/*
 * 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
 *
 *       https://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.Iterator;
import java.util.Objects;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;

import org.reactivestreams.Publisher;
import reactor.core.CoreSubscriber;

Concatenates a fixed array of Publishers' values.
Type parameters:
  • <T> – the value type
See Also:
/** * Concatenates a fixed array of Publishers' values. * * @param <T> the value type * * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a> */
final class FluxConcatIterable<T> extends Flux<T> implements SourceProducer<T> { final Iterable<? extends Publisher<? extends T>> iterable; FluxConcatIterable(Iterable<? extends Publisher<? extends T>> iterable) { this.iterable = Objects.requireNonNull(iterable, "iterable"); } @Override public void subscribe(CoreSubscriber<? super T> actual) { Iterator<? extends Publisher<? extends T>> it; try { it = Objects.requireNonNull(iterable.iterator(), "The Iterator returned is null"); } catch (Throwable e) { Operators.error(actual, Operators.onOperatorError(e, actual.currentContext())); return; } ConcatIterableSubscriber<T> parent = new ConcatIterableSubscriber<>(actual, it); actual.onSubscribe(parent); if (!parent.isCancelled()) { parent.onComplete(); } } @Override public Object scanUnsafe(Attr key) { if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC; return null; } static final class ConcatIterableSubscriber<T> extends Operators.MultiSubscriptionSubscriber<T, T> { final Iterator<? extends Publisher<? extends T>> it; volatile int wip; @SuppressWarnings("rawtypes") static final AtomicIntegerFieldUpdater<ConcatIterableSubscriber> WIP = AtomicIntegerFieldUpdater.newUpdater(ConcatIterableSubscriber.class, "wip"); long produced; ConcatIterableSubscriber(CoreSubscriber<? super T> actual, Iterator<? extends Publisher<? extends T>> it) { super(actual); this.it = it; } @Override public void onNext(T t) { produced++; actual.onNext(t); } @Override public void onComplete() { if (WIP.getAndIncrement(this) == 0) { Iterator<? extends Publisher<? extends T>> a = this.it; do { if (isCancelled()) { return; } boolean b; try { b = a.hasNext(); } catch (Throwable e) { onError(Operators.onOperatorError(this, e, actual.currentContext())); return; } if (isCancelled()) { return; } if (!b) { actual.onComplete(); return; } Publisher<? extends T> p; try { p = Objects.requireNonNull(it.next(), "The Publisher returned by the iterator is null"); } catch (Throwable e) { actual.onError(Operators.onOperatorError(this, e, actual.currentContext())); return; } if (isCancelled()) { return; } long c = produced; if (c != 0L) { produced = 0L; produced(c); } p.subscribe(this); if (isCancelled()) { return; } } while (WIP.decrementAndGet(this) != 0); } } @Override public Object scanUnsafe(Attr key) { if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC; return super.scanUnsafe(key); } } }