/* Wrap void* pointers to be passed between C modules */

#include "Python.h"

/* Declarations for objects of type PyCObject */

typedef void (*destructor1)(void *);

typedef void (*destructor2)(void *, void*);

PyObject *

PyCObject_FromVoidPtr(void *cobj, void (*destr)(void *))

{

    PyCObject *self;

    self = PyObject_NEW(PyCObject, &PyCObject_Type);

    if (self == NULL)

        return NULL;

    self->cobject=cobj;

    self->destructor=destr;

    self->desc=NULL;

    return (PyObject *)self;

}

PyObject *

PyCObject_FromVoidPtrAndDesc(void *cobj, void *desc,

                             void (*destr)(void *, void *))

{

    PyCObject *self;

    if (!desc) {

        PyErr_SetString(PyExc_TypeError,

                        "PyCObject_FromVoidPtrAndDesc called with null"

                        " description");

        return NULL;

    }

    self = PyObject_NEW(PyCObject, &PyCObject_Type);

    if (self == NULL)

        return NULL;

    self->cobject = cobj;

    self->destructor = (destructor1)destr;

    self->desc = desc;

    return (PyObject *)self;

}

void *

PyCObject_AsVoidPtr(PyObject *self)

{

    if (self) {

        if (self->ob_type == &PyCObject_Type)

            return ((PyCObject *)self)->cobject;

        PyErr_SetString(PyExc_TypeError,

                        "PyCObject_AsVoidPtr with non-C-object");

    }

    if (!PyErr_Occurred())

        PyErr_SetString(PyExc_TypeError,

                        "PyCObject_AsVoidPtr called with null pointer");

    return NULL;

}

void *

PyCObject_GetDesc(PyObject *self)

{

    if (self) {

        if (self->ob_type == &PyCObject_Type)

            return ((PyCObject *)self)->desc;

        PyErr_SetString(PyExc_TypeError,

                        "PyCObject_GetDesc with non-C-object");

    }

    if (!PyErr_Occurred())

        PyErr_SetString(PyExc_TypeError,

                        "PyCObject_GetDesc called with null pointer");

    return NULL;

}

void *

PyCObject_Import(char *module_name, char *name)

{

    PyObject *m, *c;

    void *r = NULL;

    if ((m = PyImport_ImportModule(module_name))) {

        if ((c = PyObject_GetAttrString(m,name))) {

            r = PyCObject_AsVoidPtr(c);

            Py_DECREF(c);

	}

        Py_DECREF(m);

    }

    return r;

}

int

PyCObject_SetVoidPtr(PyObject *self, void *cobj)

{

    PyCObject* cself = (PyCObject*)self;

    if (cself == NULL || !PyCObject_Check(cself) ||

	cself->destructor != NULL) {

	PyErr_SetString(PyExc_TypeError, 

			"Invalid call to PyCObject_SetVoidPtr");

	return 0;

    }

    cself->cobject = cobj;

    return 1;

}

static void

PyCObject_dealloc(PyCObject *self)

{

    if (self->destructor) {

        if(self->desc)

            ((destructor2)(self->destructor))(self->cobject, self->desc);

        else

            (self->destructor)(self->cobject);

    }

    PyObject_DEL(self);

}

PyDoc_STRVAR(PyCObject_Type__doc__,

"C objects to be exported from one extension module to another\n\

\n\

C objects are used for communication between extension modules.  They\n\

provide a way for an extension module to export a C interface to other\n\

extension modules, so that extension modules can use the Python import\n\

mechanism to link to one another.");

PyTypeObject PyCObject_Type = {

    PyVarObject_HEAD_INIT(&PyType_Type, 0)

    "PyCObject",		/*tp_name*/

    sizeof(PyCObject),		/*tp_basicsize*/

    0,				/*tp_itemsize*/

    /* methods */

    (destructor)PyCObject_dealloc, /*tp_dealloc*/

    0,				/*tp_print*/

    0,				/*tp_getattr*/

    0,				/*tp_setattr*/

    0,				/*tp_compare*/

    0,				/*tp_repr*/

    0,				/*tp_as_number*/

    0,				/*tp_as_sequence*/

    0,				/*tp_as_mapping*/

    0,				/*tp_hash*/

    0,				/*tp_call*/

    0,				/*tp_str*/

    0,				/*tp_getattro*/

    0,				/*tp_setattro*/

    0,				/*tp_as_buffer*/

    0,				/*tp_flags*/

    PyCObject_Type__doc__	/*tp_doc*/

};