diff options
Diffstat (limited to 'plugins')
| -rw-r--r-- | plugins/InProcessCache/InProcessCachePlugin.php | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/plugins/InProcessCache/InProcessCachePlugin.php b/plugins/InProcessCache/InProcessCachePlugin.php new file mode 100644 index 000000000..1b6fbcdbe --- /dev/null +++ b/plugins/InProcessCache/InProcessCachePlugin.php @@ -0,0 +1,197 @@ +<?php +/** + * StatusNet - the distributed open-source microblogging tool + * Copyright (C) 2010, StatusNet, Inc. + * + * Extra level of caching, in memory + * + * 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 2010 StatusNet, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 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); +} + +/** + * Extra level of caching + * + * This plugin adds an extra level of in-process caching to any regular + * cache system like APC, XCache, or Memcache. + * + * Note that since most caching plugins return false for StartCache* + * methods, you should add this plugin before them, i.e. + * + * addPlugin('InProcessCache'); + * addPlugin('XCache'); + * + * @category Cache + * @package StatusNet + * @author Evan Prodromou <evan@status.net> + * @copyright 2010 StatusNet, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0 + * @link http://status.net/ + */ + +class InProcessCachePlugin extends Plugin +{ + private $_items = array(); + private $_hits = array(); + + /** + * Get an item from the cache + * + * Called before other cache systems are called (iif this + * plugin was loaded correctly, see class comment). If we + * have the data, return it, and don't hit the other cache + * systems. + * + * @param string &$key Key to fetch + * @param mixed &$value Resulting value or false for miss + * + * @return boolean false if found, else true + */ + + function onStartCacheGet(&$key, &$value) + { + if (array_key_exists($key, $this->_items)) { + $value = $this->_items[$key]; + if (array_key_exists($key, $this->_hits)) { + $this->_hits[$key]++; + } else { + $this->_hits[$key] = 1; + } + Event::handle('EndCacheGet', array($key, &$value)); + return false; + } + return true; + } + + /** + * Called at the end of a cache get + * + * If we don't already have the data, we cache it. This + * keeps us from having to call the external cache if the + * key is requested again. + * + * @param string $key Key to fetch + * @param mixed &$value Resulting value or false for miss + * + * @return boolean hook value, true + */ + + function onEndCacheGet($key, &$value) + { + if (!array_key_exists($key, $this->_items) || + $this->_items[$key] != $value) { + $this->_items[$key] = $value; + } + return true; + } + + /** + * Called at the end of setting a cache element + * + * Always set the cache element; may overwrite existing + * data. + * + * @param string $key Key to fetch + * @param mixed $value Resulting value or false for miss + * @param integer $flag ignored + * @param integer $expiry ignored + * + * @return boolean true + */ + + function onEndCacheSet($key, $value, $flag, $expiry) + { + $this->_items[$key] = $value; + return true; + } + + /** + * Called at the end of deleting a cache element + * + * If stuff's deleted from the other cache, we + * delete it too. + * + * @param string &$key Key to delete + * @param boolean &$success Success flag; ignored + * + * @return boolean true + */ + + function onStartCacheDelete(&$key, &$success) + { + if (array_key_exists($key, $this->_items)) { + unset($this->_items[$key]); + } + return true; + } + + /** + * Version info + * + * @param array &$versions Array of version blocks + * + * @return boolean true + */ + + function onPluginVersion(&$versions) + { + $url = 'http://status.net/wiki/Plugin:InProcessCache'; + + $versions[] = array('name' => 'InProcessCache', + 'version' => STATUSNET_VERSION, + 'author' => 'Evan Prodromou', + 'homepage' => $url, + 'description' => + _m('Additional in-process cache for plugins.')); + return true; + } + + /** + * Cleanup function; called at end of process + * + * If the inprocess/stats config value is true, we dump + * stats to the log file + * + * @return boolean true + */ + + function cleanup() + { + if (common_config('inprocess', 'stats')) { + $this->log(LOG_INFO, "cache size: " . + count($this->_items)); + $sum = 0; + foreach ($this->_hits as $hitcount) { + $sum += $hitcount; + } + $this->log(LOG_INFO, $sum . " hits on " . + count($this->_hits) . " keys"); + } + return true; + } +} |