Method set_db

sql/sql_class.cc:1636–1671

*/

bool THD::set_db(const LEX_CSTRING *new_db)
{
  bool result= 0;
  /*
    Acquiring mutex LOCK_thd_data as we either free the memory allocated
    for the database and reallocating the memory for the new db or memcpy
    the new_db to the db.
  */
  /* Do not reallocate memory if current chunk is big enough. */
  if (db.str && new_db->str && db.length >= new_db->length)
  {
    mysql_mutex_lock(&LOCK_thd_data);
    db.length= new_db->length;
    memcpy((char*) db.str, new_db->str, new_db->length+1);
    mysql_mutex_unlock(&LOCK_thd_data);
  }
  else
  {
    const char *org_db= db.str;
    const char *tmp= NULL;
    if (new_db->str)
    {
      if (!(tmp= my_strndup(key_memory_THD_db, new_db->str, new_db->length,
                            MYF(MY_WME | ME_FATAL))))
        result= 1;
    }

    mysql_mutex_lock(&LOCK_thd_data);
    db.str= tmp;
    db.length= tmp ? new_db->length : 0;
    mysql_mutex_unlock(&LOCK_thd_data);
    my_free((char*) org_db);
  }
  PSI_CALL_set_thread_db(db.str, (int) db.length);
  return result;
}


/**