3 * StatusNet - the distributed open-source microblogging tool
4 * Copyright (C) 2011, StatusNet, Inc.
10 * This program is free software: you can redistribute it and/or modify
11 * it under the terms of the GNU Affero General Public License as published by
12 * the Free Software Foundation, either version 3 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU Affero General Public License for more details.
20 * You should have received a copy of the GNU Affero General Public License
21 * along with this program. If not, see <http://www.gnu.org/licenses/>.
25 * @author Evan Prodromou <evan@status.net>
26 * @copyright 2011 StatusNet, Inc.
27 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
28 * @link http://status.net/
31 if (!defined('STATUSNET')) {
32 // This check helps protect against security problems;
33 // your code file can't be executed directly from the web.
38 * Class for notice streams
42 * @author Evan Prodromou <evan@status.net>
43 * @copyright 2011 StatusNet, Inc.
44 * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html AGPL 3.0
45 * @link http://status.net/
49 const CACHE_WINDOW = 200;
51 public $generator = null;
53 public $cachekey = null;
55 function __construct($generator, $args, $cachekey)
57 $this->generator = $generator;
59 $this->cachekey = $cachekey;
62 function getNotices($offset=0, $limit=20, $sinceId=0, $maxId=0)
64 $ids = $this->getNoticeIds($offset, $limit, $sinceId, $maxId);
66 $notices = self::getStreamByIds($ids);
71 function getNoticeIds($offset=0, $limit=20, $sinceId=0, $maxId=0)
73 $cache = Cache::instance();
75 // We cache self::CACHE_WINDOW elements at the tip of the stream.
76 // If the cache won't be hit, just generate directly.
79 $sinceId != 0 || $maxId != 0 ||
81 ($offset + $limit) > self::CACHE_WINDOW) {
82 return $this->generate($offset, $limit, $sinceId, $maxId);
85 // Check the cache to see if we have the stream.
87 $idkey = Cache::key($this->cachekey);
89 $idstr = $cache->get($idkey);
91 if ($idstr !== false) {
93 $window = explode(',', $idstr);
94 $ids = array_slice($window, $offset, $limit);
98 // Check the cache to see if we have a "last-known-good" version.
99 // The actual cache gets blown away when new notices are added, but
100 // the "last" value holds a lot of info. We might need to only generate
101 // a few at the "tip", which can bound our queries and save lots
104 $laststr = $cache->get($idkey.';last');
106 if ($laststr !== false) {
107 $window = explode(',', $laststr);
108 $last_id = $window[0];
109 $new_ids = $this->generate(0, self::CACHE_WINDOW, $last_id, 0);
111 $new_window = array_merge($new_ids, $window);
113 $new_windowstr = implode(',', $new_window);
115 $result = $cache->set($idkey, $new_windowstr);
116 $result = $cache->set($idkey . ';last', $new_windowstr);
118 $ids = array_slice($new_window, $offset, $limit);
123 // No cache hits :( Generate directly and stick the results
124 // into the cache. Note we generate the full cache window.
126 $window = $this->generate(0, self::CACHE_WINDOW, 0, 0);
128 $windowstr = implode(',', $window);
130 $result = $cache->set($idkey, $windowstr);
131 $result = $cache->set($idkey . ';last', $windowstr);
133 // Return just the slice that was requested
135 $ids = array_slice($window, $offset, $limit);
140 static function getStreamByIds($ids)
142 $cache = Cache::instance();
144 if (!empty($cache)) {
146 foreach ($ids as $id) {
147 $n = Notice::staticGet('id', $id);
152 return new ArrayWrapper($notices);
154 $notice = new Notice();
156 //if no IDs requested, just return the notice object
159 $notice->whereAdd('id in (' . implode(', ', $ids) . ')');
165 while ($notice->fetch()) {
166 $temp[$notice->id] = clone($notice);
171 foreach ($ids as $id) {
172 if (array_key_exists($id, $temp)) {
173 $wrapped[] = $temp[$id];
177 return new ArrayWrapper($wrapped);
181 function generate($offset, $limit, $sinceId, $maxId)
183 $args = array_merge($this->args, array($offset,
188 return call_user_func_array($this->generator, $args);