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 if (!defined('LACONICA')) { exit(1); }
  23
  24 require_once(INSTALLDIR.'/lib/daemon.php');
  25
  26 class QueueHandler extends Daemon {
  27
  28         var $_id = 'generic';
  29
  30         function QueueHandler($id=NULL) {
  31                 if ($id) {
  32                         $this->set_id($id);
  33                 }
  34         }
  35
  36         function class_name() {
  37                 return ucfirst($this->transport()) . 'Handler';
  38         }
  39
  40         function name() {
  41                 return strtolower($this->class_name().'.'.$this->get_id());
  42         }
  43
  44         function get_id() {
  45                 return $this->_id;
  46         }
  47
  48         function set_id($id) {
  49                 $this->_id = $id;
  50         }
  51
  52         function transport() {
  53                 return NULL;
  54         }
  55
  56         function start() {
  57         }
  58
  59         function finish() {
  60         }
  61
  62         function handle_notice($notice) {
  63                 return true;
  64         }
  65
  66         function run() {
  67                 if (!$this->start()) {
  68                         return false;
  69                 }
  70                 $this->log(LOG_INFO, 'checking for queued notices');
  71                 $transport = $this->transport();
  72                 do {
  73                         $qi = Queue_item::top($transport);
  74                         if ($qi) {
  75                                 $this->log(LOG_INFO, 'Got item enqueued '.common_exact_date($qi->created));
  76                                 $notice = Notice::staticGet($qi->notice_id);
  77                                 if ($notice) {
  78                                         $this->log(LOG_INFO, 'broadcasting notice ID = ' . $notice->id);
  79                                         # XXX: what to do if broadcast fails?
  80                                         $result = $this->handle_notice($notice);
  81                                         if (!$result) {
  82                                                 $this->log(LOG_WARNING, 'Failed broadcast for notice ID = ' . $notice->id);
  83                                                 $orig = $qi;
  84                                                 $qi->claimed = NULL;
  85                                                 $qi->update($orig);
  86                                                 $this->log(LOG_WARNING, 'Abandoned claim for notice ID = ' . $notice->id);
  87                                                 continue;
  88                                         }
  89                                         $this->log(LOG_INFO, 'finished broadcasting notice ID = ' . $notice->id);
  90                                         $notice = NULL;
  91                                 } else {
  92                                         $this->log(LOG_WARNING, 'queue item for notice that does not exist');
  93                                 }
  94                                 $qi->delete();
  95                                 $this->idle(0);
  96                         } else {
  97                                 $this->clear_old_claims();
  98                                 $this->idle(5);
  99                         }
 100                 } while (true);
 101                 if (!$this->finish()) {
 102                         return false;
 103                 }
 104                 return true;
 105         }
 106
 107         function idle($timeout=0) {
 108                 if ($timeout>0) {
 109                         sleep($timeout);
 110                 }
 111         }
 112
 113         function clear_old_claims() {
 114                 $qi = new Queue_item();
 115                 $qi->transport = $this->transport();
 116                 $qi->whereAdd('now() - claimed > '.CLAIM_TIMEOUT);
 117                 $qi->update(DB_DATAOBJECT_WHEREADD_ONLY);
 118         }
 119
 120         function log($level, $msg) {
 121                 common_log($level, $this->class_name() . ' ('. $this->get_id() .'): '.$msg);
 122         }
 123 }
 124