<?php

/**
* this class provide a function like session handling engine
* @author Logan Cai (cailongqun [at] yahoo [dot] com [dot] cn)
* @link www.phpletter.com
* @since 22/May/2007
*
*/

require_once(dirname(__FILE__) . DIRECTORY_SEPARATOR . "class.file.php");
class Session
{
var $lifeTime;
var $fp = null;
var $dir = null;
var $mTime = null;
var $sessionDir = null;
var $sessionFile = null;
var $ext = '.txt';
var $gcCounter = 5; //call gc to delete expired session each ten request
var $gcCounterFileName = 'gc_counter.ajax.php';
var $gcCounterFile = null;
var $gcLogFileName = 'gc_log.ajax.php';
var $gcLogFile = null;
var $debug = true; //turn it on when you want to see gc log


/**
* constructor
*
*/
function __construct()
{
//check if the session folder read and writable
$dir = new file();
if(!file_exists(CONFIG_SYS_DIR_SESSION_PATH))
{
if(!$dir->mkdir(CONFIG_SYS_DIR_SESSION_PATH))
{
die('Unable to create session folder.');
}
}
if(!$dir->isReadable(CONFIG_SYS_DIR_SESSION_PATH))
{
die('Permission denied: ' . CONFIG_SYS_DIR_SESSION_PATH . " is not readable.");
}
if(!$dir->isWritable(CONFIG_SYS_DIR_SESSION_PATH))
{
die('Permission denied: ' . CONFIG_SYS_DIR_SESSION_PATH . " is not writable.");
}
$this->dir = backslashToSlash(addTrailingSlash(CONFIG_SYS_DIR_SESSION_PATH));
$this->lifeTime = get_cfg_var("session.gc_maxlifetime");
$this->gcCounterFile = $this->dir . $this->gcCounterFileName;
$this->gcLogFile = $this->dir . $this->gcLogFileName;
$this->sessionDir = backslashToSlash($this->dir.session_id().DIRECTORY_SEPARATOR);
$this->init();
}
/**
* constructor
*
*/
function Session()
{
$this->__construct();
}
/**
* session init
* @return boolean
*/
function init()
{



}

function gc()
{
//init the counter file
$fp = @fopen($this->gcCounterFile, 'a+');
if($fp)
{
$count = intval(fgets($fp, 999999)) + 1;
if($count > $this->gcCounter || rand(0, 23) == date('h'))
{
$this->_gc();
$count = 0;
}
@ftruncate($fp, 0);
if(!@fputs($fp, $count))
{
die(SESSION_COUNTER_FILE_WRITE_FAILED);
}
@fclose($fp);
}else
{
die(SESSION_COUNTER_FILE_CREATE_FAILED);
}
}

/**
* garbage collection function
*
*/
function _gc()
{
//remove expired file from session folder
$dirHandler = @opendir($this->dir);
$output = '';
$output .= "gc start at " . date('d/M/Y H:i:s') . "\n";
$fo = new file();
if($dirHandler)
{
while(false !== ($file = readdir($dirHandler)))
{
if($file != '.' && $file != '..' && $file != $this->gcCounterFileName && $file != $this->gcLogFileName && $file != session_id() )
{
$path=$this->dir.$file;
$output .= $path ;
//check if this is a expired session file
if(filemtime($path) + $this->lifeTime < time())
{
if($fo->delete($path))
{
$output .= ' Deleted at ' . date('d/M/Y H:i:s');
}else
{
$output .= " Failed at " . date('d/M/Y H:i:s');
}
}
$output .= "\n";

}
}
if($this->debug)
{
$this->_log($output);
}

@closedir($dirHandler);

}
if(CONFIG_SYS_DEMO_ENABLE)
{
//remove expired files from uploaded folder
$dirHandler = @opendir(CONFIG_SYS_ROOT_PATH);
$output = '';
$output .= "gc start at " . date('d/M/Y H:i:s') . "\n";
$fo = new file();
if($dirHandler)
{
while(false !== ($file = readdir($dirHandler)))
{
if($file != '.' && $file != '..')
{
$path=CONFIG_SYS_ROOT_PATH.$file;
$output .= $path ;
//check if this is a expired session file
if(filemtime($path) + $this->lifeTime < time())
{
if($fo->delete($path))
{
$output .= ' Deleted at ' . date('d/M/Y H:i:s');
}else
{
$output .= " Failed at " . date('d/M/Y H:i:s');
}
}
$output .= "\n";

}
}
if($this->debug)
{
$this->_log($output);
}

@closedir($dirHandler);

}
}

}
/**
* log action taken by the gc
*
* @param unknown_type $msg
*/
function _log($msg)
{
$msg = "<?php die(); ?>\n" . $msg;
$fp = @fopen($this->gcLogFile, 'w+');
if($fp)
{
@ftruncate($fp, 0);
!@fputs($fp, $msg);
@fclose($fp);
}
}

/**
* get the current session directory
*
* @return string return empty if failed
*/
function getSessionDir()
{
if(!file_exists($this->sessionDir) && !is_dir($this->sessionDir))
{
$dir = new file();
if(!$dir->mkdir($this->sessionDir))
{
return '';
}
}else
{
if(!@is_dir($this->sessionDir))
{
return '';
}
}
return $this->sessionDir;
}



}
?>