return false;
}
int n = a.length;
InnerSubscriber[] b = new InnerSubscriber[n + 1];
System.arraycopy(a, 0, b, 0, n);
b[n] = inner;
if (subscribers.compareAndSet(a, b)) {
return true;
}
}
}
void removeInner(InnerSubscriber inner) {
for (;;) {
InnerSubscriber[] a = subscribers.get();
int n = a.length;
if (n == 0) {
return;
}
int j = -1;
for (int i = 0; i < n; i++) {
if (a[i] == inner) {
j = i;
break;
}
}
if (j < 0) {
return;
}
InnerSubscriber[] b;
if (n == 1) {
b = EMPTY;
} else {
b = new InnerSubscriber[n - 1];
System.arraycopy(a, 0, b, 0, j);
System.arraycopy(a, j + 1, b, j, n - j - 1);
}
if (subscribers.compareAndSet(a, b)) {
return;
}
}
}
SimpleQueue getMainQueue() {
SimplePlainQueue q = queue;
if (q == null) {
if (maxConcurrency == Integer.MAX_VALUE) {
q = new SpscLinkedArrayQueue(bufferSize);
} else {
q = new SpscArrayQueue(maxConcurrency);
}
queue = q;
}
return q;
}
void tryEmitScalar(U value) {
if (get() == 0 && compareAndSet(0, 1)) {
long r = requested.get();
SimpleQueue q = queue;
if (r != 0L && (q == null || q.isEmpty())) {
downstream.onNext(value);
if (r != Long.MAX_VALUE) {
requested.decrementAndGet();
}
if (maxConcurrency != Integer.MAX_VALUE && !cancelled
&& ++scalarEmitted == scalarLimit) {
scalarEmitted = 0;
upstream.request(scalarLimit);
}
} else {
if (q == null) {
q = getMainQueue();
}
if (!q.offer(value)) {
onError(new IllegalStateException("Scalar queue full?!"));
return;
}
}
if (decrementAndGet() == 0) {
return;
}
} else {
SimpleQueue q = getMainQueue();
if (!q.offer(value)) {
onError(new IllegalStateException("Scalar queue full?!"));
return;
}
if (getAndIncrement() != 0) {
return;
}
}
drainLoop();
}
SimpleQueue getInnerQueue(InnerSubscriber inner) {
SimpleQueue q = inner.queue;
if (q == null) {
q = new SpscArrayQueue(bufferSize);
inner.queue = q;
}
return q;
}
void tryEmit(U value, InnerSubscriber inner) {
if (get() == 0 && compareAndSet(0, 1)) {
long r = requested.get();
SimpleQueue q = inner.queue;
if (r != 0L && (q == null || q.isEmpty())) {
downstream.onNext(value);
if (r != Long.MAX_VALUE) {
requested.decrementAndGet();
}
inner.requestMore(1);
} else {
if (q == null) {
q = getInnerQueue(inner);
}
if (!q.offer(value)) {
onError(new MissingBackpressureException("Inner queue full?!"));
return;
}
}
if (decrementAndGet() == 0) {
return;
}
} else {
SimpleQueue q = inner.queue;
if (q == null) {
q = new SpscArrayQueue(bufferSize);
inner.queue = q;
}
if (!q.offer(value)) {
onError(new MissingBackpressureException("Inner queue full?!"));
return;
}
if (getAndIncrement() != 0) {
return;
}
}
drainLoop();
}
@Override
public void onError(Throwable t) {
// safeguard against misbehaving sources
if (done) {
RxJavaPlugins.onError(t);
return;
}
if (errs.addThrowable(t)) {
done = true;
drain();
} else {
RxJavaPlugins.onError(t);
}
}
@Override
public void onComplete() {
// safeguard against misbehaving sources
if (done) {
return;
}
done = true;
drain();
}
@Override
public void request(long n) {
if (SubscriptionHelper.validate(n)) {
BackpressureHelper.add(requested, n);
drain();
}
}
@Override
public void cancel() {
if (!cancelled) {
cancelled = true;
upstream.cancel();
disposeAll();
if (getAndIncrement() == 0) {
SimpleQueue q = queue;
if (q != null) {
q.clear();
}
}
}
}
void drain() {
if (getAndIncrement() == 0) {
drainLoop();
}
}
void drainLoop() {
final Subscriber child = this.downstream;
int missed = 1;
for (;;) {
if (checkTerminate()) {
return;
}
SimplePlainQueue svq = queue;
long r = requested.get();
boolean unbounded = r == Long.MAX_VALUE;
long replenishMain = 0;
if (svq != null) {
for (;;) {
long scalarEmission = 0;
U o = null;
while (r != 0L) {
o = svq.poll();
if (checkTerminate()) {
return;
}
if (o == null) {
break;
}
child.onNext(o);
replenishMain++;
scalarEmission++;
r--;
}
if (scalarEmission != 0L) {
if (unbounded) {
r = Long.MAX_VALUE;
} else {
r = requested.addAndGet(-scalarEmission);
}
}
if (r == 0L || o == null) {
break;
}
}
}
boolean d = done;
svq = queue;
InnerSubscriber[] inner = subscribers.get();
int n = inner.length;
if (d && (svq == null || svq.isEmpty()) && n == 0) {
Throwable ex = errs.terminate();
if (ex != ExceptionHelper.TERMINATED) {
if (ex == null) {
child.onComplete();
} else {
child.onError(ex);
}
}
return;
}
boolean innerCompleted = false;
if (n != 0) {
long startId = lastId;
int index = lastIndex;
if (n <= index || inner[index].id != startId) {
if (n <= index) {
index = 0;
}
int j = index;
for (int i = 0; i < n; i++) {
if (inner[j].id == startId) {
break;
}
j++;
if (j == n) {
j = 0;
}
}
index = j;
lastIndex = j;
lastId = inner[j].id;
}
int j = index;
sourceLoop:
for (int i = 0; i < n; i++) {
if (checkTerminate()) {
return;
}
@SuppressWarnings("unchecked")
InnerSubscriber is = (InnerSubscriber)inner[j];
U o = null;
for (;;) {
if (checkTerminate()) {
return;
}
SimpleQueue q = is.queue;
if (q == null) {
break;
}
long produced = 0;
while (r != 0L) {
try {
o = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
is.dispose();
errs.addThrowable(ex);
if (!delayErrors) {
upstream.cancel();
}
if (checkTerminate()) {
return;
}
removeInner(is);
innerCompleted = true;
i++;
continue sourceLoop;
}
if (o == null) {
break;
}
child.onNext(o);
if (checkTerminate()) {
return;
}
r--;
produced++;
}
if (produced != 0L) {
if (!unbounded) {
r = requested.addAndGet(-produced);
} else {
r = Long.MAX_VALUE;
}
is.requestMore(produced);
}
if (r == 0 || o == null) {
break;
}
}
boolean innerDone = is.done;
SimpleQueue innerQueue = is.queue;
if (innerDone && (innerQueue == null || innerQueue.isEmpty())) {
removeInner(is);
if (checkTerminate()) {
return;
}
replenishMain++;
innerCompleted = true;
}
if (r == 0L) {
break;
}
j++;
if (j == n) {
j = 0;
}
}
lastIndex = j;
lastId = inner[j].id;
}
if (replenishMain != 0L && !cancelled) {
upstream.request(replenishMain);
}
if (innerCompleted) {
continue;
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
boolean checkTerminate() {
if (cancelled) {
clearScalarQueue();
return true;
}
if (!delayErrors && errs.get() != null) {
clearScalarQueue();
Throwable ex = errs.terminate();
if (ex != ExceptionHelper.TERMINATED) {
downstream.onError(ex);
}
return true;
}
return false;
}
void clearScalarQueue() {
SimpleQueue q = queue;
if (q != null) {
q.clear();
}
}
void disposeAll() {
InnerSubscriber[] a = subscribers.get();
if (a != CANCELLED) {
a = subscribers.getAndSet(CANCELLED);
if (a != CANCELLED) {
for (InnerSubscriber inner : a) {
inner.dispose();
}
Throwable ex = errs.terminate();
if (ex != null && ex != ExceptionHelper.TERMINATED) {
RxJavaPlugins.onError(ex);
}
}
}
}
void innerError(InnerSubscriber inner, Throwable t) {
if (errs.addThrowable(t)) {
inner.done = true;
if (!delayErrors) {
upstream.cancel();
for (InnerSubscriber a : subscribers.getAndSet(CANCELLED)) {
a.dispose();
}
}
drain();
} else {
RxJavaPlugins.onError(t);
}
}
}
static final class InnerSubscriber extends AtomicReference
implements FlowableSubscriber, Disposable {
private static final long serialVersionUID = -4606175640614850599L;
final long id;
final MergeSubscriber parent;
final int limit;
final int bufferSize;
volatile boolean done;
volatile SimpleQueue queue;
long produced;
int fusionMode;
InnerSubscriber(MergeSubscriber parent, long id) {
this.id = id;
this.parent = parent;
this.bufferSize = parent.bufferSize;
this.limit = bufferSize >> 2;
}
@Override
public void onSubscribe(Subscription s) {
if (SubscriptionHelper.setOnce(this, s)) {
if (s instanceof QueueSubscription) {
@SuppressWarnings("unchecked")
QueueSubscription qs = (QueueSubscription) s;
int m = qs.requestFusion(QueueSubscription.ANY | QueueSubscription.BOUNDARY);
if (m == QueueSubscription.SYNC) {
fusionMode = m;
queue = qs;
done = true;
parent.drain();
return;
}
if (m == QueueSubscription.ASYNC) {
fusionMode = m;
queue = qs;
}
}
s.request(bufferSize);
}
}
@Override
public void onNext(U t) {
if (fusionMode != QueueSubscription.ASYNC) {
parent.tryEmit(t, this);
} else {
parent.drain();
}
}
@Override
public void onError(Throwable t) {
lazySet(SubscriptionHelper.CANCELLED);
parent.innerError(this, t);
}
@Override
public void onComplete() {
done = true;
parent.drain();
}
void requestMore(long n) {
if (fusionMode != QueueSubscription.SYNC) {
long p = produced + n;
if (p >= limit) {
produced = 0;
get().request(p);
} else {
produced = p;
}
}
}
@Override
public void dispose() {
SubscriptionHelper.cancel(this);
}
@Override
public boolean isDisposed() {
return get() == SubscriptionHelper.CANCELLED;
}
}
}