windows下实现gettimeofday

#include <stdio.h>
#include <time.h>
#include <windows.h>

#define SECS_TO_FT_MULT 10000000
static LARGE_INTEGER base_time;

typedef struct win_time_val
{
/** The seconds part of the time. */
long    sec;

/** The miliseconds fraction of the time. */
long    msec;

} win_time_val_t;

typedef struct win_time
{
/** This represents day of week where value zero means Sunday */
int wday;

/** This represents day of month: 1-31 */
int day;

/** This represents month, with the value is 0 - 11 (zero is January) */
int mon;

/** This represent the actual year (unlike in ANSI libc where
*  the value must be added by 1900).
*/
int year;

/** This represents the second part, with the value is 0-59 */
int sec;

/** This represents the minute part, with the value is: 0-59 */
int min;

/** This represents the hour part, with the value is 0-23 */
int hour;

/** This represents the milisecond part, with the value is 0-999 */
int msec;

}win_time_t;

// Find 1st Jan 1970 as a FILETIME
static void get_base_time(LARGE_INTEGER *base_time)
{
SYSTEMTIME st;
FILETIME ft;

memset(&st,0,sizeof(st));
st.wYear=1970;
st.wMonth=1;
st.wDay=1;
SystemTimeToFileTime(&st, &ft);

base_time->LowPart = ft.dwLowDateTime;
base_time->HighPart = ft.dwHighDateTime;
base_time->QuadPart /= SECS_TO_FT_MULT;
}

int win_gettimeofday(win_time_val_t *tv)
{
SYSTEMTIME st;
FILETIME ft;
LARGE_INTEGER li;
static char get_base_time_flag=0;

if (get_base_time_flag == 0)
{
get_base_time(&base_time);
}

/* Standard Win32 GetLocalTime */
GetLocalTime(&st);
SystemTimeToFileTime(&st, &ft);

li.LowPart = ft.dwLowDateTime;
li.HighPart = ft.dwHighDateTime;
li.QuadPart /= SECS_TO_FT_MULT;
li.QuadPart -= base_time.QuadPart;

tv->sec = li.LowPart;
tv->msec = st.wMilliseconds;

return 0;
}

int win_time(const win_time_val_t *tv, win_time_t *time)
{
LARGE_INTEGER li;
FILETIME ft;
SYSTEMTIME st;

li.QuadPart = tv->sec;
li.QuadPart += base_time.QuadPart;
li.QuadPart *= SECS_TO_FT_MULT;

ft.dwLowDateTime = li.LowPart;
ft.dwHighDateTime = li.HighPart;
FileTimeToSystemTime(&ft, &st);

time->year = st.wYear;
time->mon = st.wMonth-1;
time->day = st.wDay;
time->wday = st.wDayOfWeek;

time->hour = st.wHour;
time->min = st.wMinute;
time->sec = st.wSecond;
time->msec = tv->msec;

return 0;
}

int main(int argc, char *argv[])
{
win_time_val_t wintv;
win_time_t wintime;
win_gettimeofday(&wintv);
win_time(&wintv,&wintime);

printf("%d年%d月%d日%d时%d分%d秒%d毫秒 星期%d\r\n",
wintime.year,wintime.mon+1,wintime.day,
wintime.hour,wintime.min, wintime.sec,wintime.msec,wintime.wday);

return 0;
}