289 lines
8.3 KiB
PHP
289 lines
8.3 KiB
PHP
<?php
|
|
/**
|
|
* StatusNet, the distributed open-source microblogging tool
|
|
*
|
|
* Cache interface plus default in-memory cache implementation
|
|
*
|
|
* PHP version 5
|
|
*
|
|
* LICENCE: 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/
|
|
*/
|
|
|
|
/**
|
|
* Interface for caching
|
|
*
|
|
* An abstract interface for caching. Because we originally used the
|
|
* Memcache plugin directly, the interface uses a small subset of the
|
|
* Memcache interface.
|
|
*
|
|
* @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 AGPL 3.0
|
|
* @link http://status.net/
|
|
*/
|
|
class Cache
|
|
{
|
|
/**
|
|
* @var array additional in-process cache for web requests;
|
|
* disabled on CLI, unsafe for long-running daemons
|
|
*/
|
|
var $_items = array();
|
|
var $_inlineCache = true;
|
|
static $_inst = null;
|
|
|
|
const COMPRESSED = 1;
|
|
|
|
private function __construct() {
|
|
// Potentially long-running daemons or maintenance scripts
|
|
// should not use an in-process cache as it becomes out of
|
|
// date.
|
|
$this->_inlineCache = (php_sapi_name() != 'cli');
|
|
}
|
|
|
|
/**
|
|
* Singleton constructor
|
|
*
|
|
* Use this to get the singleton instance of Cache.
|
|
*
|
|
* @return Cache cache object
|
|
*/
|
|
static function instance()
|
|
{
|
|
if (is_null(self::$_inst)) {
|
|
self::$_inst = new Cache();
|
|
}
|
|
|
|
return self::$_inst;
|
|
}
|
|
|
|
/**
|
|
* Create a cache key from input text
|
|
*
|
|
* Builds a cache key from input text. Helps to namespace
|
|
* the cache area (if shared with other applications or sites)
|
|
* and prevent conflicts.
|
|
*
|
|
* @param string $extra the real part of the key
|
|
*
|
|
* @return string full key
|
|
*/
|
|
static function key($extra)
|
|
{
|
|
$base_key = common_config('cache', 'base');
|
|
|
|
if (empty($base_key)) {
|
|
$base_key = self::keyize(common_config('site', 'name'));
|
|
}
|
|
|
|
return 'gnusocial:' . $base_key . ':' . $extra;
|
|
}
|
|
|
|
/**
|
|
* Create a cache key for data dependent on code
|
|
*
|
|
* For cache elements that are dependent on changes in code, this creates
|
|
* a more-or-less fingerprint of the current running code and adds it to
|
|
* the cache key. In the case of an upgrade of core, or addition or
|
|
* removal of plugins, a new unique fingerprint is generated and used.
|
|
*
|
|
* There can still be problems with a) differences in versions of the
|
|
* plugins and b) people running code between official versions. This is
|
|
* usually a problem only for experienced users like developers, who know
|
|
* how to clear their cache.
|
|
*
|
|
* For sites that run code between versions (like the status.net cloud),
|
|
* there's an additional build number configuration setting.
|
|
*
|
|
* @param string $extra the real part of the key
|
|
*
|
|
* @return string full key
|
|
*/
|
|
|
|
static function codeKey($extra)
|
|
{
|
|
static $prefix = null;
|
|
|
|
if (empty($prefix)) {
|
|
|
|
$plugins = StatusNet::getActivePlugins();
|
|
$names = array();
|
|
|
|
foreach ($plugins as $plugin) {
|
|
$names[] = $plugin[0];
|
|
}
|
|
|
|
$names = array_unique($names);
|
|
asort($names);
|
|
|
|
// Unique enough.
|
|
|
|
$uniq = crc32(implode(',', $names));
|
|
|
|
$build = common_config('site', 'build');
|
|
|
|
$prefix = GNUSOCIAL_VERSION.':'.$build.':'.$uniq;
|
|
}
|
|
|
|
return Cache::key($prefix.':'.$extra);
|
|
}
|
|
|
|
/**
|
|
* Make a string suitable for use as a key
|
|
*
|
|
* Useful for turning primary keys of tables into cache keys.
|
|
*
|
|
* @param string $str string to turn into a key
|
|
*
|
|
* @return string keyized string
|
|
*/
|
|
static function keyize($str)
|
|
{
|
|
$str = strtolower($str);
|
|
$str = preg_replace('/\s/', '_', $str);
|
|
return $str;
|
|
}
|
|
|
|
/**
|
|
* Get a value associated with a key
|
|
*
|
|
* The value should have been set previously.
|
|
*
|
|
* @param string $key Lookup key
|
|
*
|
|
* @return string retrieved value or null if unfound
|
|
*/
|
|
function get($key)
|
|
{
|
|
$value = false;
|
|
|
|
common_perf_counter('Cache::get', $key);
|
|
if (Event::handle('StartCacheGet', array(&$key, &$value))) {
|
|
if ($this->_inlineCache && array_key_exists($key, $this->_items)) {
|
|
$value = unserialize($this->_items[$key]);
|
|
}
|
|
Event::handle('EndCacheGet', array($key, &$value));
|
|
}
|
|
|
|
return $value;
|
|
}
|
|
|
|
/**
|
|
* Set the value associated with a key
|
|
*
|
|
* @param string $key The key to use for lookups
|
|
* @param string $value The value to store
|
|
* @param integer $flag Flags to use, may include Cache::COMPRESSED
|
|
* @param integer $expiry Expiry value, mostly ignored
|
|
*
|
|
* @return boolean success flag
|
|
*/
|
|
function set($key, $value, $flag=null, $expiry=null)
|
|
{
|
|
$success = false;
|
|
|
|
common_perf_counter('Cache::set', $key);
|
|
if (Event::handle('StartCacheSet', array(&$key, &$value, &$flag,
|
|
&$expiry, &$success))) {
|
|
|
|
if ($this->_inlineCache) {
|
|
$this->_items[$key] = serialize($value);
|
|
}
|
|
|
|
$success = true;
|
|
|
|
Event::handle('EndCacheSet', array($key, $value, $flag,
|
|
$expiry));
|
|
}
|
|
|
|
return $success;
|
|
}
|
|
|
|
/**
|
|
* Atomically increment an existing numeric value.
|
|
* Existing expiration time should remain unchanged, if any.
|
|
*
|
|
* @param string $key The key to use for lookups
|
|
* @param int $step Amount to increment (default 1)
|
|
*
|
|
* @return mixed incremented value, or false if not set.
|
|
*/
|
|
function increment($key, $step=1)
|
|
{
|
|
$value = false;
|
|
common_perf_counter('Cache::increment', $key);
|
|
if (Event::handle('StartCacheIncrement', array(&$key, &$step, &$value))) {
|
|
// Fallback is not guaranteed to be atomic,
|
|
// and may original expiry value.
|
|
$value = $this->get($key);
|
|
if ($value !== false) {
|
|
$value += $step;
|
|
$ok = $this->set($key, $value);
|
|
$got = $this->get($key);
|
|
}
|
|
Event::handle('EndCacheIncrement', array($key, $step, $value));
|
|
}
|
|
return $value;
|
|
}
|
|
|
|
/**
|
|
* Delete the value associated with a key
|
|
*
|
|
* @param string $key Key to delete
|
|
*
|
|
* @return boolean success flag
|
|
*/
|
|
function delete($key)
|
|
{
|
|
$success = false;
|
|
|
|
common_perf_counter('Cache::delete', $key);
|
|
if (Event::handle('StartCacheDelete', array(&$key, &$success))) {
|
|
if ($this->_inlineCache && array_key_exists($key, $this->_items)) {
|
|
unset($this->_items[$key]);
|
|
}
|
|
$success = true;
|
|
Event::handle('EndCacheDelete', array($key));
|
|
}
|
|
|
|
return $success;
|
|
}
|
|
|
|
/**
|
|
* Close or reconnect any remote connections, such as to give
|
|
* daemon processes a chance to reconnect on a fresh socket.
|
|
*
|
|
* @return boolean success flag
|
|
*/
|
|
function reconnect()
|
|
{
|
|
$success = false;
|
|
|
|
if (Event::handle('StartCacheReconnect', array(&$success))) {
|
|
$success = true;
|
|
Event::handle('EndCacheReconnect', array());
|
|
}
|
|
|
|
return $success;
|
|
}
|
|
}
|