108 lines
3.2 KiB
C++
108 lines
3.2 KiB
C++
// Copyright Ralf W. Grosse-Kunstleve 2002-2004. Distributed under the Boost
|
|
// Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
/*
|
|
This example shows how to make an Extension Class "pickleable".
|
|
|
|
The world class below contains member data (secret_number) that
|
|
cannot be restored by any of the constructors. Therefore it is
|
|
necessary to provide the __getstate__/__setstate__ pair of pickle
|
|
interface methods.
|
|
|
|
The object's __dict__ is included in the result of __getstate__.
|
|
This requires more code (compare with pickle2.cpp), but is
|
|
unavoidable if the object's __dict__ is not always empty.
|
|
|
|
For more information refer to boost/libs/python/doc/pickle.html.
|
|
*/
|
|
|
|
#include <boost/python/module.hpp>
|
|
#include <boost/python/def.hpp>
|
|
#include <boost/python/class.hpp>
|
|
#include <boost/python/tuple.hpp>
|
|
#include <boost/python/dict.hpp>
|
|
#include <boost/python/extract.hpp>
|
|
#include <boost/python/back_reference.hpp>
|
|
|
|
namespace boost_python_test {
|
|
|
|
// A friendly class.
|
|
class world
|
|
{
|
|
public:
|
|
world(const std::string& _country) : secret_number(0) {
|
|
this->country = _country;
|
|
}
|
|
std::string greet() const { return "Hello from " + country + "!"; }
|
|
std::string get_country() const { return country; }
|
|
void set_secret_number(int number) { secret_number = number; }
|
|
int get_secret_number() const { return secret_number; }
|
|
private:
|
|
std::string country;
|
|
int secret_number;
|
|
};
|
|
|
|
struct world_pickle_suite : boost::python::pickle_suite
|
|
{
|
|
static
|
|
boost::python::tuple
|
|
getinitargs(const world& w)
|
|
{
|
|
return boost::python::make_tuple(w.get_country());
|
|
}
|
|
|
|
static
|
|
boost::python::tuple
|
|
getstate(boost::python::object w_obj)
|
|
{
|
|
world const& w = boost::python::extract<world const&>(w_obj)();
|
|
|
|
return boost::python::make_tuple(
|
|
w_obj.attr("__dict__"),
|
|
w.get_secret_number());
|
|
}
|
|
|
|
static
|
|
void
|
|
setstate(boost::python::object w_obj, boost::python::tuple state)
|
|
{
|
|
using namespace boost::python;
|
|
world& w = extract<world&>(w_obj)();
|
|
|
|
if (len(state) != 2)
|
|
{
|
|
PyErr_SetObject(PyExc_ValueError,
|
|
("expected 2-item tuple in call to __setstate__; got %s"
|
|
% state).ptr()
|
|
);
|
|
throw_error_already_set();
|
|
}
|
|
|
|
// restore the object's __dict__
|
|
dict d = extract<dict>(w_obj.attr("__dict__"))();
|
|
d.update(state[0]);
|
|
|
|
// restore the internal state of the C++ object
|
|
long number = extract<long>(state[1]);
|
|
if (number != 42)
|
|
w.set_secret_number(number);
|
|
}
|
|
|
|
static bool getstate_manages_dict() { return true; }
|
|
};
|
|
|
|
}
|
|
|
|
BOOST_PYTHON_MODULE(pickle3_ext)
|
|
{
|
|
using namespace boost_python_test;
|
|
boost::python::class_<world>(
|
|
"world", boost::python::init<const std::string&>())
|
|
.def("greet", &world::greet)
|
|
.def("get_secret_number", &world::get_secret_number)
|
|
.def("set_secret_number", &world::set_secret_number)
|
|
.def_pickle(world_pickle_suite())
|
|
;
|
|
}
|