3 * StatusNet - the distributed open-source microblogging tool
4 * Copyright (C) 2011, StatusNet, Inc.
6 * A notice stream that filters its upstream content
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 * A class for presenting a filtered notice stream based on an upstream stream
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/
48 abstract class FilteringNoticeStream extends NoticeStream
52 function __construct(NoticeStream $upstream)
54 $this->upstream = $upstream;
58 * @return boolean true if we allow it, false if we deny it
60 abstract protected function filter(Notice $notice);
62 function getNoticeIds($offset, $limit, $since_id, $max_id)
64 // "offset" is virtual; we have to get a lot
65 $total = $offset + $limit;
72 // Keep going till we have $total notices in $notices array,
73 // or we get nothing from upstream.
79 $raw = $this->upstream->getNotices($startAt, $askFor, $since_id, $max_id);
86 $notices = $raw->fetchAll();
87 $this->prefill($notices);
88 foreach ($notices as $notice) {
89 if ($this->filter($notice)) {
90 $filtered[] = $notice->id;
91 if (count($filtered) >= $total) {
97 // XXX: make these smarter; factor hit rate into $askFor
99 $hits = count($filtered);
103 $askFor = max(min(2 * $askFor, NOTICES_PER_PAGE * 50), NOTICES_PER_PAGE);
105 $askFor = max(min(intval(ceil(($total - $hits)*$startAt/$hits)), NOTICES_PER_PAGE * 50), NOTICES_PER_PAGE);
109 } while (count($filtered) < $total && $results >= $lastAsk);
111 return array_slice(array_values($filtered), $offset, $limit);
114 function prefill($notices)