lib/queuehandler.php

   1 <?php
   2 /*
   3  * Laconica - a distributed open-source microblogging tool
   4  * Copyright (C) 2008, Controlez-Vous, Inc.
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Affero General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Affero General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Affero General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 define('CLAIM_TIMEOUT', 1200);
  21
  22 class QueueHandler {
  23
  24         var $_id = 'generic';
  25
  26         function QueueHandler($id=NULL) {
  27                 if ($id) {
  28                         $this->set_id($id);
  29                 }
  30         }
  31
  32         function class_name() {
  33                 return ucfirst($this->transport()) . 'Handler';
  34         }
  35
  36         function get_id() {
  37                 return $this->_id;
  38         }
  39
  40         function set_id($id) {
  41                 $this->_id = $id;
  42         }
  43
  44         function transport() {
  45                 return NULL;
  46         }
  47
  48         function start() {
  49         }
  50
  51         function finish() {
  52         }
  53
  54         function handle_notice($notice) {
  55                 return true;
  56         }
  57
  58         function handle_queue() {
  59                 $this->log(LOG_INFO, 'checking for queued notices');
  60                 $cnt = 0;
  61                 $transport = $this->transport();
  62                 do {
  63                         $qi = Queue_item::top($transport);
  64                         if ($qi) {
  65                                 $this->log(LOG_INFO, 'Got item enqueued '.common_exact_date($qi->created));
  66                                 $notice = Notice::staticGet($qi->notice_id);
  67                                 if ($notice) {
  68                                         $this->log(LOG_INFO, 'broadcasting notice ID = ' . $notice->id);
  69                                         # XXX: what to do if broadcast fails?
  70                                         $result = $this->handle_notice($notice);
  71                                         if (!$result) {
  72                                                 $this->log(LOG_WARNING, 'Failed broadcast for notice ID = ' . $notice->id);
  73                                                 $orig = $qi;
  74                                                 $qi->claimed = NULL;
  75                                                 $qi->update($orig);
  76                                                 $this->log(LOG_WARNING, 'Abandoned claim for notice ID = ' . $notice->id);
  77                                                 continue;
  78                                         }
  79                                         $this->log(LOG_INFO, 'finished broadcasting notice ID = ' . $notice->id);
  80                                         $notice = NULL;
  81                                 } else {
  82                                         $this->log(LOG_WARNING, 'queue item for notice that does not exist');
  83                                 }
  84                                 $qi->delete();
  85                                 $cnt++;
  86                         } else {
  87                                 $this->clear_old_claims();
  88                                 sleep(10);
  89                         }
  90                 } while (true);
  91         }
  92
  93         function clear_old_claims() {
  94                 $qi = new Queue_item();
  95                 $qi->transport = $this->transport();
  96                 $qi->whereAdd('now() - claimed > '.CLAIM_TIMEOUT);
  97                 $qi->update(DB_DATAOBJECT_WHEREADD_ONLY);
  98         }
  99
 100         function log($level, $msg) {
 101                 common_log($level, $this->class_name() . ' ('. $this->get_id() .'): '.$msg);
 102         }
 103 }
 104