/*
  getrusage
  Implementation according to:
  The Open Group Base Specifications Issue 6
  IEEE Std 1003.1, 2004 Edition

  THIS SOFTWARE IS NOT COPYRIGHTED

  This source code is offered for use in the public domain. You may
  use, modify or distribute it freely.

  This code is distributed in the hope that it will be useful but
  WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
  DISCLAIMED. This includes but is not limited to warranties of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

  Contributed by:
  Ramiro Polla <ramiro@lisha.ufsc.br>

  Modified by: 
 
  Manuel Lopez-Ibanez <manuel.lopez-ibanez@ulb.ac.be>
    * Remove dependency with <sys/resources.h>
    
**************************************************************************/

/* Include only the minimum from windows.h */
#define WIN32_LEAN_AND_MEAN 
#include "resource.h"
#include <errno.h>
#include <stdint.h>
#include <windows.h>

static inline
void FILETIME_to_timeval (struct timeval *tv, FILETIME *ft)
{
    int64_t fulltime = ((((int64_t) ft->dwHighDateTime) << 32) 
                        | ((int64_t) ft->dwLowDateTime));
    fulltime /= 10LL; /* 100-ns -> us */

    tv->tv_sec  = fulltime / 1000000L;
    tv->tv_usec = fulltime % 1000000L;
}

int __cdecl
getrusage(int who, struct rusage *r_usage)
{
    FILETIME starttime;
    FILETIME exittime;
    FILETIME kerneltime;
    FILETIME usertime;
    
    if (!r_usage) {
        errno = EFAULT;
        return -1;
    }

    if (who != RUSAGE_SELF) {
        errno = EINVAL;
        return -1;
    }

    if (GetProcessTimes (GetCurrentProcess (),
                         &starttime, &exittime, 
                         &kerneltime, &usertime) == 0) {
        return -1;
    }
    FILETIME_to_timeval (&r_usage->ru_stime, &kerneltime);
    FILETIME_to_timeval (&r_usage->ru_utime, &usertime);
    return 0;
}