130 lines
4.0 KiB
PHP
130 lines
4.0 KiB
PHP
<?php
|
|
/**
|
|
* StatusNet - the distributed open-source microblogging tool
|
|
* Copyright (C) 2011, StatusNet, Inc.
|
|
*
|
|
* A stream of notices
|
|
*
|
|
* 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 Stream
|
|
* @package StatusNet
|
|
* @author Evan Prodromou <evan@status.net>
|
|
* @copyright 2011 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);
|
|
}
|
|
|
|
/**
|
|
* Class for notice streams
|
|
*
|
|
* @category Stream
|
|
* @package StatusNet
|
|
* @author Evan Prodromou <evan@status.net>
|
|
* @copyright 2011 StatusNet, Inc.
|
|
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
|
|
* @link http://status.net/
|
|
*/
|
|
|
|
class CachingNoticeStream extends NoticeStream
|
|
{
|
|
const CACHE_WINDOW = 200;
|
|
|
|
public $stream = null;
|
|
public $cachekey = null;
|
|
|
|
function __construct($stream, $cachekey)
|
|
{
|
|
$this->stream = $stream;
|
|
$this->cachekey = $cachekey;
|
|
}
|
|
|
|
function getNoticeIds($offset=0, $limit=20, $sinceId=0, $maxId=0)
|
|
{
|
|
$cache = Cache::instance();
|
|
|
|
// We cache self::CACHE_WINDOW elements at the tip of the stream.
|
|
// If the cache won't be hit, just generate directly.
|
|
|
|
if (empty($cache) ||
|
|
$sinceId != 0 || $maxId != 0 ||
|
|
is_null($limit) ||
|
|
($offset + $limit) > self::CACHE_WINDOW) {
|
|
return $this->stream->getNoticeIds($offset, $limit, $sinceId, $maxId);
|
|
}
|
|
|
|
// Check the cache to see if we have the stream.
|
|
|
|
$idkey = Cache::key($this->cachekey);
|
|
|
|
$idstr = $cache->get($idkey);
|
|
|
|
if ($idstr !== false) {
|
|
// Cache hit! Woohoo!
|
|
$window = explode(',', $idstr);
|
|
$ids = array_slice($window, $offset, $limit);
|
|
return $ids;
|
|
}
|
|
|
|
// Check the cache to see if we have a "last-known-good" version.
|
|
// The actual cache gets blown away when new notices are added, but
|
|
// the "last" value holds a lot of info. We might need to only generate
|
|
// a few at the "tip", which can bound our queries and save lots
|
|
// of time.
|
|
|
|
$laststr = $cache->get($idkey.';last');
|
|
|
|
if ($laststr !== false) {
|
|
$window = explode(',', $laststr);
|
|
$last_id = $window[0];
|
|
$new_ids = $this->stream->getNoticeIds(0, self::CACHE_WINDOW, $last_id, 0);
|
|
|
|
$new_window = array_merge($new_ids, $window);
|
|
|
|
$new_windowstr = implode(',', $new_window);
|
|
|
|
$result = $cache->set($idkey, $new_windowstr);
|
|
$result = $cache->set($idkey . ';last', $new_windowstr);
|
|
|
|
$ids = array_slice($new_window, $offset, $limit);
|
|
|
|
return $ids;
|
|
}
|
|
|
|
// No cache hits :( Generate directly and stick the results
|
|
// into the cache. Note we generate the full cache window.
|
|
|
|
$window = $this->stream->getNoticeIds(0, self::CACHE_WINDOW, 0, 0);
|
|
|
|
$windowstr = implode(',', $window);
|
|
|
|
$result = $cache->set($idkey, $windowstr);
|
|
$result = $cache->set($idkey . ';last', $windowstr);
|
|
|
|
// Return just the slice that was requested
|
|
|
|
$ids = array_slice($window, $offset, $limit);
|
|
|
|
return $ids;
|
|
}
|
|
}
|