fw: add strategy parameters to configure exponential retx suppression

Supported by ASF, BestRoute, and Multicast strategies

Refs: #4924
Change-Id: I215d9212d90b93fa622cc65278703dc5198d0c9d
diff --git a/daemon/fw/retx-suppression-exponential.hpp b/daemon/fw/retx-suppression-exponential.hpp
index 8455b5e..3c3be60 100644
--- a/daemon/fw/retx-suppression-exponential.hpp
+++ b/daemon/fw/retx-suppression-exponential.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2017,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -28,27 +28,30 @@
 
 #include "algorithm.hpp"
 #include "retx-suppression.hpp"
+#include "strategy.hpp"
 
 namespace nfd {
 namespace fw {
 
-/** \brief a retransmission suppression decision algorithm that
- *         suppresses retransmissions using exponential backoff
+/**
+ * \brief A retransmission suppression decision algorithm that suppresses
+ *        retransmissions using exponential backoff.
  *
- *  The i-th retransmission will be suppressed if the last transmission (out-record)
- *  occurred within MIN(initialInterval * multiplier^(i-1), maxInterval)
+ * The i-th retransmission will be suppressed if the last transmission (out-record)
+ * occurred within `MIN(initialInterval * multiplier^(i-1), maxInterval)`.
  */
 class RetxSuppressionExponential
 {
 public:
-  /** \brief time granularity
+  /**
+   * \brief Time granularity.
    */
-  typedef time::microseconds Duration;
+  using Duration = time::milliseconds;
 
   explicit
-  RetxSuppressionExponential(const Duration& initialInterval = DEFAULT_INITIAL_INTERVAL,
-                             float multiplier = DEFAULT_MULTIPLIER,
-                             const Duration& maxInterval = DEFAULT_MAX_INTERVAL);
+  RetxSuppressionExponential(Duration initialInterval = DEFAULT_INITIAL_INTERVAL,
+                             Duration maxInterval = DEFAULT_MAX_INTERVAL,
+                             float multiplier = DEFAULT_MULTIPLIER);
 
   /** \brief determines whether Interest is a retransmission per pit entry
    *         and if so, whether it shall be forwarded or suppressed
@@ -67,20 +70,27 @@
   void
   incrementIntervalForOutRecord(pit::OutRecord& outRecord);
 
-public:
-  /** \brief StrategyInfo on pit::Entry
-   */
-  class PitInfo;
+  static std::unique_ptr<RetxSuppressionExponential>
+  construct(const StrategyParameters& params);
+
+private: // non-member operators (hidden friends)
+  friend std::ostream&
+  operator<<(std::ostream& os, const RetxSuppressionExponential& retxSupp)
+  {
+    return os << "RetxSuppressionExponential initial-interval=" << retxSupp.m_initialInterval
+              << " max-interval=" << retxSupp.m_maxInterval
+              << " multiplier=" << retxSupp.m_multiplier;
+  }
 
 public:
   static const Duration DEFAULT_INITIAL_INTERVAL;
-  static const float DEFAULT_MULTIPLIER;
   static const Duration DEFAULT_MAX_INTERVAL;
+  static const float DEFAULT_MULTIPLIER;
 
-private:
+NFD_PUBLIC_WITH_TESTS_ELSE_PRIVATE:
   const Duration m_initialInterval;
-  const float m_multiplier;
   const Duration m_maxInterval;
+  const float m_multiplier;
 };
 
 } // namespace fw