<?php
/**
 * MySQLSessionHandler.inc.php
 * Code by Strangecode :: www.strangecode.com :: This document contains copyrighted information.
 * @author  Quinn Comendant <quinn@strangecode.com>
 * @version 1.1
 * @since   1999
 */

 
/*
DROP TABLE IF EXISTS session_tbl;
CREATE TABLE session_tbl (
    session_id char(32) NOT NULL default '',
    session_data mediumtext NOT NULL,
    last_access timestamp(14) NOT NULL,
    PRIMARY KEY (session_id),
    KEY last_access (last_access)
) TYPE=MyISAM;
*/

function mysqlSessionOpen($save_path, $sess_name)
{
    global $sess_mysql;

    if (!isset($sess_mysql['dbh']) && (!isset($sess_mysql['hostname']) || !isset($sess_mysql['user']) || !isset($sess_mysql['password']) || !isset($sess_mysql['db']) || !isset($sess_mysql['table']))) {
        trigger_error('mysqlSessionOpen(): Database session handling global variables not specified.', E_USER_WARNING); 
    }

    // Connect and select.
    if (!$sess_mysql['dbh']) {
        $sess_mysql['dbh'] = @mysql_connect($sess_mysql['hostname'], $sess_mysql['user'], $sess_mysql['password']);
    }
    @mysql_select_db($sess_mysql['db'], $sess_mysql['dbh']);
    
    // Check for errors
    if (mysql_error($sess_mysql['dbh'])) {
        trigger_error('mysqlSessionOpen(): Cannot connect to database. ' . mysql_error($sess_mysql['dbh']), E_USER_WARNING); 
        return false; 
    }
    return true; 
}

function mysqlSessionClose()
{
    return true;
}

function mysqlSessionRead($session_id)
{
    global $sess_mysql;
    
    // Select the data belonging to session $session_id from the MySQL session table    
    $qid = mysql_query("SELECT session_data FROM " . $sess_mysql['table'] . " WHERE session_id = '" . mysql_real_escape_string($session_id) . "'", $sess_mysql['dbh']);
    
    // Check for errors
    if (mysql_error($sess_mysql['dbh'])) { 
        trigger_error('mysqlSessionRead(): Failed to read sessions.' . mysql_error($sess_mysql['dbh']), E_USER_WARNING); 
        return ''; 
    }
    
    // Return the session data that was found
    if (mysql_num_rows($qid) == 1) {
        $row = mysql_fetch_row($qid);
        return $row[0];
    }
    
    // NOTICE: Output is expected to be an empty string always rather than 'false'.
    return '';
}

function mysqlSessionWrite($session_id, $session_data)
{
    global $sess_mysql;
    
    // Write the serialized session data ($session_data) to the MySQL session table
    mysql_query("REPLACE INTO " . $sess_mysql['table'] . "(session_id, session_data, last_access) VALUES ('" . mysql_real_escape_string($session_id) . "', '" . mysql_real_escape_string($session_data) . "', null)", $sess_mysql['dbh']);
    
    // Check for errors
    if (mysql_error($sess_mysql['dbh'])) { 
        trigger_error('mysqlSessionWrite(): Failed to write session. ' . mysql_error($sess_mysql['dbh']), E_USER_WARNING); 
        return false; 
    }
        
    return true;     
}

function mysqlSessionDestroy($session_id)
{
    global $sess_mysql;

    // Delete from the MySQL table all data for the session $session_id
    mysql_query("DELETE FROM " . $sess_mysql['table'] . " WHERE session_id = '" . mysql_real_escape_string($session_id) . "'", $sess_mysql['dbh']);
            
    // Check for errors
    if (mysql_error($sess_mysql['dbh'])) { 
        trigger_error('mysqlSessionDestroy(): Failed to delete old session. ' . mysql_error($sess_mysql['dbh']), E_USER_WARNING); 
        return false; 
    }

    return true;     
}

function mysqlSessionGarbage($max_lifetime=4000)
{
    global $sess_mysql;

    // Delete old values from the MySQL session table
    $qid = mysql_query("DELETE FROM " . $sess_mysql['table'] . " WHERE UNIX_TIMESTAMP(last_access) < " . (time() - $max_lifetime), $sess_mysql['dbh']);
            
    // Check for errors
    if (mysql_error($sess_mysql['dbh'])) { 
        trigger_error('mysqlSessionGarbage(): Failed to delete old session. ' . mysql_error($sess_mysql['dbh']), E_USER_WARNING); 
        return false; 
    }
        
    return true;     
}


?>