break up monolithic xmppdaemon into multiple queue handlers

Eventually, the poor xmppdaemon has become overloaded with extra
tasks. So, I've broken it up. Now, we have 5 background scripts, and
more coming:

* xmppdaemon.php - handles incoming XMPP messages only.
* xmppqueuehandler.php - sends notices from the queue out through XMPP.
* smsqueuehandler.php - sends notices from the queue out over SMS
* ombqueuehandler.php - sends notices from the queue out over OMB
* xmppconfirmhandler.php - sends confirmation requests out over XMPP.

This is in addition to maildaemon.php, which takes incoming messages.

None of these are "true" daemons -- they don't daemonize themselves
automatically. Use nohup or another tool to background them. monit can
also be useful to keep them running.

At some point, these might become fork()'ing daemons, able to handle
more than one notice at a time. For now, I'm just running multiple
instances, hoping they don't interfere.

darcs-hash:20080827205407-84dde-97884a12f5f4e54c93bc785bd280683d1ee7e749.gz

1 files changed, 105 insertions, 0 deletions

diff --git a/lib/queuehandler.php b/lib/queuehandler.php
new file mode 100644
index 000000000..f12b880b1
--- /dev/null
+++ b/lib/queuehandler.php
@@ -0,0 +1,105 @@
+<?php
+/*
+ * Laconica - a distributed open-source microblogging tool
+ * Copyright (C) 2008, Controlez-Vous, Inc.
+ *
+ * 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/>.
+ */
+
+define('CLAIM_TIMEOUT', 1200);
+
+class QueueHandler {
+
+	var $_id = 'generic';
+
+	function QueueHandler($id=NULL) {
+		if ($id) {
+			$this->set_id($id);
+		}
+	}
+	
+	function class_name() {
+		return ucfirst($this->transport()) . 'Handler';
+	}
+	
+	function get_id() {
+		return $this->_id;
+	}
+
+	function set_id($id) {
+		$this->_id = $id;
+	}
+	
+	function transport() {
+		return NULL;
+	}
+	
+	function start() {
+	}
+	
+	function finish() {
+	}
+
+	function handle_notice($notice) {
+		return true;
+	}
+	
+	function handle_queue() {
+		$this->clear_old_claims();
+		$this->log(LOG_INFO, 'checking for queued notices');
+		$cnt = 0;
+		$transport = $this->transport();
+		do {
+			$qi = Queue_item::top($transport);
+			if ($qi) {
+				$this->log(LOG_INFO, 'Got item enqueued '.common_exact_date($qi->created));
+				$notice = Notice::staticGet($qi->notice_id);
+				if ($notice) {
+					$this->log(LOG_INFO, 'broadcasting notice ID = ' . $notice->id);
+					# XXX: what to do if broadcast fails?
+					$result = $this->handle_notice($notice);
+					if (!$result) {
+						$this->log(LOG_WARNING, 'Failed broadcast for notice ID = ' . $notice->id);
+						$orig = $qi;
+						$qi->claimed = NULL;
+						$qi->update($orig);
+						$this->log(LOG_WARNING, 'Abandoned claim for notice ID = ' . $notice->id);
+						continue;
+					}
+					$this->log(LOG_INFO, 'finished broadcasting notice ID = ' . $notice->id);
+					$notice = NULL;
+				} else {
+					$this->log(LOG_WARNING, 'queue item for notice that does not exist');
+				}
+				$qi->delete();
+				$cnt++;
+			} else {
+				$this->clear_old_claims();
+				sleep(10);
+			}	
+		} while (true);
+	}
+
+	function clear_old_claims() {
+		$qi = new Queue_item();
+		$qi->transport = $this->transport();
+		$qi->whereAdd('now() - claimed > '.CLAIM_TIMEOUT);
+		$qi->update(DB_DATAOBJECT_WHEREADD_ONLY);
+	}
+	
+	function log($level, $msg) {
+		common_log($level, $this->class_name() . ' ('. $this->get_id() .'): '.$msg);
+	}
+}
+	
\ No newline at end of file