Method get_share

storage/sequence/sequence.cc:305–342

Sequence_share *ha_seq::get_share()
{
  Sequence_share *tmp_share;
  lock_shared_ha_data();
  if (!(tmp_share= static_cast<Sequence_share*>(get_ha_share_ptr())))
  {
    bool reverse;
    ulonglong from, to, step;

    parse_table_name(table_share->table_name.str,
                     table_share->table_name.length, &from, &to, &step);
    
    if ((reverse = from > to))
    {
      if (step > from - to)
        to = from;
      else
        swap_variables(ulonglong, from, to);
      /*
        when keyread is allowed, optimizer will always prefer an index to a
        table scan for our tables, and we'll never see the range reversed.
      */
      table_share->keys_for_keyread.clear_all();
    }

    to= (to - from) / step * step + step + from;

    tmp_share= new Sequence_share(Lex_ident_table(table_share->normalized_path),
                                  from, to, step, reverse);

    if (!tmp_share)
      goto err;
    set_ha_share_ptr(static_cast<Handler_share*>(tmp_share));
  }
err:
  unlock_shared_ha_data();
  return tmp_share;
}


static int discover_table(handlerton *hton, THD *thd, TABLE_SHARE *share)