Added Dispatcher class (plus test). This converts incoming MessageTransfer framesets to Messages and pumps them to registered listeners.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@576935 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 150 insertions, 0 deletions

diff --git a/cpp/src/qpid/client/Dispatcher.cpp b/cpp/src/qpid/client/Dispatcher.cpp
new file mode 100644
index 0000000000..8f3ed8bcbe
--- /dev/null
+++ b/cpp/src/qpid/client/Dispatcher.cpp
@@ -0,0 +1,150 @@
+/*
+ *
+ * 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 "Dispatcher.h"
+
+#include "qpid/client/Session.h"
+#include "qpid/framing/FrameSet.h"
+#include "qpid/framing/MessageTransferBody.h"
+#include "qpid/log/Statement.h"
+#include "BlockingQueue.h"
+#include "ClientMessage.h"
+
+using qpid::framing::FrameSet;
+using qpid::framing::MessageTransferBody;
+using qpid::sys::Mutex;
+using qpid::sys::ScopedLock;
+using qpid::sys::Thread;
+
+namespace qpid {
+namespace client {
+
+    Subscriber::Subscriber(Session& s, MessageListener* l, bool a, uint f) : session(s), listener(l), autoAck(a), ackFrequency(f), count(0) {}
+
+void Subscriber::received(Message& msg)
+{
+    if (listener) {
+        listener->received(msg);
+        if (autoAck) {
+            bool send = (++count >= ackFrequency);
+            msg.acknowledge(session, true, send);
+            if (send) count = 0;
+        }
+    }
+}
+
+
+    Dispatcher::Dispatcher(Session& s, const std::string& q) : session(s), queue(q), running(false), stopped(false)
+{
+}
+
+void Dispatcher::start()
+{
+    worker = Thread(this);
+}
+
+void Dispatcher::run()
+{    
+    BlockingQueue<FrameSet::shared_ptr>& q = queue.empty() ? 
+        session.execution().getDemux().getDefault() : 
+        session.execution().getDemux().get(queue); 
+
+    startRunning();
+    stopped = false;
+    while (!isStopped()) {
+        FrameSet::shared_ptr content = q.pop();
+        if (content->isA<MessageTransferBody>()) {
+            Message msg(*content);
+            Subscriber::shared_ptr listener = find(msg.getDestination());
+            if (!listener) {
+                QPID_LOG(error, "No message listener set: " << content->getMethod());                                        
+            } else {
+                listener->received(msg);
+            }
+        } else {
+            if (handler.get()) {
+                handler->handle(*content);
+            } else {
+                QPID_LOG(error, "Unhandled method: " << content->getMethod());                                        
+            }
+        }
+    }
+    stopRunning();
+}
+
+void Dispatcher::stop()
+{
+    ScopedLock<Mutex> l(lock);
+    stopped = true;
+}
+
+bool Dispatcher::isStopped()
+{
+    ScopedLock<Mutex> l(lock);
+    return stopped;
+}
+
+/**
+ * Prevent concurrent threads invoking run.
+ */
+void Dispatcher::startRunning()
+{
+    ScopedLock<Mutex> l(lock);
+    if (running) {
+        throw Exception("Dispatcher is already running.");
+    }
+    running = true;
+}
+
+void Dispatcher::stopRunning()
+{
+    ScopedLock<Mutex> l(lock);
+    running = false;
+}
+
+Subscriber::shared_ptr Dispatcher::find(const std::string& name)
+{
+    ScopedLock<Mutex> l(lock);
+    Listeners::iterator i = listeners.find(name);
+    if (i == listeners.end()) {
+        return defaultListener;
+    }
+    return i->second;
+}
+
+void Dispatcher::listen(MessageListener* listener, bool autoAck, uint ackFrequency)
+{
+    ScopedLock<Mutex> l(lock);
+    defaultListener = Subscriber::shared_ptr(new Subscriber(session, listener, autoAck, ackFrequency));
+}
+
+void Dispatcher::listen(const std::string& destination, MessageListener* listener, bool autoAck, uint ackFrequency)
+{
+    ScopedLock<Mutex> l(lock);
+    listeners[destination] = Subscriber::shared_ptr(new Subscriber(session, listener, autoAck, ackFrequency));
+}
+
+void Dispatcher::cancel(const std::string& destination)
+{
+    ScopedLock<Mutex> l(lock);
+    listeners.erase(destination);
+}
+
+}}