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/*
* Calendar Functions
* (C) 1999-2010,2017 Jack Lloyd
* (C) 2015 Simon Warta (Kullo GmbH)
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/calendar.h>
#include <botan/exceptn.h>
#include <ctime>
#include <sstream>
#include <iomanip>
#include <stdlib.h>
namespace Botan {
namespace {
std::tm do_gmtime(std::time_t time_val)
{
std::tm tm;
#if defined(BOTAN_TARGET_OS_HAS_GMTIME_S)
::gmtime_s(&tm, &time_val); // Windows
#elif defined(BOTAN_TARGET_OS_HAS_GMTIME_R)
::gmtime_r(&time_val, &tm); // Unix/SUSv2
#else
std::tm* tm_p = std::gmtime(&time_val);
if (tm_p == nullptr)
throw Encoding_Error("time_t_to_tm could not convert");
tm = *tm_p;
#endif
return tm;
}
/*
Portable replacement for timegm, _mkgmtime, etc
Algorithm due to Howard Hinnant
See https://howardhinnant.github.io/date_algorithms.html#days_from_civil
for details and explaination. The code is slightly simplified by our assumption
that the date is at least 1970, which is sufficient for our purposes.
*/
size_t days_since_epoch(uint32_t year, uint32_t month, uint32_t day)
{
if(month <= 2)
year -= 1;
const uint32_t era = year / 400;
const uint32_t yoe = year - era * 400; // [0, 399]
const uint32_t doy = (153*(month + (month > 2 ? -3 : 9)) + 2)/5 + day-1; // [0, 365]
const uint32_t doe = yoe * 365 + yoe/4 - yoe/100 + doy; // [0, 146096]
return era * 146097 + doe - 719468;
}
}
std::chrono::system_clock::time_point calendar_point::to_std_timepoint() const
{
if(get_year() < 1970)
throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years before 1970");
// 32 bit time_t ends at January 19, 2038
// https://msdn.microsoft.com/en-us/library/2093ets1.aspx
// Throw after 2037 if 32 bit time_t is used
if(get_year() > 2037 && sizeof(std::time_t) == 4)
{
throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years after 2037 on this system");
}
else if(get_year() >= 2400)
{
// This upper bound is somewhat arbitrary
throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years after 2400");
}
const uint64_t seconds_64 = (days_since_epoch(get_year(), get_month(), get_day()) * 86400) +
(get_hour() * 60 * 60) + (get_minutes() * 60) + get_seconds();
const time_t seconds_time_t = static_cast<time_t>(seconds_64);
if(seconds_64 - seconds_time_t != 0)
{
throw Invalid_Argument("calendar_point::to_std_timepoint time_t overflow");
}
return std::chrono::system_clock::from_time_t(seconds_time_t);
}
std::string calendar_point::to_string() const
{
// desired format: <YYYY>-<MM>-<dd>T<HH>:<mm>:<ss>
std::stringstream output;
{
using namespace std;
output << setfill('0')
<< setw(4) << get_year() << "-" << setw(2) << get_month() << "-" << setw(2) << get_day()
<< "T"
<< setw(2) << get_hour() << ":" << setw(2) << get_minutes() << ":" << setw(2) << get_seconds();
}
return output.str();
}
calendar_point calendar_value(
const std::chrono::system_clock::time_point& time_point)
{
std::tm tm = do_gmtime(std::chrono::system_clock::to_time_t(time_point));
return calendar_point(tm.tm_year + 1900,
tm.tm_mon + 1,
tm.tm_mday,
tm.tm_hour,
tm.tm_min,
tm.tm_sec);
}
}
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