/* glpenv06.c (standard time) */

 /***********************************************************************

 *  This code is part of GLPK (GNU Linear Programming Kit).

 *

 *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,

 *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,

 *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.

 *  E-mail: <mao@gnu.org>.

 *

 *  GLPK 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 3 of the License, or

 *  (at your option) any later version.

 *

 *  GLPK 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 GLPK. If not, see <http://www.gnu.org/licenses/>.

 ***********************************************************************/

 #ifdef HAVE_CONFIG_H

 #include <config.h>

 #endif

 #include "glpapi.h"

 /***********************************************************************

 *  NAME

 *

 *  glp_time - determine current universal time

 *

 *  SYNOPSIS

 *

 *  glp_long glp_time(void);

 *

 *  RETURNS

 *

 *  The routine glp_time returns the current universal time (UTC), in

 *  milliseconds, elapsed since 00:00:00 GMT January 1, 1970. */

 static const int epoch = 2440588; /* = jday(1, 1, 1970) */

 /* POSIX version ******************************************************/

 #if defined(HAVE_SYS_TIME_H) && defined(HAVE_GETTIMEOFDAY)

 #include <sys/time.h>

 #include <time.h>

 glp_long glp_time(void)

 {     struct timeval tv;

       struct tm *tm;

       glp_long t;

       int j;

       gettimeofday(&tv, NULL);

       tm = gmtime(&tv.tv_sec);

       j = jday(tm->tm_mday, tm->tm_mon + 1, 1900 + tm->tm_year);

       xassert(j >= 0);

       t = xlset(j - epoch);

       t = xlmul(t, xlset(24));

       t = xladd(t, xlset(tm->tm_hour));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(tm->tm_min));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(tm->tm_sec));

       t = xlmul(t, xlset(1000));

       t = xladd(t, xlset(tv.tv_usec / 1000));

       return t;

 }

 /* Windows version ****************************************************/

 #elif defined(__WOE__)

 #include <windows.h>

 glp_long glp_time(void)

 {     SYSTEMTIME st;

       glp_long t;

       int j;

       GetSystemTime(&st);

       j = jday(st.wDay, st.wMonth, st.wYear);

       xassert(j >= 0);

       t = xlset(j - epoch);

       t = xlmul(t, xlset(24));

       t = xladd(t, xlset(st.wHour));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(st.wMinute));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(st.wSecond));

       t = xlmul(t, xlset(1000));

       t = xladd(t, xlset(st.wMilliseconds));

       return t;

 }

 /* portable ISO C version *********************************************/

 #else

 #include <time.h>

 glp_long glp_time(void)

 {     time_t timer;

       struct tm *tm;

       glp_long t;

       int j;

       timer = time(NULL);

       tm = gmtime(&timer);

       j = jday(tm->tm_mday, tm->tm_mon + 1, 1900 + tm->tm_year);

       xassert(j >= 0);

       t = xlset(j - epoch);

       t = xlmul(t, xlset(24));

       t = xladd(t, xlset(tm->tm_hour));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(tm->tm_min));

       t = xlmul(t, xlset(60));

       t = xladd(t, xlset(tm->tm_sec));

       t = xlmul(t, xlset(1000));

       return t;

 }

 #endif

 /***********************************************************************

 *  NAME

 *

 *  glp_difftime - compute difference between two time values

 *

 *  SYNOPSIS

 *

 *  double glp_difftime(glp_long t1, glp_long t0);

 *

 *  RETURNS

 *

 *  The routine glp_difftime returns the difference between two time

 *  values t1 and t0, expressed in seconds. */

 double glp_difftime(glp_long t1, glp_long t0)

 {     return

          xltod(xlsub(t1, t0)) / 1000.0;

 }

 /**********************************************************************/

 #if 0

 int main(void)

 {     glp_long t;

       glp_ldiv d;

       int ttt, ss, mm, hh, day, month, year;

       char s[50];

       t = glp_time();

       xprintf("t = %s\n", xltoa(t, s));

       d = xldiv(t, xlset(1000));

       ttt = d.rem.lo, t = d.quot;

       d = xldiv(t, xlset(60));

       ss = d.rem.lo, t = d.quot;

       d = xldiv(t, xlset(60));

       mm = d.rem.lo, t = d.quot;

       d = xldiv(t, xlset(24));

       hh = d.rem.lo, t = d.quot;

       xassert(jdate(t.lo + epoch, &day, &month, &year) == 0);

       xprintf("%04d-%02d-%02d %02d:%02d:%02d.%03d\n", year, month, day,

          hh, mm, ss, ttt);

       return 0;

 }

 #endif

 /* eof */