<?php /** * StatusNet - the distributed open-source microblogging tool * Copyright (C) 2011, StatusNet, Inc. * * A notice stream that filters its upstream content * * 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); } /** * A class for presenting a filtered notice stream based on an upstream stream * * @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/ */ abstract class FilteringNoticeStream extends NoticeStream { protected $upstream; function __construct($upstream) { $this->upstream = $upstream; } abstract function filter($notice); function getNoticeIds($offset, $limit, $since_id, $max_id) { // "offset" is virtual; we have to get a lot $total = $offset + $limit; $filtered = array(); $startAt = 0; $askFor = $total; // Keep going till we have $total notices in $notices array, // or we get nothing from upstream. $results = null; $round = 0; do { $raw = $this->upstream->getNotices($startAt, $askFor, $since_id, $max_id); $results = $raw->N; if ($results == 0) { break; } $notices = $raw->fetchAll(); $this->prefill($notices); foreach ($notices as $notice) { if ($this->filter($notice)) { $filtered[] = $notice->id; if (count($filtered) >= $total) { break; } } } // XXX: make these smarter; factor hit rate into $askFor $startAt += $askFor; $hits = count($filtered); $lastAsk = $askFor; if ($hits === 0) { $askFor = max(min(2 * $askFor, NOTICES_PER_PAGE * 50), NOTICES_PER_PAGE); } else { $askFor = max(min(intval(ceil(($total - $hits)*$startAt/$hits)), NOTICES_PER_PAGE * 50), NOTICES_PER_PAGE); } $round++; } while (count($filtered) < $total && $results >= $lastAsk); return array_slice(array_values($filtered), $offset, $limit); } function prefill($notices) { return; } }