Fixing inefficient session handling

[eluser]Unknown[/eluser]
Example of session handling as of CI 1.7.1: http://ellislab.com/forums/viewthread/120044/

I am using CI sessions with database. The problem with CI sessions is that it writes to DB each time you call $this->session->set_userdata('item', 'value') or $this->session->set_flashdata('item', 'value') and it is not the behaviour you want or expect.

To fix it, I am going to extend the original Session class without breaking the existing system. It will use following methods:

$this->session->set('item', 'value'); (instead of set_userdata())
$this->session->get('item'); (instead of get_userdata()) *if used without 'item', it will return full session array
$this->session->rm('item'); (instead of unset_userdata())

$this->session->setFlash('item', 'value');
$this->session->getFlash('item');
$this->session->keepFlash('item');

Manual save of all session data in one go:

$this->session->save(TRUE); (if true is not passed, the session data will not be saved, you will understand why if you examine the code).

If you do not want to change your code, just rename the methods, to match the original names used in the session class.

#1 Download file gin_CI_Session.tar.gz and extract it your library folder;

#2 Add this line to /application/config/hooks.php:

$hook['post_controller'] = array(

'class'=>'SaveSession',
'function'=>'save',
'filename'=>'SaveSession.php',
'filepath'=>'libraries'
);

#3 Enable hooks in /application/config/config.php:
$config['enable_hooks'] = TRUE;

Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
* More efficient session handling
*
* @package        CodeIgniter
* @author        Gin - http://soho.lt, http://oldornot.com
*/
class MY_Session extends CI_Session
{
    private $saveSession = FALSE;

    /**
     * Add or change data in the "userdata" array
     *
     * @access    public
     * @param     string|array
     * @return    void
     */
    public function set($data = array(), $value = '')
    {
        if (is_string($data)) $data = array($data => $value);

        if (count($data) > 0):
        
            foreach ($data as $key => $val):
            
                $this->userdata[$key] = $val;
                
            endforeach;
            
        $this->saveSession = TRUE;
        
        endif;
        
    }
    
    /**
     * Just a shorter version of $this->session->userdata('myData')
     * If no key suppled, will return full session array
     *
     * @access    public
     * @param    string
     * @return    string|array
     */
    public function get($key = '')
    {
        return ($key != '') ? $this->userdata($key) : $this->all_userdata();
    }
    
    /**
     * Removes data from the "userdata" array
     *
     * @access    public
     * @param    string|array $key
     * @return    void
     */
    public function rm($key)
    {
        if (is_string($key)) $key = array($key => '');

        if(count($keys) > 0):
        
            foreach ($keys as $key => $val):

                unset($this->userdata[$key]);
            
            endforeach;
            
            $this->saveSession = TRUE;
            
        endif;
    }
    
    /**
     * Add or change flashdata, only available
     * until the next request
     *
     * @access    public
     * @param    mixed
     * @param    string
     * @return    void
     */
    public function setFlash($data, $value)
    {
        
        if (is_string($data)) $data = array($data => $value);

        if (count($data) > 0)
        {
            foreach ($newdata as $key => $val)
            {
                $flashdata_key = $this->flashdata_key.':new:'.$key;
                #$this->set_userdata($flashdata_key, $val);
            }
            
        $this->saveSession = TRUE;
        
        }

    }
    
    /**
     * Fetch a specific flashdata item from the session array
     *
     * @access    public
     * @param    string
     * @return    string
     */
    public function getFlash($key)
    {
        $flashdata_key = $this->flashdata_key.':old:'.$key;
        return $this->userdata($flashdata_key);
    }
    
    /**
     * Keeps existing flashdata available to next request.
     *
     * @access    public
     * @param    string
     * @return    void
     */
    public function keepFlash($key)
    {
        $old_flashdata_key = $this->flashdata_key.':old:'.$key;
        $value = $this->userdata($old_flashdata_key);

        $new_flashdata_key = $this->flashdata_key.':new:'.$key;
        #$this->set_userdata($new_flashdata_key, $value);
        
        $this->saveSession = TRUE;
    }
    
    /**
     * Saves session data if it has been changed
     * Call it directly $this->session->save(TRUE); or add as a hook
     *
     * @access    public
     * @param     bool
     * @return    void
     */
    public function save($save = FALSE)
    {
        if($save || $this->saveSession) $this->sess_write();
    }
}

// END MY_Session class

/* End of file My_Session.php */
/* Location: ./system/application/libraries/My_Session.php */

Code:

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**
* More efficient session handling
*
* This class is used by a 'hook' to save the session data.
* You should not call $this->session->save() method directly from a hook
* as it would create a new instance of session class...
* ...(would consume memory, time, money and repeat SELECT query :)-
*
* @package        CodeIgniter
* @author        Gin - http://soho.lt, http://oldornot.com
*/
class SaveSession {

    public function save()
    {
        $CI =& get_instance();
        $CI->session->save();
    }
}

/* End of file SaveSession.php */
/* Location: ./system/application/libraries/SaveSession.php */