diff options
Diffstat (limited to 'lib/dbqueuemanager.php')
| -rw-r--r-- | lib/dbqueuemanager.php | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/lib/dbqueuemanager.php b/lib/dbqueuemanager.php new file mode 100644 index 000000000..6e7172de0 --- /dev/null +++ b/lib/dbqueuemanager.php @@ -0,0 +1,166 @@ +<?php +/** + * Laconica, the distributed open-source microblogging tool + * + * 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 + * @package Laconica + * @author Evan Prodromou <evan@controlyourself.ca> + * @author Sarven Capadisli <csarven@controlyourself.ca> + * @copyright 2009 Control Yourself, Inc. + * @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0 + * @link http://laconi.ca/ + */ + +class DBQueueManager extends QueueManager +{ + var $qis = array(); + + function enqueue($object, $queue) + { + $notice = $object; + + $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($qi, 'INSERT', __FILE__); + throw new ServerException('DB error inserting queue item'); + } + + return true; + } + + function service($queue, $handler) + { + while (true) { + $this->_log(LOG_DEBUG, 'Checking for notices...'); + $notice = $this->_nextItem($queue, null); + if (empty($notice)) { + $this->_log(LOG_DEBUG, 'No notices waiting; idling.'); + // Nothing in the queue. Do you + // have other tasks, like servicing your + // XMPP connection, to do? + $handler->idle(QUEUE_HANDLER_MISS_IDLE); + } else { + $this->_log(LOG_INFO, 'Got notice '. $notice->id); + // Yay! Got one! + if ($handler->handle_notice($notice)) { + $this->_log(LOG_INFO, 'Successfully handled notice '. $notice->id); + $this->_done($notice, $queue); + } else { + $this->_log(LOG_INFO, 'Failed to handle notice '. $notice->id); + $this->_fail($notice, $queue); + } + // Chance to e.g. service your XMPP connection + $this->_log(LOG_DEBUG, 'Idling after success.'); + $handler->idle(QUEUE_HANDLER_HIT_IDLE); + } + // XXX: when do we give up? + } + } + + function _nextItem($queue, $timeout=null) + { + $start = time(); + $result = null; + + do { + $qi = Queue_item::top($queue); + if (!empty($qi)) { + $notice = Notice::staticGet('id', $qi->notice_id); + if (!empty($notice)) { + $result = $notice; + } else { + $this->_log(LOG_INFO, 'dequeued non-existent notice ' . $notice->id); + $qi->delete(); + $qi->free(); + $qi = null; + } + } + } while (empty($result) && (is_null($timeout) || (time() - $start) < $timeout)); + + return $result; + } + + function _done($object, $queue) + { + // XXX: right now, we only handle notices + + $notice = $object; + + $qi = Queue_item::pkeyGet(array('notice_id' => $notice->id, + 'transport' => $queue)); + + if (empty($qi)) { + $this->_log(LOG_INFO, 'Cannot find queue item for notice '.$notice->id.', queue '.$queue); + } else { + if (empty($qi->claimed)) { + $this->_log(LOG_WARNING, 'Reluctantly releasing unclaimed queue item '. + 'for '.$notice->id.', queue '.$queue); + } + $qi->delete(); + $qi->free(); + $qi = null; + } + + $this->_log(LOG_INFO, 'done with notice ID = ' . $notice->id); + + $notice->free(); + $notice = null; + } + + function _fail($object, $queue) + { + // XXX: right now, we only handle notices + + $notice = $object; + + $qi = Queue_item::pkeyGet(array('notice_id' => $notice->id, + 'transport' => $queue)); + + if (empty($qi)) { + $this->_log(LOG_INFO, 'Cannot find queue item for notice '.$notice->id.', queue '.$queue); + } else { + if (empty($qi->claimed)) { + $this->_log(LOG_WARNING, 'Ignoring failure for unclaimed queue item '. + 'for '.$notice->id.', queue '.$queue); + } else { + $orig = clone($qi); + $qi->claimed = null; + $qi->update($orig); + $qi = null; + } + } + + $this->_log(LOG_INFO, 'done with notice ID = ' . $notice->id); + + $notice->free(); + $notice = null; + } + + function _log($level, $msg) + { + common_log($level, 'DBQueueManager: '.$msg); + } +} |