diff options
Diffstat (limited to 'system/database/DB_cache.php')
| -rw-r--r-- | system/database/DB_cache.php | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php new file mode 100644 index 000000000..8b0ad4fb4 --- /dev/null +++ b/system/database/DB_cache.php @@ -0,0 +1,195 @@ +<?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 - 2009, 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, DIR_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 */
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