dll/win32/kernel32/wine/timezone.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS system libraries
   4  * FILE:            lib/kernel32/misc/time.c
   5  * PURPOSE:         Time conversion functions
   6  * PROGRAMMER:      Ariadne
   7  *                  DOSDATE and DOSTIME structures from Onno Hovers
   8  * UPDATE HISTORY:
   9  *                  Created 19/01/99
  10  */
  11
  12 /* INCLUDES ******************************************************************/
  13
  14 #include <k32.h>
  15
  16 #define NDEBUG
  17 #include <debug.h>
  18
  19 /* TYPES *********************************************************************/
  20
  21 #define TICKSPERMIN 600000000
  22
  23 #define LL2FILETIME( ll, pft )\
  24     (pft)->dwLowDateTime = (UINT)(ll); \
  25     (pft)->dwHighDateTime = (UINT)((ll) >> 32);
  26 #define FILETIME2LL( pft, ll) \
  27     ll = (((LONGLONG)((pft)->dwHighDateTime))<<32) + (pft)-> dwLowDateTime ;
  28
  29 static const int MonthLengths[2][12] =
  30 {
  31     { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
  32     { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
  33 };
  34
  35 /* STATIC FUNTIONS **********************************************************/
  36
  37 static inline int IsLeapYear(int Year)
  38 {
  39     return Year % 4 == 0 && (Year % 100 != 0 || Year % 400 == 0) ? 1 : 0;
  40 }
  41
  42 /***********************************************************************
  43  *  TIME_DayLightCompareDate
  44  *
  45  * Compares two dates without looking at the year.
  46  *
  47  * PARAMS
  48  *   date        [in] The local time to compare.
  49  *   compareDate [in] The daylight savings begin or end date.
  50  *
  51  * RETURNS
  52  *
  53  *  -1 if date < compareDate
  54  *   0 if date == compareDate
  55  *   1 if date > compareDate
  56  *  -2 if an error occurs
  57  */
  58 static int
  59 TIME_DayLightCompareDate(const SYSTEMTIME *date, const SYSTEMTIME *compareDate)
  60 {
  61     int limit_day, dayinsecs;
  62
  63     if (date->wMonth < compareDate->wMonth)
  64         return -1; /* We are in a month before the date limit. */
  65
  66     if (date->wMonth > compareDate->wMonth)
  67         return 1; /* We are in a month after the date limit. */
  68
  69     /* if year is 0 then date is in day-of-week format, otherwise
  70      * it's absolute date.
  71      */
  72     if (compareDate->wYear == 0)
  73     {
  74         WORD First;
  75         /* compareDate->wDay is interpreted as number of the week in the month
  76          * 5 means: the last week in the month */
  77         int weekofmonth = compareDate->wDay;
  78           /* calculate the day of the first DayOfWeek in the month */
  79         First = ( 6 + compareDate->wDayOfWeek - date->wDayOfWeek + date->wDay
  80                ) % 7 + 1;
  81         limit_day = First + 7 * (weekofmonth - 1);
  82         /* check needed for the 5th weekday of the month */
  83         if(limit_day > MonthLengths[date->wMonth==2 && IsLeapYear(date->wYear)]
  84                 [date->wMonth - 1])
  85             limit_day -= 7;
  86     }
  87     else
  88     {
  89        limit_day = compareDate->wDay;
  90     }
  91
  92     /* convert to seconds */
  93     limit_day = ((limit_day * 24  + compareDate->wHour) * 60 +
  94             compareDate->wMinute ) * 60;
  95     dayinsecs = ((date->wDay * 24  + date->wHour) * 60 +
  96             date->wMinute ) * 60 + date->wSecond;
  97     /* and compare */
  98     return dayinsecs < limit_day ? -1 :
  99            dayinsecs > limit_day ? 1 :
 100            0;   /* date is equal to the date limit. */
 101 }
 102
 103 /***********************************************************************
 104  *  TIME_CompTimeZoneID
 105  *
 106  *  Computes the local time bias for a given time and time zone.
 107  *
 108  *  PARAMS
 109  *      pTZinfo     [in] The time zone data.
 110  *      lpFileTime  [in] The system or local time.
 111  *      islocal     [in] it is local time.
 112  *
 113  *  RETURNS
 114  *      TIME_ZONE_ID_INVALID    An error occurred
 115  *      TIME_ZONE_ID_UNKNOWN    There are no transition time known
 116  *      TIME_ZONE_ID_STANDARD   Current time is standard time
 117  *      TIME_ZONE_ID_DAYLIGHT   Current time is daylight savings time
 118  */
 119 static
 120 DWORD
 121 TIME_CompTimeZoneID( const TIME_ZONE_INFORMATION *pTZinfo, FILETIME *lpFileTime, BOOL islocal )
 122 {
 123     int ret;
 124     BOOL beforeStandardDate, afterDaylightDate;
 125     DWORD retval = TIME_ZONE_ID_INVALID;
 126     LONGLONG llTime = 0; /* initialized to prevent gcc complaining */
 127     SYSTEMTIME SysTime;
 128     FILETIME ftTemp;
 129
 130     if (pTZinfo->DaylightDate.wMonth != 0)
 131     {
 132         /* if year is 0 then date is in day-of-week format, otherwise
 133          * it's absolute date.
 134          */
 135         if (pTZinfo->StandardDate.wMonth == 0 ||
 136             (pTZinfo->StandardDate.wYear == 0 &&
 137             (pTZinfo->StandardDate.wDay<1 ||
 138             pTZinfo->StandardDate.wDay>5 ||
 139             pTZinfo->DaylightDate.wDay<1 ||
 140             pTZinfo->DaylightDate.wDay>5)))
 141         {
 142             SetLastError(ERROR_INVALID_PARAMETER);
 143             return TIME_ZONE_ID_INVALID;
 144         }
 145
 146         if (!islocal) {
 147             FILETIME2LL( lpFileTime, llTime );
 148             llTime -= ( pTZinfo->Bias + pTZinfo->DaylightBias )
 149                 * (LONGLONG)TICKSPERMIN;
 150             LL2FILETIME( llTime, &ftTemp)
 151             lpFileTime = &ftTemp;
 152         }
 153
 154         FileTimeToSystemTime(lpFileTime, &SysTime);
 155
 156          /* check for daylight savings */
 157         ret = TIME_DayLightCompareDate( &SysTime, &pTZinfo->StandardDate);
 158         if (ret == -2)
 159           return TIME_ZONE_ID_INVALID;
 160
 161         beforeStandardDate = ret < 0;
 162
 163         if (!islocal) {
 164             llTime -= ( pTZinfo->StandardBias - pTZinfo->DaylightBias )
 165                 * (LONGLONG)TICKSPERMIN;
 166             LL2FILETIME( llTime, &ftTemp)
 167             FileTimeToSystemTime(lpFileTime, &SysTime);
 168         }
 169
 170         ret = TIME_DayLightCompareDate( &SysTime, &pTZinfo->DaylightDate);
 171         if (ret == -2)
 172           return TIME_ZONE_ID_INVALID;
 173
 174         afterDaylightDate = ret >= 0;
 175
 176         retval = TIME_ZONE_ID_STANDARD;
 177         if( pTZinfo->DaylightDate.wMonth <  pTZinfo->StandardDate.wMonth ) {
 178             /* Northern hemisphere */
 179             if( beforeStandardDate && afterDaylightDate )
 180                 retval = TIME_ZONE_ID_DAYLIGHT;
 181         } else    /* Down south */
 182             if( beforeStandardDate || afterDaylightDate )
 183             retval = TIME_ZONE_ID_DAYLIGHT;
 184     } else
 185         /* No transition date */
 186         retval = TIME_ZONE_ID_UNKNOWN;
 187
 188     return retval;
 189 }
 190
 191 /***********************************************************************
 192  *  TIME_TimeZoneID
 193  *
 194  *  Calculates whether daylight savings is on now.
 195  *
 196  *  PARAMS
 197  *      pTzi [in] Timezone info.
 198  *
 199  *  RETURNS
 200  *      TIME_ZONE_ID_INVALID    An error occurred
 201  *      TIME_ZONE_ID_UNKNOWN    There are no transition time known
 202  *      TIME_ZONE_ID_STANDARD   Current time is standard time
 203  *      TIME_ZONE_ID_DAYLIGHT   Current time is daylight savings time
 204  */
 205 static DWORD TIME_ZoneID( const TIME_ZONE_INFORMATION *pTzi )
 206 {
 207     FILETIME ftTime;
 208     GetSystemTimeAsFileTime( &ftTime);
 209     return TIME_CompTimeZoneID( pTzi, &ftTime, FALSE);
 210 }
 211
 212 /***********************************************************************
 213  *  TIME_GetTimezoneBias
 214  *
 215  *  Calculates the local time bias for a given time zone.
 216  *
 217  * PARAMS
 218  *  pTZinfo    [in]  The time zone data.
 219  *  lpFileTime [in]  The system or local time.
 220  *  islocal    [in]  It is local time.
 221  *  pBias      [out] The calculated bias in minutes.
 222  *
 223  * RETURNS
 224  *  TRUE when the time zone bias was calculated.
 225  */
 226 static BOOL
 227 TIME_GetTimezoneBias(const TIME_ZONE_INFORMATION *pTZinfo, FILETIME *lpFileTime, BOOL islocal, LONG *pBias)
 228 {
 229     LONG bias = pTZinfo->Bias;
 230     DWORD tzid = TIME_CompTimeZoneID(pTZinfo, lpFileTime, islocal);
 231
 232     if( tzid == TIME_ZONE_ID_INVALID)
 233         return FALSE;
 234     if (tzid == TIME_ZONE_ID_DAYLIGHT)
 235         bias += pTZinfo->DaylightBias;
 236     else if (tzid == TIME_ZONE_ID_STANDARD)
 237         bias += pTZinfo->StandardBias;
 238     *pBias = bias;
 239     return TRUE;
 240 }
 241
 242
 243 /* FUNCTIONS ****************************************************************/
 244
 245 /*
 246  * @implemented
 247  */
 248 DWORD
 249 WINAPI
 250 GetTimeZoneInformation(LPTIME_ZONE_INFORMATION lpTimeZoneInformation)
 251 {
 252     NTSTATUS Status;
 253
 254     DPRINT("GetTimeZoneInformation()\n");
 255
 256     Status = NtQuerySystemInformation(SystemCurrentTimeZoneInformation,
 257                                       lpTimeZoneInformation,
 258                                       sizeof(TIME_ZONE_INFORMATION),
 259                                       NULL);
 260     if (!NT_SUCCESS(Status))
 261     {
 262         BaseSetLastNTError(Status);
 263         return TIME_ZONE_ID_INVALID;
 264     }
 265
 266     return TIME_ZoneID(lpTimeZoneInformation);
 267 }
 268
 269
 270 /*
 271  * @implemented
 272  */
 273 BOOL
 274 WINAPI
 275 SetTimeZoneInformation(CONST TIME_ZONE_INFORMATION *lpTimeZoneInformation)
 276 {
 277     NTSTATUS Status;
 278
 279     DPRINT("SetTimeZoneInformation()\n");
 280
 281     Status = RtlSetTimeZoneInformation((LPTIME_ZONE_INFORMATION)lpTimeZoneInformation);
 282     if (!NT_SUCCESS(Status))
 283     {
 284         DPRINT1("RtlSetTimeZoneInformation() failed (Status %lx)\n", Status);
 285         BaseSetLastNTError(Status);
 286         return FALSE;
 287     }
 288
 289     Status = NtSetSystemInformation(SystemCurrentTimeZoneInformation,
 290                                     (PVOID)lpTimeZoneInformation,
 291                                     sizeof(TIME_ZONE_INFORMATION));
 292     if (!NT_SUCCESS(Status))
 293     {
 294         DPRINT1("NtSetSystemInformation() failed (Status %lx)\n", Status);
 295         BaseSetLastNTError(Status);
 296         return FALSE;
 297     }
 298
 299     return TRUE;
 300 }
 301
 302 /*
 303  * @implemented
 304  */
 305 BOOL
 306 WINAPI
 307 SystemTimeToTzSpecificLocalTime(CONST TIME_ZONE_INFORMATION *lpTimeZoneInformation,
 308                                 CONST SYSTEMTIME *lpUniversalTime,
 309                                 LPSYSTEMTIME lpLocalTime)
 310 {
 311     TIME_ZONE_INFORMATION TzInfo;
 312     FILETIME FileTime;
 313     LONGLONG llTime;
 314     LONG lBias;
 315
 316     if (lpTimeZoneInformation != NULL)
 317     {
 318         TzInfo = *lpTimeZoneInformation;
 319     }
 320     else
 321     {
 322         if (GetTimeZoneInformation(&TzInfo) == TIME_ZONE_ID_INVALID)
 323             return FALSE;
 324     }
 325
 326     if (!lpUniversalTime || !lpLocalTime)
 327         return FALSE;
 328
 329     if (!SystemTimeToFileTime(lpUniversalTime, &FileTime))
 330         return FALSE;
 331
 332     FILETIME2LL(&FileTime, llTime)
 333
 334     if (!TIME_GetTimezoneBias(&TzInfo, &FileTime, FALSE, &lBias))
 335         return FALSE;
 336
 337     /* convert minutes to 100-nanoseconds-ticks */
 338     llTime -= (LONGLONG)lBias * TICKSPERMIN;
 339
 340     LL2FILETIME( llTime, &FileTime)
 341
 342     return FileTimeToSystemTime(&FileTime, lpLocalTime);
 343 }
 344
 345
 346 /*
 347  * @implemented (Wine 13 sep 2008)
 348  */
 349 BOOL
 350 WINAPI
 351 TzSpecificLocalTimeToSystemTime(LPTIME_ZONE_INFORMATION lpTimeZoneInformation,
 352                                 LPSYSTEMTIME lpLocalTime,
 353                                 LPSYSTEMTIME lpUniversalTime)
 354 {
 355     FILETIME ft;
 356     LONG lBias;
 357     LONGLONG t;
 358     TIME_ZONE_INFORMATION tzinfo;
 359
 360     if (lpTimeZoneInformation != NULL)
 361     {
 362         tzinfo = *lpTimeZoneInformation;
 363     }
 364     else
 365     {
 366         if (GetTimeZoneInformation(&tzinfo) == TIME_ZONE_ID_INVALID)
 367             return FALSE;
 368     }
 369
 370     if (!SystemTimeToFileTime(lpLocalTime, &ft))
 371         return FALSE;
 372     FILETIME2LL( &ft, t)
 373     if (!TIME_GetTimezoneBias(&tzinfo, &ft, TRUE, &lBias))
 374         return FALSE;
 375     /* convert minutes to 100-nanoseconds-ticks */
 376     t += (LONGLONG)lBias * TICKSPERMIN;
 377     LL2FILETIME( t, &ft)
 378     return FileTimeToSystemTime(&ft, lpUniversalTime);
 379 }
 380
 381 /* EOF */