import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
private void verifyAddition(long blockId, long genStamp, long size) {
  final ReplicaInfo replicainfo;
  replicainfo = FsDatasetTestUtil.fetchReplicaInfo(fds, bpid, blockId);
  assertNotNull(replicainfo);

  // Added block has the same file as the one created by the test
  File file = new File(getBlockFile(blockId));
  assertEquals(file.getName(),
      FsDatasetTestUtil.getFile(fds, bpid, blockId).getName());

  // Generation stamp is same as that of created file
  assertEquals(genStamp, replicainfo.getGenerationStamp());

  // File size matches
  assertEquals(size, replicainfo.getNumBytes());
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/** Truncate a block file */
private long truncateBlockFile() throws IOException {
  synchronized (fds) {
    for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
      File f = b.getBlockFile();
      File mf = b.getMetaFile();
      // Truncate a block file that has a corresponding metadata file
      if (f.exists() && f.length() != 0 && mf.exists()) {
        FileOutputStream s = null;
        FileChannel channel = null;
        try {
          s = new FileOutputStream(f);
          channel = s.getChannel();
          channel.truncate(0);
          LOG.info("Truncated block file " + f.getAbsolutePath());
          return b.getBlockId();
        } finally {
          IOUtils.cleanup(LOG, channel, s);
        }
      }
    }
  }
  return 0;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/** Truncate a block file */
private long truncateBlockFile() throws IOException {
  synchronized (fds) {
    for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
      File f = b.getBlockFile();
      File mf = b.getMetaFile();
      // Truncate a block file that has a corresponding metadata file
      if (f.exists() && f.length() != 0 && mf.exists()) {
        FileOutputStream s = new FileOutputStream(f);
        FileChannel channel = s.getChannel();
        channel.truncate(0);
        LOG.info("Truncated block file " + f.getAbsolutePath());
        return b.getBlockId();
      }
    }
  }
  return 0;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/**
 * Truncate a block file
 */
private long truncateBlockFile() throws IOException {
  synchronized (fds) {
    for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
      File f = b.getBlockFile();
      File mf = b.getMetaFile();
      // Truncate a block file that has a corresponding metadata file
      if (f.exists() && f.length() != 0 && mf.exists()) {
        FileOutputStream s = new FileOutputStream(f);
        FileChannel channel = s.getChannel();
        channel.truncate(0);
        LOG.info("Truncated block file " + f.getAbsolutePath());
        return b.getBlockId();
      }
    }
  }
  return 0;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
private static ReplicaInPipeline getReplica(final DataNode datanode,
    final String bpid, final ReplicaState expectedState) throws InterruptedException {
  final Collection<ReplicaInfo> replicas = FsDatasetTestUtil.getReplicas(
      datanode.getFSDataset(), bpid);
  for(int i = 0; i < 5 && replicas.size() == 0; i++) {
    LOG.info("wait since replicas.size() == 0; i=" + i);
    Thread.sleep(1000);
  }
  Assert.assertEquals(1, replicas.size());
  final ReplicaInfo r = replicas.iterator().next();
  Assert.assertEquals(expectedState, r.getState());
  return (ReplicaInPipeline)r;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/**
 * Asserts that the storage lock file in each given directory has been
 * released.  This method works by trying to acquire the lock file itself.  If
 * locking fails here, then the main code must have failed to release it.
 *
 * @param dirs every storage directory to check
 * @throws IOException if there is an unexpected I/O error
 */
private static void assertFileLocksReleased(Collection<String> dirs)
    throws IOException {
  for (String dir: dirs) {
    try {
      FsDatasetTestUtil.assertFileLockReleased(dir);
    } catch (IOException e) {
      LOG.warn(e);
    }
  }
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/** Delete a block file */
private long deleteBlockFile() {
  synchronized(fds) {
    for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
      File f = b.getBlockFile();
      File mf = b.getMetaFile();
      // Delete a block file that has corresponding metadata file
      if (f.exists() && mf.exists() && f.delete()) {
        LOG.info("Deleting block file " + f.getAbsolutePath());
        return b.getBlockId();
      }
    }
  }
  return 0;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/** Delete block meta file */
private long deleteMetaFile() {
  synchronized(fds) {
    for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
      File file = b.getMetaFile();
      // Delete a metadata file
      if (file.exists() && file.delete()) {
        LOG.info("Deleting metadata file " + file.getAbsolutePath());
        return b.getBlockId();
      }
    }
  }
  return 0;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/**
 * Duplicate the given block on all volumes.
 * @param blockId
 * @throws IOException
 */
private void duplicateBlock(long blockId) throws IOException {
  synchronized (fds) {
    ReplicaInfo b = FsDatasetTestUtil.fetchReplicaInfo(fds, bpid, blockId);
    for (FsVolumeSpi v : fds.getVolumes()) {
      if (v.getStorageID().equals(b.getVolume().getStorageID())) {
        continue;
      }

      // Volume without a copy of the block. Make a copy now.
      File sourceBlock = b.getBlockFile();
      File sourceMeta = b.getMetaFile();
      String sourceRoot = b.getVolume().getBasePath();
      String destRoot = v.getBasePath();

      String relativeBlockPath = new File(sourceRoot).toURI().relativize(sourceBlock.toURI()).getPath();
      String relativeMetaPath = new File(sourceRoot).toURI().relativize(sourceMeta.toURI()).getPath();

      File destBlock = new File(destRoot, relativeBlockPath);
      File destMeta = new File(destRoot, relativeMetaPath);

      destBlock.getParentFile().mkdirs();
      FileUtils.copyFile(sourceBlock, destBlock);
      FileUtils.copyFile(sourceMeta, destMeta);

      if (destBlock.exists() && destMeta.exists()) {
        LOG.info("Copied " + sourceBlock + " ==> " + destBlock);
        LOG.info("Copied " + sourceMeta + " ==> " + destMeta);
      }
    }
  }
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/** Get a random blockId that is not used already */
private long getFreeBlockId() {
  long id = rand.nextLong();
  while (true) {
    id = rand.nextLong();
    if (FsDatasetTestUtil.fetchReplicaInfo(fds, bpid, id) == null) {
      break;
    }
  }
  return id;
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
@Test (timeout=300000)
public void testRetainBlockOnPersistentStorage() throws Exception {
  cluster = new MiniDFSCluster
      .Builder(CONF)
      .storageTypes(new StorageType[] { StorageType.RAM_DISK, StorageType.DEFAULT })
      .numDataNodes(1)
      .build();
  try {
    cluster.waitActive();
    DataNode dataNode = cluster.getDataNodes().get(0);
    bpid = cluster.getNamesystem().getBlockPoolId();
    fds = DataNodeTestUtils.getFSDataset(cluster.getDataNodes().get(0));
    client = cluster.getFileSystem().getClient();
    scanner = new DirectoryScanner(dataNode, fds, CONF);
    scanner.setRetainDiffs(true);
    FsDatasetTestUtil.stopLazyWriter(cluster.getDataNodes().get(0));

    // Add a file with 1 block
    List<LocatedBlock> blocks =
        createFile(GenericTestUtils.getMethodName(), BLOCK_LENGTH, false);

    // Ensure no difference between volumeMap and disk.
    scan(1, 0, 0, 0, 0, 0);

    // Make a copy of the block on RAM_DISK and ensure that it is
    // picked up by the scanner.
    duplicateBlock(blocks.get(0).getBlock().getBlockId());
    scan(2, 1, 0, 0, 0, 0, 1);
    verifyStorageType(blocks.get(0).getBlock().getBlockId(), false);
    scan(1, 0, 0, 0, 0, 0);

  } finally {
    if (scanner != null) {
      scanner.shutdown();
      scanner = null;
    }
    cluster.shutdown();
    cluster = null;
  }
}
 

import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil; //导入依赖的package包/类
/**
 * Duplicate the given block on all volumes.
 * @param blockId
 * @throws IOException
 */
private void duplicateBlock(long blockId) throws IOException {
  synchronized (fds) {
    ReplicaInfo b = FsDatasetTestUtil.fetchReplicaInfo(fds, bpid, blockId);
    try (FsDatasetSpi.FsVolumeReferences volumes =
        fds.getFsVolumeReferences()) {
      for (FsVolumeSpi v : volumes) {
        if (v.getStorageID().equals(b.getVolume().getStorageID())) {
          continue;
        }

        // Volume without a copy of the block. Make a copy now.
        File sourceBlock = b.getBlockFile();
        File sourceMeta = b.getMetaFile();
        String sourceRoot = b.getVolume().getBasePath();
        String destRoot = v.getBasePath();

        String relativeBlockPath =
            new File(sourceRoot).toURI().relativize(sourceBlock.toURI())
                .getPath();
        String relativeMetaPath =
            new File(sourceRoot).toURI().relativize(sourceMeta.toURI())
                .getPath();

        File destBlock = new File(destRoot, relativeBlockPath);
        File destMeta = new File(destRoot, relativeMetaPath);

        destBlock.getParentFile().mkdirs();
        FileUtils.copyFile(sourceBlock, destBlock);
        FileUtils.copyFile(sourceMeta, destMeta);

        if (destBlock.exists() && destMeta.exists()) {
          LOG.info("Copied " + sourceBlock + " ==> " + destBlock);
          LOG.info("Copied " + sourceMeta + " ==> " + destMeta);
        }
      }
    }
  }
}