diff options
Diffstat (limited to 'comm/third_party/botan/src/lib/utils/calendar.cpp')
-rw-r--r-- | comm/third_party/botan/src/lib/utils/calendar.cpp | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/comm/third_party/botan/src/lib/utils/calendar.cpp b/comm/third_party/botan/src/lib/utils/calendar.cpp new file mode 100644 index 0000000000..1c34a71572 --- /dev/null +++ b/comm/third_party/botan/src/lib/utils/calendar.cpp @@ -0,0 +1,124 @@ +/* +* 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_WIN32) + ::gmtime_s(&tm, &time_val); // Windows +#elif defined(BOTAN_TARGET_OS_HAS_POSIX1) + ::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 + + BOTAN_IF_CONSTEXPR(sizeof(std::time_t) == 4) + { + if(get_year() > 2037) + { + throw Invalid_Argument("calendar_point::to_std_timepoint() does not support years after 2037 on this system"); + } + } + + // This upper bound is completely arbitrary + if(get_year() >= 2400) + { + 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; + output << std::setfill('0') + << std::setw(4) << get_year() << "-" + << std::setw(2) << get_month() << "-" + << std::setw(2) << get_day() << "T" + << std::setw(2) << get_hour() << ":" + << std::setw(2) << get_minutes() << ":" + << std::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); + } + +} |