Add a caching plugin for APC variable cache

plugins/APCPlugin.php

@@ -0,0 +1,108 @@
+<?php
+/**
+ * StatusNet - the distributed open-source microblogging tool
+ * Copyright (C) 2009, StatusNet, Inc.
+ *
+ * Plugin to implement cache interface for APC variable cache
+ *
+ * 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 APC's variable cache for the cache interface
+ *
+ * New plugin interface lets us use alternative cache systems
+ * for caching. This one uses APC's variable cache.
+ *
+ * @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 APCPlugin extends Plugin
+{
+    /**
+     * 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)
+    {
+        $value = apc_fetch($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)
+    {
+        $success = apc_store($key, $value, ((is_null($expiry)) ? 0 : $expiry));
+
+        Event::handle('EndCacheSet', array($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)
+    {
+        $success = apc_delete($key);
+        Event::handle('EndCacheDelete', array($key));
+        return false;
+    }
+}
+