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 * Copyright (c) 2011-Present VMware Inc. or its affiliates, 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 org.reactivestreams.Publisher;
import reactor.core.CoreSubscriber;
import reactor.util.annotation.Nullable;

Given a set of source Publishers the values of that Publisher is forwarded to the actual which responds first with any signal.
Type parameters:
  • <T> – the value type
See Also:
/** * Given a set of source Publishers the values of that Publisher is forwarded to the * actual which responds first with any signal. * * @param <T> the value type * * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a> */
final class MonoFirstWithSignal<T> extends Mono<T> implements SourceProducer<T> { final Mono<? extends T>[] array; final Iterable<? extends Mono<? extends T>> iterable; @SafeVarargs MonoFirstWithSignal(Mono<? extends T>... array) { this.array = Objects.requireNonNull(array, "array"); this.iterable = null; } MonoFirstWithSignal(Iterable<? extends Mono<? extends T>> iterable) { this.array = null; this.iterable = Objects.requireNonNull(iterable); } @Nullable Mono<T> orAdditionalSource(Mono<? extends T> other) { if (array != null) { int n = array.length; @SuppressWarnings("unchecked") Mono<? extends T>[] newArray = new Mono[n + 1]; System.arraycopy(array, 0, newArray, 0, n); newArray[n] = other; return new MonoFirstWithSignal<>(newArray); } return null; } @SuppressWarnings("unchecked") @Override public void subscribe(CoreSubscriber<? super T> actual) { Publisher<? extends T>[] a = array; int n; if (a == null) { n = 0; a = new Publisher[8]; 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; } for (; ; ) { boolean b; try { b = it.hasNext(); } catch (Throwable e) { Operators.error(actual, Operators.onOperatorError(e, actual.currentContext())); return; } if (!b) { break; } Publisher<? extends T> p; try { p = Objects.requireNonNull(it.next(), "The Publisher returned by the iterator is null"); } catch (Throwable e) { Operators.error(actual, Operators.onOperatorError(e, actual.currentContext())); return; } if (n == a.length) { Publisher<? extends T>[] c = new Publisher[n + (n >> 2)]; System.arraycopy(a, 0, c, 0, n); a = c; } a[n++] = p; } } else { n = a.length; } if (n == 0) { Operators.complete(actual); return; } if (n == 1) { Publisher<? extends T> p = a[0]; if (p == null) { Operators.error(actual, Operators.onOperatorError(new NullPointerException("The single source Publisher is null"), actual.currentContext())); } else { p.subscribe(actual); } return; } FluxFirstWithSignal.RaceCoordinator<T> coordinator = new FluxFirstWithSignal.RaceCoordinator<>(n); coordinator.subscribe(a, n, actual); } @Override public Object scanUnsafe(Attr key) { if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC; return null; } }