content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.journal;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.fail;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.atLeastOnce;
  import static org.mockito.Mockito.doNothing;
  import static org.mockito.Mockito.doThrow;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.verify;
  
  import alluxio.conf.Configuration;
  import alluxio.conf.PropertyKey;
  import alluxio.proto.journal.Journal.JournalEntry;
  
  import org.junit.After;
  import org.junit.Test;
  
  import java.io.IOException;
  import java.util.Collections;
  
  /**
   * Unit tests for {@link AsyncJournalWriter}.
   */
  public class AsyncJournalWriterTest {
  
    private JournalWriter mMockJournalWriter;
    private AsyncJournalWriter mAsyncJournalWriter;
  
    @After
    public void after() throws Exception {
      Configuration.reloadProperties();
    }
  
    private void setupAsyncJournalWriter(boolean batchingEnabled) throws Exception {
      if (batchingEnabled) {
        Configuration.set(PropertyKey.MASTER_JOURNAL_FLUSH_BATCH_TIME_MS, "500ms");
      } else {
        Configuration.set(PropertyKey.MASTER_JOURNAL_FLUSH_BATCH_TIME_MS, "0ms");
      }
  
      mMockJournalWriter = mock(JournalWriter.class);
      doNothing().when(mMockJournalWriter).write(any(JournalEntry.class));
      doNothing().when(mMockJournalWriter).flush();
      mAsyncJournalWriter = new AsyncJournalWriter(mMockJournalWriter, Collections::emptySet);
    }
  
    /**
     * Simulation for normal write and flush.
     *
     * @param batchingEnabled whether to use a batch flush or not
     */
    public void writesAndFlushesInternal(boolean batchingEnabled) throws Exception {
      setupAsyncJournalWriter(batchingEnabled);
      int entries = 5;
  
      for (int i = 0; i < entries; i++) {
        long flushCounter = mAsyncJournalWriter.appendEntry(JournalEntry.getDefaultInstance());
        // Assuming the flush counter starts from 0.
        assertEquals(i + 1, flushCounter);
      }
  
      for (int i = 1; i <= entries; i++) {
        mAsyncJournalWriter.flush(i);
      }
      verify(mMockJournalWriter, atLeastOnce()).flush();
    }
  
    @Test(timeout = 10000)
    public void writesAndFlushes() throws Exception {
      writesAndFlushesInternal(false);
    }
  
    @Test(timeout = 10000)
    public void writesAndFlushesWithBatching() throws Exception {
      writesAndFlushesInternal(true);
    }
  
    /**
     * Simulates that exception occurs when writing {@link JournalEntry}.
     *
     * @param batchingEnabled whether to use a batch flush or not
     */
    public void failedWriteInternal(boolean batchingEnabled) throws Exception {
      setupAsyncJournalWriter(batchingEnabled);
  
      // Start failing journal writes.
      // PS: Need to stop the writer before mocking because mMockJournalWriter could be
      // acceessed concurrently by the internal flush thread.
      mAsyncJournalWriter.stop();
      doThrow(new IOException("entry write failed")).when(mMockJournalWriter)
              .write(any(JournalEntry.class));
      mAsyncJournalWriter.start();
  
      int entries = 5;
  
      for (int i = 0; i < entries; i++) {
        long flushCounter = mAsyncJournalWriter.appendEntry(JournalEntry.getDefaultInstance());
        // Assuming the flush counter starts from 0
        assertEquals(i + 1, flushCounter);
      }
  
      // Flushes should fail.
      for (int i = 1; i <= entries; i++) {
        try {
          mAsyncJournalWriter.flush(1);
          fail("journal flush should not succeed if journal write fails.");
        } catch (IOException e) {
          // This is expected.
        }
      }
  
      // Allow journal writes to succeed.
      // PS: Need to stop the writer before mocking because mMockJournalWriter could be
      // acceessed concurrently by the internal flush thread.
      mAsyncJournalWriter.stop();
      doNothing().when(mMockJournalWriter).write(any(JournalEntry.class));
      mAsyncJournalWriter.start();
  
      // Flushes should succeed.
      for (int i = 1; i <= entries; i++) {
        mAsyncJournalWriter.flush(i);
      }
      verify(mMockJournalWriter, atLeastOnce()).flush();
    }
  
    @Test(timeout = 10000)
    public void failedWrite() throws Exception {
      failedWriteInternal(false);
    }
  
    @Test(timeout = 10000)
    public void failedWriteWithBatching() throws Exception {
      failedWriteInternal(true);
    }
  
    /**
     * Simulates that exception occurs when flush.
     *
     * @param batchingEnabled whether to use a batch flush or not
     */
    public void failedFlushInternal(boolean batchingEnabled) throws Exception {
      setupAsyncJournalWriter(batchingEnabled);
      int entries = 5;
  
      // Start failing journal flushes.
      // PS: Need to stop the writer before mocking because mMockJournalWriter could be
      // acceessed concurrently by the internal flush thread.
      mAsyncJournalWriter.stop();
      doThrow(new IOException("flush failed")).when(mMockJournalWriter).flush();
      mAsyncJournalWriter.start();
  
      for (int i = 0; i < entries; i++) {
        long flushCounter = mAsyncJournalWriter.appendEntry(JournalEntry.getDefaultInstance());
        // Assuming the flush counter starts from 0
        assertEquals(i + 1, flushCounter);
      }
  
      // Flushes should fail.
      for (int i = 1; i <= entries; i++) {
        try {
          mAsyncJournalWriter.flush(1);
          fail("journal flush should not succeed if journal flush fails.");
        } catch (IOException e) {
          // This is expected.
        }
      }
  
      // Allow journal flushes to succeed.
      // PS: Need to stop the writer before mocking because mMockJournalWriter could be
      // acceessed concurrently by the internal flush thread.
      mAsyncJournalWriter.stop();
      doNothing().when(mMockJournalWriter).flush();
      mAsyncJournalWriter.start();
  
      // Flushes should succeed.
      for (int i = 1; i <= entries; i++) {
        mAsyncJournalWriter.flush(i);
      }
      verify(mMockJournalWriter, atLeastOnce()).flush();
    }
  
    @Test(timeout = 10000)
    public void failedFlush() throws Exception {
      failedFlushInternal(false);
    }
  
    @Test(timeout = 10000)
    public void failedFlushWithBatching() throws Exception {
      failedFlushInternal(true);
    }
  }
  