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Diffstat (limited to 'src/vm/comdatetime.cpp')
| -rw-r--r-- | src/vm/comdatetime.cpp | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/src/vm/comdatetime.cpp b/src/vm/comdatetime.cpp new file mode 100644 index 0000000000..c20c05deb2 --- /dev/null +++ b/src/vm/comdatetime.cpp @@ -0,0 +1,125 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. + + +#include "common.h" +#include "object.h" +#include "excep.h" +#include "frames.h" +#include "vars.hpp" +#include "comdatetime.h" + +const INT64 COMDateTime::TicksPerMillisecond = 10000; +const INT64 COMDateTime::TicksPerSecond = TicksPerMillisecond * 1000; +const INT64 COMDateTime::TicksPerMinute = TicksPerSecond * 60; +const INT64 COMDateTime::TicksPerHour = TicksPerMinute * 60; +const INT64 COMDateTime::TicksPerDay = TicksPerHour * 24; + +const INT64 COMDateTime::MillisPerSecond = 1000; +const INT64 COMDateTime::MillisPerDay = MillisPerSecond * 60 * 60 * 24; + +const int COMDateTime::DaysPer4Years = 365 * 4 + 1; +const int COMDateTime::DaysPer100Years = DaysPer4Years * 25 - 1; +const int COMDateTime::DaysPer400Years = DaysPer100Years * 4 + 1; + +// Number of days from 1/1/0001 to 1/1/10000 +const int COMDateTime::DaysTo10000 = DaysPer400Years * 25 - 366; + +const int COMDateTime::DaysTo1899 = DaysPer400Years * 4 + DaysPer100Years * 3 - 367; + +const INT64 COMDateTime::DoubleDateOffset = DaysTo1899 * TicksPerDay; + +// OA Min Date is Jan 1, 100 AD. This is after converting to ticks. +const INT64 COMDateTime::OADateMinAsTicks = (DaysPer100Years - 365) * TicksPerDay; + +// All OA dates must be greater than (not >=) OADateMinAsDouble +const double COMDateTime::OADateMinAsDouble = -657435.0; + +// All OA dates must be less than (not <=) OADateMaxAsDouble +const double COMDateTime::OADateMaxAsDouble = 2958466.0; + +const INT64 COMDateTime::MaxTicks = DaysTo10000 * TicksPerDay; +const INT64 COMDateTime::MaxMillis = DaysTo10000 * MillisPerDay; + +const INT64 TicksMask = I64(0x3FFFFFFFFFFFFFFF); + +// This function is duplicated in DateTime.cs +INT64 COMDateTime::DoubleDateToTicks(const double d) +{ + CONTRACTL + { + THROWS; + GC_TRIGGERS; + MODE_COOPERATIVE; + } CONTRACTL_END; + + // Make sure this date is a valid OleAut date. This is the check from the internal + // OleAut macro IsValidDate, found in oledisp.h. Eventually at least the 64 bit + // build of oleaut will define these gregorian max and min values as public constants. + // The check done this way will take care of NaN + if (!(d < OADateMaxAsDouble) || !(d > OADateMinAsDouble)) + COMPlusThrow(kArgumentException, W("Arg_OleAutDateInvalid")); + + // Conversion to int64 will not cause an overflow here, as at this point the "d" is in between OADateMinAsDouble and OADateMaxAsDouble + INT64 millis = (INT64)(d * MillisPerDay + (d >= 0? 0.5: -0.5)); + if (millis < 0) millis -= (millis % MillisPerDay) * 2; + // There are cases when we are very close to -1 and 1 in which case millis%MillisPerDay is 0 since we have exactly one day due to rounding issues. + millis += DoubleDateOffset / TicksPerMillisecond; + + if (millis < 0 || millis >= MaxMillis) + { + COMPlusThrow(kArgumentException, W("Arg_OleAutDateScale")); // Cannot be equal to MaxMillis. + } + return millis * TicksPerMillisecond; +} + +// This function is duplicated in DateTime.cs +double COMDateTime::TicksToDoubleDate(INT64 ticks) +{ + CONTRACTL + { + THROWS; + GC_TRIGGERS; + MODE_COOPERATIVE; + } CONTRACTL_END; + + // + + // Workaround to handle uninitialized DateTime objects in the CLR + // See explanation in DateTime.cs's TicksToOADate function. + + // Strip off the extra kind state + ticks = (ticks & TicksMask); + + if (ticks == 0) + return 0.0; // OA's 0 date (12/30/1899). + + if (ticks < OADateMinAsTicks) + { + //We've special-cased day 0 (01/01/0001 in the Gregorian Calendar) such that the + //date can be used to represent a DateTime the contains only a time. OA uses + //day 0 (12/30/1899) for the same purpose, so we'll do a mapping from our day 0 + //to their day 0. + if (ticks < TicksPerDay) + ticks+=DoubleDateOffset; + else + COMPlusThrow(kOverflowException, W("Arg_OleAutDateInvalid")); + } + + INT64 millis = (ticks - DoubleDateOffset) / TicksPerMillisecond; + if (millis < 0) + { + INT64 frac = millis % MillisPerDay; + if (frac != 0) millis -= (MillisPerDay + frac) * 2; + } + + double d = (double)millis / MillisPerDay; + + // Make sure this date is a valid OleAut date. This is the check from the internal + // OleAut macro IsValidDate, found in oledisp.h. Eventually at least the 64 bit + // build of oleaut will define these gregorian max and min values as public constants. + _ASSERTE(d < OADateMaxAsDouble && d > OADateMinAsDouble); + + return d; +} |