3 * StatusNet, the distributed open-source microblogging tool
5 * Simple-minded queue manager for storing items in the database
9 * LICENCE: This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Affero General Public License as published by
11 * the Free Software Foundation, either version 3 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU Affero General Public License for more details.
19 * You should have received a copy of the GNU Affero General Public License
20 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 * @category QueueManager
24 * @author Evan Prodromou <evan@status.net>
25 * @author Brion Vibber <brion@status.net>
26 * @copyright 2009-2010 StatusNet, Inc.
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/
31 class DBQueueManager extends QueueManager
34 * Saves an object into the queue item table.
35 * @return boolean true on success
36 * @throws ServerException on failure
38 public function enqueue($object, $queue)
40 $qi = new Queue_item();
42 $qi->frame = serialize($object);
43 $qi->transport = $queue;
44 $qi->created = common_sql_now();
45 $result = $qi->insert();
48 common_log_db_error($qi, 'INSERT', __FILE__);
49 throw new ServerException('DB error inserting queue item');
52 $this->stats('enqueued', $queue);
58 * Poll every minute for new events during idle periods.
59 * We'll look in more often when there's data available.
63 public function pollInterval()
69 * Run a polling cycle during idle processing in the input loop.
70 * @return boolean true if we had a hit
72 public function poll()
74 $this->_log(LOG_DEBUG, 'Checking for queued objects...');
75 $qi = $this->_nextItem();
77 $this->_log(LOG_DEBUG, 'No queue items waiting; idling.');
81 // We dequeued an entry for a deleted or invalid object.
82 // Consider it a hit for poll rate purposes.
86 $queue = $qi->transport;
87 $object = unserialize($qi->frame);
88 $this->_log(LOG_INFO, 'Got item id=' . $qi->id . ' for transport ' . $queue);
91 $handler = $this->getHandler($queue);
93 if ($handler->handle($object)) {
94 $this->_log(LOG_INFO, "[$queue] Successfully handled object");
97 $this->_log(LOG_INFO, "[$queue] Failed to handle object");
101 $this->_log(LOG_INFO, "[$queue] No handler for queue $queue; discarding.");
108 * Pop the oldest unclaimed item off the queue set and claim it.
110 * @return mixed false if no items; true if bogus hit; otherwise Queue_item
112 protected function _nextItem()
117 $qi = Queue_item::top();
126 * Delete our claimed item from the queue after successful processing.
128 * @param QueueItem $qi
130 protected function _done($qi)
133 $this->_log(LOG_INFO, "_done passed an empty queue item");
135 if (empty($qi->claimed)) {
136 $this->_log(LOG_WARNING, "Reluctantly releasing unclaimed queue item");
142 $this->_log(LOG_INFO, "done with item");
146 * Free our claimed queue item for later reprocessing in case of
149 * @param QueueItem $qi
151 protected function _fail($qi)
154 $this->_log(LOG_INFO, "_fail passed an empty queue item");
156 if (empty($qi->claimed)) {
157 $this->_log(LOG_WARNING, "Ignoring failure for unclaimed queue item");
166 $this->_log(LOG_INFO, "done with queue item");
169 protected function _log($level, $msg)
171 common_log($level, 'DBQueueManager: '.$msg);