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 static org.junit.Assert.*;
  import static org.mockito.Mockito.*;
  
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.junit.Test;
  
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.core.Observable;
  import io.reactivex.rxjava3.core.Observer;
  import io.reactivex.rxjava3.disposables.Disposable;
  import io.reactivex.rxjava3.exceptions.TestException;
  import io.reactivex.rxjava3.functions.*;
  import io.reactivex.rxjava3.observers.TestObserver;
  import io.reactivex.rxjava3.schedulers.Schedulers;
  import io.reactivex.rxjava3.subjects.PublishSubject;
  import io.reactivex.rxjava3.testsupport.*;
  
  public class ObservableCacheTest extends RxJavaTest {
      @Test
      public void coldReplayNoBackpressure() {
          ObservableCache<Integer> source = new ObservableCache<>(Observable.range(0, 1000), 16);
  
          assertFalse("Source is connected!", source.isConnected());
  
          TestObserverEx<Integer> to = new TestObserverEx<>();
  
          source.subscribe(to);
  
          assertTrue("Source is not connected!", source.isConnected());
          assertFalse("Subscribers retained!", source.hasObservers());
  
          to.assertNoErrors();
          to.assertTerminated();
          List<Integer> onNextEvents = to.values();
          assertEquals(1000, onNextEvents.size());
  
          for (int i = 0; i < 1000; i++) {
              assertEquals((Integer)i, onNextEvents.get(i));
          }
      }
  
      @Test
      public void cache() throws InterruptedException {
          final AtomicInteger counter = new AtomicInteger();
          Observable<String> o = Observable.unsafeCreate(new ObservableSource<String>() {
  
              @Override
              public void subscribe(final Observer<? super String> observer) {
                  observer.onSubscribe(Disposable.empty());
                  new Thread(new Runnable() {
  
                      @Override
                      public void run() {
                          counter.incrementAndGet();
                          System.out.println("published Observable being executed");
                          observer.onNext("one");
                          observer.onComplete();
                      }
                  }).start();
              }
          }).cache();
  
          // we then expect the following 2 subscriptions to get that same value
          final CountDownLatch latch = new CountDownLatch(2);
  
          // subscribe once
          o.subscribe(new Consumer<String>() {
              @Override
              public void accept(String v) {
                      assertEquals("one", v);
                      System.out.println("v: " + v);
                      latch.countDown();
              }
          });
  
          // subscribe again
          o.subscribe(new Consumer<String>() {
              @Override
              public void accept(String v) {
                      assertEquals("one", v);
                      System.out.println("v: " + v);
                      latch.countDown();
              }
          });
  
          if (!latch.await(1000, TimeUnit.MILLISECONDS)) {
              fail("subscriptions did not receive values");
          }
          assertEquals(1, counter.get());
      }
  
      @Test
      public void unsubscribeSource() throws Throwable {
          Action unsubscribe = mock(Action.class);
          Observable<Integer> o = Observable.just(1).doOnDispose(unsubscribe).cache();
          o.subscribe();
          o.subscribe();
          o.subscribe();
          verify(unsubscribe, never()).run();
      }
  
      @Test
      public void take() {
          TestObserver<Integer> to = new TestObserver<>();
  
          ObservableCache<Integer> cached = new ObservableCache<>(Observable.range(1, 1000), 16);
          cached.take(10).subscribe(to);
  
          to.assertNoErrors();
          to.assertComplete();
          to.assertValues(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
  //        ts.assertUnsubscribed(); // FIXME no longer valid
          assertFalse(cached.hasObservers());
      }
  
      @Test
      public void async() {
          Observable<Integer> source = Observable.range(1, 10000);
          for (int i = 0; i < 100; i++) {
              TestObserver<Integer> to1 = new TestObserver<>();
  
              ObservableCache<Integer> cached = new ObservableCache<>(source, 16);
  
              cached.observeOn(Schedulers.computation()).subscribe(to1);
  
              to1.awaitDone(2, TimeUnit.SECONDS);
              to1.assertNoErrors();
              to1.assertComplete();
              assertEquals(10000, to1.values().size());
  
              TestObserver<Integer> to2 = new TestObserver<>();
              cached.observeOn(Schedulers.computation()).subscribe(to2);
  
              to2.awaitDone(2, TimeUnit.SECONDS);
              to2.assertNoErrors();
              to2.assertComplete();
              assertEquals(10000, to2.values().size());
          }
      }
  
      @Test
      public void asyncComeAndGo() {
          Observable<Long> source = Observable.interval(1, 1, TimeUnit.MILLISECONDS)
                  .take(1000)
                  .subscribeOn(Schedulers.io());
          ObservableCache<Long> cached = new ObservableCache<>(source, 16);
  
          Observable<Long> output = cached.observeOn(Schedulers.computation());
  
          List<TestObserver<Long>> list = new ArrayList<>(100);
          for (int i = 0; i < 100; i++) {
              TestObserver<Long> to = new TestObserver<>();
              list.add(to);
              output.skip(i * 10).take(10).subscribe(to);
          }
  
          List<Long> expected = new ArrayList<>();
          for (int i = 0; i < 10; i++) {
              expected.add((long)(i - 10));
          }
          int j = 0;
          for (TestObserver<Long> to : list) {
              to.awaitDone(3, TimeUnit.SECONDS);
              to.assertNoErrors();
              to.assertComplete();
  
              for (int i = j * 10; i < j * 10 + 10; i++) {
                  expected.set(i - j * 10, (long)i);
              }
  
              to.assertValueSequence(expected);
  
              j++;
          }
      }
  
      @Test
      public void noMissingBackpressureException() {
          final int m = 4 * 1000 * 1000;
          Observable<Integer> firehose = Observable.unsafeCreate(new ObservableSource<Integer>() {
              @Override
              public void subscribe(Observer<? super Integer> t) {
                  t.onSubscribe(Disposable.empty());
                  for (int i = 0; i < m; i++) {
                      t.onNext(i);
                  }
                  t.onComplete();
              }
          });
  
          TestObserver<Integer> to = new TestObserver<>();
          firehose.cache().observeOn(Schedulers.computation()).takeLast(100).subscribe(to);
  
          to.awaitDone(3, TimeUnit.SECONDS);
          to.assertNoErrors();
          to.assertComplete();
  
          assertEquals(100, to.values().size());
      }
  
      @Test
      public void valuesAndThenError() {
          Observable<Integer> source = Observable.range(1, 10)
                  .concatWith(Observable.<Integer>error(new TestException()))
                  .cache();
  
          TestObserver<Integer> to = new TestObserver<>();
          source.subscribe(to);
  
          to.assertValues(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
          to.assertNotComplete();
          to.assertError(TestException.class);
  
          TestObserver<Integer> to2 = new TestObserver<>();
          source.subscribe(to2);
  
          to2.assertValues(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
          to2.assertNotComplete();
          to2.assertError(TestException.class);
      }
  
      @Test
      public void observers() {
          PublishSubject<Integer> ps = PublishSubject.create();
          ObservableCache<Integer> cache = (ObservableCache<Integer>)Observable.range(1, 5).concatWith(ps).cache();
  
          assertFalse(cache.hasObservers());
  
          assertEquals(0, cache.cachedEventCount());
  
          TestObserver<Integer> to = cache.test();
  
          assertTrue(cache.hasObservers());
  
          assertEquals(5, cache.cachedEventCount());
  
          ps.onComplete();
  
          to.assertResult(1, 2, 3, 4, 5);
      }
  
      @Test
      public void disposeOnArrival() {
          Observable.range(1, 5).cache()
          .test(true)
          .assertEmpty();
      }
  
      @Test
      public void disposeOnArrival2() {
          Observable<Integer> o = PublishSubject.<Integer>create().cache();
  
          o.test();
  
          o.test(true)
          .assertEmpty();
      }
  
      @Test
      public void dispose() {
          TestHelper.checkDisposed(Observable.range(1, 5).cache());
      }
  
      @Test
      public void take2() {
          Observable<Integer> cache = Observable.range(1, 5).cache();
  
          cache.take(2).test().assertResult(1, 2);
          cache.take(3).test().assertResult(1, 2, 3);
      }
  
      @Test
      public void subscribeEmitRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              final PublishSubject<Integer> ps = PublishSubject.<Integer>create();
  
              final Observable<Integer> cache = ps.cache();
  
              cache.test();
  
              final TestObserverEx<Integer> to = new TestObserverEx<>();
  
              Runnable r1 = new Runnable() {
                  @Override
                  public void run() {
                      cache.subscribe(to);
                  }
              };
  
              Runnable r2 = new Runnable() {
                  @Override
                  public void run() {
                      for (int j = 0; j < 500; j++) {
                          ps.onNext(j);
                      }
                      ps.onComplete();
                  }
              };
  
              TestHelper.race(r1, r2);
  
              to
              .awaitDone(5, TimeUnit.SECONDS)
              .assertSubscribed().assertValueCount(500).assertComplete().assertNoErrors();
          }
      }
  
      @Test
      public void cancelledUpFront() {
          final AtomicInteger call = new AtomicInteger();
          Observable<Object> f = Observable.fromCallable(new Callable<Object>() {
              @Override
              public Object call() throws Exception {
                  return call.incrementAndGet();
              }
          }).concatWith(Observable.never())
          .cache();
  
          f.test().assertValuesOnly(1);
  
          f.test(true)
          .assertEmpty();
  
          assertEquals(1, call.get());
      }
  
      @Test
      public void addRemoveRace() {
          for (int i = 0; i < TestHelper.RACE_DEFAULT_LOOPS; i++) {
              Observable<Object> o = Observable.never().cache();
  
              TestObserver<Object> to = o.test();
  
              TestHelper.race(
                      () -> to.dispose(),
                      () -> o.test()
              );
          }
      }
  }
  