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/*************************************************************************
* odil - Copyright (C) Universite de Strasbourg
* Distributed under the terms of the CeCILL-B license, as published by
* the CEA-CNRS-INRIA. Refer to the LICENSE file or to
* http://www.cecill.info/licences/Licence_CeCILL-B_V1-en.html
* for details.
************************************************************************/
#include "streambuf.h"
#include <algorithm>
#include <ios>
#include <streambuf>
#include <string>
#include <vector>
#include <pybind11/pybind11.h>
#include "odil/Exception.h"
#include "opaque_types.h"
#include "type_casters.h"
#if PY_MAJOR_VERSION >= 3
#define FromStringAndSize(v, len) PyBytes_FromStringAndSize(v, len)
#else
#define IS_PY2
#define FromStringAndSize(v, len) PyString_FromStringAndSize(v, len)
#endif
namespace odil
{
namespace wrappers
{
namespace python
{
streambuf
::streambuf(pybind11::object object, std::string::size_type buffer_size)
: _object(object),
_buffer_size(buffer_size), _buffer(), _current(std::string::npos)
{
this->setg(nullptr, nullptr, nullptr);
this->setp(nullptr, nullptr);
}
// Python objects do not differentiate between input and output sequence: the
// "which" parameter is unused.
std::streambuf::pos_type
streambuf
::seekoff(
std::streambuf::off_type off, std::ios_base::seekdir dir,
std::ios_base::openmode /* which */)
{
std::streambuf::off_type adjusted_offset;
if(dir == std::ios_base::cur && this->_current != std::string::npos)
{
// We need to adjust the offset since the position of the Python
// file-like object is at the end of the buffer.
std::streambuf::off_type const position_offset =
this->_buffer.size()-this->_current;
adjusted_offset = off-position_offset;
}
else
{
// Either
// - beg or end,
// - or at the end of buffer (_current == std::string::npos)
// In those cases, the semantics don't change
adjusted_offset = off;
}
int whence;
if(dir == std::ios::beg)
{
whence = 0;
}
else if(dir == std::ios::cur)
{
whence = 1;
}
else if(dir == std::ios::end)
{
whence = 2;
}
else
{
throw Exception("Invalid direction");
}
this->_object.attr("seek")(adjusted_offset, whence);
this->_update_buffer();
return (
pybind11::cast<int>(this->_object.attr("tell")())
- this->_buffer.size());
}
std::streambuf::pos_type
streambuf
::seekpos(std::streambuf::pos_type pos, std::ios_base::openmode which)
{
return this->seekoff(pos, std::ios_base::beg, which);
}
int
streambuf
::underflow()
{
if(this->_current == std::string::npos)
{
this->_update_buffer();
}
if(this->_current == std::string::npos)
{
return std::char_traits<char>::eof();
}
else
{
auto const character = this->_buffer.at(this->_current);
return std::char_traits<char>::to_int_type(character);
}
}
int
streambuf
::uflow()
{
auto const character = this->underflow();
if(character != std::char_traits<char>::eof())
{
++this->_current;
if(this->_current >= this->_buffer.size())
{
this->_current = std::string::npos;
}
}
return character;
}
int
streambuf
::overflow(int ch)
{
if(ch != std::char_traits<char>::eof())
{
char const cast_ch(ch);
pybind11::bytes bytes_ch(&cast_ch, 1);
this->_object.attr("write")(bytes_ch);
}
return ch;
}
void
streambuf
::_update_buffer()
{
auto data = this->_object.attr("read")(this->_buffer_size);
if(pybind11::len(data) == 0)
{
// EOF
this->_current = std::string::npos;
}
else
{
this->_buffer = pybind11::cast<std::string>(data);
this->_current = 0;
}
}
}
}
}
void wrap_iostream(pybind11::module & m)
{
using namespace pybind11;
using namespace odil::wrappers::python;
class_<iostream>(m, "iostream")
.def(init<object>());
}
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