From e5b758dbbef6774943abf453a43114a2c3371b4a Mon Sep 17 00:00:00 2001
From: Evan Prodromou <evan@controlyourself.ca>
Date: Sun, 28 Jun 2009 14:38:31 -0400
Subject: [PATCH] start of queuemanager code

---
 lib/dbqueuemanager.php    | 106 +++++++++++++++++++++++++++++++++
 lib/queuemanager.php      |  78 ++++++++++++++++++++++++
 lib/stompqueuemanager.php | 122 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 306 insertions(+)
 create mode 100644 lib/dbqueuemanager.php
 create mode 100644 lib/queuemanager.php
 create mode 100644 lib/stompqueuemanager.php

diff --git a/lib/dbqueuemanager.php b/lib/dbqueuemanager.php
new file mode 100644
index 0000000000..c0d4dcd293
--- /dev/null
+++ b/lib/dbqueuemanager.php
@@ -0,0 +1,106 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * Simple-minded queue manager for storing items in the database
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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/>.
+ *
+ * @category  QueueManager
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @author    Sarven Capadisli <csarven@controlyourself.ca>
+ * @copyright 2009 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+class DBQueueManager extends QueueManager
+{
+    var $qis = array();
+
+    function enqueue($object, $queue)
+    {
+        $notice = (Notice)$object;
+
+        $qi = new Queue_item();
+
+        $qi->notice_id = $notice->id;
+        $qi->transport = $queue;
+        $qi->created   = $notice->created;
+        $result        = $qi->insert();
+
+        if (!$result) {
+            common_log_db_error($qi, 'INSERT', __FILE__);
+            throw new ServerException('DB error inserting queue item');
+        }
+
+        return true;
+    }
+
+    function nextItem($queue, $timeout=null)
+    {
+        $start = time();
+        $result = null;
+
+        do {
+            $qi = Queue_item::top($queue);
+            if (!empty($qi)) {
+                $notice = Notice::staticGet('id', $qi->notice_id);
+                if (!empty($notice)) {
+                    $result = $notice;
+                } else {
+                    $this->_log(LOG_INFO, 'dequeued non-existent notice ' . $notice->id);
+                    $qi->delete();
+                    $qi->free();
+                    $qi = null;
+                }
+            }
+        } while (empty($result) && (is_null($timeout) || (time() - $start) < $timeout));
+
+        return $result;
+    }
+
+    function done($object, $queue)
+    {
+        $notice = (Notice)$object;
+
+        $qi = Queue_item::pkeyGet(array('notice_id' => $notice->id,
+                                        'transport' => $queue));
+
+        if (empty($qi)) {
+            $this->log(LOG_INFO, 'Cannot find queue item for notice '.$notice->id.', queue '.$queue);
+        } else {
+            if (empty($qi->claimed)) {
+                $this->log(LOG_WARNING, 'Reluctantly releasing unclaimed queue item '.
+                           'for '.$notice->id.', queue '.$queue);
+            }
+            $qi->delete();
+            $qi->free();
+            $qi = null;
+        }
+
+        $this->log(LOG_INFO, 'done with notice ID = ' . $notice->id);
+
+        $notice->free();
+        $notice = null;
+    }
+
+    function _log($level, $msg)
+    {
+        common_log($level, 'DBQueueManager: '.$msg);
+    }
+}
diff --git a/lib/queuemanager.php b/lib/queuemanager.php
new file mode 100644
index 0000000000..64aca1bc12
--- /dev/null
+++ b/lib/queuemanager.php
@@ -0,0 +1,78 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * Abstract class for queue managers
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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/>.
+ *
+ * @category  QueueManager
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @author    Sarven Capadisli <csarven@controlyourself.ca>
+ * @copyright 2009 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+class QueueManager
+{
+    static $qm = null;
+
+    static function get()
+    {
+        if (empty(self::$qm)) {
+
+            if (Event::handle('StartNewQueueManager', self::$qm)) {
+
+                $type = common_config('queue', 'sub');
+
+                switch ($type) {
+                 case 'db':
+                    self::$qm = new DBQueueManager();
+                    break;
+                 case 'stomp':
+                    self::$qm = new StompQueueManager();
+                    break;
+                 default:
+                    throw new ServerException("No queue manager class for type '$type'");
+                }
+            }
+
+            return self::$qm;
+        }
+    }
+
+    function enqueue($object, $queue)
+    {
+        throw ServerException("Unimplemented function 'enqueue' called");
+    }
+
+    function peek($queue)
+    {
+        throw ServerException("Unimplemented function 'peek' called");
+    }
+
+    function nextItem($queue, $timeout=null)
+    {
+        throw ServerException("Unimplemented function 'nextItem' called");
+    }
+
+    function done($object, $queue)
+    {
+        throw ServerException("Unimplemented function 'done' called");
+    }
+}
diff --git a/lib/stompqueuemanager.php b/lib/stompqueuemanager.php
new file mode 100644
index 0000000000..20c6e7a341
--- /dev/null
+++ b/lib/stompqueuemanager.php
@@ -0,0 +1,122 @@
+<?php
+/**
+ * Laconica, the distributed open-source microblogging tool
+ *
+ * Abstract class for queue managers
+ *
+ * PHP version 5
+ *
+ * LICENCE: 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/>.
+ *
+ * @category  QueueManager
+ * @package   Laconica
+ * @author    Evan Prodromou <evan@controlyourself.ca>
+ * @author    Sarven Capadisli <csarven@controlyourself.ca>
+ * @copyright 2009 Control Yourself, Inc.
+ * @license   http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
+ * @link      http://laconi.ca/
+ */
+
+require_once 'Stomp.php';
+
+class QueueManager
+{
+    var $server = null;
+    var $username = null;
+    var $password = null;
+    var $base = null;
+    var $con = null;
+    var $frames = array();
+
+    function __construct()
+    {
+        $this->server   = common_config('queue', 'stomp_server');
+        $this->username = common_config('queue', 'stomp_username');
+        $this->password = common_config('queue', 'stomp_password');
+        $this->base     = common_config('queue', 'queue_basename');
+    }
+
+    function _connect()
+    {
+        if (empty($this->con)) {
+            $this->con = new Stomp($this->server);
+
+            if (!$this->con->connect($this->username, $this->password)) {
+                $this->_log(LOG_ERR, 'Failed to connect to queue server');
+                throw new ServerException('Failed to connect to queue server');
+            }
+        }
+    }
+
+    function enqueue($object, $queue)
+    {
+        $notice = (Notice)$object;
+
+        $this->_connect();
+
+        $result = $this->con->send($this->_queueName($queue),
+                                   $notice->id, 		// BODY of the message
+                                   array ('created' => $notice->created));
+
+        if (!$result) {
+            common_log(LOG_ERR, 'Error sending to '.$transport.' queue');
+            return false;
+        }
+
+        common_log(LOG_DEBUG, 'complete remote queueing notice ID = '
+                   . $notice->id . ' for ' . $transport);
+    }
+
+    function nextItem($queue, $timeout=null)
+    {
+        $result = null;
+
+        $this->_connect();
+
+        $frame = $this->con->readFrame();
+
+        if ($frame) {
+            $this->log(LOG_INFO, 'Got item enqueued '.common_exact_date($frame->headers['created']));
+
+            // XXX: Now the queue handler receives only the ID of the
+            // notice, and it has to get it from the DB
+            // A massive improvement would be avoid DB query by transmitting
+            // all the notice details via queue server...
+            $notice = Notice::staticGet($frame->body);
+
+            if ($notice) {
+            } else {
+                $this->log(LOG_WARNING, 'queue item for notice that does not exist');
+            }
+        }
+    }
+
+    function done($object, $queue)
+    {
+        $notice = (Notice)$object;
+
+        $this->_connect();
+
+        $frame = $this->_getFrame($notice, $queue);
+
+        if (empty($frame)) {
+            $this->log(LOG_ERR, 'Cannot find frame for notice '.$notice->id.' in queue '.$queue);
+        } else {
+            // if the msg has been handled positively, ack it
+            // and the queue server will remove it from the queue
+            $this->con->ack($frame);
+            $this->log(LOG_INFO, 'finished broadcasting notice ID = ' . $notice->id);
+        }
+    }
+}