register_shutdown_function
在 init.php 文件中引入了 cls_session.php 类文件，然后实例化，代码如下：
/* 初始化session */
require(ROOT_PATH . 'includes/cls_session.php');
$sess = new cls_session($db, $ecs->table('sessions'), $ecs->table('sessions_data'),'ECSCP_ID');
传递的参数主要是： 数据库对象，session表，session历史表，session名字，sessionID
cls_session.php 类说明如下
<?php
if (!defined('IN_ECS')) {
die('Hacking attempt');
}
class cls_session {
var $db = NULL; # 数据库连接
var $session_table = ''; # Session 表
var $max_life_time = 144000; # SESSION 生存时间
var $session_name = ''; # Session 名称
var $session_id = ''; # Session ID
var $session_expiry = ''; # Session 过期时间
var $session_md5 = ''; # Session md5值
var $session_cookie_path = '/'; # Session 保存的 Cookie 路径
var $session_cookie_domain = ''; # Session 保存的 Cookie 域名
var $session_cookie_secure = false; # Session 保存的 Cookie 安全域
var $_ip = ''; # IP地址
var $_time = 0; # 当前时间
# PHP5的构造函数,用于创建一个SESSION对象,为了保证对PHP4的兼容,其实是在该函数
function __construct(&$db, $session_table, $session_data_table, $session_name = 'ECS_ID', $session_id = '') {
$this->cls_session($db, $session_table, $session_data_table, $session_name, $session_id);
}
function cls_session(&$db, $session_table, $session_data_table, $session_name = 'ECS_ID', $session_id = '') {
// 将系统自带的$_SESSION初始化为一个空数组并放进全局函数里
$GLOBALS['_SESSION'] = array();
//根据配置文件设置相关的类属性
if (!empty($GLOBALS['cookie_path'])) {
$this->session_cookie_path = $GLOBALS['cookie_path'];
} else {
$this->session_cookie_path = '/';
}
if (!empty($GLOBALS['cookie_domain'])) {
$this->session_cookie_domain = $GLOBALS['cookie_domain'];
} else {
$this->session_cookie_domain = '';
}
# 这里稍微提一下,如果你使用的是HTTPS连接,那么这里需要设置为true
if (!empty($GLOBALS['cookie_secure'])) {
$this->session_cookie_secure = $GLOBALS['cookie_secure'];
} else {
$this->session_cookie_secure = false;
}
$this->session_name = $session_name;
$this->session_table = $session_table;
$this->session_data_table = $session_data_table;
$this->db = &$db;
$this->_ip = real_ip();
# 如果没有传递 Session ID ，就检查 cookie 中是否保存了
if ($session_id == '' && !empty($_COOKIE[$this->session_name])) {
$this->session_id = $_COOKIE[$this->session_name];
} else {
$this->session_id = $session_id;
}
# 如果存在 Session ID，则判断是否与加密的SessionID一样
# 如果COOKIE中已经存在session_id,取他的前32位做CRC32位校检保证值的正确性
if ($this->session_id) {
$tmp_session_id = substr($this->session_id, 0, 32);
if ($this->gen_session_key($tmp_session_id) == substr($this->session_id, 32)) {
$this->session_id = $tmp_session_id;
} else {
$this->session_id = '';
}
}
$this->_time = time();
# 如果存在Session_id 就调用加载方法，否则就重新生成，并保存到 Cookie中
if ($this->session_id) {
# 从数据库中取对应session_id的记录保存到$_SESSION中
$this->load_session();
} else {
# 如果COOKIE中无值或者没能通过校检则创建一个全新且唯一的session_id
$this->gen_session_id();
# 写COOKIE
setcookie(
$this->session_name,
$this->session_id . $this->gen_session_key($this->session_id),
time()+86400*7,
$this->session_cookie_path,
$this->session_cookie_domain,
$this->session_cookie_secure
);
}
register_shutdown_function(array(&$this, 'close_session'));
}
/** 生成一个唯一的session_id，并插入到数据库 */
function gen_session_id() {
$this->session_id = md5(uniqid(mt_rand(), true));
return $this->insert_session();
}
/** 对COOKIE中的session_id做CRC32校检 */
function gen_session_key($session_id) {
static $ip = '';
if ($ip == '') {
$ip = substr($this->_ip, 0, strrpos($this->_ip, '.'));
}
return sprintf('%08x', crc32(ROOT_PATH . $ip . $session_id));
}
/** 如果数据库中对应COOKIE内session_id的记录已经不存在,则创建一条对应的空记录 */
function insert_session() {
$sql = 'INSERT INTO ' . $this->session_table . " (sesskey, expiry, ip, data) VALUES ('" . $this->session_id . "', '". $this->_time ."', '". $this->_ip ."', 'a:0:{}')";
return $this->db->query($sql);
}
/** 检索对应session_id的记录,如果不存在则创建一条空记录 */
function load_session() {
$sSql = 'SELECT userid, adminid, user_name, user_rank, discount, email, data, expiry FROM ' . $this->session_table . " WHERE sesskey = '" . $this->session_id . "'";
$session = $this->db->getRow($sSql);
# 如果没有查询到相应的session,就重新初始化
if (empty($session)) {
$this->insert_session();
$this->session_expiry = 0;
$this->session_md5 = '40cd750bba9870f18aada2478b24840a';
$GLOBALS['_SESSION'] = array();
} else {
// 如果Session中的data不是空的，且未过期
if (!empty($session['data']) && $this->_time - $session['expiry'] <= $this->max_life_time) {
$this->session_expiry = $session['expiry'];
// 对记录的值做一个MD5校检,以检测后边SESSION值是否发生变化
$this->session_md5 = md5($session['data']);
// 反序列化$session['data']将值存到$_SESSION中
$GLOBALS['_SESSION'] = unserialize($session['data']);
$GLOBALS['_SESSION']['user_id'] = $session['userid'];
$GLOBALS['_SESSION']['admin_id'] = $session['adminid'];
$GLOBALS['_SESSION']['user_name'] = $session['user_name'];
$GLOBALS['_SESSION']['user_rank'] = $session['user_rank'];
$GLOBALS['_SESSION']['discount'] = $session['discount'];
$GLOBALS['_SESSION']['email'] = $session['email'];
} else {
// 如果Session中的data是空的，则SESSION_DATA_TABLE表查询相应的Session记录
$session_data = $this->db->getRow('SELECT data, expiry FROM ' . $this->session_data_table . " WHERE sesskey = '" . $this->session_id . "'");
// 在SESSION_DATA_TABLE表中有数据且没有过期，则做相关赋值
if (!empty($session_data['data']) && $this->_time - $session_data['expiry'] <= $this->max_life_time) {
$this->session_expiry = $session_data['expiry'];
// 对记录的值做一个MD5校检,以检测后边SESSION值是否发生变化
$this->session_md5 = md5($session_data['data']);
// 反序列化$session['data']将值存到$_SESSION中
$GLOBALS['_SESSION'] = unserialize($session_data['data']);
$GLOBALS['_SESSION']['user_id'] = $session['userid'];
$GLOBALS['_SESSION']['admin_id'] = $session['adminid'];
$GLOBALS['_SESSION']['user_name'] = $session['user_name'];
$GLOBALS['_SESSION']['user_rank'] = $session['user_rank'];
$GLOBALS['_SESSION']['discount'] = $session['discount'];
$GLOBALS['_SESSION']['email'] = $session['email'];
} else {
$this->session_expiry = 0;
$this->session_md5 = '40cd750bba9870f18aada2478b24840a';
$GLOBALS['_SESSION'] = array();
}
}
}
}
/** 更新Session 操作 */
function update_session() {
$adminid = !empty($GLOBALS['_SESSION']['admin_id']) ? intval($GLOBALS['_SESSION']['admin_id']) : 0;
$userid = !empty($GLOBALS['_SESSION']['user_id']) ? intval($GLOBALS['_SESSION']['user_id']) : 0;
$user_name = !empty($GLOBALS['_SESSION']['user_name']) ? trim($GLOBALS['_SESSION']['user_name']) : 0;
$user_rank = !empty($GLOBALS['_SESSION']['user_rank']) ? intval($GLOBALS['_SESSION']['user_rank']) : 0;
$discount = !empty($GLOBALS['_SESSION']['discount']) ? round($GLOBALS['_SESSION']['discount'], 2) : 0;
$email = !empty($GLOBALS['_SESSION']['email']) ? trim($GLOBALS['_SESSION']['email']) : 0;
unset($GLOBALS['_SESSION']['admin_id']);
unset($GLOBALS['_SESSION']['user_id']);
unset($GLOBALS['_SESSION']['user_name']);
unset($GLOBALS['_SESSION']['user_rank']);
unset($GLOBALS['_SESSION']['discount']);
unset($GLOBALS['_SESSION']['email']);
$data = serialize($GLOBALS['_SESSION']);
$this->_time = time();
// 如果页面上SESSION的值没有发生变化并且最后一次SESSION更新时间距离当前时间小于10秒则跳出函数
if ($this->session_md5 == md5($data) && $this->_time < $this->session_expiry + 10) {
return true;
}
// 转义SESSION的值用于安全入库
$data = addslashes($data);
# 如果data 超过255个字符就把数据移动到 session_data_table 表,并清空
if (isset($data{255})) {
$this->db->autoReplace($this->session_data_table, array('sesskey' => $this->session_id, 'expiry' => $this->_time, 'data' => $data), array('expiry' => $this->_time,'data' => $data));
$data = '';
}
// 更新SESSION个字段的值,主要作用是更新expiry这个字段,以此来判断用户是否处于活动状态
$uSql = 'UPDATE ' . $this->session_table . " SET expiry = '" . $this->_time . "', ip = '" . $this->_ip . "', userid = '" . $userid . "', adminid = '" . $adminid . "', user_name='" . $user_name . "', user_rank='" . $user_rank . "', discount='" . $discount . "', email='" . $email . "', data = '$data' WHERE sesskey = '" . $this->session_id . "' LIMIT 1";
return $this->db->query($uSql);
}
/** register_shutdown_function将调用这个函数进行SESSION的更新和删除过期数据的操作 */
function close_session() {
# 更新 Session
$this->update_session();
# 清除过期的会话，并优化表
if (mt_rand(0, 2) == 2) {
$this->db->query('DELETE FROM ' . $this->session_data_table . ' WHERE expiry < ' . ($this->_time - $this->max_life_time));
$this->db->query('OPTIMIZE TABLE ' . $this->session_table);
}
if ((time() % 2) == 0) {
$this->db->query('DELETE FROM ' . $this->session_table . ' WHERE expiry < ' . ($this->_time - $this->max_life_time));
return $this->db->query('OPTIMIZE TABLE ' . $this->session_table);
}
return true;
}
// 清除指定管事员的session会话
function delete_spec_admin_session($adminid) {
if (!empty($GLOBALS['_SESSION']['admin_id']) && $adminid) {
return $this->db->query('DELETE FROM ' . $this->session_table . " WHERE adminid = '$adminid'");
} else {
return false;
}
}
// 清空$_SESSION
function destroy_session() {
# 此处清除了所有的SESSION，如果在同一个浏览器中登陆了商家后台与总后台，一个退出就全部退出了
$GLOBALS['_SESSION'] = array();
$this->db->query('DELETE FROM ' . $this->session_data_table . " WHERE sesskey = '" . $this->session_id . "' LIMIT 1");
$this->db->query('DELETE FROM ' . $this->session_table . " WHERE sesskey = '" . $this->session_id . "' LIMIT 1");
return $this->db->query('OPTIMIZE TABLE ' . $this->session_table);
}
// 返回Session ID
function get_session_id() {
return $this->session_id;
}
// 统计在线活动用户
function get_users_count() {
return $this->db->getOne('SELECT count(*) FROM ' . $this->session_table);
}
}