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.observable;
  
  import io.reactivex.rxjava3.annotations.Nullable;
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.internal.observers.BasicIntQueueDisposable;
  
  public final class ObservableRangeLong extends Observable<Long> {
      private final long start;
      private final long count;
  
      public ObservableRangeLong(long start, long count) {
          this.start = start;
          this.count = count;
      }
  
      @Override
      protected void subscribeActual(Observer<? super Long> o) {
          RangeDisposable parent = new RangeDisposable(o, start, start + count);
          o.onSubscribe(parent);
          parent.run();
      }
  
      static final class RangeDisposable
      extends BasicIntQueueDisposable<Long> {
  
          private static final long serialVersionUID = 396518478098735504L;
  
          final Observer<? super Long> downstream;
  
          final long end;
  
          long index;
  
          boolean fused;
  
          RangeDisposable(Observer<? super Long> actual, long start, long end) {
              this.downstream = actual;
              this.index = start;
              this.end = end;
          }
  
          void run() {
              if (fused) {
                  return;
              }
              Observer<? super Long> actual = this.downstream;
              long e = end;
              for (long i = index; i != e && get() == 0; i++) {
                  actual.onNext(i);
              }
              if (get() == 0) {
                  lazySet(1);
                  actual.onComplete();
              }
          }
  
          @Nullable
          @Override
          public Long poll() {
              long i = index;
              if (i != end) {
                  index = i + 1;
                  return i;
              }
              lazySet(1);
              return null;
          }
  
          @Override
          public boolean isEmpty() {
              return index == end;
          }
  
          @Override
          public void clear() {
              index = end;
              lazySet(1);
          }
  
          @Override
          public void dispose() {
              set(1);
          }
  
          @Override
          public boolean isDisposed() {
              return get() != 0;
          }
  
          @Override
          public int requestFusion(int mode) {
              if ((mode & SYNC) != 0) {
                  fused = true;
                  return SYNC;
              }
              return NONE;
          }
      }
  }
  