windows下实现gettimeofday

#include 
#include 
#include 

#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;
}

本代码得于pjlib，用于日志接口实现，打印日志时间信息，精度到毫秒级

码海拾贝 date&time 后续会涉及mktime localtime  gmttime等于时间相关的api