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.core;
  
  import java.util.concurrent.TimeUnit;
  
  import org.openjdk.jmh.annotations.*;
  import org.reactivestreams.Publisher;
  
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  
  @BenchmarkMode(Mode.Throughput)
  @OutputTimeUnit(TimeUnit.SECONDS)
  @State(Scope.Thread)
  public class OperatorFlatMapPerf {
  
      @State(Scope.Thread)
      public static class Input extends InputWithIncrementingInteger {
  
          @Param({ "1", "1000", "1000000" })
          public int size;
  
          @Override
          public int getSize() {
              return size;
          }
  
      }
  
      @Benchmark
      public void flatMapIntPassthruSync(Input input) {
          input.flowable.flatMap(new Function<Integer, Publisher<Integer>>() {
              @Override
              public Publisher<Integer> apply(Integer v) {
                  return Flowable.just(v);
              }
          }).subscribe(input.newSubscriber());
      }
  
      @Benchmark
      public void flatMapIntPassthruAsync(Input input) throws InterruptedException {
          PerfSubscriber latchedObserver = input.newLatchedObserver();
          input.flowable.flatMap(new Function<Integer, Publisher<Integer>>() {
              @Override
              public Publisher<Integer> apply(Integer i) {
                      return Flowable.just(i).subscribeOn(Schedulers.computation());
              }
          }).subscribe(latchedObserver);
          if (input.size == 1) {
              while (latchedObserver.latch.getCount() != 0) { }
          } else {
              latchedObserver.latch.await();
          }
      }
  
      @Benchmark
      public void flatMapTwoNestedSync(final Input input) {
          Flowable.range(1, 2).flatMap(new Function<Integer, Publisher<Integer>>() {
              @Override
              public Publisher<Integer> apply(Integer i) {
                      return input.flowable;
              }
          }).subscribe(input.newSubscriber());
      }
  
      // this runs out of memory currently
      //    @Benchmark
      //    public void flatMapTwoNestedAsync(final Input input) throws InterruptedException {
      //        Observable.range(1, 2).flatMap(new Func1<Integer, Observable<Integer>>() {
      //
      //            @Override
      //            public Observable<Integer> call(Integer i) {
      //                return input.observable.subscribeOn(Schedulers.computation());
      //            }
      //
      //        }).subscribe(input.observer);
      //    }
  
  }
  