tims-todo/system/database/DB_cache.php

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2014-08-08 15:41:59 -04:00
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP 5.2.4 or newer
*
* NOTICE OF LICENSE
*
* Licensed under the Open Software License version 3.0
*
* This source file is subject to the Open Software License (OSL 3.0) that is
* bundled with this package in the files license.txt / license.rst. It is
* also available through the world wide web at this URL:
* http://opensource.org/licenses/OSL-3.0
* If you did not receive a copy of the license and are unable to obtain it
* through the world wide web, please send an email to
* licensing@ellislab.com so we can send you a copy immediately.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
* @license http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
* @link http://codeigniter.com
* @since Version 1.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* Database Cache Class
*
* @category Database
* @author EllisLab Dev Team
* @link http://codeigniter.com/user_guide/database/
*/
class CI_DB_Cache {
/**
* CI Singleton
*
* @var object
*/
public $CI;
/**
* Database object
*
* Allows passing of DB object so that multiple database connections
* and returned DB objects can be supported.
*
* @var object
*/
public $db;
// --------------------------------------------------------------------
/**
* Constructor
*
* @param object &$db
* @return void
*/
public function __construct(&$db)
{
// Assign the main CI object to $this->CI and load the file helper since we use it a lot
$this->CI =& get_instance();
$this->db =& $db;
$this->CI->load->helper('file');
$this->check_path();
}
// --------------------------------------------------------------------
/**
* Set Cache Directory Path
*
* @param string $path Path to the cache directory
* @return bool
*/
public function check_path($path = '')
{
if ($path === '')
{
if ($this->db->cachedir === '')
{
return $this->db->cache_off();
}
$path = $this->db->cachedir;
}
// Add a trailing slash to the path if needed
$path = realpath($path)
? rtrim(realpath($path), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR
: rtrim($path, '/').'/';
if ( ! is_dir($path))
{
log_message('debug', 'DB cache path error: '.$path);
// If the path is wrong we'll turn off caching
return $this->db->cache_off();
}
if ( ! is_really_writable($path))
{
log_message('debug', 'DB cache dir not writable: '.$path);
// If the path is not really writable we'll turn off caching
return $this->db->cache_off();
}
$this->db->cachedir = $path;
return TRUE;
}
// --------------------------------------------------------------------
/**
* Retrieve a cached query
*
* The URI being requested will become the name of the cache sub-folder.
* An MD5 hash of the SQL statement will become the cache file name.
*
* @param string $sql
* @return string
*/
public function read($sql)
{
$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql);
if (FALSE === ($cachedata = @file_get_contents($filepath)))
{
return FALSE;
}
return unserialize($cachedata);
}
// --------------------------------------------------------------------
/**
* Write a query to a cache file
*
* @param string $sql
* @param object $object
* @return bool
*/
public function write($sql, $object)
{
$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';
$filename = md5($sql);
if ( ! is_dir($dir_path))
{
if ( ! @mkdir($dir_path, 0777))
{
return FALSE;
}
@chmod($dir_path, 0777);
}
if (write_file($dir_path.$filename, serialize($object)) === FALSE)
{
return FALSE;
}
@chmod($dir_path.$filename, 0666);
return TRUE;
}
// --------------------------------------------------------------------
/**
* Delete cache files within a particular directory
*
* @param string $segment_one
* @param string $segment_two
* @return void
*/
public function delete($segment_one = '', $segment_two = '')
{
if ($segment_one === '')
{
$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
}
if ($segment_two === '')
{
$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
}
$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';
delete_files($dir_path, TRUE);
}
// --------------------------------------------------------------------
/**
* Delete all existing cache files
*
* @return void
*/
public function delete_all()
{
delete_files($this->db->cachedir, TRUE, TRUE);
}
}
/* End of file DB_cache.php */
/* Location: ./system/database/DB_cache.php */