Merge branch 'MDL-57742_master' of git://github.com/markn86/moodle
[moodle.git] / lib / adodb / adodb-memcache.lib.inc.php
blob42d2be62eb919bb04529958f3110ecf34b719a3f
1 <?php
3 // security - hide paths
4 if (!defined('ADODB_DIR')) die();
6 global $ADODB_INCLUDED_MEMCACHE;
7 $ADODB_INCLUDED_MEMCACHE = 1;
9 global $ADODB_INCLUDED_CSV;
10 if (empty($ADODB_INCLUDED_CSV)) include_once(ADODB_DIR.'/adodb-csvlib.inc.php');
14 @version v5.20.9 21-Dec-2016
15 @copyright (c) 2000-2013 John Lim (jlim#natsoft.com). All rights reserved.
16 @copyright (c) 2014 Damien Regad, Mark Newnham and the ADOdb community
17 Released under both BSD license and Lesser GPL library license.
18 Whenever there is any discrepancy between the two licenses,
19 the BSD license will take precedence. See License.txt.
20 Set tabs to 4 for best viewing.
22 Latest version is available at http://adodb.sourceforge.net
24 Usage:
26 $db = NewADOConnection($driver);
27 $db->memCache = true; /// should we use memCache instead of caching in files
28 $db->memCacheHost = array($ip1, $ip2, $ip3);
29 $db->memCachePort = 11211; /// this is default memCache port
30 $db->memCacheCompress = false; /// Use 'true' to store the item compressed (uses zlib)
32 $db->Connect(...);
33 $db->CacheExecute($sql);
35 Note the memcache class is shared by all connections, is created during the first call to Connect/PConnect.
37 Class instance is stored in $ADODB_CACHE
40 class ADODB_Cache_MemCache {
41 var $createdir = false; // create caching directory structure?
43 //-----------------------------
44 // memcache specific variables
46 var $hosts; // array of hosts
47 var $port = 11211;
48 var $compress = false; // memcache compression with zlib
50 var $_connected = false;
51 var $_memcache = false;
53 function __construct(&$obj)
55 $this->hosts = $obj->memCacheHost;
56 $this->port = $obj->memCachePort;
57 $this->compress = $obj->memCacheCompress;
60 // implement as lazy connection. The connection only occurs on CacheExecute call
61 function connect(&$err)
63 if (!function_exists('memcache_pconnect')) {
64 $err = 'Memcache module PECL extension not found!';
65 return false;
68 $memcache = new MemCache;
70 if (!is_array($this->hosts)) $this->hosts = array($this->hosts);
72 $failcnt = 0;
73 foreach($this->hosts as $host) {
74 if (!@$memcache->addServer($host,$this->port,true)) {
75 $failcnt += 1;
78 if ($failcnt == sizeof($this->hosts)) {
79 $err = 'Can\'t connect to any memcache server';
80 return false;
82 $this->_connected = true;
83 $this->_memcache = $memcache;
84 return true;
87 // returns true or false. true if successful save
88 function writecache($filename, $contents, $debug, $secs2cache)
90 if (!$this->_connected) {
91 $err = '';
92 if (!$this->connect($err) && $debug) ADOConnection::outp($err);
94 if (!$this->_memcache) return false;
96 if (!$this->_memcache->set($filename, $contents, $this->compress ? MEMCACHE_COMPRESSED : 0, $secs2cache)) {
97 if ($debug) ADOConnection::outp(" Failed to save data at the memcached server!<br>\n");
98 return false;
101 return true;
104 // returns a recordset
105 function readcache($filename, &$err, $secs2cache, $rsClass)
107 $false = false;
108 if (!$this->_connected) $this->connect($err);
109 if (!$this->_memcache) return $false;
111 $rs = $this->_memcache->get($filename);
112 if (!$rs) {
113 $err = 'Item with such key doesn\'t exists on the memcached server.';
114 return $false;
117 // hack, should actually use _csv2rs
118 $rs = explode("\n", $rs);
119 unset($rs[0]);
120 $rs = join("\n", $rs);
121 $rs = unserialize($rs);
122 if (! is_object($rs)) {
123 $err = 'Unable to unserialize $rs';
124 return $false;
126 if ($rs->timeCreated == 0) return $rs; // apparently have been reports that timeCreated was set to 0 somewhere
128 $tdiff = intval($rs->timeCreated+$secs2cache - time());
129 if ($tdiff <= 2) {
130 switch($tdiff) {
131 case 2:
132 if ((rand() & 15) == 0) {
133 $err = "Timeout 2";
134 return $false;
136 break;
137 case 1:
138 if ((rand() & 3) == 0) {
139 $err = "Timeout 1";
140 return $false;
142 break;
143 default:
144 $err = "Timeout 0";
145 return $false;
148 return $rs;
151 function flushall($debug=false)
153 if (!$this->_connected) {
154 $err = '';
155 if (!$this->connect($err) && $debug) ADOConnection::outp($err);
157 if (!$this->_memcache) return false;
159 $del = $this->_memcache->flush();
161 if ($debug)
162 if (!$del) ADOConnection::outp("flushall: failed!<br>\n");
163 else ADOConnection::outp("flushall: succeeded!<br>\n");
165 return $del;
168 function flushcache($filename, $debug=false)
170 if (!$this->_connected) {
171 $err = '';
172 if (!$this->connect($err) && $debug) ADOConnection::outp($err);
174 if (!$this->_memcache) return false;
176 $del = $this->_memcache->delete($filename);
178 if ($debug)
179 if (!$del) ADOConnection::outp("flushcache: $key entry doesn't exist on memcached server!<br>\n");
180 else ADOConnection::outp("flushcache: $key entry flushed from memcached server!<br>\n");
182 return $del;
185 // not used for memcache
186 function createdir($dir, $hash)
188 return true;