QPID-1567: Initial support for asynchronous queue state replication

* Added QueueEvents class with per broker instance
* Modified qpid::broker::Queue to notify QueueEvents of enqueues and dequeues (based on configuration)
* Added replication subdir containing two plugins:
  - an event listener that registers with QueueEvents and creates messages representing received 
    events on a replication queue
  - a custom exchange type for processing messages of the format created by the listener plugin
* Added new option for controlling event generation to qpid::client::QueueOptions
* Added new queue option to qpid-config script for the same



git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@734674 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 87 insertions, 0 deletions

diff --git a/cpp/src/qpid/broker/QueueEvents.cpp b/cpp/src/qpid/broker/QueueEvents.cpp
new file mode 100644
index 0000000000..a6517e1bfe
--- /dev/null
+++ b/cpp/src/qpid/broker/QueueEvents.cpp
@@ -0,0 +1,87 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include "QueueEvents.h"
+#include "qpid/Exception.h"
+
+namespace qpid {
+namespace broker {
+
+QueueEvents::QueueEvents(const boost::shared_ptr<sys::Poller>& poller) : 
+    eventQueue(boost::bind(&QueueEvents::handle, this, _1), poller) 
+{
+    eventQueue.start();
+}
+
+QueueEvents::~QueueEvents() 
+{
+    eventQueue.stop();
+}
+
+void QueueEvents::enqueued(const QueuedMessage& m)
+{
+    eventQueue.push(Event(ENQUEUE, m));
+}
+
+void QueueEvents::dequeued(const QueuedMessage& m)
+{
+    eventQueue.push(Event(DEQUEUE, m));
+}
+
+void QueueEvents::registerListener(const std::string& id, const EventListener& listener)
+{
+    qpid::sys::Mutex::ScopedLock l(lock);
+    if (listeners.find(id) == listeners.end()) {
+        listeners[id] = listener;
+    } else {
+        throw Exception(QPID_MSG("Event listener already registered for '" << id << "'"));
+    }
+}
+
+void QueueEvents::unregisterListener(const std::string& id)
+{
+    qpid::sys::Mutex::ScopedLock l(lock);
+    if (listeners.find(id) == listeners.end()) {
+        throw Exception(QPID_MSG("No event listener registered for '" << id << "'"));
+    } else {
+        listeners.erase(id);
+    }
+}
+
+void QueueEvents::handle(EventQueue::Queue& events)
+{
+    qpid::sys::Mutex::ScopedLock l(lock);
+    while (!events.empty()) {
+        for (Listeners::iterator i = listeners.begin(); i != listeners.end(); i++) {
+            i->second(events.front());
+        }
+        events.pop_front();
+    }
+}
+
+void QueueEvents::shutdown()
+{
+    if (!eventQueue.empty() && !listeners.empty()) eventQueue.shutdown();
+}
+
+QueueEvents::Event::Event(EventType t, const QueuedMessage& m) : type(t), msg(m) {}
+
+
+}} // namespace qpid::broker