private boolean isCompactionResultFile(FileStatus file, HStore store) {
    return store.getStoreFilesBeingWritten().contains(file.getPath());
  }
This Chore, every time it runs, will clear the unsused HFiles in the data folder.
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/BrokenStoreFileCleaner.java