code: private void updateStreamPosition() throws IOException {
      try {
        currentEditLogInputStreamPosition = currentEditLogInputStream
            .getPosition();
      } catch (IOException e) {
        LOG.error("Failed to get edit log file position", e);
        throw new IOException("updateStreamPosition failed");
      }
    }
docs: Sets the current position of the input stream, after a transaction has been
  successfully consumed.
  
  @throws IOException
  if a fatal error occurred.