1/* 2 pybind11/chrono.h: Transparent conversion between std::chrono and python's datetime 3 4 Copyright (c) 2016 Trent Houliston <trent@houliston.me> and 5 Wenzel Jakob <wenzel.jakob@epfl.ch> 6 7 All rights reserved. Use of this source code is governed by a 8 BSD-style license that can be found in the LICENSE file. 9*/ 10 11#pragma once 12 13#include "pybind11.h" 14#include <cmath> 15#include <ctime> 16#include <chrono> 17#include <datetime.h> 18 19// Backport the PyDateTime_DELTA functions from Python3.3 if required 20#ifndef PyDateTime_DELTA_GET_DAYS 21#define PyDateTime_DELTA_GET_DAYS(o) (((PyDateTime_Delta*)o)->days) 22#endif 23#ifndef PyDateTime_DELTA_GET_SECONDS 24#define PyDateTime_DELTA_GET_SECONDS(o) (((PyDateTime_Delta*)o)->seconds) 25#endif 26#ifndef PyDateTime_DELTA_GET_MICROSECONDS 27#define PyDateTime_DELTA_GET_MICROSECONDS(o) (((PyDateTime_Delta*)o)->microseconds) 28#endif 29 30NAMESPACE_BEGIN(PYBIND11_NAMESPACE) 31NAMESPACE_BEGIN(detail) 32 33template <typename type> class duration_caster { 34public: 35 typedef typename type::rep rep; 36 typedef typename type::period period; 37 38 typedef std::chrono::duration<uint_fast32_t, std::ratio<86400>> days; 39 40 bool load(handle src, bool) { 41 using namespace std::chrono; 42 43 // Lazy initialise the PyDateTime import 44 if (!PyDateTimeAPI) { PyDateTime_IMPORT; } 45 46 if (!src) return false; 47 // If invoked with datetime.delta object 48 if (PyDelta_Check(src.ptr())) { 49 value = type(duration_cast<duration<rep, period>>( 50 days(PyDateTime_DELTA_GET_DAYS(src.ptr())) 51 + seconds(PyDateTime_DELTA_GET_SECONDS(src.ptr())) 52 + microseconds(PyDateTime_DELTA_GET_MICROSECONDS(src.ptr())))); 53 return true; 54 } 55 // If invoked with a float we assume it is seconds and convert 56 else if (PyFloat_Check(src.ptr())) { 57 value = type(duration_cast<duration<rep, period>>(duration<double>(PyFloat_AsDouble(src.ptr())))); 58 return true; 59 } 60 else return false; 61 } 62 63 // If this is a duration just return it back 64 static const std::chrono::duration<rep, period>& get_duration(const std::chrono::duration<rep, period> &src) { 65 return src; 66 } 67 68 // If this is a time_point get the time_since_epoch 69 template <typename Clock> static std::chrono::duration<rep, period> get_duration(const std::chrono::time_point<Clock, std::chrono::duration<rep, period>> &src) { 70 return src.time_since_epoch(); 71 } 72 73 static handle cast(const type &src, return_value_policy /* policy */, handle /* parent */) { 74 using namespace std::chrono; 75 76 // Use overloaded function to get our duration from our source 77 // Works out if it is a duration or time_point and get the duration 78 auto d = get_duration(src); 79 80 // Lazy initialise the PyDateTime import 81 if (!PyDateTimeAPI) { PyDateTime_IMPORT; } 82 83 // Declare these special duration types so the conversions happen with the correct primitive types (int) 84 using dd_t = duration<int, std::ratio<86400>>; 85 using ss_t = duration<int, std::ratio<1>>; 86 using us_t = duration<int, std::micro>; 87 88 auto dd = duration_cast<dd_t>(d); 89 auto subd = d - dd; 90 auto ss = duration_cast<ss_t>(subd); 91 auto us = duration_cast<us_t>(subd - ss); 92 return PyDelta_FromDSU(dd.count(), ss.count(), us.count()); 93 } 94 95 PYBIND11_TYPE_CASTER(type, _("datetime.timedelta")); 96}; 97 98// This is for casting times on the system clock into datetime.datetime instances 99template <typename Duration> class type_caster<std::chrono::time_point<std::chrono::system_clock, Duration>> { 100public: 101 typedef std::chrono::time_point<std::chrono::system_clock, Duration> type; 102 bool load(handle src, bool) { 103 using namespace std::chrono; 104 105 // Lazy initialise the PyDateTime import 106 if (!PyDateTimeAPI) { PyDateTime_IMPORT; } 107 108 if (!src) return false; 109 110 std::tm cal; 111 microseconds msecs; 112 113 if (PyDateTime_Check(src.ptr())) { 114 cal.tm_sec = PyDateTime_DATE_GET_SECOND(src.ptr()); 115 cal.tm_min = PyDateTime_DATE_GET_MINUTE(src.ptr()); 116 cal.tm_hour = PyDateTime_DATE_GET_HOUR(src.ptr()); 117 cal.tm_mday = PyDateTime_GET_DAY(src.ptr()); 118 cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1; 119 cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900; 120 cal.tm_isdst = -1; 121 msecs = microseconds(PyDateTime_DATE_GET_MICROSECOND(src.ptr())); 122 } else if (PyDate_Check(src.ptr())) { 123 cal.tm_sec = 0; 124 cal.tm_min = 0; 125 cal.tm_hour = 0; 126 cal.tm_mday = PyDateTime_GET_DAY(src.ptr()); 127 cal.tm_mon = PyDateTime_GET_MONTH(src.ptr()) - 1; 128 cal.tm_year = PyDateTime_GET_YEAR(src.ptr()) - 1900; 129 cal.tm_isdst = -1; 130 msecs = microseconds(0); 131 } else if (PyTime_Check(src.ptr())) { 132 cal.tm_sec = PyDateTime_TIME_GET_SECOND(src.ptr()); 133 cal.tm_min = PyDateTime_TIME_GET_MINUTE(src.ptr()); 134 cal.tm_hour = PyDateTime_TIME_GET_HOUR(src.ptr()); 135 cal.tm_mday = 1; // This date (day, month, year) = (1, 0, 70) 136 cal.tm_mon = 0; // represents 1-Jan-1970, which is the first 137 cal.tm_year = 70; // earliest available date for Python's datetime 138 cal.tm_isdst = -1; 139 msecs = microseconds(PyDateTime_TIME_GET_MICROSECOND(src.ptr())); 140 } 141 else return false; 142 143 value = system_clock::from_time_t(std::mktime(&cal)) + msecs; 144 return true; 145 } 146 147 static handle cast(const std::chrono::time_point<std::chrono::system_clock, Duration> &src, return_value_policy /* policy */, handle /* parent */) { 148 using namespace std::chrono; 149 150 // Lazy initialise the PyDateTime import 151 if (!PyDateTimeAPI) { PyDateTime_IMPORT; } 152 153 std::time_t tt = system_clock::to_time_t(time_point_cast<system_clock::duration>(src)); 154 // this function uses static memory so it's best to copy it out asap just in case 155 // otherwise other code that is using localtime may break this (not just python code) 156 std::tm localtime = *std::localtime(&tt); 157 158 // Declare these special duration types so the conversions happen with the correct primitive types (int) 159 using us_t = duration<int, std::micro>; 160 161 return PyDateTime_FromDateAndTime(localtime.tm_year + 1900, 162 localtime.tm_mon + 1, 163 localtime.tm_mday, 164 localtime.tm_hour, 165 localtime.tm_min, 166 localtime.tm_sec, 167 (duration_cast<us_t>(src.time_since_epoch() % seconds(1))).count()); 168 } 169 PYBIND11_TYPE_CASTER(type, _("datetime.datetime")); 170}; 171 172// Other clocks that are not the system clock are not measured as datetime.datetime objects 173// since they are not measured on calendar time. So instead we just make them timedeltas 174// Or if they have passed us a time as a float we convert that 175template <typename Clock, typename Duration> class type_caster<std::chrono::time_point<Clock, Duration>> 176: public duration_caster<std::chrono::time_point<Clock, Duration>> { 177}; 178 179template <typename Rep, typename Period> class type_caster<std::chrono::duration<Rep, Period>> 180: public duration_caster<std::chrono::duration<Rep, Period>> { 181}; 182 183NAMESPACE_END(detail) 184NAMESPACE_END(PYBIND11_NAMESPACE) 185