First version of Memcache plugin

1 files changed, 162 insertions, 0 deletions

diff --git a/plugins/MemcachePlugin.php b/plugins/MemcachePlugin.php
new file mode 100644
index 000000000..acbec135e
--- /dev/null
+++ b/plugins/MemcachePlugin.php
@@ -0,0 +1,162 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * Plugin to implement cache interface for memcache
+ *
+ * PHP version 5
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @category  Cache
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2009 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+if (!defined('STATUSNET')) {
+    // This check helps protect against security problems;
+    // your code file can't be executed directly from the web.
+    exit(1);
+}
+
+/**
+ * A plugin to use memcache for the cache interface
+ *
+ * This used to be encoded as config-variable options in the core code;
+ * it's now broken out to a separate plugin. The same interface can be
+ * implemented by other plugins.
+ *
+ * @category  Cache
+ * @package   StatusNet
+ * @author    Evan Prodromou <evan@status.net>
+ * @copyright 2009 StatusNet, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://status.net/
+ */
+
+class MemcachePlugin extends Plugin
+{
+    private $_conn  = null;
+    public $servers = array('127.0.0.1;11211');
+
+    /**
+     * Initialize the plugin
+     *
+     * Note that onStartCacheGet() may have been called before this!
+     *
+     * @return boolean flag value
+     */
+
+    function onInitializePlugin()
+    {
+        $this->_ensureConn();
+        return true;
+    }
+
+    /**
+     * Get a value associated with a key
+     *
+     * The value should have been set previously.
+     *
+     * @param string &$key   in; Lookup key
+     * @param mixed  &$value out; value associated with key
+     *
+     * @return boolean hook success
+     */
+
+    function onStartCacheGet(&$key, &$value)
+    {
+        $this->_ensureConn();
+        $value = $this->_conn->get($key);
+        Event::handle('EndCacheGet', array($key, &$value));
+        return false;
+    }
+
+    /**
+     * Associate a value with a key
+     *
+     * @param string  &$key     in; Key to use for lookups
+     * @param mixed   &$value   in; Value to associate
+     * @param integer &$flag    in; Flag (passed through to Memcache)
+     * @param integer &$expiry  in; Expiry (passed through to Memcache)
+     * @param boolean &$success out; Whether the set was successful
+     *
+     * @return boolean hook success
+     */
+
+    function onStartCacheSet(&$key, &$value, &$flag, &$expiry, &$success)
+    {
+        $this->_ensureConn();
+        $success = $this->_conn->set($key, $value, $flag, $expiry);
+        Event::handle('EndCacheSet', array($key, $value, $flag,
+                                           $expiry));
+        return false;
+    }
+
+    /**
+     * Delete a value associated with a key
+     *
+     * @param string  &$key     in; Key to lookup
+     * @param boolean &$success out; whether it worked
+     *
+     * @return boolean hook success
+     */
+
+    function onStartCacheDelete(&$key, &$success)
+    {
+        $this->_ensureConn();
+        $success = $this->_conn->delete($key);
+        Event::handle('EndCacheDelete', array($key));
+        return false;
+    }
+
+    /**
+     * Ensure that a connection exists
+     *
+     * Checks the instance $_conn variable and connects
+     * if it is empty.
+     *
+     * @return void
+     */
+
+    private function _ensureConn()
+    {
+        if (empty($this->_conn)) {
+            $this->_conn = new Memcache();
+
+            if (is_array($this->servers)) {
+                foreach ($this->servers as $server) {
+                    list($host, $port) = explode(';', $server);
+                    if (empty($port)) {
+                        $port = 11211;
+                    }
+
+                    $this->_conn->addServer($host, $port);
+                }
+            } else {
+                $this->_conn->addServer($this->servers);
+                list($host, $port) = explode(';', $this->servers);
+                if (empty($port)) {
+                    $port = 11211;
+                }
+                $this->_conn->addServer($host, $port);
+            }
+        }
+    }
+}
+