/**
 * File:      TimeMs.cc
 * Project:   libvdr - classes taken from vdr-project
 * 
 * from "Video Disk Recorder":
 * 
 * Copyright (C) 2000, 2003, 2006, 2008 Klaus Schmidinger
 * 
 * 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
 * Or, point your browser to http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * The original author can be reached at kls@tvdr.de
 * 
 * The vdr project's page is at http://www.tvdr.de
 * 
 */
#include <TimeMs.h>
#include <Logging.h>
#include <stddef.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <utime.h>

cTimeMs::cTimeMs(int Ms)
{
  if (Ms >= 0)
     Set(Ms);
  else
     begin = 0;
}

uint64_t cTimeMs::Now(void)
{
#if _POSIX_TIMERS > 0 && defined(_POSIX_MONOTONIC_CLOCK)
#define MIN_RESOLUTION 5 // ms
  static bool initialized = false;
  static bool monotonic = false;
  struct timespec tp;
  if (!initialized) {
     // check if monotonic timer is available and provides enough accurate resolution:
     if (clock_getres(CLOCK_MONOTONIC, &tp) == 0) {
        long Resolution = tp.tv_nsec;
        // require a minimum resolution:
        if (tp.tv_sec == 0 && tp.tv_nsec <= MIN_RESOLUTION * 1000000) {
           if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
              dsyslog("cTimeMs: using monotonic clock (resolution is %ld ns)", Resolution);
              monotonic = true;
              }
           else
              esyslog("cTimeMs: clock_gettime(CLOCK_MONOTONIC) failed");
           }
        else
           dsyslog("cTimeMs: not using monotonic clock - resolution is too bad (%ld s %ld ns)", tp.tv_sec, tp.tv_nsec);
        }
     else
        esyslog("cTimeMs: clock_getres(CLOCK_MONOTONIC) failed");
     initialized = true;
     }
  if (monotonic) {
     if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
        return (uint64_t(tp.tv_sec)) * 1000 + tp.tv_nsec / 1000000;
     esyslog("cTimeMs: clock_gettime(CLOCK_MONOTONIC) failed");
     monotonic = false;
     // fall back to gettimeofday()
     }
#else
#  warning Posix monotonic clock not available
#endif
  struct timeval t;
  if (gettimeofday(&t, NULL) == 0)
     return (uint64_t(t.tv_sec)) * 1000 + t.tv_usec / 1000;
  return 0;
}

void cTimeMs::Set(int Ms)
{
  begin = Now() + Ms;
}

bool cTimeMs::TimedOut(void)
{
  return Now() >= begin;
}

uint64_t cTimeMs::Elapsed(void)
{
  return Now() - begin;
}