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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
<?php
/**
* Memcache wrapper class.
*
* @package Elgg.Core
* @subpackage Memcache
*/
class ElggMemcache extends ElggSharedMemoryCache {
/**
* Minimum version of memcached needed to run
*
*/
private static $MINSERVERVERSION = '1.1.12';
/**
* Memcache object
*/
private $memcache;
/**
* Expiry of saved items (default timeout after a day to prevent anything getting too stale)
*/
private $expires = 86400;
/**
* The version of memcache running
*/
private $version = 0;
/**
* Connect to memcache.
*
* @param string $namespace The namespace for this cache to write to -
* note, namespaces of the same name are shared!
*/
function __construct($namespace = 'default') {
global $CONFIG;
$this->setNamespace($namespace);
// Do we have memcache?
if (!class_exists('Memcache')) {
throw new ConfigurationException(elgg_echo('memcache:notinstalled'));
}
// Create memcache object
$this->memcache = new Memcache;
// Now add servers
if (!$CONFIG->memcache_servers) {
throw new ConfigurationException(elgg_echo('memcache:noservers'));
}
if (is_callable(array($this->memcache, 'addServer'))) {
foreach ($CONFIG->memcache_servers as $server) {
if (is_array($server)) {
$this->memcache->addServer(
$server[0],
isset($server[1]) ? $server[1] : 11211,
isset($server[2]) ? $server[2] : FALSE,
isset($server[3]) ? $server[3] : 1,
isset($server[4]) ? $server[4] : 1,
isset($server[5]) ? $server[5] : 15,
isset($server[6]) ? $server[6] : TRUE
);
} else {
$this->memcache->addServer($server, 11211);
}
}
} else {
// don't use elgg_echo() here because most of the config hasn't been loaded yet
// and it caches the language, which is hard coded in $CONFIG->language as en.
// overriding it with real values later has no effect because it's already cached.
elgg_log("This version of the PHP memcache API doesn't support multiple servers.", 'ERROR');
$server = $CONFIG->memcache_servers[0];
if (is_array($server)) {
$this->memcache->connect($server[0], $server[1]);
} else {
$this->memcache->addServer($server, 11211);
}
}
// Get version
$this->version = $this->memcache->getVersion();
if (version_compare($this->version, ElggMemcache::$MINSERVERVERSION, '<')) {
$msg = elgg_echo('memcache:versiontoolow',
array(ElggMemcache::$MINSERVERVERSION,
$this->version
));
throw new ConfigurationException($msg);
}
// Set some defaults
if (isset($CONFIG->memcache_expires)) {
$this->expires = $CONFIG->memcache_expires;
}
}
/**
* Set the default expiry.
*
* @param int $expires The lifetime as a unix timestamp or time from now. Defaults forever.
*
* @return void
*/
public function setDefaultExpiry($expires = 0) {
$this->expires = $expires;
}
/**
* Combine a key with the namespace.
* Memcache can only accept <250 char key. If the given key is too long it is shortened.
*
* @deprecated 1.8 Use ElggMemcache::_makeMemcacheKey()
*
* @param string $key The key
*
* @return string The new key.
*/
private function make_memcache_key($key) {
elgg_deprecated_notice('ElggMemcache::make_memcache_key() is deprecated by ::_makeMemcacheKey()', 1.8);
return $this->_makeMemcacheKey($key);
}
/**
* Combine a key with the namespace.
* Memcache can only accept <250 char key. If the given key is too long it is shortened.
*
* @param string $key The key
*
* @return string The new key.
*/
private function _makeMemcacheKey($key) {
$prefix = $this->getNamespace() . ":";
if (strlen($prefix . $key) > 250) {
$key = md5($key);
}
return $prefix . $key;
}
/**
* Saves a name and value to the cache
*
* @param string $key Name
* @param string $data Value
* @param integer $expires Expires (in seconds)
*
* @return bool
*/
public function save($key, $data, $expires = null) {
$key = $this->_makeMemcacheKey($key);
if ($expires === null) {
$expires = $this->expires;
}
$result = $this->memcache->set($key, $data, null, $expires);
if (!$result) {
elgg_log("MEMCACHE: FAILED TO SAVE $key", 'ERROR');
}
return $result;
}
/**
* Retrieves data.
*
* @param string $key Name of data to retrieve
* @param int $offset Offset
* @param int $limit Limit
*
* @return mixed
*/
public function load($key, $offset = 0, $limit = null) {
$key = $this->_makeMemcacheKey($key);
$result = $this->memcache->get($key);
if (!$result) {
elgg_log("MEMCACHE: FAILED TO LOAD $key", 'ERROR');
}
return $result;
}
/**
* Delete data
*
* @param string $key Name of data
*
* @return bool
*/
public function delete($key) {
$key = $this->_makeMemcacheKey($key);
return $this->memcache->delete($key, 0);
}
/**
* Clears the entire cache?
*
* @todo write or remove.
*
* @return true
*/
public function clear() {
// DISABLE clearing for now - you must use delete on a specific key.
return true;
// @todo Namespaces as in #532
}
}
|
