include/wipal/filter/time_adjuster.hxx

/*
 * WiPal - A library and a set of tools to manipulate wireless traces.
 * Copyright (C) 2007, 2008, 2009  Universite Pierre et Marie Curie - Paris 6
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301  USA
 *
 * Author: Thomas Claveirole <thomas.claveirole@lip6.fr>
 */
#ifndef FILTER_TIME_ADJUSTER_HXX_
# define FILTER_TIME_ADJUSTER_HXX_

# include "time_adjuster.hh"

# include <boost/shared_ptr.hpp>
# include <boost/shared_array.hpp>

# include <wipal/filter/timetracker.hh>
# include <wipal/filter/linear_regression_synchronizer.hh>

namespace wpl
{

  namespace filter
  {

    namespace internals
    {

      template <class I1, class I2, class HT, class B1, class B2>
      time_adjuster_iterator<I1, I2, HT, B1, B2>::
      time_adjuster_iterator(const iterable_type& i, bool end):
        super_type (),
        iterable_ (&i),
        next1_ (end ? i.last1_ : i.first1_),
        next2_ (end ? i.last2_ : i.first2_)
      {
        if (not end)
          increment();
      }

      template <class I1, class I2, class HT, class B1, class B2>
      bool
      time_adjuster_iterator<I1, I2, HT, B1, B2>::
      equal(const time_adjuster_iterator& rhs) const
      {
        if (not rhs.value())
          return not this->value();
        return next1_ == rhs.next1_;
      }

      template <class I1, class I2, class HT, class B1, class B2>
      void
      time_adjuster_iterator<I1, I2, HT, B1, B2>::increment()
      {
        using tool::end::endianness;

        typedef typename wifi::time_converter<HT>::time_values  time_values;
        typedef typename I1::value_type::original_type          packet;

        if (next1_ == iterable_->last1_)
          {
            this->value() = boost::none_t ();

            // Flush next2_ so it may print a summary of its operation.
            while (next2_ != iterable_->last2_)
              ++next2_;

            return;
          }
        update_coefs();

        const tool::microseconds us (next1_->microseconds() * coefs_->first +
                                     coefs_->second);
        const time_values        tv = iterable_->convert_(us);
        const bool               swapped = tool::need_swap(iterable_->phy_end_,
                                                           next1_->swapped());

        boost::optional<value_type>& v = this->value();

        if (not v or not v->unique())
          v = value_type (us, packet (next1_->meta()));
        else
          {
            v->microseconds() = us;
            v->meta() = next1_->meta();
          }
        memcpy(v->bytes(), next1_->bytes(), next1_->meta().caplen);
        internals::adjust(v->meta(), static_cast<HT*> (v->bytes()),
                          swapped, tv);
        ++next1_;
      }

      template <class I1, class I2, class HT, class B1, class B2>
      void
      time_adjuster_iterator<I1, I2, HT, B1, B2>::update_coefs()
      {
        const tool::microseconds        us = next1_->microseconds();
        const I2&                       last2 = iterable_->last2_;

        // FIXME: There used to be a bug in the following check.  It checked
        // FIXME: for next2_->*second*.microseconds() <= us instead of
        // FIXME: next2_->first.microseconds().  Unfortunately the current
        // FIXME: test suite does not catch this bug, though this is a
        // FIXME: dramatic malfunction.  One should write a regression
        // FIXME: test for this case.
        while (next2_ != last2 and next2_->first.microseconds() <= us)
          {
            coefs_ = next2_->coefs;
            ++next2_;
          }
        if (not coefs_)
          {
            if (next2_ != last2)
              coefs_ = next2_->coefs;
            else
              throw std::runtime_error ("No reference frames: "
                                        "impossible to synchronize");
          }
      }

      template <class HT, class S>
      wifi::time_converter<HT>
      time_reference(const pkt::packet<S>&      p,
                     tool::end::endianness      phy_end,
                     bool                       pcap_tstamps)
      {
        using tool::need_swap;
        typedef typename HT::time_type time_type;

        const pkt::metadata&    m = p.meta();

        const HT* const         bytes = static_cast<const HT*> (p.bytes());
        const bool              swapped  = need_swap(phy_end, p.swapped());

        if (m.caplen < bytes->len(m.caplen, swapped))
          throw std::runtime_error ("First frame too short to make a "
                                    "suitable time reference");

        time_type               time = bytes->time_get(swapped);
        phy::timetracker<>      tracker (pcap_tstamps);

        tracker.tick<HT>(p, phy_end);
        return wifi::time_converter<HT> (m.ts, time, tracker.microseconds());
      }

      template <class HT>
      inline
      void
      adjust(pkt::metadata&                                             meta,
             HT*                                                        bytes,
             bool                                                       swap,
             const typename wifi::time_converter<HT>::time_values&      tv)
      {
        meta.ts = tv.pcap_time;

        if (meta.caplen < bytes->len(meta.caplen, swap))
          return;
        bytes->time_set(tv.phy_time, swap);
      }

    } // End of namespace wpl::filter::internals.


    template <class I1, class I2, class HT, class B>
    template <class S>
    time_adjuster<I1, I2, HT, B>::
    time_adjuster(const I1& first1, const I1& last1,
                  const I2& first2, const I2& last2,
                  const pkt::packet<S>&         tref,
                  tool::end::endianness         phy_end,
                  bool                          pcap_tstamps):
      convert_ (internals::time_reference<HT>(tref, phy_end, pcap_tstamps)),
      phy_end_ (phy_end),
      first1_ (first1),
      last1_ (last1),
      first2_ (first2),
      last2_ (last2)
    {
    }

    namespace internals
    {

      template <class HT, class I1, class I2, class F>
      struct time_adjuster_wrapper
      {
        time_adjuster_wrapper(const I1& first1, const I1& last1,
                              const I2& first2, const I2& last2,
                              opt::list&        options,
                              F&                func):
          first1_ (first1),
          last1_ (last1),
          first2_ (first2),
          last2_ (last2),
          options_ (options),
          func_ (func)
        {
        }

        template <class Synchronizer>
        void
        operator () (const Synchronizer& s)
        {
          typedef tool::end::endianness endianness;

          if (first2_ == last2_)
            throw std::runtime_error ("No packets in reference trace. "
                                      "Cannot synchronize with no time "
                                      "reference and no unique frames");

          const endianness&     end = options_["endianness"].get<endianness>();
          const bool            pcts = not options_["phy_tstamps"].get<bool>();

          if (options_["ignore_noisy_prism"].get<bool>())
            {
              typedef non_noisy_prism<I1>                       nnp;
              typedef typename nnp::const_iterator              nnp_iterator;
              typedef timetracker<nnp_iterator, HT>             tt;
              typedef typename tt::const_iterator               tt_iterator;
              typedef typename Synchronizer::const_iterator     s_iterator;
              typedef time_adjuster<tt_iterator, s_iterator, HT> adjuster;

              nnp       n (first1_, last1_);
              tt        u (n.begin(), n.end(), end, pcts);
              adjuster  a (u.begin(), u.end(), s.begin(), s.end(),
                           *first2_, end, pcts);
              func_(a);
            }
          else
            {
              typedef timetracker<I1, HT>                        tt;
              typedef typename tt::const_iterator                tt_iterator;
              typedef typename Synchronizer::const_iterator      s_iterator;
              typedef time_adjuster<tt_iterator, s_iterator, HT> adjuster;

              tt        u (first1_, last1_, end, pcts);
              adjuster  a (u.begin(), u.end(), s.begin(), s.end(),
                           *first2_, end, pcts);
              func_(a);
            }
        }

      private:
        const I1&       first1_;
        const I1&       last1_;
        const I2&       first2_;
        const I2&       last2_;
        opt::list&      options_;
        F&              func_;
      };

    } // End of namespace wifi::filter::internals.

    template <class U, class HT, template <class, class, class> class Int,
              class I1, class I2, class F>
    void
    provide_time_adjuster(const I1& first1, const I1&   last1,
                          const I2& first2, const I2&   last2,
                          opt::list&    options,
                          F&            func)
    {
      typedef internals::time_adjuster_wrapper<HT, I1, I2, F>   wrapper;

      wrapper   wrap (first1, last1, first2, last2, options, func);

      provide_lr_synchronizer<U, HT, Int>(first1, last1,
                                          first2, last2, options, wrap);
    }

  } // End of namespace wpl::filter.

} // End of namespace wpl.

#endif // ! FILTER_TIME_ADJUSTER_HXX_

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