fw: rename RetransmissionSuppression to RetxSuppressionFixed

This commit also declares RetxSuppression base class as the API
for any retransmission suppression decision algorithms,
so that other algorithms can be introduced.

refs #1913

Change-Id: I5539565d2dd238d1421f5bd828fde4ecfba0a820
diff --git a/daemon/fw/retx-suppression-fixed.hpp b/daemon/fw/retx-suppression-fixed.hpp
new file mode 100644
index 0000000..f88c83e
--- /dev/null
+++ b/daemon/fw/retx-suppression-fixed.hpp
@@ -0,0 +1,60 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD 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.
+ *
+ * NFD 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
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NFD_DAEMON_FW_RETX_SUPPRESSION_FIXED_HPP
+#define NFD_DAEMON_FW_RETX_SUPPRESSION_FIXED_HPP
+
+#include "retx-suppression.hpp"
+
+namespace nfd {
+namespace fw {
+
+/** \brief a retransmission suppression decision algorithm that
+ *         suppresses retransmissions within a fixed duration
+ */
+class RetxSuppressionFixed : public RetxSuppression
+{
+public:
+  explicit
+  RetxSuppressionFixed(const time::milliseconds& minRetxInterval = DEFAULT_MIN_RETX_INTERVAL);
+
+  /** \brief determines whether Interest is a retransmission,
+   *         and if so, whether it shall be forwarded or suppressed
+   */
+  virtual Result
+  decide(const Face& inFace, const Interest& interest,
+         const pit::Entry& pitEntry) const DECL_OVERRIDE;
+
+public:
+  static const time::milliseconds DEFAULT_MIN_RETX_INTERVAL;
+
+private:
+  const time::milliseconds m_minRetxInterval;
+};
+
+} // namespace fw
+} // namespace nfd
+
+#endif // NFD_DAEMON_FW_RETX_SUPPRESSION_FIXED_HPP