【thinkphp3.1.x】thinkphp3.1.x中有关session存储机制的相关文件

<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

defined('THINK_PATH') or exit();
/**
* 数据库方式Session驱动
*    CREATE TABLE think_session (
*      session_id varchar(255) NOT NULL,
*      session_expire int(11) NOT NULL,
*      session_data blob,
*      UNIQUE KEY `session_id` (`session_id`)
*    );
* @category   Extend
* @package  Extend
* @subpackage  Driver.Session
* @author    liu21st <liu21st@gmail.com>
*/
class SessionDb {

/**
* Session有效时间
*/
protected $lifeTime      = '';

/**
* session保存的数据库名
*/
protected $sessionTable  = '';

/**
* 数据库句柄
*/
protected $hander  = array();

/**
* 打开Session
* @access public
* @param string $savePath
* @param mixed $sessName
*/
public function open($savePath, $sessName) {
$this->lifeTime = C('SESSION_EXPIRE')?C('SESSION_EXPIRE'):ini_get('session.gc_maxlifetime');
$this->sessionTable  =   C('SESSION_TABLE')?C('SESSION_TABLE'):C("DB_PREFIX")."session";
//分布式数据库
$host = explode(',',C('DB_HOST'));
$port = explode(',',C('DB_PORT'));
$name = explode(',',C('DB_NAME'));
$user = explode(',',C('DB_USER'));
$pwd  = explode(',',C('DB_PWD'));
if(1 == C('DB_DEPLOY_TYPE')){
//读写分离
if(C('DB_RW_SEPARATE')){
$w = floor(mt_rand(0,C('DB_MASTER_NUM')-1));
if(is_numeric(C('DB_SLAVE_NO'))){//指定服务器读
$r = C('DB_SLAVE_NO');
}else{
$r = floor(mt_rand(C('DB_MASTER_NUM'),count($host)-1));
}
//主数据库链接
$hander = mysql_connect(
$host[$w].(isset($port[$w])?':'.$port[$w]:':'.$port[0]),
isset($user[$w])?$user[$w]:$user[0],
isset($pwd[$w])?$pwd[$w]:$pwd[0]
);
$dbSel = mysql_select_db(
isset($name[$w])?$name[$w]:$name[0]
,$hander);
if(!$hander || !$dbSel)
return false;
$this->hander[0] = $hander;
//从数据库链接
$hander = mysql_connect(
$host[$r].(isset($port[$r])?':'.$port[$r]:':'.$port[0]),
isset($user[$r])?$user[$r]:$user[0],
isset($pwd[$r])?$pwd[$r]:$pwd[0]
);
$dbSel = mysql_select_db(
isset($name[$r])?$name[$r]:$name[0]
,$hander);
if(!$hander || !$dbSel)
return false;
$this->hander[1] = $hander;
return true;
}
}
//从数据库链接
$r = floor(mt_rand(0,count($host)-1));
$hander = mysql_connect(
$host[$r].(isset($port[$r])?':'.$port[$r]:':'.$port[0]),
isset($user[$r])?$user[$r]:$user[0],
isset($pwd[$r])?$pwd[$r]:$pwd[0]
);
$dbSel = mysql_select_db(
isset($name[$r])?$name[$r]:$name[0]
,$hander);
if(!$hander || !$dbSel)
return false;
$this->hander = $hander;
return true;
}

/**
* 关闭Session
* @access public
*/
public function close() {
if(is_array($this->hander)){
$this->gc($this->lifeTime);
return (mysql_close($this->hander[0]) && mysql_close($this->hander[1]));
}
$this->gc($this->lifeTime);
return mysql_close($this->hander);
}

/**
* 读取Session
* @access public
* @param string $sessID
*/
public function read($sessID) {
$hander = is_array($this->hander)?$this->hander[1]:$this->hander;
$res = mysql_query("SELECT session_data AS data FROM ".$this->sessionTable." WHERE session_id = '$sessID'   AND session_expire >".time(),$hander);
if($res) {
$row = mysql_fetch_assoc($res);
return $row['data'];
}
return "";
}

/**
* 写入Session
* @access public
* @param string $sessID
* @param String $sessData
*/
public function write($sessID,$sessData) {
$hander = is_array($this->hander)?$this->hander[0]:$this->hander;
$expire = time() + $this->lifeTime;
mysql_query("REPLACE INTO  ".$this->sessionTable." (  session_id, session_expire, session_data)  VALUES( '$sessID', '$expire',  '$sessData')",$hander);
if(mysql_affected_rows($hander))
return true;
return false;
}

/**
* 删除Session
* @access public
* @param string $sessID
*/
public function destroy($sessID) {
$hander = is_array($this->hander)?$this->hander[0]:$this->hander;
mysql_query("DELETE FROM ".$this->sessionTable." WHERE session_id = '$sessID'",$hander);
if(mysql_affected_rows($hander))
return true;
return false;
}

/**
* Session 垃圾回收
* @access public
* @param string $sessMaxLifeTime
*/
public function gc($sessMaxLifeTime) {
$hander = is_array($this->hander)?$this->hander[0]:$this->hander;
mysql_query("DELETE FROM ".$this->sessionTable." WHERE session_expire < ".time(),$hander);
return mysql_affected_rows($hander);
}

/**
* 打开Session
* @access public
*/
public function execute() {
session_set_save_handler(array(&$this,"open"),
array(&$this,"close"),
array(&$this,"read"),
array(&$this,"write"),
array(&$this,"destroy"),
array(&$this,"gc"));
}
}