Java FSUtils.computeHDFSBlocksDistribution方法代码示例

import org.apache.hadoop.hbase.util.FSUtils; //导入方法依赖的package包/类
/**
 * return the top hosts of the store files, used by the Split
 */
private static String[] getStoreDirHosts(final FileSystem fs, final Path path)
    throws IOException {
  FileStatus[] files = FSUtils.listStatus(fs, path);
  if (files == null) {
    return new String[] {};
  }

  HDFSBlocksDistribution hdfsBlocksDistribution = new HDFSBlocksDistribution();
  for (FileStatus hfileStatus: files) {
    HDFSBlocksDistribution storeFileBlocksDistribution =
      FSUtils.computeHDFSBlocksDistribution(fs, hfileStatus, 0, hfileStatus.getLen());
    hdfsBlocksDistribution.add(storeFileBlocksDistribution);
  }

  List<String> hosts = hdfsBlocksDistribution.getTopHosts();
  return hosts.toArray(new String[hosts.size()]);
}
 

import org.apache.hadoop.hbase.util.FSUtils; //导入方法依赖的package包/类
/**
 * helper function to compute HDFS blocks distribution of a given reference file.For reference
 * file, we don't compute the exact value. We use some estimate instead given it might be good
 * enough. we assume bottom part takes the first half of reference file, top part takes the second
 * half of the reference file. This is just estimate, given midkey ofregion != midkey of HFile,
 * also the number and size of keys vary. If this estimate isn't good enough, we can improve it
 * later.
 *
 * @param fs        The FileSystem
 * @param reference The reference
 * @param status    The reference FileStatus
 * @return HDFS blocks distribution
 */
private static HDFSBlocksDistribution computeRefFileHDFSBlockDistribution(final FileSystem fs,
    final Reference reference, final FileStatus status) throws IOException {
  if (status == null) {
    return null;
  }

  long start = 0;
  long length = 0;

  if (Reference.isTopFileRegion(reference.getFileRegion())) {
    start = status.getLen() / 2;
    length = status.getLen() - status.getLen() / 2;
  } else {
    start = 0;
    length = status.getLen() / 2;
  }
  return FSUtils.computeHDFSBlocksDistribution(fs, status, start, length);
}
 

import org.apache.hadoop.hbase.util.FSUtils; //导入方法依赖的package包/类
private HDFSBlocksDistribution computeHDFSBlocksDistributionInternal(final FileSystem fs)
    throws IOException {
  FileStatus status = getReferencedFileStatus(fs);
  if (this.reference != null) {
    return computeRefFileHDFSBlockDistribution(fs, reference, status);
  } else {
    return FSUtils.computeHDFSBlocksDistribution(fs, status, 0, status.getLen());
  }
}