Method append_possible_keys_stat

sql/sql_explain.cc:3058–3086

*/

int Explain_range_checked_fer::append_possible_keys_stat(MEM_ROOT *alloc,
                                                         TABLE *table,
                                                         key_map possible_keys)
{
  uint j;
  multi_alloc_root(alloc, &keys_stat, sizeof(ha_rows) * table->s->keys,
                   &keys_stat_names, sizeof(char *) * table->s->keys, NULL);
  if ((!keys_stat) || (!keys_stat_names))
  {
    keys_stat= NULL;
    keys_stat_names= NULL;
    return 1;
  }
  keys_map= possible_keys;
  keys= table->s->keys;
  bzero(keys_stat, sizeof(ha_rows) * table->s->keys);
  for (j= 0; j < table->s->keys; j++)
  {
    if (possible_keys.is_set(j))
    {
      if (!(keys_stat_names[j]= key_set.append_str(alloc,
                                                   table->key_info[j].name.str)))
        return 1;
    }
    else
      keys_stat_names[j]= NULL;
  }
  return 0;
}

void Explain_range_checked_fer::collect_data(QUICK_SELECT_I *quick)
{