code: public void delete() throws IOException {
      close();
      if (osFile != null) {
        boolean deleted = osFile.delete();
        while (!deleted) {
          OMemoryWatchDog.freeMemory(100);
          deleted = osFile.delete();
        }
      }
    }
docs: /*
  (non-Javadoc)
  
  @see com.orientechnologies.orient.core.storage.fs.OFileAAA#delete()