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/*
* 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 the value type
* @see Reactive-Streams-Commons
*/
final class FluxRepeatPredicate extends FluxOperator {
final BooleanSupplier predicate;
FluxRepeatPredicate(Flux source, BooleanSupplier predicate) {
super(source);
this.predicate = Objects.requireNonNull(predicate, "predicate");
}
@Override
public void subscribe(CoreSubscriber actual) {
RepeatPredicateSubscriber parent = new RepeatPredicateSubscriber<>(source,
actual, predicate);
actual.onSubscribe(parent);
if (!parent.isCancelled()) {
parent.resubscribe();
}
}
static final class RepeatPredicateSubscriber
extends Operators.MultiSubscriptionSubscriber {
final Publisher source;
final BooleanSupplier predicate;
volatile int wip;
@SuppressWarnings("rawtypes")
static final AtomicIntegerFieldUpdater WIP =
AtomicIntegerFieldUpdater.newUpdater(RepeatPredicateSubscriber.class, "wip");
long produced;
RepeatPredicateSubscriber(Publisher source,
CoreSubscriber 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);
}
}
}
}