本文實例講述了php基於session實現數據庫交互的類。分享給大家供大家參考。具體如下：
<?php
/**
* session 數據庫存儲類
*/
class Session {
private static $session_id = 0;
private static $session_data = array();
private static $is_update = FALSE;
private static $is_del = FALSE;
private static $is_gc = FALSE;
private static $dbo = NULL; //數據庫連接句柄
private static $gc_max_time = 1440;
private static $table = 'sessions';
private static $pre_key = 'weige';//session 密鑰
//捆綁使用哈
private static $gc_rate_de = 100;//代表分母
private static $gc_rate_co = 20;//代表分子
private static $path = '/';//保存路徑
private static $domain = null; //域
private static $secure = false;//默認
private static $httponly = false;//默認
/**
* 獲取數據庫句柄 私有
*/
private static function open()
{
if (!self::$dbo)
{
self::$dbo = Db::factory();
}
return TRUE;
}
/**
* 設置
* */
public static function set($key, $val=NULL)
{
self::open();
$data = self::read();
if ($data === FALSE)
{
$data = array();
}
if (!$val && is_array($key))
{
$data = $key;
}
else if ($val && is_string($key))
{
$data[$key] = $val;
}
self::write($data);
self::close();
}
/**
*獲取值
*
*/
public static function get($key=NULL) {
self::open();
self::$session_data = self::read();
$ret = '';
if (!$key) {
$ret = self::$session_data;
} else if(is_array(self::$session_data) && isset(self::$session_data[$key])) {
$ret = self::$session_data[$key];
}
self::update();
self::close();
return $ret;
}
/**
* 刪除或者重置
* */
public static function del($key)
{
if (!self::$is_del)
{
self::open();
$val = self::read();
if (isset($val[$key]))
{
unset($val[$key]);
}
$session_id = self::$session_id;
$session_data = serialize($val);
$session_expire = TIME + self::get_gc_maxtime();
self::$dbo->query("update ".self::$table." set value='$session_data', expiry='$session_expire' where session_id='$session_id'");
self::close();
}
self::$is_del = TRUE;
}
/**
* 銷毀
*
* */
public static function destroy()
{
$session_id = self::get_session_id();
$_COOKIE['WBSID'] = '';
self::open();
self::$dbo->query("delete from ".self::$table." where session_id='$session_id'");
self::close();
}
/**
* 讀取 私有
* */
private static function read()
{
$session_id = self::$session_id;
if (!$session_id) {
$session_id = self::get_session_id();
}
if (!$session_id) return array();
$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? md5($_SERVER['HTTP_USER_AGENT']) : '';
$client_ip = Fun::getIp();
$session_expire = TIME - self::get_gc_maxtime();
$rs = self::$dbo->fetchRow("select session_id, value, agent, ip from ".self::$table."
where session_id='$session_id' and expiry>'$session_expire'");
if (!$rs || $rs['agent'] != $user_agent || $rs['ip'] != $client_ip)
{
return FALSE;
}
self::$session_id = $rs['session_id'];
return unserialize($rs['value']);
}
/**
* session 寫入 私有
* */
private static function write(array $session_data)
{
$session_id = self::$session_id;
if (!$session_id)
{
$session_id = self::get_session_id();
}
$session_expire = TIME + self::get_gc_maxtime();
$user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? md5($_SERVER['HTTP_USER_AGENT']) : '';
$client_ip = Fun::getIp();
$session_data = serialize($session_data);
if (self::$session_id && self::$session_id === $session_id)
{
self::$dbo->query("update ".self::$table." set value='$session_data', expiry='$session_expire', agent='$user_agent', ip='$client_ip' where session_id='$session_id'");
}
else
{
self::$session_id = $session_id = self::create_session_id();
self::$dbo->query("insert into ".self::$table."(session_id, value, expiry, agent, ip)
values('$session_id', '$session_data', '$session_expire', '$user_agent', '$client_ip')");
}
return true;
}
/**
* session 更新 私有
* */
private static function update()
{
if (!self::$is_update)
{
$session_id = self::$session_id;
$session_expire = TIME + self::get_gc_maxtime();
self::$dbo->query("update ".self::$table." set expiry='$session_expire' where session_id='$session_id'");
}
self::$is_update = TRUE;
}
private static function close()
{
if (!self::$is_gc && mt_rand(1, self::$gc_rate_de)%self::$gc_rate_co == 0)
{
self::gc();
}
self::$is_gc = TRUE;
}
/**
* 過期session 清除 隨機觸發
* */
private static function gc()
{
$session_expire = TIME - self::get_gc_maxtime();
self::$dbo->query("delete from ".self::$table." where expiry<'$session_expire'");
}
private static function get_session_id()
{
if (isset($_COOKIE['WBSID']) && strlen($_COOKIE['WBSID'])==32)
{
$sid = $_COOKIE['WBSID'];
setcookie('WBSID', $sid, TIME + self::get_gc_maxtime(), self::$path, self::$domain, self::$secure, self::$httponly);
return $sid;
}
return null;
}
private static function create_session_id()
{
$sid = self::get_session_id();
if (!$sid)
{
$sid = Fun::getIp() . TIME . microtime(TRUE) . mt_rand(mt_rand(0, 100), mt_rand(100000, 90000000));
$sid = md5(self::$pre_key . $sid);
setcookie('WBSID', substr($sid, 0, 32), TIME + self::get_gc_maxtime(), self::$path, self::$domain, self::$secure, self::$httponly);
}
return $sid;
}
public static function get_gc_maxtime()
{
return self::$gc_max_time;
}
}
希望本文所述對大家的php程序設計有所幫助。
