<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social 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.
//
// GNU social 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 GNU social. If not, see <http://www.gnu.org/licenses/>.
/**
* A plugin to use memcached for the interface with memcache
*
* @category Cache
* @package GNUsocial
* @author Evan Prodromou <evan@status.net>
* @author Craig Andrews <candrews@integralblue.com>
* @author Miguel Dantas <biodantas@gmail.com>
* @copyright 2009, 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
defined('GNUSOCIAL') || die();
/**
* A plugin to use memcached 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.
*
* @copyright 2009, 2019 Free Software Foundation, Inc http://www.fsf.org
* @license https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
*/
class MemcachedPlugin extends Plugin
{
const PLUGIN_VERSION = '2.1.0';
public static $cacheInitialized = false;
public $servers = ['127.0.0.1'];
public $defaultExpiry = 86400; // 24h
private $_conn = null;
/**
* Initialize the plugin
*
* Note that onStartCacheGet() may have been called before this!
*
* @return bool flag value
*/
public function initialize(): bool
{
if (self::$cacheInitialized) {
$this->persistent = true;
} else {
// If we're a parent command-line process we need
// to be able to close out the connection after
// forking, so disable persistence.
//
// We'll turn it back on again the second time
// through which will either be in a child process,
// or a single-process script which is switching
// configurations.
$this->persistent = (php_sapi_name() == 'cli') ? false : true;
}
try {
$this->_ensureConn();
self::$cacheInitialized = true;
} catch (MemcachedException $e) {
common_log(LOG_ERR, 'Memcached encountered exception ' . get_class($e) . ': ' . $e->getMessage());
}
return true;
}
/**
* Get a value associated with a key
*
* The value should have been set previously.
*
* @param string &$key in; Lookup key
* @param mixed &$value out; value associated with key
*
* @return bool hook success
*/
public function onStartCacheGet(&$key, &$value): bool
{
try {
$this->_ensureConn();
$value = $this->_conn->get($key);
} catch (MemcachedException $e) {
common_log(LOG_ERR, 'Memcached encountered exception ' . get_class($e) . ': ' . $e->getMessage());
return true;
}
if ($value === false) {
// If not found, let other plugins handle it
return $this->_conn->getResultCode() === Memcached::RES_NOTFOUND;
} else {
return false;
}
}
/**
* Associate a value with a key
*
* @param string &$key in; Key to use for lookups
* @param mixed &$value in; Value to associate
* @param integer &$flag in; Flag empty or Memcached::OPT_COMPRESSION (translated by the `flag` method)
* @param integer &$expiry in; Expiry (passed through to Memcache)
* @param bool &$success out; Whether the set was successful
*
* @return bool hook success
*/
public function onStartCacheSet(&$key, &$value, &$flag, &$expiry, &$success): bool
{
if ($expiry === null) {
$expiry = $this->defaultExpiry;
}
try {
$this->_ensureConn();
if (!empty($flag)) {
$this->_conn->setOption(Memcached::OPT_COMPRESSION, $flag);
}
$success = $this->_conn->set($key, $value, $expiry);
} catch (MemcachedException $e) {
common_log(LOG_ERR, 'Memcached encountered exception ' . get_class($e) . ': ' . $e->getMessage());
return true;
}
return !$success;
}
/**
* Atomically increment an existing numeric key value.
* Existing expiration time will not be changed.
*
* @param string &$key in; Key to use for lookups
* @param int &$step in; Amount to increment (default 1)
* @param mixed &$value out; Incremented value, or false if key not set.
*
* @return bool hook success
*/
public function onStartCacheIncrement(&$key, &$step, &$value): bool
{
try {
$this->_ensureConn();
$value = $this->_conn->increment($key, $step);
} catch (MemcachedException $e) {
common_log(LOG_ERR, 'Memcached encountered exception ' . get_class($e) . ': ' . $e->getMessage());
return true;
}
if ($value === false) {
// If not found, let other plugins handle it
return $this->_conn->getResultCode() === Memcached::RES_NOTFOUND;
} else {
return false;
}
}
/**
* Delete a value associated with a key
*
* @param string &$key in; Key to lookup
* @param bool &$success out; whether it worked
*
* @return bool hook success
*/
public function onStartCacheDelete(&$key, &$success): bool
{
try {
$this->_ensureConn();
$success = $this->_conn->delete($key);
} catch (MemcachedException $e) {
common_log(LOG_ERR, 'Memcached encountered exception ' . get_class($e) . ': ' . $e->getMessage());
return true;
}
return !$success;
}
/**
* @param $success
* @return bool
*/
public function onStartCacheReconnect(&$success): bool
{
if (empty($this->_conn)) {
// nothing to do
return true;
}
if ($this->persistent) {
common_log(LOG_ERR, "Cannot close persistent memcached connection");
$success = false;
} else {
common_log(LOG_INFO, "Closing memcached connection");
$success = $this->_conn->quit();
$this->_conn = null;
}
return false;
}
/**
* Ensure that a connection exists
*
* Checks the instance $_conn variable and connects
* if it is empty.
*
* @return void
*/
private function _ensureConn(): void
{
if (empty($this->_conn)) {
$this->_conn = new Memcached(common_config('site', 'nickname'));
if (!count($this->_conn->getServerList())) {
if (is_array($this->servers)) {
$servers = $this->servers;
} else {
$servers = [$this->servers];
}
foreach ($servers as $server) {
if (is_array($server) && count($server) === 2) {
list($host, $port) = $server;
} else {
$host = is_array($server) ? $server[0] : $server;
$port = 11211;
}
$this->_conn->addServer($host, $port);
}
// Compress items stored in the cache.
// Allows the cache to store objects larger than 1MB (if they
// compress to less than 1MB), and improves cache memory efficiency.
$this->_conn->setOption(Memcached::OPT_COMPRESSION, true);
}
}
}
/**
* Translate general flags to Memcached-specific flags
* @param int $flag
* @return int
*/
protected function flag(int $flag): int
{
$out = 0;
if ($flag & Cache::COMPRESSED == Cache::COMPRESSED) {
$out |= Memcached::OPT_COMPRESSION;
}
return $out;
}
public function onPluginVersion(array &$versions): bool
{
$versions[] = array('name' => 'Memcached',
'version' => self::PLUGIN_VERSION,
'author' => 'Evan Prodromou, Craig Andrews',
'homepage' => GNUSOCIAL_ENGINE_REPO_URL . 'tree/master/plugins/Memcached',
'rawdescription' =>
// TRANS: Plugin description.
_m('Use <a href="http://memcached.org/">Memcached</a> to cache query results.'));
return true;
}
}