OVMS3/OVMS.V3/components/duktape/src-input/duk_bi_date_windows.c

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/*
* Windows Date providers
*
* Platform specific links:
*
* - http://msdn.microsoft.com/en-us/library/windows/desktop/ms725473(v=vs.85).aspx
*/
#include "duk_internal.h"
/* The necessary #includes are in place in duk_config.h. */
#if defined(DUK_USE_DATE_NOW_WINDOWS) || defined(DUK_USE_DATE_TZO_WINDOWS)
/* Shared Windows helpers. */
DUK_LOCAL void duk__convert_systime_to_ularge(const SYSTEMTIME *st, ULARGE_INTEGER *res) {
FILETIME ft;
if (SystemTimeToFileTime(st, &ft) == 0) {
DUK_D(DUK_DPRINT("SystemTimeToFileTime() failed, returning 0"));
res->QuadPart = 0;
} else {
res->LowPart = ft.dwLowDateTime;
res->HighPart = ft.dwHighDateTime;
}
}
#if defined(DUK_USE_DATE_NOW_WINDOWS_SUBMS)
DUK_LOCAL void duk__convert_filetime_to_ularge(const FILETIME *ft, ULARGE_INTEGER *res) {
res->LowPart = ft->dwLowDateTime;
res->HighPart = ft->dwHighDateTime;
}
#endif /* DUK_USE_DATE_NOW_WINDOWS_SUBMS */
DUK_LOCAL void duk__set_systime_jan1970(SYSTEMTIME *st) {
duk_memzero((void *) st, sizeof(*st));
st->wYear = 1970;
st->wMonth = 1;
st->wDayOfWeek = 4; /* not sure whether or not needed; Thursday */
st->wDay = 1;
DUK_ASSERT(st->wHour == 0);
DUK_ASSERT(st->wMinute == 0);
DUK_ASSERT(st->wSecond == 0);
DUK_ASSERT(st->wMilliseconds == 0);
}
#endif /* defined(DUK_USE_DATE_NOW_WINDOWS) || defined(DUK_USE_DATE_TZO_WINDOWS) */
#if defined(DUK_USE_DATE_NOW_WINDOWS)
DUK_INTERNAL duk_double_t duk_bi_date_get_now_windows(void) {
/* Suggested step-by-step method from documentation of RtlTimeToSecondsSince1970:
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms724928(v=vs.85).aspx
*/
SYSTEMTIME st1, st2;
ULARGE_INTEGER tmp1, tmp2;
GetSystemTime(&st1);
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st1, &tmp1);
duk__set_systime_jan1970(&st2);
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st2, &tmp2);
/* Difference is in 100ns units, convert to milliseconds, keeping
* fractions since Duktape 2.2.0. This is only theoretical because
* SYSTEMTIME is limited to milliseconds.
*/
return (duk_double_t) ((LONGLONG) tmp1.QuadPart - (LONGLONG) tmp2.QuadPart) / 10000.0;
}
#endif /* DUK_USE_DATE_NOW_WINDOWS */
#if defined(DUK_USE_DATE_NOW_WINDOWS_SUBMS)
DUK_INTERNAL duk_double_t duk_bi_date_get_now_windows_subms(void) {
/* Variant of the basic algorithm using GetSystemTimePreciseAsFileTime()
* for more accuracy.
*/
FILETIME ft1;
SYSTEMTIME st2;
ULARGE_INTEGER tmp1, tmp2;
GetSystemTimePreciseAsFileTime(&ft1);
duk__convert_filetime_to_ularge((const FILETIME *) &ft1, &tmp1);
duk__set_systime_jan1970(&st2);
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st2, &tmp2);
/* Difference is in 100ns units, convert to milliseconds, keeping
* fractions since Duktape 2.2.0.
*/
return (duk_double_t) ((LONGLONG) tmp1.QuadPart - (LONGLONG) tmp2.QuadPart) / 10000.0;
}
#endif /* DUK_USE_DATE_NOW_WINDOWS */
#if defined(DUK_USE_DATE_TZO_WINDOWS)
DUK_INTERNAL duk_int_t duk_bi_date_get_local_tzoffset_windows(duk_double_t d) {
SYSTEMTIME st1;
SYSTEMTIME st2;
SYSTEMTIME st3;
ULARGE_INTEGER tmp1;
ULARGE_INTEGER tmp2;
ULARGE_INTEGER tmp3;
FILETIME ft1;
/* XXX: handling of timestamps outside Windows supported range.
* How does Windows deal with dates before 1600? Does windows
* support all ECMAScript years (like -200000 and +200000)?
* Should equivalent year mapping be used here too? If so, use
* a shared helper (currently integrated into timeval-to-parts).
*/
/* Use the approach described in "Remarks" of FileTimeToLocalFileTime:
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms724277(v=vs.85).aspx
*/
duk__set_systime_jan1970(&st1);
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st1, &tmp1);
tmp2.QuadPart = (ULONGLONG) (d * 10000.0); /* millisec -> 100ns units since jan 1, 1970 */
tmp2.QuadPart += tmp1.QuadPart; /* input 'd' in Windows UTC, 100ns units */
ft1.dwLowDateTime = tmp2.LowPart;
ft1.dwHighDateTime = tmp2.HighPart;
if (FileTimeToSystemTime((const FILETIME *) &ft1, &st2) == 0) {
DUK_D(DUK_DPRINT("FileTimeToSystemTime() failed, return tzoffset 0"));
return 0;
}
if (SystemTimeToTzSpecificLocalTime((LPTIME_ZONE_INFORMATION) NULL, &st2, &st3) == 0) {
DUK_D(DUK_DPRINT("SystemTimeToTzSpecificLocalTime() failed, return tzoffset 0"));
return 0;
}
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st3, &tmp3);
/* Positive if local time ahead of UTC. */
return (duk_int_t) (((LONGLONG) tmp3.QuadPart - (LONGLONG) tmp2.QuadPart) / DUK_I64_CONSTANT(10000000)); /* seconds */
}
#endif /* DUK_USE_DATE_TZO_WINDOWS */
#if defined(DUK_USE_DATE_TZO_WINDOWS_NO_DST)
DUK_INTERNAL duk_int_t duk_bi_date_get_local_tzoffset_windows_no_dst(duk_double_t d) {
SYSTEMTIME st1;
SYSTEMTIME st2;
FILETIME ft1;
FILETIME ft2;
ULARGE_INTEGER tmp1;
ULARGE_INTEGER tmp2;
/* Do a similar computation to duk_bi_date_get_local_tzoffset_windows
* but without accounting for daylight savings time. Use this on
* Windows platforms (like Durango) that don't support the
* SystemTimeToTzSpecificLocalTime() call.
*/
/* current time not needed for this computation */
DUK_UNREF(d);
duk__set_systime_jan1970(&st1);
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st1, &tmp1);
ft1.dwLowDateTime = tmp1.LowPart;
ft1.dwHighDateTime = tmp1.HighPart;
if (FileTimeToLocalFileTime((const FILETIME *) &ft1, &ft2) == 0) {
DUK_D(DUK_DPRINT("FileTimeToLocalFileTime() failed, return tzoffset 0"));
return 0;
}
if (FileTimeToSystemTime((const FILETIME *) &ft2, &st2) == 0) {
DUK_D(DUK_DPRINT("FileTimeToSystemTime() failed, return tzoffset 0"));
return 0;
}
duk__convert_systime_to_ularge((const SYSTEMTIME *) &st2, &tmp2);
return (duk_int_t) (((LONGLONG) tmp2.QuadPart - (LONGLONG) tmp1.QuadPart) / DUK_I64_CONSTANT(10000000)); /* seconds */
}
#endif /* DUK_USE_DATE_TZO_WINDOWS_NO_DST */
#if defined(DUK_USE_GET_MONOTONIC_TIME_WINDOWS_QPC)
DUK_INTERNAL duk_double_t duk_bi_date_get_monotonic_time_windows_qpc(void) {
LARGE_INTEGER count, freq;
/* There are legacy issues with QueryPerformanceCounter():
* - Potential jumps: https://support.microsoft.com/en-us/help/274323/performance-counter-value-may-unexpectedly-leap-forward
* - Differences between cores (XP): https://msdn.microsoft.com/en-us/library/windows/desktop/dn553408(v=vs.85).aspx#qpc_support_in_windows_versions
*
* We avoid these by enabling QPC by default only for Vista or later.
*/
if (QueryPerformanceCounter(&count) && QueryPerformanceFrequency(&freq)) {
/* XXX: QueryPerformanceFrequency() can be cached */
return (duk_double_t) count.QuadPart / (duk_double_t) freq.QuadPart * 1000.0;
} else {
/* MSDN: "On systems that run Windows XP or later, the function
* will always succeed and will thus never return zero."
* Provide minimal error path just in case user enables this
* feature in pre-XP Windows.
*/
return 0.0;
}
}
#endif /* DUK_USE_GET_MONOTONIC_TIME_WINDOWS_QPC */