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, 0 insertions, 142 deletions

diff --git a/lib/xmppqueuehandler.php b/lib/xmppqueuehandler.php
deleted file mode 100644
index f28fc9088..000000000
--- a/lib/xmppqueuehandler.php
+++ /dev/null
@@ -1,142 +0,0 @@
-<?php
-/*
- * StatusNet - the distributed open-source microblogging tool
- * Copyright (C) 2008, 2009, StatusNet, 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/>.
- */
-
-if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }
-
-require_once(INSTALLDIR.'/lib/queuehandler.php');
-
-define('PING_INTERVAL', 120);
-
-/**
- * Common superclass for all XMPP-using queue handlers. They all need to
- * service their message queues on idle, and forward any incoming messages
- * to the XMPP listener connection. So, we abstract out common code to a
- * superclass.
- */
-
-class XmppQueueHandler extends QueueHandler
-{
-    var $pingid = 0;
-    var $lastping = null;
-
-    function start()
-    {
-        # Low priority; we don't want to receive messages
-
-        $this->log(LOG_INFO, "INITIALIZE");
-        $this->conn = jabber_connect($this->_id.$this->transport());
-
-        if (empty($this->conn)) {
-            $this->log(LOG_ERR, "Couldn't connect to server.");
-            return false;
-        }
-
-        $this->conn->addEventHandler('message', 'forward_message', $this);
-        $this->conn->addEventHandler('reconnect', 'handle_reconnect', $this);
-        $this->conn->setReconnectTimeout(600);
-        jabber_send_presence("Send me a message to post a notice", 'available', null, 'available', -1);
-
-        return !is_null($this->conn);
-    }
-
-    function timeout()
-    {
-        return 10;
-    }
-
-    function handle_reconnect(&$pl)
-    {
-        $this->log(LOG_NOTICE, 'reconnected');
-
-        $this->conn->processUntil('session_start');
-        $this->conn->presence(null, 'available', null, 'available', -1);
-    }
-
-    function idle($timeout=0)
-    {
-        # Process the queue for as long as needed
-        try {
-            if ($this->conn) {
-                $this->log(LOG_DEBUG, "Servicing the XMPP queue.");
-                $this->conn->processTime($timeout);
-                $now = time();
-                if (empty($this->lastping) || $now - $this->lastping > PING_INTERVAL) {
-                    $this->sendPing();
-                    $this->lastping = $now;
-                }
-            }
-        } catch (XMPPHP_Exception $e) {
-            $this->log(LOG_ERR, "Got an XMPPHP_Exception: " . $e->getMessage());
-            die($e->getMessage());
-        }
-    }
-
-    function sendPing()
-    {
-        $jid = jabber_daemon_address().'/'.$this->_id.$this->transport();
-        $server = common_config('xmpp', 'server');
-
-        if (!isset($this->pingid)) {
-            $this->pingid = 0;
-        } else {
-            $this->pingid++;
-        }
-
-        $this->log(LOG_DEBUG, "Sending ping #{$this->pingid}");
-
-		$this->conn->send("<iq from='{$jid}' to='{$server}' id='ping_{$this->pingid}' type='get'><ping xmlns='urn:xmpp:ping'/></iq>");
-    }
-
-    function forward_message(&$pl)
-    {
-        if ($pl['type'] != 'chat') {
-            $this->log(LOG_DEBUG, 'Ignoring message of type ' . $pl['type'] . ' from ' . $pl['from']);
-            return;
-        }
-        $listener = $this->listener();
-        if (strtolower($listener) == strtolower($pl['from'])) {
-            $this->log(LOG_WARNING, 'Ignoring loop message.');
-            return;
-        }
-        $this->log(LOG_INFO, 'Forwarding message from ' . $pl['from'] . ' to ' . $listener);
-        $this->conn->message($this->listener(), $pl['body'], 'chat', null, $this->ofrom($pl['from']));
-    }
-
-    function ofrom($from)
-    {
-        $address = "<addresses xmlns='http://jabber.org/protocol/address'>\n";
-        $address .= "<address type='ofrom' jid='$from' />\n";
-        $address .= "</addresses>\n";
-        return $address;
-    }
-
-    function listener()
-    {
-        if (common_config('xmpp', 'listener')) {
-            return common_config('xmpp', 'listener');
-        } else {
-            return jabber_daemon_address() . '/' . common_config('xmpp','resource') . 'daemon';
-        }
-    }
-
-    function getSockets()
-    {
-        return array($this->conn->getSocket());
-    }
-}