1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
<?php
/* vim:set tabstop=8 softtabstop=8 shiftwidth=8 noexpandtab: */
/**
* database_object Class
*
*
* LICENSE: GNU General Public License, version 2 (GPLv2)
* Copyright (c) 2001 - 2011 Ampache.org All Rights Reserved
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License v2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* @package Ampache
* @copyright 2001 - 2011 Ampache.org
* @license http://opensource.org/licenses/gpl-2.0 GPLv2
* @link http://www.ampache.org/
*/
/**
* database_object
*
* This is a general object that is extended by all of the basic
* database based objects in ampache. It attempts to do some standard
* caching for all of the objects to cut down on the database calls
*
* @package Ampache
* @copyright 2001 - 2011 Ampache.org
* @license http://opensource.org/licenses/gpl-2.0 GPLv2
* @link http://www.ampache.org/
* @abstract
*/
abstract class database_object {
private static $object_cache = array();
// Statistics for debugging
public static $cache_hit = 0;
private static $_enabled = false;
/**
* get_info
* retrieves the info from the database and puts it in the cache
*/
public function get_info($id,$table_name='') {
$table_name = $table_name ? Dba::escape($table_name) : Dba::escape(strtolower(get_class($this)));
// Make sure we've got a real id
if (!is_numeric($id)) { return array(); }
if (self::is_cached($table_name,$id)) {
return self::get_from_cache($table_name,$id);
}
$sql = "SELECT * FROM `$table_name` WHERE `id`='$id'";
$db_results = Dba::read($sql);
if (!$db_results) { return array(); }
$row = Dba::fetch_assoc($db_results);
self::add_to_cache($table_name,$id,$row);
return $row;
} // get_info
/**
* is_cached
* this checks the cache to see if the specified object is there
*/
public static function is_cached($index,$id) {
// Make sure we've got some parents here before we dive below
if (!isset(self::$object_cache[$index])) { return false; }
return isset(self::$object_cache[$index][$id]);
} // is_cached
/**
* get_from_cache
* This attempts to retrive the specified object from the cache we've got here
*/
public static function get_from_cache($index,$id) {
// Check if the object is set
if (isset(self::$object_cache[$index])
&& isset(self::$object_cache[$index][$id])
) {
self::$cache_hit++;
return self::$object_cache[$index][$id];
}
return false;
} // get_from_cache
/**
* add_to_cache
* This adds the specified object to the specified index in the cache
*/
public static function add_to_cache($index,$id,$data) {
if (!self::$_enabled) { return false; }
$value = is_null($data) ? false : $data;
self::$object_cache[$index][$id] = $value;
} // add_to_cache
/**
* remove_from_cache
* This function clears something from the cache, there are a few places we need to do this
* in order to have things display correctly
*/
public static function remove_from_cache($index,$id) {
if (isset(self::$object_cache[$index]) && isset(self::$object_cache[$index][$id])) {
unset(self::$object_cache[$index][$id]);
}
} // remove_from_cache
/**
* _auto_init
* Load in the cache settings once so we can avoid function calls
*/
public static function _auto_init() {
self::$_enabled = Config::get('memory_cache');
} // _auto_init
} // end database_object
|
