PHP : save session Handler to memcached by class
use this class to save session to memcache by class
<?php
/**
* Memcache PHP Session Handler
*/
define("SESSION_MEMCACHED_HOST","127.0.0.1"); //Memcache server address
if(! interface_exists('SessionHandlerInterface'))
{
interface SessionHandlerInterface {
public function close();
public function destroy($session_id);
public function gc($maxlifetime);
public function open($save_path, $name);
public function read($session_id);
public function write($session_id, $session_data);
}
}
class Memcached_SessionHandler implements SessionHandlerInterface{
/**
* @var int
*/
public $lifeTime;
/**
* @var Memcached
*/
public $memcached;
/**
* @var MySQLi
*/
public $mysqli;
/**
* @var string
*/
public $initSessionData;
/**
* interval for session expiration update in the DB
* @var int
*/
protected $_refreshTime = 1800; //30 minutes
private $sessionPrefix="";
/**
* constructor of the handler - initialises Memcached object
*
* @return bool
*/
public function __construct()
{
$this->sessionPrefix=".session.";
// this ensures to write down and close the session when destroying the
// handler object
ini_set('session.save_handler', 'user');
register_shutdown_function("session_write_close");
$this->lifeTime = intval(ini_get("session.gc_maxlifetime"));
$this->initSessionData = null;
session_set_save_handler(
array($this, "open"),
array($this, "close"),
array($this, "read"),
array($this, "write"),
array($this, "destroy"),
array($this, "gc"));
return true;
} // __construct()
/**
* Init memcached connection.
*/
protected function initMemcached()
{
/*
if($this->memcached instanceOf Memcached)
{
return false;
}
*/
$this->memcached = new Memcache;
$this->memcached->addServer(SESSION_MEMCACHED_HOST, 11211);
return true;
} // initMemcached()
/**
* opening of the session - mandatory arguments won't be needed
* we'll get the session id and load session data, it the session exists
*
* @param string $savePath
* @param string $sessionName
* @return bool
*/
public function open($savePath, $sessionName)
{
$this->initMemcached();
$session_id = session_id();
if ($session_id !== "") {
$this->initSessionData = $this->read($session_id);
}
return true;
} // open()
/**
* closing the session
*
* @return bool
*/
public function close()
{
$this->lifeTime = null;
$this->initSessionData = null;
unset($this->memcached);
return true;
} // close()
/**
* reading of the session data
* if the data couldn't be found in the Memcache, we try to load it from the
* DB we have to update the time of data expiration in the db using
* _updateDbExpiration() the life time in Memcache is updated automatically
* by write operation
*
* @param string $session_id
* @return string
*/
public function read($session_id)
{
$now = time();
$data = $this->memcached->get($this->sessionPrefix.$session_id);
$this->memcached->set($this->sessionPrefix.$session_id, $data,MEMCACHE_COMPRESSED, $this->lifeTime);
return $data ? $data : '';
} // read()
/**
* cache write - this is called when the script is about to finish,
* or when session_write_close() is called
* data are written only when something has changed
*
* @param string $session_id
* @param string $data
* @return bool
*/
public function write($session_id, $data){
// we store time of the db record expiration in the Memcache
$result = $this->memcached->set($this->sessionPrefix.$session_id, $data, MEMCACHE_COMPRESSED,$this->lifeTime);
return $result;
} // write()
/**
* destroy of the session
*
* @param string $session_id
* @return bool
*/
public function destroy($session_id){
$this->memcached->delete($this->sessionPrefix.$session_id);
return true;
} // destroy()
/**
* called by the garbage collector
*
* @param int $maxlifetime
* @return bool
*/
public function gc($maxlifetime){
return true;
} // gc()
}
Useage :
<?php
// Initialize custom session management.
new Memcached_SessionHandler();
Enjoy!
