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/*
* Date and time functions of libewf .net managed wrapper
*
* Copyright (C) 2006-2017, Joachim Metz <joachim.metz@gmail.com>
*
* Refer to AUTHORS for acknowledgements.
*
* This software is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this software. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma managed( push, off )
#include <common.h>
#include <types.h>
#pragma managed( pop )
#include "ewf.net_datetime.h"
#using <mscorlib.dll>
using namespace System;
namespace EWF {
/* Creates a new datetime object from a filetime
* Returns a DateTime object if successful or nullptr on error
*/
System::DateTime^ DateTime::FromFiletime( System::UInt64 filetime )
{
System::DateTime^ date_time_object = nullptr;
System::String^ error_string = nullptr;
System::String^ function = "DateTime::FromFiletime";
System::Int32 days_in_century = 0;
System::Int32 days_in_year = 0;
System::Int32 year = 0;
System::Int32 day = 0;
System::Int32 days_in_month = 0;
System::Int32 hours = 0;
System::Int32 micro_seconds = 0;
System::Int32 minutes = 0;
System::Int32 month = 0;
System::Int32 seconds = 0;
/* The timestamp is in units of 100 nano seconds correct the value to seconds
*/
micro_seconds = ( filetime % 10000000 ) / 10;
filetime /= 10000000;
/* There are 60 seconds in a minute correct the value to minutes
*/
seconds = filetime % 60;
filetime /= 60;
/* There are 60 minutes in an hour correct the value to hours
*/
minutes = filetime % 60;
filetime /= 60;
/* There are 24 hours in a day correct the value to days
*/
hours = filetime % 24;
filetime /= 24;
/* Add 1 day to compensate that Jan 1 1601 is represented as 0
*/
filetime += 1;
/* Determine the number of years starting at '1 Jan 1601 00:00:00'
* correct the value to days within the year
*/
year = 1601;
if( filetime >= 36159 )
{
year = 1700;
filetime -= 36159;
}
while( filetime > 0 )
{
if( ( year % 400 ) == 0 )
{
days_in_century = 36525;
}
else
{
days_in_century = 36524;
}
if( filetime <= days_in_century )
{
break;
}
filetime -= days_in_century;
year += 100;
}
while( filetime > 0 )
{
/* Check for a leap year
* The year is ( ( dividable by 4 ) and ( not dividable by 100 ) ) or ( dividable by 400 )
*/
if( ( ( ( year % 4 ) == 0 )
&& ( ( year % 100 ) != 0 ) )
|| ( ( year % 400 ) == 0 ) )
{
days_in_year = 366;
}
else
{
days_in_year = 365;
}
if( filetime <= (System::UInt64) days_in_year )
{
break;
}
filetime -= days_in_year;
year += 1;
}
/* Determine the month correct the value to days within the month
*/
month = 1;
while( filetime > 0 )
{
/* February (2)
*/
if( month == 2 )
{
if( ( ( ( year % 4 ) == 0 )
&& ( ( year % 100 ) != 0 ) )
|| ( ( year % 400 ) == 0 ) )
{
days_in_month = 29;
}
else
{
days_in_month = 28;
}
}
/* April (4), June (6), September (9), November (11)
*/
else if( ( month == 4 )
|| ( month == 6 )
|| ( month == 9 )
|| ( month == 11 ) )
{
days_in_month = 30;
}
/* Januari (1), March (3), May (5), July (7), August (8), October (10), December (12)
*/
else if( ( month == 1 )
|| ( month == 3 )
|| ( month == 5 )
|| ( month == 7 )
|| ( month == 8 )
|| ( month == 10 )
|| ( month == 12 ) )
{
days_in_month = 31;
}
/* This should never happen, but just in case
*/
else
{
error_string = gcnew System::String(
"ewf.net " + function + ": unsupported month: " + month + "." );
throw gcnew System::Exception(
error_string );
}
if( filetime <= (System::UInt64) days_in_month )
{
break;
}
filetime -= days_in_month;
month += 1;
}
/* Determine the day
*/
day = (System::Int32) filetime;
date_time_object = gcnew System::DateTime(
year,
month,
day,
hours,
minutes,
seconds,
micro_seconds );
return( date_time_object );
}
/* Creates a new datetime object from a POSIX time
* Returns a DateTime object if successful or nullptr on error
*/
System::DateTime^ DateTime::FromPOSIXTime( System::UInt32 posix_time )
{
System::DateTime^ date_time_object = nullptr;
System::String^ error_string = nullptr;
System::String^ function = "DateTime::FromPOSIXTime";
System::Int32 days_in_year = 0;
System::Int32 year = 0;
System::Int32 day = 0;
System::Int32 days_in_month = 0;
System::Int32 hours = 0;
System::Int32 minutes = 0;
System::Int32 month = 0;
System::Int32 seconds = 0;
/* There are 60 seconds in a minute correct the value to minutes
*/
seconds = posix_time % 60;
posix_time /= 60;
/* There are 60 minutes in an hour correct the value to hours
*/
minutes = posix_time % 60;
posix_time /= 60;
/* There are 24 hours in a day correct the value to days
*/
hours = posix_time % 24;
posix_time /= 24;
/* Add 1 day to compensate that Jan 1 1601 is represented as 0
*/
posix_time += 1;
/* Determine the number of years starting at '1 Jan 1970 00:00:00'
* correct the value to days within the year
*/
year = 1970;
if( posix_time >= 10957 )
{
year = 2000;
posix_time -= 10957;
}
while( posix_time > 0 )
{
/* Check for a leap year
* The year is ( ( dividable by 4 ) and ( not dividable by 100 ) ) or ( dividable by 400 )
*/
if( ( ( ( year % 4 ) == 0 )
&& ( ( year % 100 ) != 0 ) )
|| ( ( year % 400 ) == 0 ) )
{
days_in_year = 366;
}
else
{
days_in_year = 365;
}
if( posix_time <= (System::UInt64) days_in_year )
{
break;
}
posix_time -= days_in_year;
year += 1;
}
/* Determine the month correct the value to days within the month
*/
month = 1;
while( posix_time > 0 )
{
/* February (2)
*/
if( month == 2 )
{
if( ( ( ( year % 4 ) == 0 )
&& ( ( year % 100 ) != 0 ) )
|| ( ( year % 400 ) == 0 ) )
{
days_in_month = 29;
}
else
{
days_in_month = 28;
}
}
/* April (4), June (6), September (9), November (11)
*/
else if( ( month == 4 )
|| ( month == 6 )
|| ( month == 9 )
|| ( month == 11 ) )
{
days_in_month = 30;
}
/* Januari (1), March (3), May (5), July (7), August (8), October (10), December (12)
*/
else if( ( month == 1 )
|| ( month == 3 )
|| ( month == 5 )
|| ( month == 7 )
|| ( month == 8 )
|| ( month == 10 )
|| ( month == 12 ) )
{
days_in_month = 31;
}
/* This should never happen, but just in case
*/
else
{
error_string = gcnew System::String(
"ewf.net " + function + ": unsupported month: " + month + "." );
throw gcnew System::Exception(
error_string );
}
if( posix_time <= (System::UInt64) days_in_month )
{
break;
}
posix_time -= days_in_month;
month += 1;
}
/* Determine the day
*/
day = (System::Int32) posix_time;
date_time_object = gcnew System::DateTime(
year,
month,
day,
hours,
minutes,
seconds,
0 );
return( date_time_object );
}
} // namespace EWF
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