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.ufs;
  
  import alluxio.conf.Configuration;
  import alluxio.master.NoopMaster;
  import alluxio.proto.journal.Journal;
  import alluxio.underfs.UnderFileSystem;
  import alluxio.util.URIUtils;
  
  import org.junit.After;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.TemporaryFolder;
  import org.mockito.Mockito;
  
  import java.net.URI;
  import java.util.Collections;
  
  /**
   * Unit tests for {@link UfsJournalCheckpointWriter}.
   */
  public final class UfsJournalCheckpointWriterTest {
    @Rule
    public TemporaryFolder mFolder = new TemporaryFolder();
  
    private UfsJournal mJournal;
    private UnderFileSystem mUfs;
  
    @Before
    public void before() throws Exception {
      URI location = URIUtils
          .appendPathOrDie(new URI(mFolder.newFolder().getAbsolutePath()), "FileSystemMaster");
      mUfs = Mockito
          .spy(UnderFileSystem.Factory.create(location.toString(), Configuration.global()));
      mJournal = new UfsJournal(location, new NoopMaster(), mUfs, 0, Collections::emptySet);
    }
  
    @After
    public void after() throws Exception {
      Configuration.reloadProperties();
    }
  
    /**
     * Writes journal entries to the checkpoint.
     */
    @Test
    public void writeJournalEntry() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      for (int i = 0; i < 5; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.close();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      String expectedCheckpoint =
          URIUtils.appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN))
              .toString();
      Assert.assertEquals(1, snapshot.getCheckpoints().size());
      Assert.assertEquals(expectedCheckpoint,
          snapshot.getCheckpoints().get(0).getLocation().toString());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * The number of journal entries written to the checkpoint is greater than the checkpoint
     * sequence number encoded in the checkpoint file. This is to show that the journal entry's
     * sequence number in the checkpoint file is not relevant to the sequence number encoded in
     * the checkpoint file.
     */
    @Test
    public void writeJournalEntryMoreThanJournalLogSequenceNumber() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      for (int i = 0; i < endSN + 10; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.close();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      String expectedCheckpoint =
          URIUtils.appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN))
              .toString();
      Assert.assertEquals(1, snapshot.getCheckpoints().size());
      Assert.assertEquals(expectedCheckpoint,
          snapshot.getCheckpoints().get(0).getLocation().toString());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * Tests cancel.
     */
    @Test
    public void cancel() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      for (int i = 0; i < 5; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.cancel();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      Assert.assertTrue(snapshot.getCheckpoints().isEmpty());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * Tests an existing checkpoint file.
     */
    @Test
    public void checkpointExists() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      String expectedCheckpoint =
          URIUtils.appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN))
              .toString();
      mJournal.getUfs().create(expectedCheckpoint).close();
      for (int i = 0; i < 5; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.close();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      Assert.assertEquals(1, snapshot.getCheckpoints().size());
      Assert.assertEquals(expectedCheckpoint,
          snapshot.getCheckpoints().get(0).getLocation().toString());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * An older checkpoint file exists.
     */
    @Test
    public void olderCheckpointExists() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      String oldCheckpoint = URIUtils
          .appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN - 1))
          .toString();
      mJournal.getUfs().create(oldCheckpoint).close();
      String expectedCheckpoint =
          URIUtils.appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN))
              .toString();
      for (int i = 0; i < 5; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.close();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      Assert.assertEquals(2, snapshot.getCheckpoints().size());
      Assert.assertEquals(oldCheckpoint, snapshot.getCheckpoints().get(0).getLocation().toString());
      Assert.assertEquals(expectedCheckpoint,
          snapshot.getCheckpoints().get(1).getLocation().toString());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * A newer checkpoint file exists.
     */
    @Test
    public void newerCheckpointExists() throws Exception {
      long endSN = 0x20;
      UfsJournalCheckpointWriter writer = mJournal.getCheckpointWriter(endSN);
      String newerCheckpoint = URIUtils
          .appendPathOrDie(mJournal.getCheckpointDir(), String.format("0x%x-0x%x", 0, endSN + 1))
          .toString();
      mJournal.getUfs().create(newerCheckpoint).close();
      for (int i = 0; i < 5; i++) {
        newEntry(i).writeDelimitedTo(writer);
      }
      writer.close();
  
      UfsJournalSnapshot snapshot = UfsJournalSnapshot.getSnapshot(mJournal);
      Assert.assertEquals(1, snapshot.getCheckpoints().size());
      Assert.assertEquals(newerCheckpoint, snapshot.getCheckpoints().get(0).getLocation().toString());
      Assert.assertTrue(snapshot.getTemporaryCheckpoints().isEmpty());
    }
  
    /**
     * Creates a dummy journal entry with the given sequence number.
     *
     * @param sequenceNumber the sequence number
     * @return the journal entry
     */
    private Journal.JournalEntry newEntry(long sequenceNumber) {
      return Journal.JournalEntry.newBuilder().setSequenceNumber(sequenceNumber).build();
    }
  }
  