CodeIgniter installed

[living-lab-site.git] / system / database / DB_cache.php

diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
new file mode 100755 (executable)
index 0000000..3bf065c
--- /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 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 */
\ No newline at end of file