First step of refactoring code (ccnx prefix => ndn prefix)
diff --git a/apps/ndn-app.cc b/apps/ndn-app.cc
new file mode 100644
index 0000000..54ea5c6
--- /dev/null
+++ b/apps/ndn-app.cc
@@ -0,0 +1,164 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
+ */
+
+#include "ndn-app.h"
+#include "ns3/log.h"
+#include "ns3/assert.h"
+#include "ns3/packet.h"
+
+#include "ns3/ndn-interest-header.h"
+#include "ns3/ndn-content-object-header.h"
+#include "ns3/ndn.h"
+#include "ns3/ndn-fib.h"
+#include "ns3/ndn-app-face.h"
+#include "ns3/ndn-forwarding-strategy.h"
+
+NS_LOG_COMPONENT_DEFINE ("NdnApp");
+
+namespace ns3
+{    
+    
+NS_OBJECT_ENSURE_REGISTERED (NdnApp);
+    
+TypeId
+NdnApp::GetTypeId (void)
+{
+  static TypeId tid = TypeId ("ns3::NdnApp")
+    .SetGroupName ("Ndn")
+    .SetParent<Application> ()
+    .AddConstructor<NdnApp> ()
+
+    .AddTraceSource ("ReceivedInterests", "ReceivedInterests",
+                    MakeTraceSourceAccessor (&NdnApp::m_receivedInterests))
+    
+    .AddTraceSource ("ReceivedNacks", "ReceivedNacks",
+                    MakeTraceSourceAccessor (&NdnApp::m_receivedNacks))
+    
+    .AddTraceSource ("ReceivedContentObjects", "ReceivedContentObjects",
+                    MakeTraceSourceAccessor (&NdnApp::m_receivedContentObjects))
+
+    .AddTraceSource ("TransmittedInterests", "TransmittedInterests",
+                    MakeTraceSourceAccessor (&NdnApp::m_transmittedInterests))
+
+    .AddTraceSource ("TransmittedContentObjects", "TransmittedContentObjects",
+                    MakeTraceSourceAccessor (&NdnApp::m_transmittedContentObjects))
+    ;
+  return tid;
+}
+    
+NdnApp::NdnApp ()
+  : m_protocolHandler (0)
+  , m_active (false)
+  , m_face (0)
+{
+}
+    
+NdnApp::~NdnApp ()
+{
+}
+
+void
+NdnApp::DoDispose (void)
+{
+  NS_LOG_FUNCTION_NOARGS ();
+
+  // Unfortunately, this causes SEGFAULT
+  // The best reason I see is that apps are freed after ndn stack is removed
+  // StopApplication ();  
+  Application::DoDispose ();
+}
+
+void
+NdnApp::RegisterProtocolHandler (ProtocolHandler handler)
+{
+  m_protocolHandler = handler;
+}
+    
+void
+NdnApp::OnInterest (const Ptr<const NdnInterestHeader> &interest, Ptr<Packet> packet)
+{
+  NS_LOG_FUNCTION (this << interest);
+  m_receivedInterests (interest, this, m_face);
+}
+
+void
+NdnApp::OnNack (const Ptr<const NdnInterestHeader> &interest, Ptr<Packet> packet)
+{
+  NS_LOG_FUNCTION (this << interest);
+  m_receivedNacks (interest, this, m_face);
+}
+
+void
+NdnApp::OnContentObject (const Ptr<const NdnContentObjectHeader> &contentObject,
+                          Ptr<Packet> payload)
+{
+  NS_LOG_FUNCTION (this << contentObject << payload);
+  m_receivedContentObjects (contentObject, payload, this, m_face);
+}
+
+// Application Methods
+void 
+NdnApp::StartApplication () // Called at time specified by Start
+{
+  NS_LOG_FUNCTION_NOARGS ();
+  
+  NS_ASSERT (m_active != true);
+  m_active = true;
+
+  NS_ASSERT_MSG (GetNode ()->GetObject<Ndn> () != 0,
+                 "Ndn stack should be installed on the node " << GetNode ());
+
+  // step 1. Create a face
+  m_face = CreateObject<NdnAppFace> (/*Ptr<NdnApp> (this)*/this);
+    
+  // step 2. Add face to the Ndn stack
+  GetNode ()->GetObject<Ndn> ()->AddFace (m_face);
+
+  // step 3. Enable face
+  m_face->SetUp (true);
+}
+    
+void 
+NdnApp::StopApplication () // Called at time specified by Stop
+{
+  NS_LOG_FUNCTION_NOARGS ();
+
+  if (!m_active) return; //don't assert here, just return
+ 
+  NS_ASSERT (GetNode ()->GetObject<Ndn> () != 0);
+
+  m_active = false;
+
+  // step 1. Disable face
+  m_face->SetUp (false);
+
+  // step 2. Remove face from Ndn stack
+  GetNode ()->GetObject<Ndn> ()->RemoveFace (m_face);
+  GetNode ()->GetObject<NdnFib> ()->RemoveFromAll (m_face);
+  GetNode ()->GetObject<NdnForwardingStrategy> ()->RemoveFace (m_face); // notify that face is removed
+
+  // step 3. Destroy face
+  NS_ASSERT_MSG (m_face->GetReferenceCount ()==1,
+                 "At this point, nobody else should have referenced this face, but we have "
+                 << m_face->GetReferenceCount () << " references");
+  m_face = 0;
+}
+
+}