/*
 * 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 org.reactivestreams.Subscription;
import reactor.core.CoreSubscriber;
import reactor.core.Fuseable;
import reactor.util.annotation.Nullable;

See Also:
/** * @see <a href="https://github.com/reactor/reactive-streams-commons">Reactive-Streams-Commons</a> */
final class MonoHasElements<T> extends MonoFromFluxOperator<T, Boolean> implements Fuseable { MonoHasElements(Flux<? extends T> source) { super(source); } @Override public CoreSubscriber<? super T> subscribeOrReturn(CoreSubscriber<? super Boolean> actual) { return new HasElementsSubscriber<>(actual); } @Override public Object scanUnsafe(Attr key) { if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC; return super.scanUnsafe(key); } static final class HasElementsSubscriber<T> extends Operators.MonoSubscriber<T, Boolean> { Subscription s; HasElementsSubscriber(CoreSubscriber<? super Boolean> actual) { super(actual); } @Override @Nullable public Object scanUnsafe(Attr key) { if (key == Attr.PARENT) return s; if (key == Attr.RUN_STYLE) return Attr.RunStyle.SYNC; return super.scanUnsafe(key); } @Override public void cancel() { super.cancel(); s.cancel(); } @Override public void onSubscribe(Subscription s) { if (Operators.validate(this.s, s)) { this.s = s; actual.onSubscribe(this); s.request(Long.MAX_VALUE); } } @Override public void onNext(T t) { s.cancel(); complete(true); } @Override public void onComplete() { complete(false); } } }