includes/MemcachedSessions.php

   1 <?php
   2 /**
   3  * This file gets included if $wgSessionsInMemcache is set in the config.
   4  * It redirects session handling functions to store their data in memcached
   5  * instead of the local filesystem. Depending on circumstances, it may also
   6  * be necessary to change the cookie settings to work across hostnames.
   7  * See: http://www.php.net/manual/en/function.session-set-save-handler.php
   8  *
   9  * @file
  10  * @ingroup Cache
  11  */
  12
  13 /**
  14  * Get a cache key for the given session id.
  15  *
  16  * @param $id String: session id
  17  * @return String: cache key
  18  */
  19 function memsess_key( $id ) {
  20         return wfMemcKey( 'session', $id );
  21 }
  22
  23 /**
  24  * Callback when opening a session.
  25  * NOP: $wgMemc should be set up already.
  26  *
  27  * @param $save_path String: path used to store session files, unused
  28  * @param $session_name String: session name
  29  * @return Boolean: success
  30  */
  31 function memsess_open( $save_path, $session_name ) {
  32         return true;
  33 }
  34
  35 /**
  36  * Callback when closing a session.
  37  * NOP.
  38  *
  39  * @return Boolean: success
  40  */
  41 function memsess_close() {
  42         return true;
  43 }
  44
  45 /**
  46  * Callback when reading session data.
  47  *
  48  * @param $id String: session id
  49  * @return Mixed: session data
  50  */
  51 function memsess_read( $id ) {
  52         global $wgMemc;
  53         $data = $wgMemc->get( memsess_key( $id ) );
  54         if( ! $data ) return '';
  55         return $data;
  56 }
  57
  58 /**
  59  * Callback when writing session data.
  60  *
  61  * @param $id String: session id
  62  * @param $data Mixed: session data
  63  * @return Boolean: success
  64  */
  65 function memsess_write( $id, $data ) {
  66         global $wgMemc;
  67         $wgMemc->set( memsess_key( $id ), $data, 3600 );
  68         return true;
  69 }
  70
  71 /**
  72  * Callback to destroy a session when calling session_destroy().
  73  *
  74  * @param $id String: session id
  75  * @return Boolean: success
  76  */
  77 function memsess_destroy( $id ) {
  78         global $wgMemc;
  79
  80         $wgMemc->delete( memsess_key( $id ) );
  81         return true;
  82 }
  83
  84 /**
  85  * Callback to execute garbage collection.
  86  * NOP: Memcached performs garbage collection.
  87  *
  88  * @param $maxlifetime Integer: maximum session life time
  89  * @return Boolean: success
  90  */
  91 function memsess_gc( $maxlifetime ) {
  92         return true;
  93 }
  94
  95 session_set_save_handler( 'memsess_open', 'memsess_close', 'memsess_read', 'memsess_write', 'memsess_destroy', 'memsess_gc' );