system/database/DB_cache.php
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2019 - 2022, CodeIgniter Foundation
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
* @copyright Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
* @copyright Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 1.0.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* Database Cache Class
*
* @category Database
* @author EllisLab Dev Team
* @link https://codeigniter.com/userguide3/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 ( ! is_file($filepath) OR FALSE === ($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($dir_path) && ! @mkdir($dir_path, 0750))
{
return FALSE;
}
if (write_file($dir_path.$filename, serialize($object)) === FALSE)
{
return FALSE;
}
chmod($dir_path.$filename, 0640);
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);
}
}