// $Id$
//
// Copyright (C) 2007 
// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
// Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
//     Stefan Bund <g0dil@berlios.de>
//
// 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.,
// 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

/** \file
    \brief ClockService inline non-template implementation */

// Custom includes
#include "boost/date_time/posix_time/posix_time_types.hpp"

#define prefix_ inline
///////////////////////////////cci.p///////////////////////////////////////

///////////////////////////////////////////////////////////////////////////
// senf::ClockService

prefix_ senf::ClockService::clock_type senf::ClockService::now()
{
    // We must make sure to call instance() before fetching the current time since the first call to
    // instance() will construct the singleton and initialize heartbeat_. If this happens *after*
    // fetching the current time checkSkew() will detect clock skew since heartbeat_ will be <
    // current time.
    return instance().now_i();
}

prefix_ senf::ClockService::abstime_type senf::ClockService::abstime(clock_type clock)
{
#ifdef BOOST_DATE_TIME_POSIX_TIME_STD_CONFIG
    return instance().base_ + boost::posix_time::nanoseconds(clock);
#else
    return instance().base_ + boost::posix_time::microseconds((clock+500)/1000);
#endif
}

prefix_ senf::ClockService::clock_type senf::ClockService::clock(abstime_type time)
{
    boost::posix_time::time_duration delta (time - instance().base_);
    return clock_type( delta.ticks() )
        * clock_type( 1000000000UL / boost::posix_time::time_duration::ticks_per_second() );
}

prefix_ senf::ClockService::clock_type senf::ClockService::nanoseconds(clock_type v)
{
    return v;
}

prefix_ senf::ClockService::clock_type senf::ClockService::microseconds(clock_type v)
{
    return nanoseconds(1000*v);
}

prefix_ senf::ClockService::clock_type senf::ClockService::milliseconds(clock_type v)
{
    return microseconds(1000*v);
}

prefix_ senf::ClockService::clock_type senf::ClockService::seconds(clock_type v)
{
    return milliseconds(1000*v);
}

prefix_ senf::ClockService::clock_type senf::ClockService::minutes(clock_type v)
{
    return seconds(60*v);
}

prefix_ senf::ClockService::clock_type senf::ClockService::hours(clock_type v)
{
    return minutes(60*v);
}

prefix_ senf::ClockService::clock_type senf::ClockService::days(clock_type v)
{
    return hours(24*v);
}

prefix_ void senf::ClockService::restart()
{
    instance().restart_i();
}

////////////////////////////////////////
// private members

prefix_ senf::ClockService & senf::ClockService::instance()
{
    static ClockService instance;
    return instance;
}

prefix_ senf::ClockService::clock_type senf::ClockService::now_i()
{
    boost::posix_time::ptime time (boost::posix_time::microsec_clock::universal_time());
    if (checkSkew(time)) 
        updateSkew(time);
    return clock(time);
}

prefix_ bool senf::ClockService::checkSkew(boost::posix_time::ptime time)
{
    return time < heartbeat_ || (time - heartbeat_) > boost::posix_time::seconds(2*CheckInterval);
}

prefix_ void senf::ClockService::clockSkew(boost::posix_time::ptime time,
                                           boost::posix_time::ptime expected)
{
    base_ += (time - expected);
}

///////////////////////////////cci.e///////////////////////////////////////
#undef prefix_


// Local Variables:
// mode: c++
// fill-column: 100
// comment-column: 40
// c-file-style: "senf"
// indent-tabs-mode: nil
// ispell-local-dictionary: "american"
// compile-command: "scons -u test"
// End: