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.completable;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
  
  public final class CompletableFromPublisher<T> extends Completable {
  
      final Publisher<T> flowable;
  
      public CompletableFromPublisher(Publisher<T> flowable) {
          this.flowable = flowable;
      }
  
      @Override
      protected void subscribeActual(final CompletableObserver downstream) {
          flowable.subscribe(new FromPublisherSubscriber<>(downstream));
      }
  
      static final class FromPublisherSubscriber<T> implements FlowableSubscriber<T>, Disposable {
  
          final CompletableObserver downstream;
  
          Subscription upstream;
  
          FromPublisherSubscriber(CompletableObserver downstream) {
              this.downstream = downstream;
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              if (SubscriptionHelper.validate(this.upstream, s)) {
                  this.upstream = s;
  
                  downstream.onSubscribe(this);
  
                  s.request(Long.MAX_VALUE);
              }
          }
  
          @Override
          public void onNext(T t) {
              // ignored
          }
  
          @Override
          public void onError(Throwable t) {
              downstream.onError(t);
          }
  
          @Override
          public void onComplete() {
              downstream.onComplete();
          }
  
          @Override
          public void dispose() {
              upstream.cancel();
              upstream = SubscriptionHelper.CANCELLED;
          }
  
          @Override
          public boolean isDisposed() {
              return upstream == SubscriptionHelper.CANCELLED;
          }
      }
  
  }
  