/**
* 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.concurrent.atomic.*;
import io.reactivex.*;
import io.reactivex.disposables.
Disposable;
import io.reactivex.exceptions.
Exceptions;
import io.reactivex.functions.
Cancellable;
import io.reactivex.internal.disposables.*;
import io.reactivex.internal.fuseable.
SimpleQueue;
import io.reactivex.internal.queue.
SpscLinkedArrayQueue;
import io.reactivex.internal.util.
AtomicThrowable;
import io.reactivex.plugins.
RxJavaPlugins;
public final class
ObservableCreate<T> extends
Observable<T> {
final
ObservableOnSubscribe<T>
source;
public
ObservableCreate(
ObservableOnSubscribe<T>
source) {
this.
source =
source;
}
@
Override
protected void
subscribeActual(
Observer<? super T>
observer) {
CreateEmitter<T>
parent = new
CreateEmitter<T>(
observer);
observer.
onSubscribe(
parent);
try {
source.
subscribe(
parent);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
parent.
onError(
ex);
}
}
static final class
CreateEmitter<T>
extends
AtomicReference<
Disposable>
implements
ObservableEmitter<T>,
Disposable {
private static final long
serialVersionUID = -3434801548987643227L;
final
Observer<? super T>
observer;
CreateEmitter(
Observer<? super T>
observer) {
this.
observer =
observer;
}
@
Override
public void
onNext(T
t) {
if (
t == null) {
onError(new
NullPointerException("onNext called with null. Null values are generally not allowed in 2.x operators and sources."));
return;
}
if (!
isDisposed()) {
observer.
onNext(
t);
}
}
@
Override
public void
onError(
Throwable t) {
if (!
tryOnError(
t)) {
RxJavaPlugins.
onError(
t);
}
}
@
Override
public boolean
tryOnError(
Throwable t) {
if (
t == null) {
t = new
NullPointerException("onError called with null. Null values are generally not allowed in 2.x operators and sources.");
}
if (!
isDisposed()) {
try {
observer.
onError(
t);
} finally {
dispose();
}
return true;
}
return false;
}
@
Override
public void
onComplete() {
if (!
isDisposed()) {
try {
observer.
onComplete();
} finally {
dispose();
}
}
}
@
Override
public void
setDisposable(
Disposable d) {
DisposableHelper.
set(this,
d);
}
@
Override
public void
setCancellable(
Cancellable c) {
setDisposable(new
CancellableDisposable(
c));
}
@
Override
public
ObservableEmitter<T>
serialize() {
return new
SerializedEmitter<T>(this);
}
@
Override
public void
dispose() {
DisposableHelper.
dispose(this);
}
@
Override
public boolean
isDisposed() {
return
DisposableHelper.
isDisposed(
get());
}
@
Override
public
String toString() {
return
String.
format("%s{%s}",
getClass().
getSimpleName(), super.toString());
}
}
/**
* Serializes calls to onNext, onError and onComplete.
*
* @param <T> the value type
*/
static final class
SerializedEmitter<T>
extends
AtomicInteger
implements
ObservableEmitter<T> {
private static final long
serialVersionUID = 4883307006032401862L;
final
ObservableEmitter<T>
emitter;
final
AtomicThrowable error;
final
SpscLinkedArrayQueue<T>
queue;
volatile boolean
done;
SerializedEmitter(
ObservableEmitter<T>
emitter) {
this.
emitter =
emitter;
this.
error = new
AtomicThrowable();
this.
queue = new
SpscLinkedArrayQueue<T>(16);
}
@
Override
public void
onNext(T
t) {
if (
emitter.
isDisposed() ||
done) {
return;
}
if (
t == null) {
onError(new
NullPointerException("onNext called with null. Null values are generally not allowed in 2.x operators and sources."));
return;
}
if (
get() == 0 &&
compareAndSet(0, 1)) {
emitter.
onNext(
t);
if (
decrementAndGet() == 0) {
return;
}
} else {
SimpleQueue<T>
q =
queue;
synchronized (
q) {
q.
offer(
t);
}
if (
getAndIncrement() != 0) {
return;
}
}
drainLoop();
}
@
Override
public void
onError(
Throwable t) {
if (!
tryOnError(
t)) {
RxJavaPlugins.
onError(
t);
}
}
@
Override
public boolean
tryOnError(
Throwable t) {
if (
emitter.
isDisposed() ||
done) {
return false;
}
if (
t == null) {
t = new
NullPointerException("onError called with null. Null values are generally not allowed in 2.x operators and sources.");
}
if (
error.
addThrowable(
t)) {
done = true;
drain();
return true;
}
return false;
}
@
Override
public void
onComplete() {
if (
emitter.
isDisposed() ||
done) {
return;
}
done = true;
drain();
}
void
drain() {
if (
getAndIncrement() == 0) {
drainLoop();
}
}
void
drainLoop() {
ObservableEmitter<T>
e =
emitter;
SpscLinkedArrayQueue<T>
q =
queue;
AtomicThrowable error = this.
error;
int
missed = 1;
for (;;) {
for (;;) {
if (
e.
isDisposed()) {
q.
clear();
return;
}
if (
error.
get() != null) {
q.
clear();
e.
onError(
error.
terminate());
return;
}
boolean
d =
done;
T
v =
q.
poll();
boolean
empty =
v == null;
if (
d &&
empty) {
e.
onComplete();
return;
}
if (
empty) {
break;
}
e.
onNext(
v);
}
missed =
addAndGet(-
missed);
if (
missed == 0) {
break;
}
}
}
@
Override
public void
setDisposable(
Disposable d) {
emitter.
setDisposable(
d);
}
@
Override
public void
setCancellable(
Cancellable c) {
emitter.
setCancellable(
c);
}
@
Override
public boolean
isDisposed() {
return
emitter.
isDisposed();
}
@
Override
public
ObservableEmitter<T>
serialize() {
return this;
}
@
Override
public
String toString() {
return
emitter.
toString();
}
}
}