/**
* 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.subscribers;
import org.reactivestreams.*;
import io.reactivex.
FlowableSubscriber;
import io.reactivex.exceptions.*;
import io.reactivex.internal.subscriptions.*;
import io.reactivex.plugins.
RxJavaPlugins;
/**
* Wraps another Subscriber and ensures all onXXX methods conform the protocol
* (except the requirement for serialized access).
*
* @param <T> the value type
*/
public final class
SafeSubscriber<T> implements
FlowableSubscriber<T>,
Subscription {
/** The actual Subscriber. */
final
Subscriber<? super T>
downstream;
/** The subscription. */
Subscription upstream;
/** Indicates a terminal state. */
boolean
done;
/**
* Constructs a SafeSubscriber by wrapping the given actual Subscriber.
* @param downstream the actual Subscriber to wrap, not null (not validated)
*/
public
SafeSubscriber(
Subscriber<? super T>
downstream) {
this.
downstream =
downstream;
}
@
Override
public void
onSubscribe(
Subscription s) {
if (
SubscriptionHelper.
validate(this.
upstream,
s)) {
this.
upstream =
s;
try {
downstream.
onSubscribe(this);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
done = true;
// can't call onError because the actual's state may be corrupt at this point
try {
s.
cancel();
} catch (
Throwable e1) {
Exceptions.
throwIfFatal(
e1);
RxJavaPlugins.
onError(new
CompositeException(
e,
e1));
return;
}
RxJavaPlugins.
onError(
e);
}
}
}
@
Override
public void
onNext(T
t) {
if (
done) {
return;
}
if (
upstream == null) {
onNextNoSubscription();
return;
}
if (
t == null) {
Throwable ex = new
NullPointerException("onNext called with null. Null values are generally not allowed in 2.x operators and sources.");
try {
upstream.
cancel();
} catch (
Throwable e1) {
Exceptions.
throwIfFatal(
e1);
onError(new
CompositeException(
ex,
e1));
return;
}
onError(
ex);
return;
}
try {
downstream.
onNext(
t);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
try {
upstream.
cancel();
} catch (
Throwable e1) {
Exceptions.
throwIfFatal(
e1);
onError(new
CompositeException(
e,
e1));
return;
}
onError(
e);
}
}
void
onNextNoSubscription() {
done = true;
Throwable ex = new
NullPointerException("Subscription not set!");
try {
downstream.
onSubscribe(
EmptySubscription.
INSTANCE);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// can't call onError because the actual's state may be corrupt at this point
RxJavaPlugins.
onError(new
CompositeException(
ex,
e));
return;
}
try {
downstream.
onError(
ex);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// if onError failed, all that's left is to report the error to plugins
RxJavaPlugins.
onError(new
CompositeException(
ex,
e));
}
}
@
Override
public void
onError(
Throwable t) {
if (
done) {
RxJavaPlugins.
onError(
t);
return;
}
done = true;
if (
upstream == null) {
Throwable npe = new
NullPointerException("Subscription not set!");
try {
downstream.
onSubscribe(
EmptySubscription.
INSTANCE);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// can't call onError because the actual's state may be corrupt at this point
RxJavaPlugins.
onError(new
CompositeException(
t,
npe,
e));
return;
}
try {
downstream.
onError(new
CompositeException(
t,
npe));
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// if onError failed, all that's left is to report the error to plugins
RxJavaPlugins.
onError(new
CompositeException(
t,
npe,
e));
}
return;
}
if (
t == null) {
t = new
NullPointerException("onError called with null. Null values are generally not allowed in 2.x operators and sources.");
}
try {
downstream.
onError(
t);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
RxJavaPlugins.
onError(new
CompositeException(
t,
ex));
}
}
@
Override
public void
onComplete() {
if (
done) {
return;
}
done = true;
if (
upstream == null) {
onCompleteNoSubscription();
return;
}
try {
downstream.
onComplete();
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
RxJavaPlugins.
onError(
e);
}
}
void
onCompleteNoSubscription() {
Throwable ex = new
NullPointerException("Subscription not set!");
try {
downstream.
onSubscribe(
EmptySubscription.
INSTANCE);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// can't call onError because the actual's state may be corrupt at this point
RxJavaPlugins.
onError(new
CompositeException(
ex,
e));
return;
}
try {
downstream.
onError(
ex);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
// if onError failed, all that's left is to report the error to plugins
RxJavaPlugins.
onError(new
CompositeException(
ex,
e));
}
}
@
Override
public void
request(long
n) {
try {
upstream.
request(
n);
} catch (
Throwable e) {
Exceptions.
throwIfFatal(
e);
try {
upstream.
cancel();
} catch (
Throwable e1) {
Exceptions.
throwIfFatal(
e1);
RxJavaPlugins.
onError(new
CompositeException(
e,
e1));
return;
}
RxJavaPlugins.
onError(
e);
}
}
@
Override
public void
cancel() {
try {
upstream.
cancel();
} catch (
Throwable e1) {
Exceptions.
throwIfFatal(
e1);
RxJavaPlugins.
onError(
e1);
}
}
}