1#include "Python.h"
2
3
4#define GET_WEAKREFS_LISTPTR(o) \
5        ((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o))
6
7
8PyDoc_STRVAR(weakref_getweakrefcount__doc__,
9"getweakrefcount(object) -- return the number of weak references\n"
10"to 'object'.");
11
12static PyObject *
13weakref_getweakrefcount(PyObject *self, PyObject *object)
14{
15    PyObject *result = NULL;
16
17    if (PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {
18        PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);
19
20        result = PyInt_FromSsize_t(_PyWeakref_GetWeakrefCount(*list));
21    }
22    else
23        result = PyInt_FromLong(0);
24
25    return result;
26}
27
28
29PyDoc_STRVAR(weakref_getweakrefs__doc__,
30"getweakrefs(object) -- return a list of all weak reference objects\n"
31"that point to 'object'.");
32
33static PyObject *
34weakref_getweakrefs(PyObject *self, PyObject *object)
35{
36    PyObject *result = NULL;
37
38    if (PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {
39        PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);
40        Py_ssize_t count = _PyWeakref_GetWeakrefCount(*list);
41
42        result = PyList_New(count);
43        if (result != NULL) {
44            PyWeakReference *current = *list;
45            Py_ssize_t i;
46            for (i = 0; i < count; ++i) {
47                PyList_SET_ITEM(result, i, (PyObject *) current);
48                Py_INCREF(current);
49                current = current->wr_next;
50            }
51        }
52    }
53    else {
54        result = PyList_New(0);
55    }
56    return result;
57}
58
59
60PyDoc_STRVAR(weakref_proxy__doc__,
61"proxy(object[, callback]) -- create a proxy object that weakly\n"
62"references 'object'.  'callback', if given, is called with a\n"
63"reference to the proxy when 'object' is about to be finalized.");
64
65static PyObject *
66weakref_proxy(PyObject *self, PyObject *args)
67{
68    PyObject *object;
69    PyObject *callback = NULL;
70    PyObject *result = NULL;
71
72    if (PyArg_UnpackTuple(args, "proxy", 1, 2, &object, &callback)) {
73        result = PyWeakref_NewProxy(object, callback);
74    }
75    return result;
76}
77
78
79static PyMethodDef
80weakref_functions[] =  {
81    {"getweakrefcount", weakref_getweakrefcount,        METH_O,
82     weakref_getweakrefcount__doc__},
83    {"getweakrefs",     weakref_getweakrefs,            METH_O,
84     weakref_getweakrefs__doc__},
85    {"proxy",           weakref_proxy,                  METH_VARARGS,
86     weakref_proxy__doc__},
87    {NULL, NULL, 0, NULL}
88};
89
90
91PyMODINIT_FUNC
92init_weakref(void)
93{
94    PyObject *m;
95
96    m = Py_InitModule3("_weakref", weakref_functions,
97                       "Weak-reference support module.");
98    if (m != NULL) {
99        Py_INCREF(&_PyWeakref_RefType);
100        PyModule_AddObject(m, "ref",
101                           (PyObject *) &_PyWeakref_RefType);
102        Py_INCREF(&_PyWeakref_RefType);
103        PyModule_AddObject(m, "ReferenceType",
104                           (PyObject *) &_PyWeakref_RefType);
105        Py_INCREF(&_PyWeakref_ProxyType);
106        PyModule_AddObject(m, "ProxyType",
107                           (PyObject *) &_PyWeakref_ProxyType);
108        Py_INCREF(&_PyWeakref_CallableProxyType);
109        PyModule_AddObject(m, "CallableProxyType",
110                           (PyObject *) &_PyWeakref_CallableProxyType);
111    }
112}
113