knx/examples/knxPython/pybind11/include/pybind11/chrono.h
Thomas Kunze 1c6d772056 astyle
2024-09-14 11:56:47 +02:00

261 lines
9.1 KiB
C++

/*
pybind11/chrono.h: Transparent conversion between std::chrono and python's datetime
Copyright (c) 2016 Trent Houliston <trent@houliston.me> and
Wenzel Jakob <wenzel.jakob@epfl.ch>
All rights reserved. Use of this source code is governed by a
BSD-style license that can be found in the LICENSE file.
*/
#pragma once
#include "pybind11.h"
#include <chrono>
#include <cmath>
#include <ctime>
#include <datetime.h>
#include <mutex>
PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
PYBIND11_NAMESPACE_BEGIN(detail)
template <typename type>
class duration_caster
{
public:
using rep = typename type::rep;
using period = typename type::period;
// signed 25 bits required by the standard.
using days = std::chrono::duration<int_least32_t, std::ratio<86400>>;
bool load(handle src, bool)
{
using namespace std::chrono;
// Lazy initialise the PyDateTime import
if (!PyDateTimeAPI)
{
PyDateTime_IMPORT;
}
if (!src)
{
return false;
}
// If invoked with datetime.delta object
if (PyDelta_Check(src.ptr()))
{
value = type(duration_cast<duration<rep, period>>(
days(PyDateTime_DELTA_GET_DAYS(src.ptr()))
+ seconds(PyDateTime_DELTA_GET_SECONDS(src.ptr()))
+ microseconds(PyDateTime_DELTA_GET_MICROSECONDS(src.ptr()))));
return true;
}
// If invoked with a float we assume it is seconds and convert
if (PyFloat_Check(src.ptr()))
{
value = type(duration_cast<duration<rep, period>>(
duration<double>(PyFloat_AsDouble(src.ptr()))));
return true;
}
return false;
}
// If this is a duration just return it back
static const std::chrono::duration<rep, period>& get_duration(const std::chrono::duration<rep, period>& src)
{
return src;
}
// If this is a time_point get the time_since_epoch
template <typename Clock>
static std::chrono::duration<rep, period> get_duration(const std::chrono::time_point<Clock, std::chrono::duration<rep, period>>& src)
{
return src.time_since_epoch();
}
static handle cast(const type& src, return_value_policy /* policy */, handle /* parent */)
{
using namespace std::chrono;
// Use overloaded function to get our duration from our source
// Works out if it is a duration or time_point and get the duration
auto d = get_duration(src);
// Lazy initialise the PyDateTime import
if (!PyDateTimeAPI)
{
PyDateTime_IMPORT;
}
// Declare these special duration types so the conversions happen with the correct
// primitive types (int)
using dd_t = duration<int, std::ratio<86400>>;
using ss_t = duration<int, std::ratio<1>>;
using us_t = duration<int, std::micro>;
auto dd = duration_cast<dd_t>(d);
auto subd = d - dd;
auto ss = duration_cast<ss_t>(subd);
auto us = duration_cast<us_t>(subd - ss);
return PyDelta_FromDSU(dd.count(), ss.count(), us.count());
}
PYBIND11_TYPE_CASTER(type, const_name("datetime.timedelta"));
};
inline std::tm* localtime_thread_safe(const std::time_t* time, std::tm* buf)
{
#if (defined(__STDC_LIB_EXT1__) && defined(__STDC_WANT_LIB_EXT1__)) || defined(_MSC_VER)
if (localtime_s(buf, time))
return nullptr;
return buf;
#else
static std::mutex mtx;
std::lock_guard<std::mutex> lock(mtx);
std::tm* tm_ptr = std::localtime(time);
if (tm_ptr != nullptr)
{
*buf = *tm_ptr;
}
return tm_ptr;
#endif
}
// This is for casting times on the system clock into datetime.datetime instances
template <typename Duration>
class type_caster<std::chrono::time_point<std::chrono::system_clock, Duration>>
{
public:
using type = std::chrono::time_point<std::chrono::system_clock, Duration>;
bool load(handle src, bool)
{
using namespace std::chrono;
// Lazy initialise the PyDateTime import
if (!PyDateTimeAPI)
{
PyDateTime_IMPORT;
}
if (!src)
{
return false;
}
std::tm cal;
microseconds msecs;
if (PyDateTime_Check(src.ptr()))
{
cal.tm_sec = PyDateTime_DATE_GET_SECOND(src.ptr());
cal.tm_min = PyDateTime_DATE_GET_MINUTE(src.ptr());
cal.tm_hour = PyDateTime_DATE_GET_HOUR(src.ptr());
cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
cal.tm_isdst = -1;
msecs = microseconds(PyDateTime_DATE_GET_MICROSECOND(src.ptr()));
}
else if (PyDate_Check(src.ptr()))
{
cal.tm_sec = 0;
cal.tm_min = 0;
cal.tm_hour = 0;
cal.tm_mday = PyDateTime_GET_DAY(src.ptr());
cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1;
cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900;
cal.tm_isdst = -1;
msecs = microseconds(0);
}
else if (PyTime_Check(src.ptr()))
{
cal.tm_sec = PyDateTime_TIME_GET_SECOND(src.ptr());
cal.tm_min = PyDateTime_TIME_GET_MINUTE(src.ptr());
cal.tm_hour = PyDateTime_TIME_GET_HOUR(src.ptr());
cal.tm_mday = 1; // This date (day, month, year) = (1, 0, 70)
cal.tm_mon = 0; // represents 1-Jan-1970, which is the first
cal.tm_year = 70; // earliest available date for Python's datetime
cal.tm_isdst = -1;
msecs = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr()));
}
else
{
return false;
}
value = time_point_cast<Duration>(system_clock::from_time_t(std::mktime(&cal)) + msecs);
return true;
}
static handle cast(const std::chrono::time_point<std::chrono::system_clock, Duration>& src,
return_value_policy /* policy */,
handle /* parent */)
{
using namespace std::chrono;
// Lazy initialise the PyDateTime import
if (!PyDateTimeAPI)
{
PyDateTime_IMPORT;
}
// Get out microseconds, and make sure they are positive, to avoid bug in eastern
// hemisphere time zones (cfr. https://github.com/pybind/pybind11/issues/2417)
using us_t = duration<int, std::micro>;
auto us = duration_cast<us_t>(src.time_since_epoch() % seconds(1));
if (us.count() < 0)
{
us += seconds(1);
}
// Subtract microseconds BEFORE `system_clock::to_time_t`, because:
// > If std::time_t has lower precision, it is implementation-defined whether the value is
// rounded or truncated. (https://en.cppreference.com/w/cpp/chrono/system_clock/to_time_t)
std::time_t tt
= system_clock::to_time_t(time_point_cast<system_clock::duration>(src - us));
std::tm localtime;
std::tm* localtime_ptr = localtime_thread_safe(&tt, &localtime);
if (!localtime_ptr)
{
throw cast_error("Unable to represent system_clock in local time");
}
return PyDateTime_FromDateAndTime(localtime.tm_year + 1900,
localtime.tm_mon + 1,
localtime.tm_mday,
localtime.tm_hour,
localtime.tm_min,
localtime.tm_sec,
us.count());
}
PYBIND11_TYPE_CASTER(type, const_name("datetime.datetime"));
};
// Other clocks that are not the system clock are not measured as datetime.datetime objects
// since they are not measured on calendar time. So instead we just make them timedeltas
// Or if they have passed us a time as a float we convert that
template <typename Clock, typename Duration>
class type_caster<std::chrono::time_point<Clock, Duration>>
: public duration_caster<std::chrono::time_point<Clock, Duration>> {};
template <typename Rep, typename Period>
class type_caster<std::chrono::duration<Rep, Period>>
: public duration_caster<std::chrono::duration<Rep, Period>> {};
PYBIND11_NAMESPACE_END(detail)
PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)