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-rw-r--r--system/database/DB_cache.php187
1 files changed, 187 insertions, 0 deletions
diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
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+<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * Code Igniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package CodeIgniter
+ * @author Rick Ellis
+ * @copyright Copyright (c) 2006, pMachine, Inc.
+ * @license http://www.codeignitor.com/user_guide/license.html
+ * @link http://www.codeigniter.com
+ * @since Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * Database Cache Class
+ *
+ * @category Database
+ * @author Rick Ellis
+ * @link http://www.codeigniter.com/user_guide/database/
+ */
+class CI_DB_Cache {
+
+ var $obj;
+
+ /**
+ * Constructor
+ *
+ * Grabs the CI super object instance so we can access it.
+ *
+ */
+ function CI_DB_Cache()
+ {
+ // Assign the main CI object to $this->obj
+ // and load the file helper since we use it a lot
+ $this->obj =& get_instance();
+ $this->obj->load->helper('file');
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Set Cache Directory Path
+ *
+ * @access public
+ * @param string the path to the cache directory
+ * @return bool
+ */
+ function check_path($path = '')
+ {
+ if ($path == '')
+ {
+ if ($this->obj->db->cachedir == '')
+ {
+ return $this->obj->db->cache_off();
+ }
+
+ $path = $this->obj->db->cachedir;
+ }
+
+ // Add a trailing slash to the path if needed
+ $path = preg_replace("/(.+?)\/*$/", "\\1/", $path);
+
+ if ( ! is_dir($path) OR ! is_writable($path))
+ {
+ if ($this->obj->db->db_debug)
+ {
+ return $this->obj->db->display_error('db_invalid_cache_path');
+ }
+
+ // If the path is wrong we'll turn off caching
+ return $this->obj->db->cache_off();
+ }
+
+ $this->obj->db->cachedir = $path;
+ return TRUE;
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Retreive a cached query
+ *
+ * The URI being requested will become the name of the cache sub-folder.
+ * An MD5 hash of the SQL statement will become the cache file name
+ *
+ * @access public
+ * @return string
+ */
+ function read($sql)
+ {
+ if ( ! $this->check_path())
+ {
+ return $this->obj->db->cache_off();
+ }
+
+ $uri = ($this->obj->uri->segment(1) == FALSE) ? 'base' : $this->obj->uri->segment(2);
+ $uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+
+ $filepath = md5($uri).'/'.md5($sql);
+
+ if (FALSE === ($cachedata = read_file($this->obj->db->cachedir.$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->obj->db->cache_off();
+ }
+
+ $uri = ($this->obj->uri->segment(1) == FALSE) ? 'base' : $this->obj->uri->segment(2);
+ $uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+
+ $dir_path = $this->obj->db->cachedir.md5($uri).'/';
+
+ $filename = md5($sql);
+
+ if ( ! @is_dir($dir_path))
+ {
+ if ( ! @mkdir($dir_path, 0777))
+ {
+ return FALSE;
+ }
+
+ @chmod($dir_path, 0777);
+ }
+
+ if (write_file($dir_path.$filename, serialize($object)) === FALSE)
+ {
+ return FALSE;
+ }
+
+ @chmod($dir_path.$filename, 0777);
+ return TRUE;
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Delete cache files within a particular directory
+ *
+ * @access public
+ * @return bool
+ */
+ function delete()
+ {
+ $uri = ($this->obj->uri->segment(1) == FALSE) ? 'base' : $this->obj->uri->segment(2);
+ $uri .= ($this->obj->uri->segment(2) == FALSE) ? 'index' : $this->obj->uri->segment(2);
+
+ $dir_path = $this->obj->db->cachedir.md5($uri).'/';
+
+ delete_files($dir_path, TRUE);
+ }
+
+ // --------------------------------------------------------------------
+
+ /**
+ * Delete all existing cache files
+ *
+ * @access public
+ * @return bool
+ */
+ function delete_all()
+ {
+ delete_files($this->obj->db->cachedir, TRUE);
+ }
+
+}
+
+?> \ No newline at end of file