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lnkohana/modules/database/classes/Kohana/Session/Database.php
2013-04-22 14:09:50 +10:00

240 lines
5.0 KiB
PHP

<?php defined('SYSPATH') OR die('No direct script access.');
/**
* Database-based session class.
*
* Sample schema:
*
* CREATE TABLE `sessions` (
* `session_id` VARCHAR( 24 ) NOT NULL,
* `last_active` INT UNSIGNED NOT NULL,
* `contents` TEXT NOT NULL,
* PRIMARY KEY ( `session_id` ),
* INDEX ( `last_active` )
* ) ENGINE = MYISAM ;
*
* @package Kohana/Database
* @category Session
* @author Kohana Team
* @copyright (c) 2008-2009 Kohana Team
* @license http://kohanaphp.com/license
*/
class Kohana_Session_Database extends Session {
// Database instance
protected $_db;
// Database table name
protected $_table = 'sessions';
// Database column names
protected $_columns = array(
'session_id' => 'session_id',
'last_active' => 'last_active',
'contents' => 'contents'
);
// Garbage collection requests
protected $_gc = 500;
// The current session id
protected $_session_id;
// The old session id
protected $_update_id;
public function __construct(array $config = NULL, $id = NULL)
{
if ( ! isset($config['group']))
{
// Use the default group
$config['group'] = Database::$default;
}
// Load the database
$this->_db = Database::instance($config['group']);
if (isset($config['table']))
{
// Set the table name
$this->_table = (string) $config['table'];
}
if (isset($config['gc']))
{
// Set the gc chance
$this->_gc = (int) $config['gc'];
}
if (isset($config['columns']))
{
// Overload column names
$this->_columns = $config['columns'];
}
parent::__construct($config, $id);
if (mt_rand(0, $this->_gc) === $this->_gc)
{
// Run garbage collection
// This will average out to run once every X requests
$this->_gc();
}
}
public function id()
{
return $this->_session_id;
}
protected function _read($id = NULL)
{
if ($id OR $id = Cookie::get($this->_name))
{
$result = DB::select(array($this->_columns['contents'], 'contents'))
->from($this->_table)
->where($this->_columns['session_id'], '=', ':id')
->limit(1)
->param(':id', $id)
->execute($this->_db);
if ($result->count())
{
// Set the current session id
$this->_session_id = $this->_update_id = $id;
// Return the contents
return $result->get('contents');
}
}
// Create a new session id
$this->_regenerate();
return NULL;
}
protected function _regenerate()
{
// Create the query to find an ID
$query = DB::select($this->_columns['session_id'])
->from($this->_table)
->where($this->_columns['session_id'], '=', ':id')
->limit(1)
->bind(':id', $id);
do
{
// Create a new session id
$id = str_replace('.', '-', uniqid(NULL, TRUE));
// Get the the id from the database
$result = $query->execute($this->_db);
}
while ($result->count());
return $this->_session_id = $id;
}
protected function _write()
{
if ($this->_update_id === NULL)
{
// Insert a new row
$query = DB::insert($this->_table, $this->_columns)
->values(array(':new_id', ':active', ':contents'));
}
else
{
// Update the row
$query = DB::update($this->_table)
->value($this->_columns['last_active'], ':active')
->value($this->_columns['contents'], ':contents')
->where($this->_columns['session_id'], '=', ':old_id');
if ($this->_update_id !== $this->_session_id)
{
// Also update the session id
$query->value($this->_columns['session_id'], ':new_id');
}
}
$query
->param(':new_id', $this->_session_id)
->param(':old_id', $this->_update_id)
->param(':active', $this->_data['last_active'])
->param(':contents', $this->__toString());
// Execute the query
$query->execute($this->_db);
// The update and the session id are now the same
$this->_update_id = $this->_session_id;
// Update the cookie with the new session id
Cookie::set($this->_name, $this->_session_id, $this->_lifetime);
return TRUE;
}
/**
* @return bool
*/
protected function _restart()
{
$this->_regenerate();
return TRUE;
}
protected function _destroy()
{
if ($this->_update_id === NULL)
{
// Session has not been created yet
return TRUE;
}
// Delete the current session
$query = DB::delete($this->_table)
->where($this->_columns['session_id'], '=', ':id')
->param(':id', $this->_update_id);
try
{
// Execute the query
$query->execute($this->_db);
// Delete the cookie
Cookie::delete($this->_name);
}
catch (Exception $e)
{
// An error occurred, the session has not been deleted
return FALSE;
}
return TRUE;
}
protected function _gc()
{
if ($this->_lifetime)
{
// Expire sessions when their lifetime is up
$expires = $this->_lifetime;
}
else
{
// Expire sessions after one month
$expires = Date::MONTH;
}
// Delete all sessions that have expired
DB::delete($this->_table)
->where($this->_columns['last_active'], '<', ':time')
->param(':time', time() - $expires)
->execute($this->_db);
}
} // End Session_Database