kc3-lang/gnulib/lib/dtotimespec.c

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• Hash : 2deeabad
  Author :
  Date : 2011-06-30T15:14:25
  

  dtotimespec: new module
  
  * lib/timespec.h (dtotimespec): New decl.
  * lib/dtotimespec.c, modules/dtotimespec: New files.
  

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• lib/dtotimespec.c

• /* Convert double to timespec.
  
     Copyright (C) 2011 Free Software Foundation, Inc.
  
     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 3 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, see <http://www.gnu.org/licenses/>.  */
  
  /* written by Paul Eggert */
  
  /* Convert the double value SEC to a struct timespec.  Round toward
     positive infinity.  On overflow, return an extremal value.  */
  
  #include <config.h>
  
  #include "timespec.h"
  
  #include "intprops.h"
  
  struct timespec
  dtotimespec (double sec)
  {
    enum { BILLION = 1000 * 1000 * 1000 };
    double min_representable = TYPE_MINIMUM (time_t);
    double max_representable =
      ((TYPE_MAXIMUM (time_t) * (double) BILLION + (BILLION - 1))
       / BILLION);
    struct timespec r;
  
    if (! (min_representable < sec))
      {
        r.tv_sec = TYPE_MINIMUM (time_t);
        r.tv_nsec = 0;
      }
    else if (! (sec < max_representable))
      {
        r.tv_sec = TYPE_MAXIMUM (time_t);
        r.tv_nsec = BILLION - 1;
      }
    else
      {
        time_t s = sec;
        double frac = BILLION * (sec - s);
        long ns = frac;
        ns += ns < frac;
        s += ns / BILLION;
        ns %= BILLION;
  
        if (ns < 0)
          {
            s--;
            ns += BILLION;
          }
  
        r.tv_sec = s;
        r.tv_nsec = ns;
      }
  
    return r;
  }
  

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