diff options
Diffstat (limited to 'engine/classes/ElggMemcache.php')
| -rw-r--r-- | engine/classes/ElggMemcache.php | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/engine/classes/ElggMemcache.php b/engine/classes/ElggMemcache.php new file mode 100644 index 000000000..5e898c26a --- /dev/null +++ b/engine/classes/ElggMemcache.php @@ -0,0 +1,151 @@ +<?php
+/**
+ * Memcache wrapper class.
+ * @author Curverider Ltd <info@elgg.com>
+ */
+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 $cache_id The namespace for this cache to write to - note, namespaces of the same name are shared!
+ */
+ function __construct($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($this->memcache, 'addServer')) {
+ foreach ($CONFIG->memcache_servers as $server) {
+ if (is_array($server)) {
+ $this->memcache->addServer(
+ $server[0],
+ isset($server[1]) ? $server[1] : 11211,
+ isset($server[2]) ? $server[2] : true,
+ isset($server[3]) ? $server[3] : null,
+ isset($server[4]) ? $server[4] : 1,
+ isset($server[5]) ? $server[5] : 15,
+ isset($server[6]) ? $server[6] : true
+ );
+
+ } else {
+ $this->memcache->addServer($server, 11211);
+ }
+ }
+ } else {
+ elgg_log(elgg_echo('memcache:noaddserver'), '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::$MINSERVERVERSION, '<')) {
+ throw new ConfigurationException(sprintf(elgg_echo('memcache:versiontoolow'), ElggMemcache::$MINSERVERVERSION, $this->version));
+ }
+
+ // Set some defaults
+ if (isset($CONFIG->memcache_expires)) {
+ $this->expires = $CONFIG->memcache_expires;
+ }
+ }
+
+ /**
+ * Set the default expiry.
+ *
+ * @param int $expires The lifetime as a unix timestamp or time from now. Defaults forever.
+ */
+ public function setDefaultExpiry($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.
+ *
+ * @param string $key The key
+ * @return string The new key.
+ */
+ private function make_memcache_key($key) {
+ $prefix = $this->getNamespace() . ":";
+
+ if (strlen($prefix.$key)> 250) {
+ $key = md5($key);
+ }
+
+ return $prefix.$key;
+ }
+
+ public function save($key, $data) {
+ $key = $this->make_memcache_key($key);
+
+ $result = $this->memcache->set($key, $data, null, $this->expires);
+ if (!$result) {
+ elgg_log("MEMCACHE: FAILED TO SAVE $key", 'ERROR');
+ }
+
+ return $result;
+ }
+
+ public function load($key, $offset = 0, $limit = null) {
+ $key = $this->make_memcache_key($key);
+
+ $result = $this->memcache->get($key);
+ if (!$result) {
+ elgg_log("MEMCACHE: FAILED TO LOAD $key", 'ERROR');
+ }
+
+ return $result;
+ }
+
+ public function delete($key) {
+ $key = $this->make_memcache_key($key);
+
+ return $this->memcache->delete($key, 0);
+ }
+
+ public function clear() {
+ // DISABLE clearing for now - you must use delete on a specific key.
+ return true;
+
+ // @todo Namespaces as in #532
+ }
+}
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