code: private Map<Integer, Integer> getLostStripes(
                Configuration conf, FileStatus stat, FileSystem fs) 
                    throws IOException {
      Map<Integer, Integer> lostStripes = new HashMap<Integer, Integer>();
      RaidInfo raidInfo = RaidUtils.getFileRaidInfo(stat, conf);
      if (raidInfo.codec == null) {
        // Can not find the parity file, the file is not raided.
        return lostStripes;
      }
      Codec codec = raidInfo.codec;
      
      if (codec.isDirRaid) {
        RaidUtils.collectDirectoryCorruptBlocksInStripe(conf, 
            (DistributedFileSystem)fs, raidInfo, 
            stat, lostStripes);
      } else {
        RaidUtils.collectFileCorruptBlocksInStripe((DistributedFileSystem)fs, 
            raidInfo, stat, lostStripes);
      }
      return lostStripes;
    }
docs: Get the lost blocks numbers per stripe in the source file.