curator-master/curator-client/src/test/java/org/apache/curator/TestEnsurePath.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.curator;

import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.anyBoolean;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.when;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import org.apache.curator.retry.RetryOneTime;
import org.apache.curator.utils.EnsurePath;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.junit.jupiter.api.Test;
import org.mockito.Mockito;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

public class TestEnsurePath {
    @Test
    public void testBasic() throws Exception {
        ZooKeeper client = mock(ZooKeeper.class, Mockito.RETURNS_MOCKS);
        CuratorZookeeperClient curator = mock(CuratorZookeeperClient.class);
        RetryPolicy retryPolicy = new RetryOneTime(1);
        RetryLoop retryLoop = new RetryLoopImpl(retryPolicy, null);
        when(curator.getZooKeeper()).thenReturn(client);
        when(curator.getRetryPolicy()).thenReturn(retryPolicy);
        when(curator.newRetryLoop()).thenReturn(retryLoop);

        Stat fakeStat = mock(Stat.class);
        when(client.exists(Mockito.<String>any(), anyBoolean())).thenReturn(fakeStat);

        EnsurePath ensurePath = new EnsurePath("/one/two/three");
        ensurePath.ensure(curator);

        verify(client, times(3)).exists(Mockito.<String>any(), anyBoolean());

        ensurePath.ensure(curator);
        verifyNoMoreInteractions(client);
        ensurePath.ensure(curator);
        verifyNoMoreInteractions(client);
    }

    @Test
    public void testSimultaneous() throws Exception {
        ZooKeeper client = mock(ZooKeeper.class, Mockito.RETURNS_MOCKS);
        RetryPolicy retryPolicy = new RetryOneTime(1);
        RetryLoop retryLoop = new RetryLoopImpl(retryPolicy, null);
        final CuratorZookeeperClient curator = mock(CuratorZookeeperClient.class);
        when(curator.getZooKeeper()).thenReturn(client);
        when(curator.getRetryPolicy()).thenReturn(retryPolicy);
        when(curator.newRetryLoop()).thenReturn(retryLoop);

        final Stat fakeStat = mock(Stat.class);
        final CountDownLatch startedLatch = new CountDownLatch(2);
        final CountDownLatch finishedLatch = new CountDownLatch(2);
        final Semaphore semaphore = new Semaphore(0);
        when(client.exists(Mockito.<String>any(), anyBoolean())).thenAnswer(new Answer<Stat>() {
            @Override
            public Stat answer(InvocationOnMock invocation) throws Throwable {
                semaphore.acquire();
                return fakeStat;
            }
        });

        final EnsurePath ensurePath = new EnsurePath("/one/two/three");
        ExecutorService service = Executors.newCachedThreadPool();
        for (int i = 0; i < 2; ++i) {
            service.submit(new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    startedLatch.countDown();
                    ensurePath.ensure(curator);
                    finishedLatch.countDown();
                    return null;
                }
            });
        }

        assertTrue(startedLatch.await(10, TimeUnit.SECONDS));
        semaphore.release(3);
        assertTrue(finishedLatch.await(10, TimeUnit.SECONDS));
        verify(client, times(3)).exists(Mockito.<String>any(), anyBoolean());

        ensurePath.ensure(curator);
        verifyNoMoreInteractions(client);
        ensurePath.ensure(curator);
        verifyNoMoreInteractions(client);
    }
}
