#include "Python.h"

#define GET_WEAKREFS_LISTPTR(o) \

        ((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o))

PyDoc_STRVAR(weakref_getweakrefcount__doc__,

"getweakrefcount(object) -- return the number of weak references\n"

"to 'object'.");

static PyObject *

weakref_getweakrefcount(PyObject *self, PyObject *object)

{

    PyObject *result = NULL;

    if (PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {

        PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);

        result = PyInt_FromSsize_t(_PyWeakref_GetWeakrefCount(*list));

    }

    else

        result = PyInt_FromLong(0);

    return result;

}

PyDoc_STRVAR(weakref_getweakrefs__doc__,

"getweakrefs(object) -- return a list of all weak reference objects\n"

"that point to 'object'.");

static PyObject *

weakref_getweakrefs(PyObject *self, PyObject *object)

{

    PyObject *result = NULL;

    if (PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {

        PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);

        Py_ssize_t count = _PyWeakref_GetWeakrefCount(*list);

        result = PyList_New(count);

        if (result != NULL) {

            PyWeakReference *current = *list;

            Py_ssize_t i;

            for (i = 0; i < count; ++i) {

                PyList_SET_ITEM(result, i, (PyObject *) current);

                Py_INCREF(current);

                current = current->wr_next;

            }

        }

    }

    else {

        result = PyList_New(0);

    }

    return result;

}

PyDoc_STRVAR(weakref_proxy__doc__,

"proxy(object[, callback]) -- create a proxy object that weakly\n"

"references 'object'.  'callback', if given, is called with a\n"

"reference to the proxy when 'object' is about to be finalized.");

static PyObject *

weakref_proxy(PyObject *self, PyObject *args)

{

    PyObject *object;

    PyObject *callback = NULL;

    PyObject *result = NULL;

    if (PyArg_UnpackTuple(args, "proxy", 1, 2, &object, &callback)) {

        result = PyWeakref_NewProxy(object, callback);

    }

    return result;

}

static PyMethodDef

weakref_functions[] =  {

    {"getweakrefcount", weakref_getweakrefcount,        METH_O,

     weakref_getweakrefcount__doc__},

    {"getweakrefs",     weakref_getweakrefs,            METH_O,

     weakref_getweakrefs__doc__},

    {"proxy",           weakref_proxy,                  METH_VARARGS,

     weakref_proxy__doc__},

    {NULL, NULL, 0, NULL}

};

PyMODINIT_FUNC

init_weakref(void)

{

    PyObject *m;

    m = Py_InitModule3("_weakref", weakref_functions,

                       "Weak-reference support module.");

    if (m != NULL) {

        Py_INCREF(&_PyWeakref_RefType);

        PyModule_AddObject(m, "ref",

                           (PyObject *) &_PyWeakref_RefType);

        Py_INCREF(&_PyWeakref_RefType);

        PyModule_AddObject(m, "ReferenceType",

                           (PyObject *) &_PyWeakref_RefType);

        Py_INCREF(&_PyWeakref_ProxyType);

        PyModule_AddObject(m, "ProxyType",

                           (PyObject *) &_PyWeakref_ProxyType);

        Py_INCREF(&_PyWeakref_CallableProxyType);

        PyModule_AddObject(m, "CallableProxyType",

                           (PyObject *) &_PyWeakref_CallableProxyType);

    }

}