/*
* 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.
AtomicIntegerFieldUpdater;
import java.util.function.
Consumer;
import org.reactivestreams.
Subscription;
import reactor.core.
CoreSubscriber;
import reactor.core.
Exceptions;
import reactor.core.
Fuseable;
import reactor.core.
Fuseable.
ConditionalSubscriber;
import reactor.core.
Fuseable.
QueueSubscription;
import reactor.util.annotation.
Nullable;
/**
* Hook into the lifecycle events and signals of a {@link Flux} and execute
* a provided callback after any of onComplete, onError and cancel events.
* The hook is executed only once and receives the event type that triggered
* it ({@link SignalType#ON_COMPLETE}, {@link SignalType#ON_ERROR} or
* {@link SignalType#CANCEL}).
* <p>
* Note that any exception thrown by the hook are caught and bubbled up
* using {@link Operators#onErrorDropped(Throwable, reactor.util.context.Context)}.
*
* @param <T> the value type
* @author Simon Baslé
*/
final class
FluxDoFinally<T> extends
FluxOperator<T, T> {
final
Consumer<
SignalType>
onFinally;
@
SuppressWarnings("unchecked")
static <T>
CoreSubscriber<T>
createSubscriber(
CoreSubscriber<? super T>
s,
Consumer<
SignalType>
onFinally,
boolean
fuseable) {
if (
fuseable) {
if(
s instanceof
ConditionalSubscriber) {
return new
DoFinallyFuseableConditionalSubscriber<>(
(
ConditionalSubscriber<? super T>)
s,
onFinally);
}
return new
DoFinallyFuseableSubscriber<>(
s,
onFinally);
}
if (
s instanceof
ConditionalSubscriber) {
return new
DoFinallyConditionalSubscriber<>((
ConditionalSubscriber<? super T>)
s,
onFinally);
}
return new
DoFinallySubscriber<>(
s,
onFinally);
}
FluxDoFinally(
Flux<? extends T>
source,
Consumer<
SignalType>
onFinally) {
super(
source);
this.
onFinally =
onFinally;
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
source.
subscribe(
createSubscriber(
actual,
onFinally, false));
}
static class
DoFinallySubscriber<T> implements
InnerOperator<T, T> {
final
CoreSubscriber<? super T>
actual;
final
Consumer<
SignalType>
onFinally;
volatile int
once;
static final
AtomicIntegerFieldUpdater<
DoFinallySubscriber>
ONCE =
AtomicIntegerFieldUpdater.
newUpdater(
DoFinallySubscriber.class, "once");
QueueSubscription<T>
qs;
Subscription s;
boolean
syncFused;
DoFinallySubscriber(
CoreSubscriber<? super T>
actual,
Consumer<
SignalType>
onFinally) {
this.
actual =
actual;
this.
onFinally =
onFinally;
}
@
Override
@
Nullable
public
Object scanUnsafe(
Attr key) {
if (
key ==
Attr.
PARENT) return
s;
if (
key ==
Attr.
TERMINATED ||
key ==
Attr.
CANCELLED)
return
once == 1;
return
InnerOperator.super.scanUnsafe(
key);
}
@
SuppressWarnings("unchecked")
@
Override
public void
onSubscribe(
Subscription s) {
if (
Operators.
validate(this.
s,
s)) {
this.
s =
s;
if (
s instanceof
QueueSubscription) {
this.
qs = (
QueueSubscription<T>)
s;
}
actual.
onSubscribe(this);
}
}
@
Override
public void
onNext(T
t) {
actual.
onNext(
t);
}
@
Override
public void
onError(
Throwable t) {
try {
actual.
onError(
t);
}
finally {
runFinally(
SignalType.
ON_ERROR);
}
}
@
Override
public void
onComplete() {
actual.
onComplete();
runFinally(
SignalType.
ON_COMPLETE);
}
@
Override
public void
cancel() {
s.
cancel();
runFinally(
SignalType.
CANCEL);
}
@
Override
public void
request(long
n) {
s.
request(
n);
}
void
runFinally(
SignalType signalType) {
if (
ONCE.
compareAndSet(this, 0, 1)) {
try {
onFinally.
accept(
signalType);
} catch (
Throwable ex) {
Exceptions.
throwIfFatal(
ex);
Operators.
onErrorDropped(
ex,
actual.
currentContext());
}
}
}
@
Override
public
CoreSubscriber<? super T>
actual() {
return
actual;
}
}
static class
DoFinallyFuseableSubscriber<T> extends
DoFinallySubscriber<T>
implements
Fuseable,
QueueSubscription<T> {
DoFinallyFuseableSubscriber(
CoreSubscriber<? super T>
actual,
Consumer<
SignalType>
onFinally) {
super(
actual,
onFinally);
}
@
Override
public int
requestFusion(int
mode) {
QueueSubscription<T>
qs = this.
qs;
if (
qs != null && (
mode &
Fuseable.
THREAD_BARRIER) == 0) {
int
m =
qs.
requestFusion(
mode);
if (
m !=
Fuseable.
NONE) {
syncFused =
m ==
Fuseable.
SYNC;
}
return
m;
}
return
Fuseable.
NONE;
}
@
Override
public void
clear() {
if (
qs != null) {
qs.
clear();
}
}
@
Override
public boolean
isEmpty() {
return
qs == null ||
qs.
isEmpty();
}
@
Override
@
Nullable
public T
poll() {
if (
qs == null) {
return null;
}
T
v =
qs.
poll();
if (
v == null &&
syncFused) {
runFinally(
SignalType.
ON_COMPLETE);
}
return
v;
}
@
Override
public int
size() {
return
qs == null ? 0 :
qs.
size();
}
}
static final class
DoFinallyConditionalSubscriber<T> extends
DoFinallySubscriber<T>
implements
ConditionalSubscriber<T> {
DoFinallyConditionalSubscriber(
ConditionalSubscriber<? super T>
actual,
Consumer<
SignalType>
onFinally) {
super(
actual,
onFinally);
}
@
Override
@
SuppressWarnings("unchecked")
public boolean
tryOnNext(T
t) {
return ((
ConditionalSubscriber<? super T>)
actual).
tryOnNext(
t);
}
}
static final class
DoFinallyFuseableConditionalSubscriber<T> extends
DoFinallyFuseableSubscriber<T>
implements
ConditionalSubscriber<T> {
DoFinallyFuseableConditionalSubscriber(
ConditionalSubscriber<? super T>
actual,
Consumer<
SignalType>
onFinally) {
super(
actual,
onFinally);
}
@
Override
@
SuppressWarnings("unchecked")
public boolean
tryOnNext(T
t) {
return ((
ConditionalSubscriber<? super T>)
actual).
tryOnNext(
t);
}
}
}