code: public long getDoneSaving(Configuration conf) {
      try {
        DFSClient dfs = ((DistributedFileSystem)FileSystem.get(conf)).getClient();
        Counters raidedCounters = stateToSourceCounters.get(RaidState.RAIDED);
        Counters shouldRaidCounters =
            stateToSourceCounters.get(RaidState.NOT_RAIDED_BUT_SHOULD);
        long physical = estimatedDoneSourceSize + estimatedDoneParitySize;
        long logical = raidedCounters.getNumLogical() +
            shouldRaidCounters.getNumLogical();
        return logical * dfs.getDefaultReplication() - physical;
      } catch (Exception e) {
        return -1;
      }
    }
docs: Get the estimated saving of this code in bytes when RAIDing is done
  @return The saving in bytes