shiftcontroller / happ / system / database / DB_cache.php

DB_cache.php in ShiftController Employee Shift Scheduling 2.2.0, at happ/system/database/DB_cache.php

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1	<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
2	/**
3	* CodeIgniter
4	*
5	* An open source application development framework for PHP 5.1.6 or newer
6	*
7	* @package CodeIgniter
8	* @author ExpressionEngine Dev Team
9	* @copyright Copyright (c) 2008 - 2011, EllisLab, Inc.
10	* @license http://codeigniter.com/user_guide/license.html
11	* @link http://codeigniter.com
12	* @since Version 1.0
13	* @filesource
14	*/
15
16	// ------------------------------------------------------------------------
17
18	/**
19	* Database Cache Class
20	*
21	* @category Database
22	* @author ExpressionEngine Dev Team
23	* @link http://codeigniter.com/user_guide/database/
24	*/
25	class CI_DB_Cache {
26
27	var $CI;
28	var $db; // allows passing of db object so that multiple database connections and returned db objects can be supported
29
30	/**
31	* Constructor
32	*
33	* Grabs the CI super object instance so we can access it.
34	*
35	*/
36	function __construct(&$db)
37	{
38	// Assign the main CI object to $this->CI
39	// and load the file helper since we use it a lot
40	$this->CI =& ci_get_instance();
41	$this->db =& $db;
42	$this->CI->load->helper('file');
43	}
44
45	// --------------------------------------------------------------------
46
47	/**
48	* Set Cache Directory Path
49	*
50	* @access public
51	* @param string the path to the cache directory
52	* @return bool
53	*/
54	function check_path($path = '')
55	{
56	if ($path == '')
57	{
58	if ($this->db->cachedir == '')
59	{
60	return $this->db->cache_off();
61	}
62
63	$path = $this->db->cachedir;
64	}
65
66	// Add a trailing slash to the path if needed
67	$path = preg_replace("/(.+?)\/*$/", "\\1/", $path);
68
69	if ( ! is_dir($path) OR ! is_really_writable($path))
70	{
71	// If the path is wrong we'll turn off caching
72	return $this->db->cache_off();
73	}
74
75	$this->db->cachedir = $path;
76	return TRUE;
77	}
78
79	// --------------------------------------------------------------------
80
81	/**
82	* Retrieve a cached query
83	*
84	* The URI being requested will become the name of the cache sub-folder.
85	* An MD5 hash of the SQL statement will become the cache file name
86	*
87	* @access public
88	* @return string
89	*/
90	function read($sql)
91	{
92	if ( ! $this->check_path())
93	{
94	return $this->db->cache_off();
95	}
96
97	$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
98
99	$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
100
101	$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql);
102
103	if (FALSE === ($cachedata = read_file($filepath)))
104	{
105	return FALSE;
106	}
107
108	return unserialize($cachedata);
109	}
110
111	// --------------------------------------------------------------------
112
113	/**
114	* Write a query to a cache file
115	*
116	* @access public
117	* @return bool
118	*/
119	function write($sql, $object)
120	{
121	if ( ! $this->check_path())
122	{
123	return $this->db->cache_off();
124	}
125
126	$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
127
128	$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
129
130	$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';
131
132	$filename = md5($sql);
133
134	if ( ! @is_dir($dir_path))
135	{
136	if ( ! @mkdir($dir_path, DIR_WRITE_MODE))
137	{
138	return FALSE;
139	}
140
141	@chmod($dir_path, DIR_WRITE_MODE);
142	}
143
144	if (write_file($dir_path.$filename, serialize($object)) === FALSE)
145	{
146	return FALSE;
147	}
148
149	@chmod($dir_path.$filename, FILE_WRITE_MODE);
150	return TRUE;
151	}
152
153	// --------------------------------------------------------------------
154
155	/**
156	* Delete cache files within a particular directory
157	*
158	* @access public
159	* @return bool
160	*/
161	function delete($segment_one = '', $segment_two = '')
162	{
163	if ($segment_one == '')
164	{
165	$segment_one = ($this->CI->uri->segment(1) == FALSE) ? 'default' : $this->CI->uri->segment(1);
166	}
167
168	if ($segment_two == '')
169	{
170	$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
171	}
172
173	$dir_path = $this->db->cachedir.$segment_one.'+'.$segment_two.'/';
174
175	delete_files($dir_path, TRUE);
176	}
177
178	// --------------------------------------------------------------------
179
180	/**
181	* Delete all existing cache files
182	*
183	* @access public
184	* @return bool
185	*/
186	function delete_all()
187	{
188	delete_files($this->db->cachedir, TRUE);
189	}
190
191	}
192
193
194	/* End of file DB_cache.php */
195	/* Location: ./system/database/DB_cache.php */