/*
* 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.
Objects;
import java.util.concurrent.atomic.
AtomicIntegerFieldUpdater;
import java.util.function.
BooleanSupplier;
import org.reactivestreams.
Publisher;
import reactor.core.
CoreSubscriber;
/**
* Repeatedly subscribes to the source if the predicate returns true after
* completion of the previous subscription.
*
* @param <T> the value type
* @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a>
*/
final class
FluxRepeatPredicate<T> extends
FluxOperator<T, T> {
final
BooleanSupplier predicate;
FluxRepeatPredicate(
Flux<? extends T>
source,
BooleanSupplier predicate) {
super(
source);
this.
predicate =
Objects.
requireNonNull(
predicate, "predicate");
}
@
Override
public void
subscribe(
CoreSubscriber<? super T>
actual) {
RepeatPredicateSubscriber<T>
parent = new
RepeatPredicateSubscriber<>(
source,
actual,
predicate);
actual.
onSubscribe(
parent);
if (!
parent.
isCancelled()) {
parent.
resubscribe();
}
}
static final class
RepeatPredicateSubscriber<T>
extends
Operators.
MultiSubscriptionSubscriber<T, T> {
final
Publisher<? extends T>
source;
final
BooleanSupplier predicate;
volatile int
wip;
@
SuppressWarnings("rawtypes")
static final
AtomicIntegerFieldUpdater<
RepeatPredicateSubscriber>
WIP =
AtomicIntegerFieldUpdater.
newUpdater(
RepeatPredicateSubscriber.class, "wip");
long
produced;
RepeatPredicateSubscriber(
Publisher<? extends T>
source,
CoreSubscriber<? super T>
actual,
BooleanSupplier predicate) {
super(
actual);
this.
source =
source;
this.
predicate =
predicate;
}
@
Override
public void
onNext(T
t) {
produced++;
actual.
onNext(
t);
}
@
Override
public void
onComplete() {
boolean
b;
try {
b =
predicate.
getAsBoolean();
} catch (
Throwable e) {
actual.
onError(
Operators.
onOperatorError(
e,
actual.
currentContext()));
return;
}
if (
b) {
resubscribe();
} else {
actual.
onComplete();
}
}
void
resubscribe() {
if (
WIP.
getAndIncrement(this) == 0) {
do {
if (
isCancelled()) {
return;
}
long
c =
produced;
if (
c != 0L) {
produced = 0L;
produced(
c);
}
source.
subscribe(this);
} while (
WIP.
decrementAndGet(this) != 0);
}
}
}
}