code: def _compute_total_chunks(self, chunk_size):
          # type: (Descriptor, int) -> int
          
          try:
              if self._src_block_list is not None:
                  blen = len(self._src_block_list)
                  if blen > 0:
                      return blen
                  else:
                      return 1
              else:
                  return int(math.ceil(self._src_ase.size / chunk_size))
          except ZeroDivisionError:
              return 1
docs: Compute total number of chunks for entity
          :param Descriptor self: this
          :param int chunk_size: chunk size
          :rtype: int
          :return: num chunks