/*
 * Copyright (c) 2011-2018 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.Objects;
import java.util.function.BiFunction;

import org.reactivestreams.Publisher;
import reactor.core.CoreSubscriber;
import reactor.core.Fuseable;
import reactor.core.Scannable;
import reactor.util.annotation.Nullable;

Author:Stephane Maldini, Simon Baslé
/** * @author Stephane Maldini * @author Simon Baslé */
final class ParallelLiftFuseable<I, O> extends ParallelFlux<O> implements Scannable, Fuseable { final BiFunction<Publisher, ? super CoreSubscriber<? super O>, ? extends CoreSubscriber<? super I>> lifter; final ParallelFlux<I> source; ParallelLiftFuseable(ParallelFlux<I> p, BiFunction<Publisher, ? super CoreSubscriber<? super O>, ? extends CoreSubscriber<? super I>> lifter) { this.source = Objects.requireNonNull(p, "source"); this.lifter = lifter; } @Override public int getPrefetch() { return source.getPrefetch(); } @Override public int parallelism() { return source.parallelism(); } @Override @Nullable public Object scanUnsafe(Attr key) { if (key == Attr.PARENT) { return source; } if (key == Attr.PREFETCH) { return getPrefetch(); } if (key == Attr.RUN_STYLE) { return Scannable.from(source).scanUnsafe(key); } return null; } @Override public String stepName() { if (source instanceof Scannable) { return Scannable.from(source).stepName(); } return Scannable.super.stepName(); } @Override public void subscribe(CoreSubscriber<? super O>[] s) { @SuppressWarnings("unchecked") CoreSubscriber<? super I>[] subscribers = new CoreSubscriber[parallelism()]; int i = 0; while (i < subscribers.length) { CoreSubscriber<? super O> actual = s[i]; CoreSubscriber<? super I> converted = Objects.requireNonNull(lifter.apply(source, actual), "Lifted subscriber MUST NOT be null"); Objects.requireNonNull(converted, "Lifted subscriber MUST NOT be null"); if (actual instanceof Fuseable.QueueSubscription && !(converted instanceof QueueSubscription)) { //user didn't produce a QueueSubscription, original was one converted = new FluxHide.SuppressFuseableSubscriber<>(converted); } //otherwise QS is not required or user already made a compatible conversion subscribers[i] = converted; i++; } source.subscribe(subscribers); } }