1: <?php
 2: 
 3: /*
 4:  * This file is part of the Symfony package.
 5:  *
 6:  * (c) Fabien Potencier <fabien@symfony.com>
 7:  *
 8:  * For the full copyright and license information, please view the LICENSE
 9:  * file that was distributed with this source code.
10:  */
11: 
12: namespace Symfony\Component\HttpFoundation\Session\Storage\Handler;
13: 
14: /**
15:  * Wraps another SessionHandlerInterface to only write the session when it has been modified.
16:  *
17:  * @author Adrien Brault <adrien.brault@gmail.com>
18:  */
19: class WriteCheckSessionHandler implements \SessionHandlerInterface
20: {
21:     /**
22:      * @var \SessionHandlerInterface
23:      */
24:     private $wrappedSessionHandler;
25: 
26:     /**
27:      * @var array sessionId => session
28:      */
29:     private $readSessions;
30: 
31:     public function __construct(\SessionHandlerInterface $wrappedSessionHandler)
32:     {
33:         $this->wrappedSessionHandler = $wrappedSessionHandler;
34:     }
35: 
36:     /**
37:      * {@inheritdoc}
38:      */
39:     public function close()
40:     {
41:         return $this->wrappedSessionHandler->close();
42:     }
43: 
44:     /**
45:      * {@inheritdoc}
46:      */
47:     public function destroy($sessionId)
48:     {
49:         return $this->wrappedSessionHandler->destroy($sessionId);
50:     }
51: 
52:     /**
53:      * {@inheritdoc}
54:      */
55:     public function gc($maxlifetime)
56:     {
57:         return $this->wrappedSessionHandler->gc($maxlifetime);
58:     }
59: 
60:     /**
61:      * {@inheritdoc}
62:      */
63:     public function open($savePath, $sessionName)
64:     {
65:         return $this->wrappedSessionHandler->open($savePath, $sessionName);
66:     }
67: 
68:     /**
69:      * {@inheritdoc}
70:      */
71:     public function read($sessionId)
72:     {
73:         $session = $this->wrappedSessionHandler->read($sessionId);
74: 
75:         $this->readSessions[$sessionId] = $session;
76: 
77:         return $session;
78:     }
79: 
80:     /**
81:      * {@inheritdoc}
82:      */
83:     public function write($sessionId, $data)
84:     {
85:         if (isset($this->readSessions[$sessionId]) && $data === $this->readSessions[$sessionId]) {
86:             return true;
87:         }
88: 
89:         return $this->wrappedSessionHandler->write($sessionId, $data);
90:     }
91: }
92: