io.reactivex.internal.operators.observable.ObservableFlatMap 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.observable;
import java.util.*;
import java.util.concurrent.Callable;
import java.util.concurrent.atomic.*;
import io.reactivex.ObservableSource;
import io.reactivex.Observer;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.*;
import io.reactivex.functions.Function;
import io.reactivex.internal.disposables.DisposableHelper;
import io.reactivex.internal.functions.ObjectHelper;
import io.reactivex.internal.fuseable.*;
import io.reactivex.internal.queue.*;
import io.reactivex.internal.util.*;
import io.reactivex.plugins.RxJavaPlugins;
public final class ObservableFlatMap extends AbstractObservableWithUpstream {
final Function> mapper;
final boolean delayErrors;
final int maxConcurrency;
final int bufferSize;
public ObservableFlatMap(ObservableSource source,
Function> mapper,
boolean delayErrors, int maxConcurrency, int bufferSize) {
super(source);
this.mapper = mapper;
this.delayErrors = delayErrors;
this.maxConcurrency = maxConcurrency;
this.bufferSize = bufferSize;
}
@Override
public void subscribeActual(Observer t) {
if (ObservableScalarXMap.tryScalarXMapSubscribe(source, t, mapper)) {
return;
}
source.subscribe(new MergeObserver(t, mapper, delayErrors, maxConcurrency, bufferSize));
}
static final class MergeObserver extends AtomicInteger implements Disposable, Observer {
private static final long serialVersionUID = -2117620485640801370L;
final Observer downstream;
final Function> mapper;
final boolean delayErrors;
final int maxConcurrency;
final int bufferSize;
volatile SimplePlainQueue queue;
volatile boolean done;
final AtomicThrowable errors = new AtomicThrowable();
volatile boolean cancelled;
final AtomicReference[]> observers;
static final InnerObserver[] EMPTY = new InnerObserver[0];
static final InnerObserver[] CANCELLED = new InnerObserver[0];
Disposable upstream;
long uniqueId;
long lastId;
int lastIndex;
Queue> sources;
int wip;
MergeObserver(Observer actual, Function> mapper,
boolean delayErrors, int maxConcurrency, int bufferSize) {
this.downstream = actual;
this.mapper = mapper;
this.delayErrors = delayErrors;
this.maxConcurrency = maxConcurrency;
this.bufferSize = bufferSize;
if (maxConcurrency != Integer.MAX_VALUE) {
sources = new ArrayDeque>(maxConcurrency);
}
this.observers = new AtomicReference[]>(EMPTY);
}
@Override
public void onSubscribe(Disposable d) {
if (DisposableHelper.validate(this.upstream, d)) {
this.upstream = d;
downstream.onSubscribe(this);
}
}
@Override
public void onNext(T t) {
// safeguard against misbehaving sources
if (done) {
return;
}
ObservableSource p;
try {
p = ObjectHelper.requireNonNull(mapper.apply(t), "The mapper returned a null ObservableSource");
} catch (Throwable e) {
Exceptions.throwIfFatal(e);
upstream.dispose();
onError(e);
return;
}
if (maxConcurrency != Integer.MAX_VALUE) {
synchronized (this) {
if (wip == maxConcurrency) {
sources.offer(p);
return;
}
wip++;
}
}
subscribeInner(p);
}
@SuppressWarnings("unchecked")
void subscribeInner(ObservableSource p) {
for (;;) {
if (p instanceof Callable) {
if (tryEmitScalar(((Callable)p)) && maxConcurrency != Integer.MAX_VALUE) {
boolean empty = false;
synchronized (this) {
p = sources.poll();
if (p == null) {
wip--;
empty = true;
}
}
if (empty) {
drain();
break;
}
} else {
break;
}
} else {
InnerObserver inner = new InnerObserver(this, uniqueId++);
if (addInner(inner)) {
p.subscribe(inner);
}
break;
}
}
}
boolean addInner(InnerObserver inner) {
for (;;) {
InnerObserver[] a = observers.get();
if (a == CANCELLED) {
inner.dispose();
return false;
}
int n = a.length;
InnerObserver[] b = new InnerObserver[n + 1];
System.arraycopy(a, 0, b, 0, n);
b[n] = inner;
if (observers.compareAndSet(a, b)) {
return true;
}
}
}
void removeInner(InnerObserver inner) {
for (;;) {
InnerObserver[] a = observers.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;
}
InnerObserver[] b;
if (n == 1) {
b = EMPTY;
} else {
b = new InnerObserver[n - 1];
System.arraycopy(a, 0, b, 0, j);
System.arraycopy(a, j + 1, b, j, n - j - 1);
}
if (observers.compareAndSet(a, b)) {
return;
}
}
}
boolean tryEmitScalar(Callable value) {
U u;
try {
u = value.call();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
errors.addThrowable(ex);
drain();
return true;
}
if (u == null) {
return true;
}
if (get() == 0 && compareAndSet(0, 1)) {
downstream.onNext(u);
if (decrementAndGet() == 0) {
return true;
}
} else {
SimplePlainQueue q = queue;
if (q == null) {
if (maxConcurrency == Integer.MAX_VALUE) {
q = new SpscLinkedArrayQueue(bufferSize);
} else {
q = new SpscArrayQueue(maxConcurrency);
}
queue = q;
}
if (!q.offer(u)) {
onError(new IllegalStateException("Scalar queue full?!"));
return true;
}
if (getAndIncrement() != 0) {
return false;
}
}
drainLoop();
return true;
}
void tryEmit(U value, InnerObserver inner) {
if (get() == 0 && compareAndSet(0, 1)) {
downstream.onNext(value);
if (decrementAndGet() == 0) {
return;
}
} else {
SimpleQueue q = inner.queue;
if (q == null) {
q = new SpscLinkedArrayQueue(bufferSize);
inner.queue = q;
}
q.offer(value);
if (getAndIncrement() != 0) {
return;
}
}
drainLoop();
}
@Override
public void onError(Throwable t) {
if (done) {
RxJavaPlugins.onError(t);
return;
}
if (errors.addThrowable(t)) {
done = true;
drain();
} else {
RxJavaPlugins.onError(t);
}
}
@Override
public void onComplete() {
if (done) {
return;
}
done = true;
drain();
}
@Override
public void dispose() {
if (!cancelled) {
cancelled = true;
if (disposeAll()) {
Throwable ex = errors.terminate();
if (ex != null && ex != ExceptionHelper.TERMINATED) {
RxJavaPlugins.onError(ex);
}
}
}
}
@Override
public boolean isDisposed() {
return cancelled;
}
void drain() {
if (getAndIncrement() == 0) {
drainLoop();
}
}
void drainLoop() {
final Observer child = this.downstream;
int missed = 1;
for (;;) {
if (checkTerminate()) {
return;
}
SimplePlainQueue svq = queue;
if (svq != null) {
for (;;) {
if (checkTerminate()) {
return;
}
U o = svq.poll();
if (o == null) {
break;
}
child.onNext(o);
}
}
boolean d = done;
svq = queue;
InnerObserver[] inner = observers.get();
int n = inner.length;
int nSources = 0;
if (maxConcurrency != Integer.MAX_VALUE) {
synchronized (this) {
nSources = sources.size();
}
}
if (d && (svq == null || svq.isEmpty()) && n == 0 && nSources == 0) {
Throwable ex = errors.terminate();
if (ex != ExceptionHelper.TERMINATED) {
if (ex == null) {
child.onComplete();
} else {
child.onError(ex);
}
}
return;
}
int innerCompleted = 0;
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")
InnerObserver is = (InnerObserver)inner[j];
SimpleQueue q = is.queue;
if (q != null) {
for (;;) {
U o;
try {
o = q.poll();
} catch (Throwable ex) {
Exceptions.throwIfFatal(ex);
is.dispose();
errors.addThrowable(ex);
if (checkTerminate()) {
return;
}
removeInner(is);
innerCompleted++;
j++;
if (j == n) {
j = 0;
}
continue sourceLoop;
}
if (o == null) {
break;
}
child.onNext(o);
if (checkTerminate()) {
return;
}
}
}
boolean innerDone = is.done;
SimpleQueue innerQueue = is.queue;
if (innerDone && (innerQueue == null || innerQueue.isEmpty())) {
removeInner(is);
if (checkTerminate()) {
return;
}
innerCompleted++;
}
j++;
if (j == n) {
j = 0;
}
}
lastIndex = j;
lastId = inner[j].id;
}
if (innerCompleted != 0) {
if (maxConcurrency != Integer.MAX_VALUE) {
while (innerCompleted-- != 0) {
ObservableSource p;
synchronized (this) {
p = sources.poll();
if (p == null) {
wip--;
continue;
}
}
subscribeInner(p);
}
}
continue;
}
missed = addAndGet(-missed);
if (missed == 0) {
break;
}
}
}
boolean checkTerminate() {
if (cancelled) {
return true;
}
Throwable e = errors.get();
if (!delayErrors && (e != null)) {
disposeAll();
e = errors.terminate();
if (e != ExceptionHelper.TERMINATED) {
downstream.onError(e);
}
return true;
}
return false;
}
boolean disposeAll() {
upstream.dispose();
InnerObserver[] a = observers.get();
if (a != CANCELLED) {
a = observers.getAndSet(CANCELLED);
if (a != CANCELLED) {
for (InnerObserver inner : a) {
inner.dispose();
}
return true;
}
}
return false;
}
}
static final class InnerObserver extends AtomicReference
implements Observer {
private static final long serialVersionUID = -4606175640614850599L;
final long id;
final MergeObserver parent;
volatile boolean done;
volatile SimpleQueue queue;
int fusionMode;
InnerObserver(MergeObserver parent, long id) {
this.id = id;
this.parent = parent;
}
@Override
public void onSubscribe(Disposable d) {
if (DisposableHelper.setOnce(this, d)) {
if (d instanceof QueueDisposable) {
@SuppressWarnings("unchecked")
QueueDisposable qd = (QueueDisposable) d;
int m = qd.requestFusion(QueueDisposable.ANY | QueueDisposable.BOUNDARY);
if (m == QueueDisposable.SYNC) {
fusionMode = m;
queue = qd;
done = true;
parent.drain();
return;
}
if (m == QueueDisposable.ASYNC) {
fusionMode = m;
queue = qd;
}
}
}
}
@Override
public void onNext(U t) {
if (fusionMode == QueueDisposable.NONE) {
parent.tryEmit(t, this);
} else {
parent.drain();
}
}
@Override
public void onError(Throwable t) {
if (parent.errors.addThrowable(t)) {
if (!parent.delayErrors) {
parent.disposeAll();
}
done = true;
parent.drain();
} else {
RxJavaPlugins.onError(t);
}
}
@Override
public void onComplete() {
done = true;
parent.drain();
}
public void dispose() {
DisposableHelper.dispose(this);
}
}
}