time.c

See Hanoi.cpp for the implementation of this cla

    Minutes = Seconds / 60;
    lpst->wSecond = (WORD)(Seconds % 60);
    lpst->wHour = (WORD)(Minutes / 60);
    lpst->wMinute = (WORD)(Minutes % 60);
    lpst->wYear = (WORD)(Years + 1601);
    lpst->wDay = (WORD)(Days + 1);
    return TRUE;
}

/*
	@doc BOTH EXTERNAL
	
	@func BOOL | FileTimeToLocalFileTime | Converts a file time based on the 
	Coordinated Universal Time (UTC) to a local file time. 
    @parm CONST FILETIME * | lpFileTime | address of UTC file time to convert  
    @parm LPFILETIME | lpLocalFileTime | address of converted file time 

	@comm Follows the Win32 reference description without restrictions or modifications. 

*/
BOOL WINAPI FileTimeToLocalFileTime(const FILETIME * lpft, LPFILETIME lpftLocal) {
	FILETIME bias;
	bias.dwHighDateTime = 0;
	if (UserKInfo[KINX_TIMEZONEBIAS] < 0)
		bias.dwLowDateTime = - UserKInfo[KINX_TIMEZONEBIAS];
	else
		bias.dwLowDateTime = UserKInfo[KINX_TIMEZONEBIAS];
	mul64_32_64(&bias,600000000L,&bias);
	if (UserKInfo[KINX_TIMEZONEBIAS] < 0)
		add64_64_64(lpft,&bias,lpftLocal);
	else
		sub64_64_64(lpft,&bias,lpftLocal);
	return TRUE;
}

/*
	@doc BOTH EXTERNAL
	
	@func BOOL | LocalFileTimeToFileTime | Converts a local file time to a file time based 
	on the Coordinated Universal Time (UTC). 
    @parm CONST FILETIME * | lpftLocal | address of local file time to convert 
    @parm LPFILETIME | lpft | address of converted file time 

	@comm Follows the Win32 reference description without restrictions or modifications. 
*/
BOOL WINAPI LocalFileTimeToFileTime(const FILETIME *lpftLocal, LPFILETIME lpft) {
	FILETIME bias;
	bias.dwHighDateTime = 0;
	if (UserKInfo[KINX_TIMEZONEBIAS] < 0)
		bias.dwLowDateTime = - UserKInfo[KINX_TIMEZONEBIAS];
	else
		bias.dwLowDateTime = UserKInfo[KINX_TIMEZONEBIAS];
	mul64_32_64(&bias,600000000L,&bias);
	if (UserKInfo[KINX_TIMEZONEBIAS] < 0)
		sub64_64_64(lpftLocal,&bias,lpft);
	else
		add64_64_64(lpftLocal,&bias,lpft);
	return TRUE;
}

/*
	@doc BOTH EXTERNAL
	
	@func VOID | GetSystemTime | Retrieves the current system date and time. 
	The system time is expressed in Coordinated Universal Time (UTC). 
    @parm LPSYSTEMTIME | lpst | address of system time structure  

	@comm Follows the Win32 reference description without restrictions or modifications. 
*/
VOID WINAPI GetSystemTime (LPSYSTEMTIME lpSystemTime) {
	FILETIME ft;
	GetRealTime(lpSystemTime);
	SystemTimeToFileTime(lpSystemTime,&ft);
	LocalFileTimeToFileTime(&ft,&ft);
	FileTimeToSystemTime(&ft,lpSystemTime);
}

/*
	@doc BOTH EXTERNAL
	
	@func BOOL | SetSystemTime | Sets the current system time and date. The system time 
	is expressed in Coordinated Universal Time (UTC). 
    @parm CONST SYSTEMTIME * | lpst | address of system time to set 

	@comm Follows the Win32 reference description without restrictions or modifications. 
*/
BOOL WINAPI SetSystemTime (const SYSTEMTIME *lpSystemTime) {
	SYSTEMTIME st;
	FILETIME ft;
	if (!SystemTimeToFileTime(lpSystemTime,&ft) || 
		!FileTimeToLocalFileTime(&ft,&ft) ||
		!FileTimeToSystemTime(&ft,&st) ||
		!SetRealTime(&st)) {
		SetLastError(ERROR_INVALID_PARAMETER);
		return FALSE;
	}
	if (IsAPIReady(SH_WMGR))
		CeEventHasOccurred(NOTIFICATION_EVENT_TIME_CHANGE, NULL);
	RefreshKernelAlarm();
	return TRUE;
}

/*
	@doc BOTH EXTERNAL
	
	@func VOID | GetLocalTime | Retrieves the current local date and time. 
    @parm LPSYSTEMTIME |lpst | address of system time structure  

	@comm Follows the Win32 reference description without restrictions or modifications. 

*/
VOID WINAPI GetLocalTime (LPSYSTEMTIME lpSystemTime) {
	FILETIME ft;
	GetRealTime(lpSystemTime);
	SystemTimeToFileTime(lpSystemTime,&ft);
	FileTimeToSystemTime(&ft,lpSystemTime);
}

// Internal file system function - gets current UMT file time
VOID GetCurrentFT(LPFILETIME lpFileTime) {
	SYSTEMTIME st;
	GetRealTime(&st);
	SystemTimeToFileTime(&st,lpFileTime);
	LocalFileTimeToFileTime(lpFileTime,lpFileTime);
}

/*
	@doc BOTH EXTERNAL
	
	@func BOOL | SetLocalTime | Sets the current local time and date.
    @parm CONST SYSTEMTIME * | lpst | address of local time to set 

	@comm Follows the Win32 reference description without restrictions or modifications. 
*/
BOOL WINAPI SetLocalTime (const SYSTEMTIME *lpSystemTime) {
	SYSTEMTIME st;
	FILETIME ft;
	if (!SystemTimeToFileTime(lpSystemTime,&ft) || 
		!FileTimeToSystemTime(&ft,&st) ||
		!SetRealTime(&st)) {
		SetLastError(ERROR_INVALID_PARAMETER);
		return FALSE;
	}
	if (IsAPIReady(SH_WMGR))
		CeEventHasOccurred(NOTIFICATION_EVENT_TIME_CHANGE, NULL);
	RefreshKernelAlarm();
	return TRUE;
}

/*
	@doc BOTH EXTERNAL
	
	@func DWORD | GetTimeZoneInformation | Retrieves the current time-zone parameters. 
	These parameters control the translations between Coordinated Universal Time (UTC) 
	and local time. 
    @parm LPTIME_ZONE_INFORMATION | lptzi | address of time-zone settings 

	@devnote CHOOSE COMM TAG FOR ONLY ONE OF THE FOLLOWING:
	@comm Follows the Win32 reference description with the following restrictions:
			Always return TIME_ZONE_ID_UNKNOWN;

*/
#define TZIStrCpyW(D,S) memcpy(D,S,sizeof(S))

#define GetKeyHKLM(valname,keyname,lptype,data,lplen)   RegQueryValueExW(HKEY_LOCAL_MACHINE,valname,(LPDWORD)keyname,lptype,(LPBYTE)data,lplen)
#define OpenKeyHKLM(keyname,pkeyret)                    RegOpenKeyExW(HKEY_LOCAL_MACHINE,keyname,0, 0,pkeyret)

#define GetKey(keyin,valname,lptype,data,lplen)         RegQueryValueExW(keyin,valname,0,lptype,(LPBYTE)data,lplen)
#define OpenKey(keyin,keyname,pkeyret)                  RegOpenKeyExW(keyin,keyname,0, 0,pkeyret)

typedef struct tagTZREG {
    LONG    Bias;
    LONG    StandardBias;
    LONG    DaylightBias;
    SYSTEMTIME StandardDate;
    SYSTEMTIME DaylightDate;
} TZREG;

const TCHAR cszTimeZones[] = L"Time Zones";

void GetDefaultTimeZoneInformation (LPTIME_ZONE_INFORMATION lpTzi) 
{
	DWORD type, size1, size2;
	HKEY hk1=0, hk2=0;
	TZREG tzr;

	memset(lpTzi, 0, sizeof(TIME_ZONE_INFORMATION));
	memset(&tzr, 0, sizeof(tzr));
	size1 = sizeof(lpTzi->StandardName);
	size2 = sizeof(tzr);

	// see if we have a value "Default" under HKLM\Time Zones
	if(	(ERROR_SUCCESS==OpenKeyHKLM(L"Time Zones", &hk1)) &&
		(ERROR_SUCCESS==GetKey(hk1, L"Default",&type,lpTzi->StandardName,&size1)) &&
		(ERROR_SUCCESS==OpenKey(hk1, lpTzi->StandardName, &hk2)) &&
    	(ERROR_SUCCESS==GetKey(hk2,L"TZI",&type,&tzr,&size2)) )
    {
		// Read the value "TZI" and "Dlt" under HKLM\Time Zones\<time zone std name>
		size1 = sizeof(lpTzi->DaylightName);
	    GetKey(hk2,L"Dlt",&type,lpTzi->DaylightName,&size1);
   		lpTzi->Bias = tzr.Bias;
        lpTzi->StandardBias = tzr.StandardBias;
        lpTzi->DaylightBias = tzr.DaylightBias;
        lpTzi->StandardDate = tzr.StandardDate;
		lpTzi->DaylightDate = tzr.DaylightDate;
	}
	else
	{
		// Default to Redmond, WA for now
		lpTzi->Bias = 480;
		TZIStrCpyW(lpTzi->StandardName,L"Pacific Standard Time");
		lpTzi->StandardDate.wYear = 0;
		lpTzi->StandardDate.wMonth = 10;
		lpTzi->StandardDate.wDayOfWeek = 0;
		lpTzi->StandardDate.wDay = 5;
		lpTzi->StandardDate.wHour = 2;
		lpTzi->StandardDate.wMinute = 0;
		lpTzi->StandardDate.wSecond = 0;
		lpTzi->StandardDate.wMilliseconds = 0;
		lpTzi->StandardBias = 0;
		TZIStrCpyW(lpTzi->DaylightName,L"Pacific Daylight Time");
		lpTzi->DaylightDate.wYear = 0;
		lpTzi->DaylightDate.wMonth = 4;
		lpTzi->DaylightDate.wDayOfWeek = 0;
		lpTzi->DaylightDate.wDay = 1;
		lpTzi->DaylightDate.wHour = 2;
		lpTzi->DaylightDate.wMinute = 0;
		lpTzi->DaylightDate.wSecond = 0;
		lpTzi->DaylightDate.wMilliseconds = 0;
		lpTzi->DaylightBias = -60;
	}
	if(hk1) RegCloseKey(hk1);
	if(hk2) RegCloseKey(hk2);
	ASSERT(lpTzi->StandardName && lpTzi->DaylightName);
}

DWORD WINAPI GetTimeZoneInformation (LPTIME_ZONE_INFORMATION lpTzi) 
{
	DWORD type;
	DWORD size = sizeof(TIME_ZONE_INFORMATION);
	// check for existing time-zone struct
	if (GetKeyHKLM(L"TimeZoneInformation",L"Time",&type,(LPBYTE)lpTzi,&size)) 
	{
		// fallback to default
		GetDefaultTimeZoneInformation(lpTzi);
	}
	if (lpTzi->Bias + lpTzi->StandardBias == UserKInfo[KINX_TIMEZONEBIAS])
		return TIME_ZONE_ID_STANDARD;
	else if (lpTzi->Bias + lpTzi->DaylightBias == UserKInfo[KINX_TIMEZONEBIAS])
		return TIME_ZONE_ID_DAYLIGHT;
	return TIME_ZONE_ID_UNKNOWN;
}

BOOL IsValidTZISystemTime(const SYSTEMTIME *lpst) {
	if (IsValidSystemTime(lpst))
		return TRUE;
	if (!lpst->wYear && (lpst->wDayOfWeek <= 6) && (lpst->wDay >= 1) && (lpst->wDay <= 5))
		return TRUE;
	if (!lpst->wMonth)
		return TRUE;
	return FALSE;
}

/*
	@doc BOTH EXTERNAL
	
	@func BOOL | SetTimeZoneInformation | Sets the current time-zone parameters. 
	These parameters control translations from Coordinated Universal Time (UTC) to local time.
    @parm CONST TIME_ZONE_INFORMATION * | lptzi | address of time-zone settings  

	@comm Follows the Win32 reference description without restrictions or modifications. 
*/
BOOL WINAPI SetTimeZoneInformation (const TIME_ZONE_INFORMATION *lpTzi) {
	DWORD dwDisp;
	HKEY  hKey=NULL;
	
	if (!IsValidTZISystemTime(&lpTzi->StandardDate) ||
		!IsValidTZISystemTime(&lpTzi->DaylightDate)) {
		SetLastError(ERROR_INVALID_PARAMETER);
		return FALSE;
	}
	SetTimeZoneBias(lpTzi->Bias+lpTzi->StandardBias,lpTzi->Bias+lpTzi->DaylightBias);

	if(ERROR_SUCCESS==RegCreateKeyExW(HKEY_LOCAL_MACHINE, L"Time", 0, NULL, REG_OPTION_NON_VOLATILE, KEY_ALL_ACCESS, NULL, &hKey, &dwDisp) && hKey) {
		if(ERROR_SUCCESS==RegSetValueExW(hKey, L"TimeZoneInformation", 0, REG_BINARY, (LPBYTE)lpTzi,sizeof(TIME_ZONE_INFORMATION))) {
			if (IsAPIReady(SH_WMGR))
				CeEventHasOccurred(NOTIFICATION_EVENT_TZ_CHANGE, NULL);
			RegCloseKey(hKey);
			return TRUE;
		}
		RegCloseKey(hKey);
	}
	SetLastError(ERROR_OUTOFMEMORY);
	return FALSE;
}