app+utils+doc: Adding application-level trace helper to record Interest-Data delays
diff --git a/utils/tracers/ndn-app-delay-tracer.h b/utils/tracers/ndn-app-delay-tracer.h
new file mode 100644
index 0000000..af0007f
--- /dev/null
+++ b/utils/tracers/ndn-app-delay-tracer.h
@@ -0,0 +1,109 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013 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>
+ */
+
+#ifndef CCNX_APP_DELAY_TRACER_H
+#define CCNX_APP_DELAY_TRACER_H
+
+#include "ns3/ptr.h"
+#include "ns3/simple-ref-count.h"
+#include <ns3/nstime.h>
+#include <ns3/event-id.h>
+
+#include <boost/tuple/tuple.hpp>
+#include <boost/shared_ptr.hpp>
+#include <list>
+
+namespace ns3 {
+
+class Node;
+class Packet;
+
+namespace ndn {
+
+class App;
+
+/**
+ * @ingroup ndn
+ * @brief network-layer tracer for aggregate packet counts
+ */
+class AppDelayTracer : public SimpleRefCount<AppDelayTracer>
+{
+public:
+ /**
+ * @brief Helper method to install tracers on all simulation nodes
+ *
+ * @param file File to which traces will be written
+ * @param averagingPeriod How often data will be written into the trace file (default, every half second)
+ *
+ * @returns a tuple of reference to output stream and list of tracers. !!! Attention !!! This tuple needs to be preserved
+ * for the lifetime of simulation, otherwise SEGFAULTs are inevitable
+ *
+ */
+ static boost::tuple< boost::shared_ptr<std::ostream>, std::list<Ptr<AppDelayTracer> > >
+ InstallAll (const std::string &file);
+
+ /**
+ * @brief Trace constructor that attaches to all applications on the node using node's pointer
+ * @param os reference to the output stream
+ * @param node pointer to the node
+ */
+ AppDelayTracer (boost::shared_ptr<std::ostream> os, Ptr<Node> node);
+
+ /**
+ * @brief Trace constructor that attaches to all applications on the node using node's name
+ * @param os reference to the output stream
+ * @param nodeName name of the node registered using Names::Add
+ */
+ AppDelayTracer (boost::shared_ptr<std::ostream> os, const std::string &node);
+
+ /**
+ * @brief Destructor
+ */
+ ~AppDelayTracer ();
+
+ /**
+ * @brief Print head of the trace (e.g., for post-processing)
+ *
+ * @param os reference to output stream
+ */
+ void
+ PrintHeader (std::ostream &os) const;
+
+private:
+ void
+ Connect ();
+
+ void
+ LastRetransmittedInterestDataDelay (Ptr<App> app, uint32_t seqno, Time delay);
+
+ void
+ FirstInterestDataDelay (Ptr<App> app, uint32_t seqno, Time delay);
+
+private:
+ std::string m_node;
+ Ptr<Node> m_nodePtr;
+
+ boost::shared_ptr<std::ostream> m_os;
+};
+
+} // namespace ndn
+} // namespace ns3
+
+#endif // CCNX_CS_TRACER_H