object.cc

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 * LSST Data Management System
 *
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 * LSST Project (http://www.lsst.org/).
 * See the COPYRIGHT file
 *
 * This program is free software: you can redistribute it and/or modify
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 *
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#include <pybind11/pybind11.h>
#include "lsst/cpputils/python.h"
 
#include "astshim/Stream.h"
#include "astshim/Channel.h"
#include "astshim/Object.h"
 
namespace py = pybind11;
using namespace pybind11::literals;
 
namespace ast {
namespace {
 
/*
Make an Object from a string output by Object.show()
 
Used to support pickling Object and all of its subclasses
 
Note: I would prefer to use a function but defining the obvious function
and returning that as the first item of Object.__reduce__ resulted in
Python rejecting it, claiming the function was not pickleable. I know how
to make a class pickleable, I don't know how to make a function pickleable.
*/
class ObjectMaker {
public:
    ObjectMaker() = default;
    ~ObjectMaker() = default;
    std::shared_ptr<Object> operator()(std::string const &state) {
        ast::StringStream stream(state);
        ast::Channel chan(stream);
        return chan.read();
    }
};
}
 
void wrapObject(lsst::utils::python::WrapperCollection &wrappers) {
    using PyObjectMaker = py::class_<ObjectMaker, std::shared_ptr<ObjectMaker>>;
    static auto makerCls = wrappers.wrapType(PyObjectMaker(wrappers.module, "ObjectMaker"), [](auto &mod, auto &cls) {
        cls.def(py::init<>());
        cls.def("__call__", &ObjectMaker::operator());
        cls.def("__reduce__",
                     [cls](ObjectMaker const &self) { return py::make_tuple(cls, py::tuple()); });
    });
 
    using PyObject = py::class_<Object, std::shared_ptr<Object>>;
    wrappers.wrapType(PyObject(wrappers.module, "Object"), [](auto &mod, auto &cls) {
        cls.def_static("fromString", &Object::fromString);
        // do not wrap fromAstObject because it uses a bare AST pointer
        cls.def("__str__", &Object::getClassName);
        cls.def("__repr__", [](Object const &self) { return "astshim." + self.getClassName(); });
        cls.def("__eq__", &Object::operator==, py::is_operator());
        cls.def("__ne__", &Object::operator!=, py::is_operator());
 
        cls.def_property_readonly("className", &Object::getClassName);
        cls.def_property("id", &Object::getID, &Object::setID);
        cls.def_property("ident", &Object::getIdent, &Object::setIdent);
        cls.def_property_readonly("objSize", &Object::getObjSize);
        cls.def_property("useDefs", &Object::getUseDefs, &Object::setUseDefs);
 
        cls.def("copy", &Object::copy);
        cls.def("clear", &Object::clear, "attrib"_a);
        cls.def("hasAttribute", &Object::hasAttribute, "attrib"_a);
        cls.def("getNObject", &Object::getNObject);
        cls.def("getRefCount", &Object::getRefCount);
        cls.def("lock", &Object::lock, "wait"_a);
        cls.def("same", &Object::same, "other"_a);
        // do not wrap the ostream version of show, since there is no obvious Python equivalent to ostream
        cls.def("show", py::overload_cast<bool>(&Object::show, py::const_), "showComments"_a = true);
 
        cls.def("test", &Object::test, "attrib"_a);
        cls.def("unlock", &Object::unlock, "report"_a = false);
        // do not wrap getRawPtr, since it returns a bare AST pointer
 
        // add pickling support
        cls.def("__reduce__", [](Object const &self) {
            std::string state = self.show(false);
            auto unpickleArgs = py::make_tuple(state);
            return py::make_tuple(makerCls(), unpickleArgs);
        });
    });
}
 
}  // namespace ast