code: /*
   * Copyright (c) 2016-present, RxJava Contributors.
   *
   * 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 io.reactivex.rxjava3.internal.operators.maybe;
  
  import java.util.concurrent.atomic.AtomicReference;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
  import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
  import io.reactivex.rxjava3.plugins.RxJavaPlugins;
  
  /**
   * Relays the main source's event unless the other Publisher signals an item first or just completes
   * at which point the resulting Maybe is completed.
   *
   * @param <T> the value type
   * @param <U> the other's value type
   */
  public final class MaybeTakeUntilPublisher<T, U> extends AbstractMaybeWithUpstream<T, T> {
  
      final Publisher<U> other;
  
      public MaybeTakeUntilPublisher(MaybeSource<T> source, Publisher<U> other) {
          super(source);
          this.other = other;
      }
  
      @Override
      protected void subscribeActual(MaybeObserver<? super T> observer) {
          TakeUntilMainMaybeObserver<T, U> parent = new TakeUntilMainMaybeObserver<>(observer);
          observer.onSubscribe(parent);
  
          other.subscribe(parent.other);
  
          source.subscribe(parent);
      }
  
      static final class TakeUntilMainMaybeObserver<T, U>
      extends AtomicReference<Disposable> implements MaybeObserver<T>, Disposable {
  
          private static final long serialVersionUID = -2187421758664251153L;
  
          final MaybeObserver<? super T> downstream;
  
          final TakeUntilOtherMaybeObserver<U> other;
  
          TakeUntilMainMaybeObserver(MaybeObserver<? super T> downstream) {
              this.downstream = downstream;
              this.other = new TakeUntilOtherMaybeObserver<>(this);
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(this);
              SubscriptionHelper.cancel(other);
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(get());
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.setOnce(this, d);
          }
  
          @Override
          public void onSuccess(T value) {
              SubscriptionHelper.cancel(other);
              if (getAndSet(DisposableHelper.DISPOSED) != DisposableHelper.DISPOSED) {
                  downstream.onSuccess(value);
              }
          }
  
          @Override
          public void onError(Throwable e) {
              SubscriptionHelper.cancel(other);
              if (getAndSet(DisposableHelper.DISPOSED) != DisposableHelper.DISPOSED) {
                  downstream.onError(e);
              } else {
                  RxJavaPlugins.onError(e);
              }
          }
  
          @Override
          public void onComplete() {
              SubscriptionHelper.cancel(other);
              if (getAndSet(DisposableHelper.DISPOSED) != DisposableHelper.DISPOSED) {
                  downstream.onComplete();
              }
          }
  
          void otherError(Throwable e) {
              if (DisposableHelper.dispose(this)) {
                  downstream.onError(e);
              } else {
                  RxJavaPlugins.onError(e);
              }
          }
  
          void otherComplete() {
              if (DisposableHelper.dispose(this)) {
                  downstream.onComplete();
              }
          }
  
          static final class TakeUntilOtherMaybeObserver<U>
          extends AtomicReference<Subscription> implements FlowableSubscriber<U> {
  
              private static final long serialVersionUID = -1266041316834525931L;
  
              final TakeUntilMainMaybeObserver<?, U> parent;
  
              TakeUntilOtherMaybeObserver(TakeUntilMainMaybeObserver<?, U> parent) {
                  this.parent = parent;
              }
  
              @Override
              public void onSubscribe(Subscription s) {
                  SubscriptionHelper.setOnce(this, s, Long.MAX_VALUE);
              }
  
              @Override
              public void onNext(Object value) {
                  SubscriptionHelper.cancel(this);
                  parent.otherComplete();
              }
  
              @Override
              public void onError(Throwable e) {
                  parent.otherError(e);
              }
  
              @Override
              public void onComplete() {
                  parent.otherComplete();
              }
          }
      }
  
  }
  