Major refactoring of queue handlers to support running multiple sites in one daemon.

Key changes:
* Initialization code moved from common.php to StatusNet class;
  can now switch configurations during runtime.
* As a consequence, configuration files must now be idempotent...
  Be careful with constant, function or class definitions.
* Control structure for daemons/QueueManager/QueueHandler has been refactored;
  the run loop is now managed by IoMaster run via scripts/queuedaemon.php
  IoManager subclasses are woken to handle socket input or polling, and may
  cover multiple sites.
* Plugins can implement notice queue handlers more easily by registering a
  QueueHandler class; no more need to add a daemon.

The new QueueDaemon runs from scripts/queuedaemon.php:

* This replaces most of the old *handler.php scripts; they've been refactored
  to the bare handler classes.
* Spawns multiple child processes to spread load; defaults to CPU count on
  Linux and Mac OS X systems, or override with --threads=N
* When multithreaded, child processes are automatically respawned on failure.
* Threads gracefully shut down and restart when passing a soft memory limit
  (defaults to 90% of memory_limit), limiting damage from memory leaks.
* Support for UDP-based monitoring: http://www.gitorious.org/snqmon

Rough control flow diagram:
QueueDaemon -> IoMaster -> IoManager
                           QueueManager [listen or poll] -> QueueHandler
                           XmppManager [ping & keepalive]
                           XmppConfirmManager [poll updates]

Todo:

* Respawning features not currently available running single-threaded.
* When running single-site, configuration changes aren't picked up.
* New sites or config changes affecting queue subscriptions are not yet
  handled without a daemon restart.
* SNMP monitoring output to integrate with general tools (nagios, ganglia)
* Convert XMPP confirmation message sends to use stomp queue instead of polling
* Convert xmppdaemon.php to IoManager?
* Convert Twitter status, friends import polling daemons to IoManager
* Clean up some error reporting and failure modes
* May need to adjust queue priorities for best perf in backlog/flood cases

Detailed code history available in my daemon-work branch:
http://www.gitorious.org/~brion/statusnet/brion-fixes/commits/daemon-work

1 files changed, 18 insertions, 40 deletions

diff --git a/lib/unqueuemanager.php b/lib/unqueuemanager.php
index 72dbc4eed..5595eac05 100644
--- a/lib/unqueuemanager.php
+++ b/lib/unqueuemanager.php
@@ -23,57 +23,35 @@
  * @package   StatusNet
  * @author    Evan Prodromou <evan@status.net>
  * @author    Sarven Capadisli <csarven@status.net>
+ * @author    Brion Vibber <brion@status.net>
  * @copyright 2009 StatusNet, Inc.
  * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
  * @link      http://status.net/
  */
 
-class UnQueueManager
+class UnQueueManager extends QueueManager
 {
+
+    /**
+     * Dummy queue storage manager: instead of saving events for later,
+     * we just process them immediately. This is only suitable for events
+     * that can be processed quickly and don't need polling or long-running
+     * connections to another server such as XMPP.
+     *
+     * @param Notice $object
+     * @param string $queue
+     */
     function enqueue($object, $queue)
     {
         $notice = $object;
-
-        switch ($queue)
-        {
-         case 'omb':
-            if ($this->_isLocal($notice)) {
-                require_once(INSTALLDIR.'/lib/omb.php');
-                omb_broadcast_notice($notice);
-            }
-            break;
-         case 'public':
-            if ($this->_isLocal($notice)) {
-                require_once(INSTALLDIR.'/lib/jabber.php');
-                jabber_public_notice($notice);
-            }
-            break;
-         case 'ping':
-            if ($this->_isLocal($notice)) {
-                require_once INSTALLDIR . '/lib/ping.php';
-                return ping_broadcast_notice($notice);
-            }
-         case 'sms':
-            require_once(INSTALLDIR.'/lib/mail.php');
-            mail_broadcast_notice_sms($notice);
-            break;
-         case 'jabber':
-            require_once(INSTALLDIR.'/lib/jabber.php');
-            jabber_broadcast_notice($notice);
-            break;
-         case 'plugin':
-            Event::handle('HandleQueuedNotice', array(&$notice));
-            break;
-         default:
+        
+        $handler = $this->getHandler($queue);
+        if ($handler) {
+            $handler->handle_notice($notice);
+        } else {
             if (Event::handle('UnqueueHandleNotice', array(&$notice, $queue))) {
                 throw new ServerException("UnQueueManager: Unknown queue: $queue");
             }
         }
     }
-
-    function _isLocal($notice)
-    {
-        return ($notice->is_local == Notice::LOCAL_PUBLIC ||
-                $notice->is_local == Notice::LOCAL_NONPUBLIC);
-    }
-}
\ No newline at end of file
+}