ping: refactor ping client to use a modular architecture

refs #2702

Change-Id: I0ee0403f84eaec35bdbf07af7b3bb52558113452
diff --git a/tools/ping/client/ping.cpp b/tools/ping/client/ping.cpp
new file mode 100644
index 0000000..74cbcac
--- /dev/null
+++ b/tools/ping/client/ping.cpp
@@ -0,0 +1,123 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Arizona Board of Regents.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-tools 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
+ * ndn-tools, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author: Jerald Paul Abraham <jeraldabraham@email.arizona.edu>
+ * @author: Eric Newberry <enewberry@email.arizona.edu>
+ */
+
+#include "ping.hpp"
+
+namespace ndn {
+namespace ping {
+namespace client {
+
+Ping::Ping(Face& face, const Options& options)
+  : m_options(options)
+  , m_nSent(0)
+  , m_nextSeq(options.startSeq)
+  , m_nOutstanding(0)
+  , m_face(face)
+  , m_scheduler(m_face.getIoService())
+{
+  if (m_options.shouldGenerateRandomSeq) {
+    m_nextSeq = random::generateWord64();
+  }
+}
+
+void
+Ping::run()
+{
+  performPing();
+
+  m_face.processEvents();
+}
+
+void
+Ping::performPing()
+{
+  BOOST_ASSERT((m_options.nPings < 0) || (m_nSent < m_options.nPings));
+
+  Name pingPacketName = makePingName(m_nextSeq);
+
+  Interest interest(pingPacketName);
+  interest.setMustBeFresh(!m_options.shouldAllowStaleData);
+  interest.setInterestLifetime(m_options.timeout);
+  interest.setNonce(m_nextSeq);
+
+  m_face.expressInterest(interest,
+                         bind(&Ping::onData, this, _1, _2, m_nextSeq, time::steady_clock::now()),
+                         bind(&Ping::onTimeout, this, _1, m_nextSeq));
+
+  ++m_nSent;
+  ++m_nextSeq;
+  ++m_nOutstanding;
+
+  if ((m_options.nPings < 0) || (m_nSent < m_options.nPings)) {
+    m_scheduler.scheduleEvent(m_options.interval, bind(&Ping::performPing, this));
+  }
+  else {
+    finish();
+  }
+}
+
+void
+Ping::onData(const Interest& interest, Data& data, uint64_t seq, const time::steady_clock::TimePoint& sendTime)
+{
+  time::nanoseconds rtt = time::steady_clock::now() - sendTime;
+
+  afterResponse(seq, rtt);
+
+  finish();
+}
+
+void
+Ping::onTimeout(const Interest& interest, uint64_t seq)
+{
+  afterTimeout(seq);
+
+  finish();
+}
+
+void
+Ping::finish()
+{
+  if (--m_nOutstanding >= 0) {
+    return;
+  }
+
+  m_face.shutdown();
+  afterFinish();
+  m_face.getIoService().stop();
+}
+
+Name
+Ping::makePingName(uint64_t seq) const
+{
+  Name name(m_options.prefix);
+  name.append("ping");
+  if (!m_options.clientIdentifier.empty()) {
+    name.append(m_options.clientIdentifier);
+  }
+  name.append(std::to_string(seq));
+
+  return name;
+}
+
+} // namespace client
+} // namespace ping
+} // namespace ndn