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 java.util.Objects;
  import java.util.concurrent.atomic.AtomicReference;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.disposables.DisposableHelper;
  
  public final class CompletableResumeNext extends Completable {
  
      final CompletableSource source;
  
      final Function<? super Throwable, ? extends CompletableSource> errorMapper;
  
      public CompletableResumeNext(CompletableSource source,
              Function<? super Throwable, ? extends CompletableSource> errorMapper) {
          this.source = source;
          this.errorMapper = errorMapper;
      }
  
      @Override
      protected void subscribeActual(final CompletableObserver observer) {
          ResumeNextObserver parent = new ResumeNextObserver(observer, errorMapper);
          observer.onSubscribe(parent);
          source.subscribe(parent);
      }
  
      static final class ResumeNextObserver
      extends AtomicReference<Disposable>
      implements CompletableObserver, Disposable {
  
          private static final long serialVersionUID = 5018523762564524046L;
  
          final CompletableObserver downstream;
  
          final Function<? super Throwable, ? extends CompletableSource> errorMapper;
  
          boolean once;
  
          ResumeNextObserver(CompletableObserver observer, Function<? super Throwable, ? extends CompletableSource> errorMapper) {
              this.downstream = observer;
              this.errorMapper = errorMapper;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              DisposableHelper.replace(this, d);
          }
  
          @Override
          public void onComplete() {
              downstream.onComplete();
          }
  
          @Override
          public void onError(Throwable e) {
              if (once) {
                  downstream.onError(e);
                  return;
              }
              once = true;
  
              CompletableSource c;
  
              try {
                  c = Objects.requireNonNull(errorMapper.apply(e), "The errorMapper returned a null CompletableSource");
              } catch (Throwable ex) {
                  Exceptions.throwIfFatal(ex);
                  downstream.onError(new CompositeException(e, ex));
                  return;
              }
  
              c.subscribe(this);
          }
  
          @Override
          public boolean isDisposed() {
              return DisposableHelper.isDisposed(get());
          }
  
          @Override
          public void dispose() {
              DisposableHelper.dispose(this);
          }
      }
  }
  