owlps/owlps-positioner/src/timestamp.cc

/*
 * This file is part of the Owl Positioning System (OwlPS).
 * OwlPS is a project of the University of Franche-Comte
 * (Université de Franche-Comté), France.
 *
 * Copyright © Université de Franche-Comté 2007-2012.
 *
 * Corresponding author: Matteo Cypriani <mcy@lm7.fr>
 *
 ***********************************************************************
 *
 * This software is governed by the CeCILL license under French law and
 * abiding by the rules of distribution of free software. You can use,
 * modify and/or redistribute the software under the terms of the CeCILL
 * license as circulated by CEA, CNRS and INRIA at the following URL:
 * http://www.cecill.info
 *
 * As a counterpart to the access to the source code and rights to copy,
 * modify and redistribute granted by the license, users are provided
 * only with a limited warranty and the software's authors, the holder
 * of the economic rights, and the successive licensors have only
 * limited liability.
 *
 * In this respect, the user's attention is drawn to the risks
 * associated with loading, using, modifying and/or developing or
 * reproducing the software by the user in light of its specific status
 * of free software, that may mean that it is complicated to manipulate,
 * and that also therefore means that it is reserved for developers and
 * experienced professionals having in-depth computer knowledge. Users
 * are therefore encouraged to load and test the software's suitability
 * as regards their requirements in conditions enabling the security of
 * their systems and/or data to be ensured and, more generally, to use
 * and operate it in the same conditions as regards security.
 *
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL license and that you accept its terms.
 *
 ***********************************************************************
 */


#include "timestamp.hh"
#include "configuration.hh"

#include <boost/functional/hash.hpp>
#include <iostream>

using namespace std ;


Timestamp Timestamp::current_time ;



/* *** Constructors *** */


Timestamp::Timestamp()
{
  clear() ;
}


Timestamp::Timestamp(const struct timespec &source)
{
  set(source) ;
}


Timestamp::Timestamp(const owl_timestamp &source)
{
  set(source) ;
}


Timestamp::Timestamp(const uint_fast32_t source_s,
                     const uint_fast32_t source_ns)
{
  set(source_s, source_ns) ;
}


Timestamp::Timestamp(const uint64_t source)
{
  set(source) ;
}


Timestamp::Timestamp(const Timestamp &source)
{
  set(source.timestamp) ;
}



/* *** Internal accessors *** */


inline void Timestamp::set(const struct timespec &source)
{
  timestamp = source ;
}


inline void Timestamp::set(const owl_timestamp &source)
{
  set(source.tv_sec, source.tv_nsec) ;
}


inline void Timestamp::set(const uint_fast32_t source_s,
                           const uint_fast32_t source_ns)
{
  timestamp.tv_sec = source_s ;
  timestamp.tv_nsec = source_ns ;
}


inline void Timestamp::set(const uint64_t source_ms)
{
  timestamp.tv_sec = source_ms / 1000 ;
  timestamp.tv_nsec = (source_ms - timestamp.tv_sec * 1000) * 1000000 ;
}



/* *** Operations *** */


Timestamp Timestamp::get_current_time()
{
  if (! Configuration::bool_value("replay"))
    current_time.now() ;
  return current_time ;
}


/**
 * @source A pointer to the new time. If NULL, #current_time is updated
 * to the current time.
 */
void Timestamp::update_current_time(const Timestamp &source)
{
  // We should never call this function if we are in replay mode:
  assert(Configuration::bool_value("replay")) ;

  // According to human perception, time generally goes only forward:
  if (current_time < source)
    {
      current_time = source ;
      if (Configuration::is_configured("verbose"))
        cerr << "Current time set to " << current_time << ".\n" ;
    }
  else if (Configuration::is_configured("verbose"))
    cerr << "Current time left unchanged to " << current_time
         << " (time proposed: " << source << ").\n" ;
}


bool Timestamp::now()
{
  return clock_gettime(CLOCK_REALTIME, &timestamp) == 0 ;
}


/**
 * @returns A Timestamp containing the time elapsed, or an empty
 * Timestamp in case of error.
 */
Timestamp Timestamp::elapsed() const
{
  return elapsed(get_current_time()) ;
}


Timestamp Timestamp::elapsed(const Timestamp &source) const
{
  owl_timestamp
  d1 = *this,
  d2 = source,
  elapsed ;
  owl_time_elapsed(&d1, &d2, &elapsed) ;
  return elapsed ;
}


/**
 * #timestamp nanosecond field precision is set to ms, but the value
 * is still in ns.
 */
inline void Timestamp::round_to_ms()
{
  timestamp.tv_nsec = timestamp.tv_nsec / 1000000 * 1000000 ;
}



/* *** Internal comparison functions *** */


bool Timestamp::equals(const struct timespec &source) const
{
  return
    timestamp.tv_sec == source.tv_sec &&
    timestamp.tv_nsec == source.tv_nsec ;
}


bool Timestamp::equals(const uint64_t source) const
{
  Timestamp tmp(source) ;
  Timestamp me(*this) ;
  me.round_to_ms() ;
  return me == tmp ;
}


bool Timestamp::before(const struct timespec &source) const
{
  if (timestamp.tv_sec < source.tv_sec)
    return true ;

  if (timestamp.tv_sec > source.tv_sec)
    return false ;

  // Second values are equal
  if (timestamp.tv_nsec < source.tv_nsec)
    return true ;

  return false ;
}


bool Timestamp::after(const struct timespec &source) const
{
  if (equals(source))
    return false ;
  return ! before(source) ;
}



/* *** Operators *** */


Timestamp& Timestamp::operator=(const Timestamp &source)
{
  if (this == &source)
    return *this ;

  set(source.timestamp) ;

  return *this ;
}


bool Timestamp::operator==(const Timestamp &source) const
{
  if (this == &source)
    return true ;
  return equals(source.timestamp) ;
}



std::ostream& operator<<(std::ostream &os, const Timestamp &t)
{
  os << t.timestamp.tv_sec << '.' << t.timestamp.tv_nsec ;
  return os ;
}


inline Timestamp::operator owl_timestamp(void) const
{
  owl_timestamp ret ;
  ret.tv_sec = timestamp.tv_sec ;
  ret.tv_nsec = timestamp.tv_nsec ;
  return ret ;
}



size_t hash_value(const Timestamp &source)
{
  return boost::hash_value(static_cast<uint64_t>(source)) ;
}