/*
* 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.BiConsumer;
import java.util.function.Consumer;
import java.util.function.Supplier;
import org.reactivestreams.Subscriber;
import org.reactivestreams.Subscription;
import reactor.core.Exceptions;
/**
* Peek into the lifecycle events and signals of a sequence, passing around
* a per-subscription state object initialized by a {@link Supplier} {@code stateSeeder}.
* <p>
* <p>
* The callbacks are all optional.
* <p>
* <p>
* Crashes by the lambdas are ignored.
*
* @param <T> the value type
* @param <S> the state type
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class FluxPeekStateful<T, S> extends FluxSource<T, T>
implements SignalPeekStateful<T, S> {
final Supplier<S> stateSeeder;
final BiConsumer<? super Subscription, S> onSubscribeCall;
final BiConsumer<? super T, S> onNextCall;
final BiConsumer<? super Throwable, S> onErrorCall;
final Consumer<S> onCompleteCall;
final Consumer<S> onAfterTerminateCall;
final BiConsumer<Long, S> onRequestCall;
final Consumer<S> onCancelCall;
FluxPeekStateful(Flux<? extends T> source,
Supplier<S> stateSeeder,
BiConsumer<? super Subscription, S> onSubscribeCall,
BiConsumer<? super T, S> onNextCall,
BiConsumer<? super Throwable, S> onErrorCall,
Consumer<S> onCompleteCall,
Consumer<S> onAfterTerminateCall,
BiConsumer<Long, S> onRequestCall,
Consumer<S> onCancelCall) {
super(source);
this.stateSeeder = stateSeeder;
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) {
//TODO fuseable version?
//TODO conditional version?
source.subscribe(new PeekStatefulSubscriber<>(s, this, stateSeeder.get()));
}
static final class PeekStatefulSubscriber<T, S> implements InnerOperator<T, T> {
final Subscriber<? super T> actual;
final SignalPeekStateful<T, S> parent;
final S state;
Subscription s;
boolean done;
PeekStatefulSubscriber(Subscriber<? super T> actual,
SignalPeekStateful<T, S> parent, S state) {
this.actual = actual;
this.parent = parent;
this.state = state;
}
@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, state);
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
s.request(n);
}
@Override
public void cancel() {
if(parent.onCancelCall() != null) {
try {
parent.onCancelCall().accept(state);
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
s.cancel();
}
@Override
public void onSubscribe(Subscription s) {
if(parent.onSubscribeCall() != null) {
try {
parent.onSubscribeCall().accept(s, state);
}
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, state);
}
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, state);
}
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().accept(state);
}
catch (Throwable e) {
//don't invoke error callback, see https://github.com/reactor/reactor-core/issues/270
Exceptions.throwIfFatal(e);
Throwable _e = Operators.onOperatorError(null, e, t);
Operators.onErrorDropped(_e);
}
}
}
@Override
public void onComplete() {
if (done) {
return;
}
if(parent.onCompleteCall() != null) {
try {
parent.onCompleteCall().accept(state);
}
catch (Throwable e) {
onError(Operators.onOperatorError(s, e));
return;
}
}
done = true;
actual.onComplete();
if(parent.onAfterTerminateCall() != null) {
try {
parent.onAfterTerminateCall().accept(state);
}
catch (Throwable e) {
//don't invoke error callback, see https://github.com/reactor/reactor-core/issues/270
Exceptions.throwIfFatal(e);
Throwable _e = Operators.onOperatorError(e);
Operators.onErrorDropped(_e);
}
}
}
@Override
public Subscriber<? super T> actual() {
return actual;
}
}
@Override
public BiConsumer<? super Subscription, S> onSubscribeCall() {
return onSubscribeCall;
}
@Override
public BiConsumer<? super T, S> onNextCall() {
return onNextCall;
}
@Override
public BiConsumer<? super Throwable, S> onErrorCall() {
return onErrorCall;
}
@Override
public Consumer<S> onCompleteCall() {
return onCompleteCall;
}
@Override
public Consumer<S> onAfterTerminateCall() {
return onAfterTerminateCall;
}
@Override
public BiConsumer<Long, S> onRequestCall() {
return onRequestCall;
}
@Override
public Consumer<S> onCancelCall() {
return onCancelCall;
}
}