We are no longer offering accounts on this server. Consider https://gitlab.freedesktop.org/ as a place to host projects.

dbqueuemanager.php 6.24 KB
Newer Older
Evan Prodromou's avatar
Evan Prodromou committed
1 2
<?php
/**
3
 * StatusNet, the distributed open-source microblogging tool
Evan Prodromou's avatar
Evan Prodromou committed
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
 *
 * Simple-minded queue manager for storing items in the database
 *
 * 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  QueueManager
23
 * @package   StatusNet
24
 * @author    Evan Prodromou <evan@status.net>
25 26
 * @author    Brion Vibber <brion@status.net>
 * @copyright 2009-2010 StatusNet, Inc.
Evan Prodromou's avatar
Evan Prodromou committed
27
 * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
28
 * @link      http://status.net/
Evan Prodromou's avatar
Evan Prodromou committed
29 30 31 32
 */

class DBQueueManager extends QueueManager
{
33 34 35 36 37 38
    /**
     * Saves a notice object reference into the queue item table.
     * @return boolean true on success
     * @throws ServerException on failure
     */
    public function enqueue($object, $queue)
Evan Prodromou's avatar
Evan Prodromou committed
39
    {
40
        $notice = $object;
Evan Prodromou's avatar
Evan Prodromou committed
41 42 43 44 45 46 47 48 49 50 51 52 53

        $qi = new Queue_item();

        $qi->notice_id = $notice->id;
        $qi->transport = $queue;
        $qi->created   = $notice->created;
        $result        = $qi->insert();

        if (!$result) {
            common_log_db_error($qi, 'INSERT', __FILE__);
            throw new ServerException('DB error inserting queue item');
        }

54 55
        $this->stats('enqueued', $queue);

Evan Prodromou's avatar
Evan Prodromou committed
56 57 58
        return true;
    }

59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74
    /**
     * Poll every minute for new events during idle periods.
     * We'll look in more often when there's data available.
     *
     * @return int seconds
     */
    public function pollInterval()
    {
        return 60;
    }

    /**
     * Run a polling cycle during idle processing in the input loop.
     * @return boolean true if we had a hit
     */
    public function poll()
75
    {
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96
        $this->_log(LOG_DEBUG, 'Checking for notices...');
        $item = $this->_nextItem();
        if ($item === false) {
            $this->_log(LOG_DEBUG, 'No notices waiting; idling.');
            return false;
        }
        if ($item === true) {
            // We dequeued an entry for a deleted or invalid notice.
            // Consider it a hit for poll rate purposes.
            return true;
        }

        list($queue, $notice) = $item;
        $this->_log(LOG_INFO, 'Got notice '. $notice->id . ' for transport ' . $queue);

        // Yay! Got one!
        $handler = $this->getHandler($queue);
        if ($handler) {
            if ($handler->handle_notice($notice)) {
                $this->_log(LOG_INFO, "[$queue:notice $notice->id] Successfully handled notice");
                $this->_done($notice, $queue);
97
            } else {
98 99
                $this->_log(LOG_INFO, "[$queue:notice $notice->id] Failed to handle notice");
                $this->_fail($notice, $queue);
100
            }
101
        } else {
102 103
            $this->_log(LOG_INFO, "[$queue:notice $notice->id] No handler for queue $queue; discarding.");
            $this->_done($notice, $queue);
104
        }
105
        return true;
106 107
    }

108 109 110 111 112 113 114
    /**
     * Pop the oldest unclaimed item off the queue set and claim it.
     *
     * @return mixed false if no items; true if bogus hit; otherwise array(string, Notice)
     *               giving the queue transport name.
     */
    protected function _nextItem()
Evan Prodromou's avatar
Evan Prodromou committed
115 116 117 118
    {
        $start = time();
        $result = null;

119 120 121 122
        $qi = Queue_item::top();
        if (empty($qi)) {
            return false;
        }
123

124 125 126 127 128 129 130
        $queue = $qi->transport;
        $notice = Notice::staticGet('id', $qi->notice_id);
        if (empty($notice)) {
            $this->_log(LOG_INFO, "[$queue:notice $notice->id] dequeued non-existent notice");
            $qi->delete();
            return true;
        }
Evan Prodromou's avatar
Evan Prodromou committed
131

132 133
        $result = $notice;
        return array($queue, $notice);
Evan Prodromou's avatar
Evan Prodromou committed
134 135
    }

136 137 138 139 140 141 142
    /**
     * Delete our claimed item from the queue after successful processing.
     *
     * @param Notice $object
     * @param string $queue
     */
    protected function _done($object, $queue)
Evan Prodromou's avatar
Evan Prodromou committed
143
    {
144 145 146
        // XXX: right now, we only handle notices

        $notice = $object;
Evan Prodromou's avatar
Evan Prodromou committed
147 148 149 150 151

        $qi = Queue_item::pkeyGet(array('notice_id' => $notice->id,
                                        'transport' => $queue));

        if (empty($qi)) {
152
            $this->_log(LOG_INFO, "[$queue:notice $notice->id] Cannot find queue item");
Evan Prodromou's avatar
Evan Prodromou committed
153 154
        } else {
            if (empty($qi->claimed)) {
155
                $this->_log(LOG_WARNING, "[$queue:notice $notice->id] Reluctantly releasing unclaimed queue item");
Evan Prodromou's avatar
Evan Prodromou committed
156 157 158 159 160
            }
            $qi->delete();
            $qi->free();
        }

161 162
        $this->_log(LOG_INFO, "[$queue:notice $notice->id] done with item");
        $this->stats('handled', $queue);
163 164 165 166

        $notice->free();
    }

167 168 169 170 171 172 173 174
    /**
     * Free our claimed queue item for later reprocessing in case of
     * temporary failure.
     *
     * @param Notice $object
     * @param string $queue
     */
    protected function _fail($object, $queue)
175 176 177 178 179 180 181 182 183
    {
        // XXX: right now, we only handle notices

        $notice = $object;

        $qi = Queue_item::pkeyGet(array('notice_id' => $notice->id,
                                        'transport' => $queue));

        if (empty($qi)) {
184
            $this->_log(LOG_INFO, "[$queue:notice $notice->id] Cannot find queue item");
185 186
        } else {
            if (empty($qi->claimed)) {
187
                $this->_log(LOG_WARNING, "[$queue:notice $notice->id] Ignoring failure for unclaimed queue item");
188 189 190 191 192 193 194 195
            } else {
                $orig = clone($qi);
                $qi->claimed = null;
                $qi->update($orig);
                $qi = null;
            }
        }

196 197
        $this->_log(LOG_INFO, "[$queue:notice $notice->id] done with queue item");
        $this->stats('error', $queue);
Evan Prodromou's avatar
Evan Prodromou committed
198 199 200 201

        $notice->free();
    }

202
    protected function _log($level, $msg)
Evan Prodromou's avatar
Evan Prodromou committed
203 204 205 206
    {
        common_log($level, 'DBQueueManager: '.$msg);
    }
}