java多线程    Java入门    vsftp    ftp    linux配置    centos    FRP教程    HBase    Html5缓存    webp    zabbix    分布式    neo4j图数据库    

php session session_set_save_handler 机制

发表于 2017-01-05 08:22:22 by 月小升

php自身带功能，将session的数据从之前的files 改变到其他任何地方。比如mysql redis等等，方便你分布式的集群应用。
看一下原理

<?php  
    /** 
     *Session open (called by session_start( )) 
     *Session close (called at page end) 
     *Session read (called after session_start( ) ) 
     *Session write (called when session data is to be written) 
     *Session destroy (called by session_destroy( ) ) 
     *Session garbage collect (called randomly) 
     */  
    function sess_open($sess_path, $sess_name) {  
            print "Session opened.\n";  
            print "Sess_path: $sess_path\n";  
            print "Sess_name: $sess_name\n\n";  
            return true;  
    }  
 
    function sess_close( ) {  
            print "Session closed.\n";  
            return true;  
    }  
 
    function sess_read($sess_id) {  
            print "Session read.\n";  
            print "Sess_ID: $sess_id\n";  
            return '';  
    }  
 
    function sess_write($sess_id, $data) {  
            print "Session value written.\n";  
            print "Sess_ID: $sess_id\n";  
            print "Data: $data\n\n";  
            return true;  
    }  
 
    function sess_destroy($sess_id) {  
            print "Session destroy called.\n";  
            return true;  
    }  
 
    function sess_gc($sess_maxlifetime) {  
            print "Session garbage collection called.\n";  
            print "Sess_maxlifetime: $sess_maxlifetime\n";  
            return true;  
    }  
 
    session_set_save_handler("sess_open", "sess_close", "sess_read",  
                    "sess_write", "sess_destroy", "sess_gc");  
    session_start( );  
 
    $_SESSION['foo'] = "bar";  
    print "Some text\n";  
    $_SESSION['baz'] = "wombat";  
?>
<?php   
 
/*
在使用session前 
将之前的session_start（）
改成 require_once("session.class.php");
*/
$SESS_DBHOST = "localhost"; /* database server hostname */   
$SESS_DBNAME = "bigclient"; /* database name */   
$SESS_DBUSER = "urldb"; /* database user */   
$SESS_DBPASS = "123456"; /* database password */   
 
$SESS_DBH = "";   
$SESS_LIFE = get_cfg_var("session.gc_maxlifetime");   
 
function sess_open($save_path, $session_name) {   
    global $SESS_DBHOST, $SESS_DBNAME, $SESS_DBUSER, $SESS_DBPASS, $SESS_DBH;   
 
    if (! $SESS_DBH = @mysql_pconnect($SESS_DBHOST, $SESS_DBUSER, $SESS_DBPASS)) {   
        echo "<li>Can't connect to $SESS_DBHOST as $SESS_DBUSER";   
        echo "<li>MySQL Error: " . mysql_error();   
        die;   
    }   
 
    if (! mysql_select_db($SESS_DBNAME, $SESS_DBH)) {   
        echo "<li>Unable to select database $SESS_DBNAME";   
        die;   
    }   
 
    return true;   
}   
 
function sess_close() {   
    return true;   
}   
 
function sess_read($key) {   
    global $SESS_DBH, $SESS_LIFE;   
 
    $qry = "SELECT value FROM session_tbl WHERE sesskey = '$key' AND expiry > " . time();   
    $qid = mysql_query($qry, $SESS_DBH);   
 
    if (list($value) = mysql_fetch_row($qid)) {   
        return $value;   
    }   
 
    return false;   
}   
 
function sess_write($key, $val) {   
    global $SESS_DBH, $SESS_LIFE;   
 
    $expiry = time() + $SESS_LIFE; //过期时间   
    $value = addslashes($val);   
 
    $qry = "INSERT INTO session_tbl VALUES ('$key', $expiry, '$value')";   
    $qid = mysql_query($qry, $SESS_DBH);   
 
    if (! $qid) {   
        $qry = "UPDATE session_tbl SET expiry = $expiry, value = '$value' WHERE sesskey = '$key' AND expiry > " . time();   
        $qid = mysql_query($qry, $SESS_DBH);   
    }   
 
    return $qid;   
}   
 
function sess_destroy($key) {   
    global $SESS_DBH;   
 
    $qry = "DELETE FROM session_tbl WHERE sesskey = '$key'";   
    $qid = mysql_query($qry, $SESS_DBH);   
 
    return $qid;   
}   
 
function sess_gc($maxlifetime) {   
    global $SESS_DBH;   
 
    $qry = "DELETE FROM session_tbl WHERE expiry < " . time();   
    $qid = mysql_query($qry, $SESS_DBH);   
 
    return mysql_affected_rows($SESS_DBH);   
}   
 
session_set_save_handler(   
"sess_open",   
"sess_close",   
"sess_read",   
"sess_write",   
"sess_destroy",   
"sess_gc");   
 
session_start();   
 
?>

使用方法：
在使用session前
将之前的session_start（）
改成

 require_once("session.class.php");
CREATE TABLE IF NOT EXISTS `session_tbl` (
  `sesskey` varchar(255) NOT NULL,
  `expiry` varchar(255) NOT NULL,
  `value` varchar(255) NOT NULL,
  UNIQUE KEY `sesskey_2` (`sesskey`),
  KEY `sesskey` (`sesskey`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

This entry was posted in PHP and tagged , , . Bookmark the permalink.
月小升QQ 2651044202, 技术交流QQ群 178491360
首发地址：月小升博客 – https://java-er.com/blog/php-session-session_set_save_handler/
无特殊说明，文章均为月小升原创，欢迎转载，转载请注明本文地址，谢谢
您的评论是我写作的动力.

Leave a Reply

Your email address will not be published. Required fields are marked *

*

*

  

  

近期文章

  1. 软件概要设计和详细设计的区别
  2. Spring AOP理解
  3. Spring IOC的理解
  4. Java的双亲委派模型
  5. JVM中引用的分类
  6. 柔性事务是什么，分布式环境为何要放弃传统事务
  7. Spring循环依赖如何解决的
  8. 程序员如何赚钱，财富自由
  9. Java的动态代理和静态代理
  10. Java是值传递还是引用传递

标签

    Android Apache cookie frp FTP google HBase html5 iphone java java基础教程 java教程 jQuery linux Linux命令 mac mac软件 MongoDB mysql neo4j nginx nosql php php-fpm php函数 python redis shell SVN swift Ubuntu Windows wordpress wordpress插件 xcode zabbix 值得记忆 图片 多线程 密码 插件 数据库 日志 服务器 缓存

分类

  1. JAVA
  2. Linux
  3. MAC
  4. Perl
  5. PHP
  6. Python
  7. WEB前端
  8. Windows
  9. 互联网观察
  10. 吐槽
  11. 技术管理
  12. 数学与算法
  13. 数据库
  14. 日常随笔
  15. 月小升软件
  16. 电商运营
  17. 科技精品
  18. 程序视点
  19. 网络推广
  20. 运营
  21. 阅读笔记
  22. 高并发与大数据