/*
* Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
*
* 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 reactor.core.publisher;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.function.Consumer;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import reactor.core.Disposable;
import reactor.core.Exceptions;
/**
* An unbounded Java Lambda adapter to {@link Subscriber}
*
* @param <T> the value type
*/
final class LambdaSubscriber<T>
implements InnerConsumer<T>, Disposable {
final Consumer<? super T> consumer;
final Consumer<? super Throwable> errorConsumer;
final Runnable completeConsumer;
final Consumer<? super Subscription> subscriptionConsumer;
volatile Subscription subscription;
static final AtomicReferenceFieldUpdater<LambdaSubscriber, Subscription> S =
AtomicReferenceFieldUpdater.newUpdater(LambdaSubscriber.class,
Subscription.class,
"subscription");
/**
* Create a {@link Subscriber} reacting onNext, onError and onComplete. The subscriber
* will automatically request Long.MAX_VALUE onSubscribe.
* <p>
* The argument {@code subscriptionHandler} is executed once by new subscriber to
* generate a context shared by every request calls.
*
* @param consumer A {@link Consumer} with argument onNext data
* @param errorConsumer A {@link Consumer} called onError
* @param completeConsumer A {@link Runnable} called onComplete with the actual
* context if any
* @param subscriptionConsumer A {@link Consumer} called with the {@link Subscription}
* to perform initial request, or null to request max
*/
LambdaSubscriber(Consumer<? super T> consumer,
Consumer<? super Throwable> errorConsumer,
Runnable completeConsumer,
Consumer<? super Subscription> subscriptionConsumer) {
this.consumer = consumer;
this.errorConsumer = errorConsumer;
this.completeConsumer = completeConsumer;
this.subscriptionConsumer = subscriptionConsumer;
}
@Override
public final void onSubscribe(Subscription s) {
if (Operators.validate(subscription, s)) {
this.subscription = s;
try {
if (subscriptionConsumer != null) {
subscriptionConsumer.accept(s);
}
else {
s.request(Long.MAX_VALUE);
}
}
catch (Throwable t) {
Exceptions.throwIfFatal(t);
s.cancel();
onError(t);
}
}
}
@Override
public final void onComplete() {
Subscription s = S.getAndSet(this, Operators.cancelledSubscription());
if (s == Operators.cancelledSubscription()) {
return;
}
if (completeConsumer != null) {
try {
completeConsumer.run();
}
catch (Throwable t) {
Exceptions.throwIfFatal(t);
onError(t);
}
}
}
@Override
public final void onError(Throwable t) {
if (t == null) {
throw Exceptions.argumentIsNullException();
}
Subscription s = S.getAndSet(this, Operators.cancelledSubscription());
if (s == Operators.cancelledSubscription()) {
Operators.onErrorDropped(t);
return;
}
if (errorConsumer != null) {
errorConsumer.accept(t);
}
else {
throw Exceptions.errorCallbackNotImplemented(t);
}
}
@Override
public final void onNext(T x) {
if (x == null) {
throw Exceptions.argumentIsNullException();
}
try {
if (consumer != null) {
consumer.accept(x);
}
}
catch (Throwable t) {
Exceptions.throwIfFatal(t);
this.subscription.cancel();
onError(t);
}
}
@Override
public Object scan(Attr key) {
switch (key){
case PARENT:
return subscription;
case PREFETCH:
return Integer.MAX_VALUE;
case TERMINATED:
case CANCELLED:
return isDisposed();
}
return null;
}
@Override
public boolean isDisposed() {
return subscription == Operators.cancelledSubscription();
}
@Override
public void dispose() {
Subscription s = S.getAndSet(this, Operators.cancelledSubscription());
if (s != null && s != Operators.cancelledSubscription()) {
s.cancel();
}
}
}