dlib C++ Library - serialize_pickle.h

// Copyright (C) 2013 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_SERIALIZE_PiCKLE_Hh_
#define DLIB_SERIALIZE_PiCKLE_Hh_
#include <dlib/serialize.h>
#include <pybind11/pybind11.h>
#include <sstream>
#include <dlib/vectorstream.h>
namespace py = pybind11;
namespace dlib
{
 template<typename T>
 py::tuple getstate(const T& item)
 {
 using namespace dlib;
 std::vector<char> buf;
 buf.reserve(5000);
 vectorstream sout(buf);
 serialize(item, sout);
 return py::make_tuple(py::handle(
 PyBytes_FromStringAndSize(buf.size()?&buf[0]:0, buf.size())));
 }
 template<typename T>
 T setstate(py::tuple state)
 {
 using namespace dlib;
 if (len(state) != 1)
 {
 PyErr_SetObject(PyExc_ValueError,
 py::str("expected 1-item tuple in call to __setstate__; got {}").format(state).ptr()
 );
 throw py::error_already_set();
 }
 // We used to serialize by converting to a str but the boost.python routines for
 // doing this don't work in Python 3. You end up getting an error about invalid
 // UTF-8 encodings. So instead we access the python C interface directly and use
 // bytes objects. However, we keep the deserialization code that worked with str
 // for backwards compatibility with previously pickled files.
 T item;
 py::object obj = state[0];
 if (py::isinstance<py::str>(obj))
 {
 py::str data = state[0].cast<py::str>();
 std::string temp = data;
 std::istringstream sin(temp);
 deserialize(item, sin);
 }
 else if(PyBytes_Check(py::object(state[0]).ptr()))
 {
 py::object obj = state[0];
 char* data = PyBytes_AsString(obj.ptr());
 unsigned long num = PyBytes_Size(obj.ptr());
 std::istringstream sin(std::string(data, num));
 deserialize(item, sin);
 }
 else
 {
 throw error("Unable to unpickle, error in input file.");
 }
 return item;
 }
}
#endif // DLIB_SERIALIZE_PiCKLE_Hh_