chunks: segmented file transfer

refs #3071

Change-Id: I88e4fc1a8e33a0d61a95e2291cccc7b998647489
diff --git a/tools/chunks/catchunks/discover-version.hpp b/tools/chunks/catchunks/discover-version.hpp
new file mode 100644
index 0000000..bb6a477
--- /dev/null
+++ b/tools/chunks/catchunks/discover-version.hpp
@@ -0,0 +1,95 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2016,  Regents of the University of California,
+ *                      Colorado State University,
+ *                      University Pierre & Marie Curie, Sorbonne University.
+ *
+ * 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/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ *
+ * @author Wentao Shang
+ * @author Steve DiBenedetto
+ * @author Andrea Tosatto
+ */
+
+#ifndef NDN_TOOLS_CHUNKS_CATCHUNKS_DISCOVER_VERSION_HPP
+#define NDN_TOOLS_CHUNKS_CATCHUNKS_DISCOVER_VERSION_HPP
+
+#include "core/common.hpp"
+#include "options.hpp"
+
+namespace ndn {
+namespace chunks {
+
+class DataFetcher;
+
+/**
+ * @brief Base class of services for discovering the latest Data version
+ *
+ * DiscoverVersion's user is notified once after identifying the latest retrievable version or
+ * on failure to find any Data version.
+ */
+class DiscoverVersion : virtual protected Options, noncopyable
+{
+public: // signals
+  /**
+   * @brief Signal emited when the first segment of a specific version is found.
+   */
+  signal::Signal<DiscoverVersion, const Data&> onDiscoverySuccess;
+
+  /**
+   * @brief Signal emitted when a failure occurs.
+   */
+  signal::Signal<DiscoverVersion, const std::string&> onDiscoveryFailure;
+
+  DECLARE_SIGNAL_EMIT(onDiscoverySuccess)
+  DECLARE_SIGNAL_EMIT(onDiscoveryFailure)
+
+public:
+  /**
+   * @brief create a DiscoverVersion service
+   */
+  DiscoverVersion(const Name& prefix, Face& face, const Options& options);
+
+  /**
+   * @brief identify the latest Data version published.
+   */
+  virtual void
+  run() = 0;
+
+protected:
+  void
+  expressInterest(const Interest& interest, int maxRetriesNack, int maxRetriesTimeout);
+
+  virtual void
+  handleData(const Interest& interest, const Data& data);
+
+  virtual void
+  handleNack(const Interest& interest, const std::string& reason);
+
+  virtual void
+  handleTimeout(const Interest& interest, const std::string& reason);
+
+protected:
+  const Name m_prefix;
+  Face& m_face;
+  shared_ptr<DataFetcher> fetcher;
+};
+
+} // namespace chunks
+} // namespace ndn
+
+#endif // NDN_TOOLS_CHUNKS_CATCHUNKS_DISCOVER_VERSION_HPP