Stomp queue restructuring for mass scalability:

- Multiplexing queues into groups and for multiple sites.
- Sharing vs breakout configurable per site and per queue via $config['queue']['breakout']
- Detect how many times a message is redelivered, discard if it's killed too many daemons
 - count configurable with $config['queue']['max_retries']
 - can dump the items to files in $config['queue']['dead_letter_dir']

Queue daemon memory & resource leak fixes:
- avoid unnecessary reconnections to memcached server (switch persistent connections back in on second initialization, assuming it's child process)
- monkey-patch for leaky .ini loads in DB_DataObject::databaseStructure() - was leaking 200k per active switch
- applied leak fixes to Status_network as well, using intermediate base Safe_DataObject for both it and Memcache_DataObject

Misc queue fixes:
- correct handling of child processes exiting due to signal termination instead of regular exit
- shutdown instead of infinite respawn loop if we're already past the soft memory limit at startup
- Added --all option for xmppdaemon... still opens one xmpp connection per site that has xmpp active

Cache updates:
- add Cache::increment() method with native support for memcached atomic increment

1 files changed, 67 insertions, 30 deletions

diff --git a/lib/queuemanager.php b/lib/queuemanager.php
index 149617eb5..8f8c8f133 100644
--- a/lib/queuemanager.php
+++ b/lib/queuemanager.php
@@ -39,9 +39,10 @@ abstract class QueueManager extends IoManager
 {
     static $qm = null;
 
-    public $master = null;
-    public $handlers = array();
-    public $groups = array();
+    protected $master = null;
+    protected $handlers = array();
+    protected $groups = array();
+    protected $activeGroups = array();
 
     /**
      * Factory function to pull the appropriate QueueManager object
@@ -215,55 +216,64 @@ abstract class QueueManager extends IoManager
             if (class_exists($class)) {
                 return new $class();
             } else {
-                common_log(LOG_ERR, "Nonexistent handler class '$class' for queue '$queue'");
+                $this->_log(LOG_ERR, "Nonexistent handler class '$class' for queue '$queue'");
             }
         } else {
-            common_log(LOG_ERR, "Requested handler for unkown queue '$queue'");
+            $this->_log(LOG_ERR, "Requested handler for unkown queue '$queue'");
         }
         return null;
     }
 
     /**
      * Get a list of registered queue transport names to be used
-     * for this daemon.
+     * for listening in this daemon.
      *
      * @return array of strings
      */
-    function getQueues()
+    function activeQueues()
     {
-        $group = $this->activeGroup();
-        return array_keys($this->groups[$group]);
+        $queues = array();
+        foreach ($this->activeGroups as $group) {
+            if (isset($this->groups[$group])) {
+                $queues = array_merge($queues, $this->groups[$group]);
+            }
+        }
+
+        return array_keys($queues);
     }
 
     /**
-     * Initialize the list of queue handlers
+     * Initialize the list of queue handlers for the current site.
      *
      * @event StartInitializeQueueManager
      * @event EndInitializeQueueManager
      */
     function initialize()
     {
-        // @fixme we'll want to be able to listen to particular queues...
+        $this->handlers = array();
+        $this->groups = array();
+        $this->groupsByTransport = array();
+
         if (Event::handle('StartInitializeQueueManager', array($this))) {
-            $this->connect('plugin', 'PluginQueueHandler');
+            $this->connect('distrib', 'DistribQueueHandler');
             $this->connect('omb', 'OmbQueueHandler');
             $this->connect('ping', 'PingQueueHandler');
-            $this->connect('distrib', 'DistribQueueHandler');
             if (common_config('sms', 'enabled')) {
                 $this->connect('sms', 'SmsQueueHandler');
             }
 
             // XMPP output handlers...
-            $this->connect('jabber', 'JabberQueueHandler');
-            $this->connect('public', 'PublicQueueHandler');
-            // @fixme this should get an actual queue
-            //$this->connect('confirm', 'XmppConfirmHandler');
+            if (common_config('xmpp', 'enabled')) {
+                // Delivery prep, read by queuedaemon.php:
+                $this->connect('jabber', 'JabberQueueHandler');
+                $this->connect('public', 'PublicQueueHandler');
+
+                // Raw output, read by xmppdaemon.php:
+                $this->connect('xmppout', 'XmppOutQueueHandler', 'xmpp');
+            }
 
             // For compat with old plugins not registering their own handlers.
             $this->connect('plugin', 'PluginQueueHandler');
-
-            $this->connect('xmppout', 'XmppOutQueueHandler', 'xmppdaemon');
-
         }
         Event::handle('EndInitializeQueueManager', array($this));
     }
@@ -276,25 +286,41 @@ abstract class QueueManager extends IoManager
      * @param string $class
      * @param string $group
      */
-    public function connect($transport, $class, $group='queuedaemon')
+    public function connect($transport, $class, $group='main')
     {
         $this->handlers[$transport] = $class;
         $this->groups[$group][$transport] = $class;
+        $this->groupsByTransport[$transport] = $group;
     }
 
     /**
-     * @return string queue group to use for this request
+     * Set the active group which will be used for listening.
+     * @param string $group
      */
-    function activeGroup()
+    function setActiveGroup($group)
     {
-        $group = 'queuedaemon';
-        if ($this->master) {
-            // hack hack
-            if ($this->master instanceof XmppMaster) {
-                return 'xmppdaemon';
-            }
+        $this->activeGroups = array($group);
+    }
+
+    /**
+     * Set the active group(s) which will be used for listening.
+     * @param array $groups
+     */
+    function setActiveGroups($groups)
+    {
+        $this->activeGroups = $groups;
+    }
+
+    /**
+     * @return string queue group for this queue
+     */
+    function queueGroup($queue)
+    {
+        if (isset($this->groupsByTransport[$queue])) {
+            return $this->groupsByTransport[$queue];
+        } else {
+            throw new Exception("Requested group for unregistered transport $queue");
         }
-        return $group;
     }
 
     /**
@@ -318,4 +344,15 @@ abstract class QueueManager extends IoManager
             $monitor->stats($key, $owners);
         }
     }
+
+    protected function _log($level, $msg)
+    {
+        $class = get_class($this);
+        if ($this->activeGroups) {
+            $groups = ' (' . implode(',', $this->activeGroups) . ')';
+        } else {
+            $groups = '';
+        }
+        common_log($level, "$class$groups: $msg");
+    }
 }