<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); /** * CodeIgniter * * An open source application development framework for PHP 5.1.6 or newer * * @package CodeIgniter * @author ExpressionEngine Dev Team * @copyright Copyright (c) 2008 - 2011, EllisLab, Inc. * @license http://codeigniter.com/user_guide/license.html * @link http://codeigniter.com * @since Version 1.0 * @filesource */ // ------------------------------------------------------------------------ /** * Database Cache Class * * @category Database * @author ExpressionEngine Dev Team * @link http://codeigniter.com/user_guide/database/ */ class CI_DB_Cache { var $CI; var $db; // allows passing of db object so that multiple database connections and returned db objects can be supported /** * Constructor * * Grabs the CI super object instance so we can access it. * */ function CI_DB_Cache(&$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; $this->CI->load->helper('file'); } // -------------------------------------------------------------------- /** * Set Cache Directory Path * * @access public * @param string the path to the cache directory * @return bool */ function check_path($path = '') { if ($path == '') { if ($this->db->cachedir == '') { return $this->db->cache_off(); } $path = $this->db->cachedir; } // Add a trailing slash to the path if needed $path = preg_replace("/(.+?)\/*$/", "\\1/", $path); if ( ! is_dir($path) OR ! is_really_writable($path)) { // If the path is wrong we'll turn off caching return $this->db->cache_off(); } $this->db->cachedir = $path; return TRUE; } // -------------------------------------------------------------------- /** * Retrieve a cached query * * The URI being requested will become the name of the cache sub-folder. * An MD5 hash of the SQL statement will become the cache file name * * @access public * @return string */ function read($sql) { if ( ! $this->check_path()) { return $this->db->cache_off(); } $segment_one = ($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 === ($cachedata = read_file($filepath))) { return FALSE; } return unserialize($cachedata); } // -------------------------------------------------------------------- /** * Write a query to a cache file * * @access public * @return bool */ function write($sql, $object) { if ( ! $this->check_path()) { return $this->db->cache_off(); } $segment_one = ($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, DIR_WRITE_MODE)) { return FALSE; } @chmod($dir_path, DIR_WRITE_MODE); } if (write_file($dir_path.$filename, serialize($object)) === FALSE) { return FALSE; } @chmod($dir_path.$filename, FILE_WRITE_MODE); return TRUE; } // -------------------------------------------------------------------- /** * 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' : $this->CI->uri->segment(1); } if ($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 * * @access public * @return bool */ function delete_all() { delete_files($this->db->cachedir, TRUE); } } /* End of file DB_cache.php */ /* Location: ./system/database/DB_cache.php */