export_traits_chrono.cpp

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/** @file
*   @author Bram de Greve (bram@cocamware.com)
*   @author Tom De Muer (tom@cocamware.com)
*
*   *** BEGIN LICENSE INFORMATION ***
*
*   The contents of this file are subject to the Common Public Attribution License
*   Version 1.0 (the "License"); you may not use this file except in compliance with
*   the License. You may obtain a copy of the License at
*   http://lass.sourceforge.net/cpal-license. The License is based on the
*   Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover
*   use of software over a computer network and provide for limited attribution for
*   the Original Developer. In addition, Exhibit A has been modified to be consistent
*   with Exhibit B.
*
*   Software distributed under the License is distributed on an "AS IS" basis, WITHOUT
*   WARRANTY OF ANY KIND, either express or implied. See the License for the specific
*   language governing rights and limitations under the License.
*
*   The Original Code is LASS - Library of Assembled Shared Sources.
*
*   The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
*   The Original Developer is the Initial Developer.
*
*   All portions of the code written by the Initial Developer are:
*   Copyright (C) 2022-2026 the Initial Developer.
*   All Rights Reserved.
*
*   Contributor(s):
*
*   Alternatively, the contents of this file may be used under the terms of the
*   GNU General Public License Version 2 or later (the GPL), in which case the
*   provisions of GPL are applicable instead of those above.  If you wish to allow use
*   of your version of this file only under the terms of the GPL and not to allow
*   others to use your version of this file under the CPAL, indicate your decision by
*   deleting the provisions above and replace them with the notice and other
*   provisions required by the GPL License. If you do not delete the provisions above,
*   a recipient may use your version of this file under either the CPAL or the GPL.
*
*   *** END LICENSE INFORMATION ***
*/
 
#include "python_common.h"
#include "export_traits_chrono.h"
 
#include <datetime.h>
 
 
namespace lass
{
namespace python
{
 
namespace impl
{
 
PyObject* buildTimedelta(int days, int secs, int usecs)
{
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
    return PyDelta_FromDSU(days, secs, usecs);
}
 
int getTimedelta(PyObject* obj, int &days, int &secs, int &usecs)
{
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
    if (!PyDelta_Check(obj))
    {
        PyErr_SetString(PyExc_TypeError, "not a datetime.timedelta");
        return 1;
    }
    days = PyDateTime_DELTA_GET_DAYS(obj);
    secs = PyDateTime_DELTA_GET_SECONDS(obj);
    usecs = PyDateTime_DELTA_GET_MICROSECONDS(obj);
    return 0;
}
 
}
 
 
 
PyObject* PyExportTraits<std::chrono::time_point<std::chrono::system_clock>>::build(const TTimePoint& v)
{
    using namespace std::chrono_literals;
 
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
 
    using TMicroSeconds = std::chrono::duration<int, std::micro>;
 
    const TMicroSeconds uSec = std::chrono::duration_cast<TMicroSeconds>(v.time_since_epoch() % 1s);
    const std::time_t time = TClock::to_time_t(v - uSec);
 
    std::tm local;
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
    const errno_t err = localtime_s(&local, &time);
#else
    util::impl::lass_reset_errno();
    localtime_r(&time, &local);
    const int err = util::impl::lass_errno();
#endif
    if (err)
    {
        PyErr_SetString(PyExc_ValueError, util::impl::lass_strerror(err).c_str());
        return nullptr;
    }
 
    return PyDateTime_FromDateAndTime(
        1900 + local.tm_year,
        1 + local.tm_mon,
        local.tm_mday,
        local.tm_hour,
        local.tm_min,
        local.tm_sec,
        uSec.count()
    );
}
 
 
 
int PyExportTraits<std::chrono::time_point<std::chrono::system_clock>>::get(PyObject* obj, TTimePoint& v)
{
    using namespace std::chrono_literals;
 
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
    if (!PyDate_Check(obj))
    {
        PyErr_SetString(PyExc_TypeError, "not a datetime.date or datetime.datetime");
        return 1;
    }
 
    std::tm time {
        0, // tm_sec
        0, // tm_min
        0, // tm_hour
        PyDateTime_GET_DAY(obj), // tm_mday
        PyDateTime_GET_MONTH(obj) - 1, // tm_mon
        PyDateTime_GET_YEAR(obj) - 1900, // tm_year
        0, // tm_wday
        0, // tm_yday
        -1, // tm_isdst
#if LASS_PLATFORM_TYPE != LASS_PLATFORM_TYPE_WIN32
        0, // tm_gmtoff
        nullptr, // tm_zone
#endif
    };
    std::chrono::microseconds uSec{};
    PyObject* tz = Py_None;
 
    if (PyDateTime_Check(obj))
    {
        time.tm_hour = PyDateTime_DATE_GET_HOUR(obj);
        time.tm_min = PyDateTime_DATE_GET_MINUTE(obj);
        time.tm_sec = PyDateTime_DATE_GET_SECOND(obj);
        uSec = std::chrono::microseconds(PyDateTime_DATE_GET_MICROSECOND(obj));
 
        tz = PyDateTime_DATE_GET_TZINFO(obj);
    }
 
    if (tz == Py_None)
    {
        // naive datetime is assumed to be local time. dates are always naive too.
        const std::time_t t = mktime(&time);
        if (t < 0)
        {
            PyErr_SetString(PyExc_ValueError, "out of range");
            return 1;
        }
        v = TClock::from_time_t(t) + uSec;
    }
    else
    {
        TPyObjPtr timedelta{ PyObject_CallMethod(tz, "utcoffset", "O", obj) };
        if (!timedelta)
        {
            return 1;
        }
        std::chrono::system_clock::duration utcoffset{};
        if (PyExportTraits<std::chrono::system_clock::duration>::get(timedelta.get(), utcoffset) != 0)
        {
            return 1;
        }
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
        const std::time_t t = _mkgmtime(&time);
#else
        const std::time_t t = timegm(&time);
#endif
        if (t < 0)
        {
            PyErr_SetString(PyExc_ValueError, "out of range");
            return 1;
        }
        v = TClock::from_time_t(t) + uSec - utcoffset;
    }
 
    return 0;
}
 
 
 
#ifdef LASS_HAVE_STD_CHRONO_CPP20
 
PyObject* PyExportTraits<std::chrono::utc_clock::time_point>::build(const std::chrono::utc_clock::time_point& v)
{
    using namespace std::chrono_literals;
 
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
 
    using TMicroSeconds = std::chrono::duration<int, std::micro>;
 
    const auto sysTime = std::chrono::utc_clock::to_sys(v);
    const TMicroSeconds uSec = std::chrono::duration_cast<TMicroSeconds>(sysTime.time_since_epoch() % 1s);
    const std::time_t time = std::chrono::system_clock::to_time_t(sysTime - uSec);
 
    std::tm local;
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
    const errno_t err = gmtime_s(&local, &time);
#else
    util::impl::lass_reset_errno();
    gmtime_r(&time, &local);
    const int err = util::impl::lass_errno();
#endif
    if (err)
    {
        PyErr_SetString(PyExc_ValueError, util::impl::lass_strerror(err).c_str());
        return nullptr;
    }
 
    PyObject* tz = PyDateTime_TimeZone_UTC;
 
    return PyDateTimeAPI->DateTime_FromDateAndTime(
        1900 + local.tm_year,
        1 + local.tm_mon,
        local.tm_mday,
        local.tm_hour,
        local.tm_min,
        local.tm_sec,
        uSec.count(),
        tz,
        PyDateTimeAPI->DateTimeType
    );
}
 
 
 
int PyExportTraits<std::chrono::utc_clock::time_point>::get(PyObject* obj, std::chrono::utc_clock::time_point& v)
{
    std::chrono::system_clock::time_point sysTime;
    if (PyExportTraits<std::chrono::system_clock::time_point>::get(obj, sysTime) != 0)
    {
        return 1;
    }
    v = std::chrono::clock_cast<std::chrono::utc_clock>(sysTime);
    return 0;
}
 
 
 
PyObject* PyExportTraits<std::chrono::gps_clock::time_point>::build(const std::chrono::gps_clock::time_point& v)
{
    auto utcTime = std::chrono::clock_cast<std::chrono::utc_clock>(v);
    return PyExportTraits<std::chrono::utc_clock::time_point>::build(utcTime);
}
 
 
 
int PyExportTraits<std::chrono::gps_clock::time_point>::get(PyObject* obj, std::chrono::gps_clock::time_point& v)
{
    std::chrono::system_clock::time_point sysTime;
    if (PyExportTraits<std::chrono::system_clock::time_point>::get(obj, sysTime) != 0)
    {
        return 1;
    }
    v = std::chrono::clock_cast<std::chrono::gps_clock>(sysTime);
    return 0;
}
 
 
 
PyObject* PyExportTraits<std::chrono::tai_clock::time_point>::build(const std::chrono::tai_clock::time_point& v)
{
    auto utcTime = std::chrono::clock_cast<std::chrono::utc_clock>(v);
    return PyExportTraits<std::chrono::utc_clock::time_point>::build(utcTime);
}
 
 
 
int PyExportTraits<std::chrono::tai_clock::time_point>::get(PyObject* obj, std::chrono::tai_clock::time_point& v)
{
    std::chrono::system_clock::time_point sysTime;
    if (PyExportTraits<std::chrono::system_clock::time_point>::get(obj, sysTime) != 0)
    {
        return 1;
    }
    v = std::chrono::clock_cast<std::chrono::tai_clock>(sysTime);
    return 0;
}
 
 
 
PyObject* PyExportTraits<std::chrono::file_clock::time_point>::build(const std::chrono::file_clock::time_point& v)
{
    auto utcTime = std::chrono::clock_cast<std::chrono::utc_clock>(v);
    return PyExportTraits<std::chrono::utc_clock::time_point>::build(utcTime);
}
 
 
 
int PyExportTraits<std::chrono::file_clock::time_point>::get(PyObject* obj, std::chrono::file_clock::time_point& v)
{
    std::chrono::system_clock::time_point sysTime;
    if (PyExportTraits<std::chrono::system_clock::time_point>::get(obj, sysTime) != 0)
    {
        return 1;
    }
    v = std::chrono::clock_cast<std::chrono::file_clock>(sysTime);
    return 0;
}
 
 
 
PyObject* PyExportTraits<std::chrono::year_month_day>::build(const std::chrono::year_month_day& v)
{
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
    return PyDate_FromDate(
        static_cast<int>(v.year()),
        static_cast<unsigned>(v.month()),
        static_cast<unsigned>(v.day())
    );
}
 
 
 
int PyExportTraits<std::chrono::year_month_day>::get(PyObject* obj, std::chrono::year_month_day& v)
{
    if (!PyDateTimeAPI)
    {
        PyDateTime_IMPORT;
    }
    if (!PyDate_Check(obj))
    {
        PyErr_SetString(PyExc_TypeError, "not a datetime.date");
        return 1;
    }
    v = std::chrono::year_month_day
    {
        std::chrono::year{ PyDateTime_GET_YEAR(obj) },
        std::chrono::month{ PyDateTime_GET_MONTH(obj) },
        std::chrono::day{ PyDateTime_GET_DAY(obj) }
    };
    return 0;
}
 
 
#endif
 
}
}