Variable helper. Helps to save runtime configuration variables to file system.

[eluser]mezoni[/eluser]
This is a alfa version. Not tested.

Code:

<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
* Variable Helper
*
* @author        Inozemcev Andrew
* @copyright    Copyright (c) 2007, Inozemcev Andrew.
* @since        Version 1.0
*/

// ------------------------------------------------------------------------

/**
* @subpackage    Helpers
* @category    Helpers
* @author        Inozemcev Andrew
*/

// ------------------------------------------------------------------------

/**
* Variable Read
*
* Read array of variables from file system.
*
* @access    public
* @return    array
*/

function &variable_read()
{
    static $registered = FALSE;
    static $variables;

    if(!$registered)
    {
        register_shutdown_function('variable_write');
        $registered = TRUE;
    }

    if(is_array($variables))
    {
        return $variables;
    }

    $variables = array();

    $filepath = APPPATH . 'config/variables.cfg';

    if(!file_exists($filepath))
    {
        return $variables;
    }

    $size = filesize($filepath);

    if($size === 0)
    {
        return $variables;
    }

    if($fp = @fopen($filepath, 'r'))
    {
        flock($fp, LOCK_SH);
        $variables = unserialize(fread($fp, $size));
        flock($fp, LOCK_UN);
        fclose($fp);
    }

    return $variables;
}

// ------------------------------------------------------------------------

/**
* Variable Write
*
* Write array of variables to file system.
*
* @access    public
*/

function variable_write()
{
    $variables =& variable_read();

    if(!isset($variables['access']))
    {
        return;
    }

    $filepath = APPPATH . 'config/variables.cfg';

    $mode = file_exists($filepath) ? 'r+' : 'w+';

    if($fp = @fopen($filepath, $mode))
    {
        flock($fp, LOCK_EX);

        $size = filesize($filepath);

        if($size > 0)
        {
            $original = unserialize(fread($fp, $size));
        }

        else
        {
            $original = array();
        }

        $current =& $variables['current'];

        foreach($variables['access'] as $key => $val)
        {
            if($val === 'c')
            {
                $original[$key] = $current[$key];
            }

            elseif($val === 'd')
            {
                unset($original[$key]);
            }
        }

        ftruncate($fp, 0);
        fseek($fp, 0);
        fwrite($fp, serialize($original));
        flock($fp, LOCK_UN);
        fclose($fp);
    }

    @chmod($filename, 0666);
}

// ------------------------------------------------------------------------

/**
* Variable Get
*
* Get variable.
*
* @access    public
* @param    string
* @param    mixed
* @return    mixed
*/

function variable_get($name, $default = NULL)
{
    $variables =& variable_read();

    if(isset($variables['access'][$name]) AND $variables['access'][$name] === 'd')
    {
        return $default;
    }

    if(!isset($variables['current'][$name]))
    {
        return $default;
    }

    return $variables['current'][$name];
}

// ------------------------------------------------------------------------

/**
* Variable Set
*
* Set variable.
*
* @access    public
* @param    string
* @param    mixed
*/

function variable_set($name, $value)
{
    $variables =& variable_read();

    $variables['current'][$name] = $value;
    $variables['access'][$name] = 'c';
}

// ------------------------------------------------------------------------

/**
* Variable Delete
*
* Delete variable.
*
* @access    public
* @param    string
*/

function variable_delete($name)
{
    $variables =& variable_read();

    $variables['access'][$name] = 'd';
}

?>