lib/cpp/src/windows/GetTimeOfDay.cpp

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#include "GetTimeOfDay.h"
#include "config.h"

// win32
#include <time.h>

#if defined(_MSC_VER) || defined(_MSC_EXTENSIONS)
#   define DELTA_EPOCH_IN_MICROSECS  11644473600000000Ui64
#else
#   define DELTA_EPOCH_IN_MICROSECS  11644473600000000ULL
#endif

struct timezone
{
    int  tz_minuteswest; /* minutes W of Greenwich */
    int  tz_dsttime;     /* type of dst correction */
};

int gettimeofday(struct timeval * tv, struct timezone * tz)
{
    FILETIME         ft;
    unsigned __int64 tmpres(0);
    static int       tzflag;

    if (NULL != tv)
    {
        GetSystemTimeAsFileTime(&ft);

        tmpres |= ft.dwHighDateTime;
        tmpres <<= 32;
        tmpres |= ft.dwLowDateTime;

        /*converting file time to unix epoch*/
        tmpres -= DELTA_EPOCH_IN_MICROSECS; 
        tmpres /= 10;  /*convert into microseconds*/
        tv->tv_sec = (long)(tmpres / 1000000UL);
        tv->tv_usec = (long)(tmpres % 1000000UL);
    }

    if (NULL != tz)
    {
        if (!tzflag)
        {
            _tzset();
            tzflag++;
        }

        long time_zone(0);
        errno_t err(_get_timezone(&time_zone));
        if (err == NO_ERROR)
        {
            tz->tz_minuteswest = time_zone / 60;
        }
        else
        {
            return -1;
        }

        int day_light(0);
        err = (_get_daylight(&day_light));
        if (err == NO_ERROR)
        {
            tz->tz_dsttime = day_light;
            return 0;
        }
        else
        {
            return -1;
        }
    }

    return -1;
}