export_traits_filesystem.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) 2022-2024 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_filesystem.h"
 
#if LASS_HAVE_STD_FILESYSTEM
 
#if LASS_PLATFORM_TYPE != LASS_PLATFORM_TYPE_WIN32
 
namespace
{
 
int getBytes(PyObject* obj, std::string& v)
{
    const char* data = PyBytes_AsString(obj);
    if (!data)
    {
        return 1;
    }
    const Py_ssize_t size = PyBytes_GET_SIZE(obj);
    v = std::string{ data, static_cast<size_t>(size) };
    return 0;
}
 
}
 
#endif
 
 
namespace lass
{
namespace python
{
 
PyObject* PyExportTraits<std::filesystem::path>::build(const std::filesystem::path& v)
{
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
    // On Windows, paths use wchar_t: we can directly return it as unicode
    static_assert(std::is_same_v<std::filesystem::path::value_type, wchar_t>);
    TPyObjPtr path{ PyExportTraits<std::wstring>::build(v.native()) };
#else
    // On Linux, paths use char: we decode them to unicode
    static_assert(std::is_same_v<std::filesystem::path::value_type, char>);
    const std::string& s = v.native();
    if (s.size() > PY_SSIZE_T_MAX)
    {
        PyErr_SetString(PyExc_OverflowError, "input too long");
        return 0;
    }
    TPyObjPtr path{ PyUnicode_DecodeFSDefaultAndSize(s.data(), static_cast<Py_ssize_t>(s.size())) };
#endif
 
    static TPyObjPtr pathType;
    if (!pathType)
    {
        TPyObjPtr pathlib(PyImport_ImportModule("pathlib"));
        pathType.reset(PyObject_GetAttrString(pathlib.get(), "Path"));
    }
 
    return PyObject_CallFunctionObjArgs(pathType.get(), path.get(), nullptr);
}
 
 
int PyExportTraits<std::filesystem::path>::get(PyObject* obj, std::filesystem::path& v)
{
    TPyObjPtr path(PyOS_FSPath(obj));
    if (!path)
    {
        return 1;
    }
#if LASS_PLATFORM_TYPE == LASS_PLATFORM_TYPE_WIN32
    // On Windows, paths use wchar_t: decode bytes to unicode and get as wstring.
    static_assert(std::is_same_v<std::filesystem::path::value_type, wchar_t>);
    PyObject* strObj = nullptr;
    if (!PyUnicode_FSDecoder(obj, &strObj))
    {
        return 1;
    }
    std::wstring str;
    const int ret = PyExportTraits<std::wstring>::get(strObj, str);
    Py_DECREF(strObj);
    if (ret == 0)
    {
        v = std::move(str);
    }
    return ret;
#else
    // On POSIX, paths use char: encode unicode to bytes and get as string
    static_assert(std::is_same_v<std::filesystem::path::value_type, char>);
    PyObject* bytesObj = nullptr;
    if (!PyUnicode_FSConverter(obj, &bytesObj))
    {
        return 1;
    }
    std::string bytes;
    const int ret = getBytes(bytesObj, bytes);
    Py_DECREF(bytesObj);
    if (ret == 0)
    {
        v = std::move(bytes);
    }
    return ret;
#endif
}
 
}
}
 
#endif
 
// EOF