When is "an established connection" supposed to be true in CodeIgniter? - php

Question

Can't figure this one out:
In the DB_driver.php (core system/database)
this is beginning of init function...
/**
* Initialize Database Settings
*
* #return bool
*/
public function initialize()
{
/* If an established connection is available, then there's
* no need to connect and select the database.
*
* Depending on the database driver, conn_id can be either
* boolean TRUE, a resource or an object.
*/
if ($this->conn_id)
{
return TRUE;
}
// ----------------------------------------------------------------
// Connect to the database and set the connection ID
$this->conn_id = $this->db_connect($this->pconnect);
The initialize() is called wihtin CI_Controller so when creating new objects for example like this:
$x = new PartyPooper();
$y = new PartyPooper();
initialize() in the DB_driver is called twice. Nothing strange with that, but I would expect $this->conn_id to be set when creating PartyPooper() object second time ($y)?
When is "an established connection" supposed to be true? (In the example two database connections are made when there would should only be one?)
I'm using the latest database drivers in the development branch: https://github.com/EllisLab/CodeIgniter/tree/develop/system/database
I am using the mysqli-driver with persistant connections of.
UPDATE:
I'm not a huge fan messing with core-files, but I couldn't figure out another solution here. Please tell me if there's a better way of achieving of what I want to do.
I came up with this code (using sessions to handle storing and checking for existing db-connections (of the "subdriver"-object. (mysqli object in my case)):
public function initialize()
{
/* If an established connection is available, then there's
* no need to connect and select the database.
*
* Depending on the database driver, conn_id can be either
* boolean TRUE, a resource or an object.
*/
if ($this->conn_id) {
return TRUE;
}
$conn_session_id_name = 'dbsession_conn';
if (isset($_SESSION[$conn_session_id_name])) {
$sess = $_SESSION[$conn_session_id_name];
// Set connection id object or resourse and return true
// because no more connecting has to be done
if (is_object($sess) || is_resource($sess)) {
$this->conn_id = $sess;
return TRUE;
}
}
// Connect to the database and set the connection ID
$this->conn_id = $this->db_connect($this->pconnect);
// Store conn object or resource etc into session
if (is_object($this->conn_id) || is_resource($this->conn_id)) {
$_SESSION[$conn_session_id_name] = $this->conn_id;
}
// No connection resource? Check if there is a failover else throw an error
if ( ! $this->conn_id)
{
//rest of code as before...
My application got extremly much faster because it used one connection instead of around 60.
But my original question remains:
When is this supposed to be true in the initialize() function?
if ($this->conn_id) {
return TRUE;
}
(I didn't remove it when changing the code because I suppose it has some purpose-but even if I can't figure out which)
UPDAtE2 - clarification:
In a model I have a db select statement that is supposed to return PartyPooper objects:
eg. $res = $q->result('PartyPooper');
This PartyPooper is a controller that stores information about people, like names, years , birthdays etc, but it also handles stuff like calculation of info within the same object.
class PartyPooper extends CI_Controller { .... }
But as I understand from the comments below I should do like this instead?
class PartyPooper extends CI_Controller { .... }
class PartyPooperObject { .... } //Store information about people in this object
eg. $res = $q->result('PartyPooperObject');

Answer 1

This piece of code
if ($this->conn_id) {
return TRUE;
}
just assures that the initialize method is only called once per object.
If it has been called on the current object already, it must not be executed another time.