/*
* 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.function.Consumer;
import java.util.function.LongConsumer;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import reactor.core.Exceptions;
import reactor.core.Fuseable.ConditionalSubscriber;
import reactor.core.publisher.FluxPeekFuseable.PeekConditionalSubscriber;
/**
* Peek into the lifecycle events and signals of a sequence.
* <p>
* <p>
* The callbacks are all optional.
* <p>
* <p>
* Crashes by the lambdas are ignored.
*
* @param <T> the value type
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class FluxPeek<T> extends FluxSource<T, T> implements SignalPeek<T> {
final Consumer<? super Subscription> onSubscribeCall;
final Consumer<? super T> onNextCall;
final Consumer<? super Throwable> onErrorCall;
final Runnable onCompleteCall;
final Runnable onAfterTerminateCall;
final LongConsumer onRequestCall;
final Runnable onCancelCall;
FluxPeek(Flux<? extends T> source, Consumer<? super Subscription> onSubscribeCall,
Consumer<? super T> onNextCall,
Consumer<? super Throwable> onErrorCall,
Runnable onCompleteCall,
Runnable onAfterTerminateCall,
LongConsumer onRequestCall,
Runnable onCancelCall) {
super(source);
this.onSubscribeCall = onSubscribeCall;
this.onNextCall = onNextCall;
this.onErrorCall = onErrorCall;
this.onCompleteCall = onCompleteCall;
this.onAfterTerminateCall = onAfterTerminateCall;
this.onRequestCall = onRequestCall;
this.onCancelCall = onCancelCall;
}
@Override
public void subscribe(Subscriber<? super T> s) {
if (s instanceof ConditionalSubscriber) {
@SuppressWarnings("unchecked") // javac, give reason to suppress because inference anomalies
ConditionalSubscriber<T> s2 = (ConditionalSubscriber<T>) s;
source.subscribe(new PeekConditionalSubscriber<>(s2, this));
return;
}
source.subscribe(new PeekSubscriber<>(s, this));
}
static final class PeekSubscriber<T> implements InnerOperator<T, T> {
final Subscriber<? super T> actual;
final SignalPeek<T> parent;
Subscription s;
boolean done;
PeekSubscriber(Subscriber<? super T> actual, SignalPeek<T> parent) {
this.actual = actual;
this.parent = parent;
}
@Override
public Object scan(Attr key) {
switch (key) {
case PARENT:
return s;
case TERMINATED:
return done;
}
return InnerOperator.super.scan(key);
}
@Override
public void request(long n) {
if(parent.onRequestCall() != null) {
try {
parent.onRequestCall().accept(n);
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
s.request(n);
}
@Override
public void cancel() {
if(parent.onCancelCall() != null) {
try {
parent.onCancelCall().run();
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
s.cancel();
}
@Override
public void onSubscribe(Subscription s) {
if(Operators.validate(this.s, s)) {
if (parent.onSubscribeCall() != null) {
try {
parent.onSubscribeCall()
.accept(s);
}
catch (Throwable e) {
Operators.error(actual, Operators.onOperatorError(s, e));
return;
}
}
this.s = s;
actual.onSubscribe(this);
}
}
@Override
public void onNext(T t) {
if (done) {
Operators.onNextDropped(t);
return;
}
if(parent.onNextCall() != null) {
try {
parent.onNextCall().accept(t);
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e, t));
return;
}
}
actual.onNext(t);
}
@Override
public void onError(Throwable t) {
if (done) {
Operators.onErrorDropped(t);
return;
}
done = true;
if(parent.onErrorCall() != null) {
try {
parent.onErrorCall().accept(t);
}
catch (Throwable e) {
//this performs a throwIfFatal or suppresses t in e
t = Operators.onOperatorError(null, e, t);
}
}
try {
actual.onError(t);
}
catch (UnsupportedOperationException use){
if(parent.onErrorCall() == null
|| !Exceptions.isErrorCallbackNotImplemented(use) && use.getCause() != t){
throw use;
}
//ignore if missing callback
}
if(parent.onAfterTerminateCall() != null) {
try {
parent.onAfterTerminateCall().run();
}
catch (Throwable e) {
afterErrorWithFailure(parent, e, t);
}
}
}
@Override
public void onComplete() {
if (done) {
return;
}
if(parent.onCompleteCall() != null) {
try {
parent.onCompleteCall().run();
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
done = true;
actual.onComplete();
if(parent.onAfterTerminateCall() != null) {
try {
parent.onAfterTerminateCall().run();
}
catch (Throwable e) {
afterCompleteWithFailure(parent, e);
}
}
}
@Override
public Subscriber<? super T> actual() {
return actual;
}
}
@Override
public Consumer<? super Subscription> onSubscribeCall() {
return onSubscribeCall;
}
@Override
public Consumer<? super T> onNextCall() {
return onNextCall;
}
@Override
public Consumer<? super Throwable> onErrorCall() {
return onErrorCall;
}
@Override
public Runnable onCompleteCall() {
return onCompleteCall;
}
@Override
public Runnable onAfterTerminateCall() {
return onAfterTerminateCall;
}
@Override
public LongConsumer onRequestCall() {
return onRequestCall;
}
@Override
public Runnable onCancelCall() {
return onCancelCall;
}
/**
* Common method for FluxPeek and FluxPeekFuseable to deal with a doAfterTerminate
* callback that fails during onComplete. It drops the error to the global hook.
* <ul>
* <li>The callback failure is thrown immediately if fatal.</li>
* <li>{@link Operators#onOperatorError(Throwable)} is called</li>
* <li>{@link Operators#onErrorDropped(Throwable)} is called</li>
* </ul>
* <p>
*
* @param parent the {@link SignalPeek} from which to get the callbacks
* @param callbackFailure the afterTerminate callback failure
*/
//see https://github.com/reactor/reactor-core/issues/270
static <T> void afterCompleteWithFailure(SignalPeek<T> parent,
Throwable callbackFailure) {
Exceptions.throwIfFatal(callbackFailure);
Throwable _e = Operators.onOperatorError(callbackFailure);
Operators.onErrorDropped(_e);
}
/**
* Common method for FluxPeek and FluxPeekFuseable to deal with a doAfterTerminate
* callback that fails during onError. It drops the error to the global hook.
* <ul>
* <li>The callback failure is thrown immediately if fatal.</li>
* <li>{@link Operators#onOperatorError(Subscription, Throwable, Object)} is
* called, adding the original error as suppressed</li>
* <li>{@link Operators#onErrorDropped(Throwable)} is called</li>
* </ul>
* <p>
*
* @param parent the {@link SignalPeek} from which to get the callbacks
* @param callbackFailure the afterTerminate callback failure
* @param originalError the onError throwable
*/
//see https://github.com/reactor/reactor-core/issues/270
static <T> void afterErrorWithFailure(SignalPeek<T> parent,
Throwable callbackFailure, Throwable originalError) {
Exceptions.throwIfFatal(callbackFailure);
Throwable _e = Operators.onOperatorError(null, callbackFailure, originalError);
Operators.onErrorDropped(_e);
}
}