File indexing completed on 2025-02-16 05:12:15

 /*
     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 <mutex>
 
 #include <datetime.h>
 
 // Backport the PyDateTime_DELTA functions from Python3.3 if required
 #ifndef PyDateTime_DELTA_GET_DAYS
 #define PyDateTime_DELTA_GET_DAYS(o)         (((PyDateTime_Delta*)o)->days)
 #endif
 #ifndef PyDateTime_DELTA_GET_SECONDS
 #define PyDateTime_DELTA_GET_SECONDS(o)      (((PyDateTime_Delta*)o)->seconds)
 #endif
 #ifndef PyDateTime_DELTA_GET_MICROSECONDS
 #define PyDateTime_DELTA_GET_MICROSECONDS(o) (((PyDateTime_Delta*)o)->microseconds)
 #endif
 
 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;
 
     using days = std::chrono::duration<int_least32_t, std::ratio<86400>>; // signed 25 bits required by the standard.
 
     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)