/*
 * 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.
Type parameters:
  • <T> – the value type
See Also:
/** * 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); } } } }