#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);
 }
}