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<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); |
/** |
* CodeIgniter |
* |
* An open source application development framework for PHP 4.3.2 or newer |
* |
* @package CodeIgniter |
* @author ExpressionEngine Dev Team |
* @copyright Copyright (c) 2008, EllisLab, Inc. |
* @license http://codeigniter.com/user_guide/license.html |
* @link http://codeigniter.com |
* @since Version 1.0 |
* @filesource |
*/ |
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// ------------------------------------------------------------------------ |
|
/** |
* Database Cache Class |
* |
* @category Database |
* @author ExpressionEngine Dev Team |
* @link http://codeigniter.com/user_guide/database/ |
*/ |
class CI_DB_Cache { |
|
var $CI; |
var $db; // allows passing of db object so that multiple database connections and returned db objects can be supported |
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/** |
* Constructor |
* |
* Grabs the CI super object instance so we can access it. |
* |
*/ |
function CI_DB_Cache(&$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; |
$this->CI->load->helper('file'); |
} |
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// -------------------------------------------------------------------- |
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/** |
* Set Cache Directory Path |
* |
* @access public |
* @param string the path to the cache directory |
* @return bool |
*/ |
function check_path($path = '') |
{ |
if ($path == '') |
{ |
if ($this->db->cachedir == '') |
{ |
return $this->db->cache_off(); |
} |
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$path = $this->db->cachedir; |
} |
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// Add a trailing slash to the path if needed |
$path = preg_replace("/(.+?)\/*$/", "\\1/", $path); |
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if ( ! is_dir($path) OR ! is_really_writable($path)) |
{ |
// If the path is wrong we'll turn off caching |
return $this->db->cache_off(); |
} |
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$this->db->cachedir = $path; |
return TRUE; |
} |
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// -------------------------------------------------------------------- |
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/** |
* Retrieve a cached query |
* |
* The URI being requested will become the name of the cache sub-folder. |
* An MD5 hash of the SQL statement will become the cache file name |
* |
* @access public |
* @return string |
*/ |
function read($sql) |
{ |
if ( ! $this->check_path()) |
{ |
return $this->db->cache_off(); |
} |
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$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1); |
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$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2); |
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$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql); |
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if (FALSE === ($cachedata = read_file($filepath))) |
{ |
return FALSE; |
} |
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return unserialize($cachedata); |
} |
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// -------------------------------------------------------------------- |
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/** |
* Write a query to a cache file |
* |
* @access public |
* @return bool |
*/ |
function write($sql, $object) |
{ |
if ( ! $this->check_path()) |
{ |
return $this->db->cache_off(); |
} |
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$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1); |
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$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2); |
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$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'; |
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$filename = md5($sql); |
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if ( ! @is_dir($dir_path)) |
{ |
if ( ! @mkdir($dir_path, DIR_WRITE_MODE)) |
{ |
return FALSE; |
} |
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@chmod($dir_path, DIR_WRITE_MODE); |
} |
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if (write_file($dir_path.$filename, serialize($object)) === FALSE) |
{ |
return FALSE; |
} |
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@chmod($dir_path.$filename, DIR_WRITE_MODE); |
return TRUE; |
} |
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// -------------------------------------------------------------------- |
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/** |
* Delete cache files within a particular directory |
* |
* @access public |
* @return bool |
*/ |
function delete($segment_one = '', $segment_two = '') |
{ |
if ($segment_one == '') |
{ |
$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1); |
} |
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if ($segment_two == '') |
{ |
$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2); |
} |
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$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'; |
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delete_files($dir_path, TRUE); |
} |
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// -------------------------------------------------------------------- |
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/** |
* Delete all existing cache files |
* |
* @access public |
* @return bool |
*/ |
function delete_all() |
{ |
delete_files($this->db->cachedir, TRUE); |
} |
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} |
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/* End of file DB_cache.php */ |
/* Location: ./system/database/DB_cache.php */ |