利用Memcached在php下实现session机制 替换PHP的原生session支持

<?php //memcached服务器连接地址 $_MEMCACHEAUTH = array( 'host' => 'localhost' , 'port' => 11211 ); /* 获取一些初始化设置值 */ $_SESSION_NAME = ini_get("session.name"); //sessionid的名称 $_SESSION_TIME = ini_get("session.cookie_lifetime"); //sessionid这个cookie的最大保存时间 $_SESSION_EXPIRE = ini_get("session.gc_maxlifetime"); //session键值对在memcached里面的过期时间 $_SESSION_MEMKEY = ""; //sessionid值 /* 自定义的_session_start()方法，替换PHP的原生session_start()方法 逻辑应该是比较清楚的 */ function _session_start() { global $_SESSION_NAME, $_SESSION_TIME, $_SESSION_MEMKEY; global $_SESSION; global $_MEMCACHEAUTH, $_sessionmem; $_sessionmem = memcache_connect($_MEMCACHEAUTH['host'], $_MEMCACHEAUTH['port']); if ( empty($_COOKIE[$_SESSION_NAME]) ) { $_SESSION_MEMKEY = md5( uniqid() ); setcookie($_SESSION_NAME, $_SESSION_MEMKEY , $_SESSION_TIME, "/"); $_SESSION = array(); } else { $_SESSION_MEMKEY = $_COOKIE[$_SESSION_NAME]; $_SESSION = memcache_get($_sessionmem, $_SESSION_MEMKEY ); if ( $_SESSION === FALSE ) { $_SESSION = array(); } } //注册一个handler，这个函数会在页面执行完的时候执行 register_shutdown_function("_session_save_handler"); } /* 页面最后执行的方法，用于保存session值，以及关闭memcached连接 */ function _session_save_handler() { global $_sessionmem; global $_SESSION, $_SESSION_NAME, $_SESSION_EXPIRE, $_SESSION_MEMKEY; memcache_set($_sessionmem, $_SESSION_MEMKEY, $_SESSION, 0, $_SESSION_EXPIRE); memcache_close($_sessionmem); } ?>