text: //------------------------------------------------------------------------------
  /*
      This file is part of rippled: https://github.com/ripple/rippled
      Copyright (c) 2012-2017 Ripple Labs Inc
  
      Permission to use, copy, modify, and/or distribute this software for any
      purpose  with  or without fee is hereby granted, provided that the above
      copyright notice and this permission notice appear in all copies.
  
      THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
      MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
      ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
      WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
      ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
  //==============================================================================
  #ifndef RIPPLE_TEST_CSF_SUBMITTERS_H_INCLUDED
  #define RIPPLE_TEST_CSF_SUBMITTERS_H_INCLUDED
  
  #include <test/csf/Peer.h>
  #include <test/csf/Scheduler.h>
  #include <test/csf/SimTime.h>
  #include <test/csf/Tx.h>
  #include <type_traits>
  namespace ripple {
  namespace test {
  namespace csf {
  
  // Submitters are classes for simulating submission of transactions to the
  // network
  
  /** Represents rate as a count/duration */
  struct Rate
  {
      std::size_t count;
      SimDuration duration;
  
      double
      inv() const
      {
          return duration.count() / double(count);
      }
  };
  
  /** Submits transactions to a specified peer
  
      Submits successive transactions beginning at start, then spaced according
      to succesive calls of distribution(), until stop.
  
      @tparam Distribution is a `UniformRandomBitGenerator` from the STL that
              is used by random distributions to generate random samples
      @tparam Generator is an object with member
  
              T operator()(Generator &g)
  
              which generates the delay T in SimDuration units to the next
              transaction. For the current definition of SimDuration, this is
              currently the number of nanoseconds. Submitter internally casts
              arithmetic T to SimDuration::rep units to allow using standard
              library distributions as a Distribution.
  */
  template <class Distribution, class Generator, class Selector>
  class Submitter
  {
      Distribution dist_;
      SimTime stop_;
      std::uint32_t nextID_ = 0;
      Selector selector_;
      Scheduler& scheduler_;
      Generator& g_;
  
      // Convert generated durations to SimDuration
      static SimDuration
      asDuration(SimDuration d)
      {
          return d;
      }
  
      template <class T>
      static std::enable_if_t<std::is_arithmetic<T>::value, SimDuration>
      asDuration(T t)
      {
          return SimDuration{static_cast<SimDuration::rep>(t)};
      }
  
      void
      submit()
      {
          selector_()->submit(Tx{nextID_++});
          if (scheduler_.now() < stop_)
          {
              scheduler_.in(asDuration(dist_(g_)), [&]() { submit(); });
          }
      }
  
  public:
      Submitter(
          Distribution dist,
          SimTime start,
          SimTime end,
          Selector& selector,
          Scheduler& s,
          Generator& g)
          : dist_{dist}, stop_{end}, selector_{selector}, scheduler_{s}, g_{g}
      {
          scheduler_.at(start, [&]() { submit(); });
      }
  };
  
  template <class Distribution, class Generator, class Selector>
  Submitter<Distribution, Generator, Selector>
  makeSubmitter(
      Distribution dist,
      SimTime start,
      SimTime end,
      Selector& sel,
      Scheduler& s,
      Generator& g)
  {
      return Submitter<Distribution, Generator, Selector>(
          dist, start, end, sel, s, g);
  }
  
  }  // namespace csf
  }  // namespace test
  }  // namespace ripple
  
  #endif
  