1 #include "Python.h"

     2 

     3 

     4 #define GET_WEAKREFS_LISTPTR(o) \

     5         ((PyWeakReference **) PyObject_GET_WEAKREFS_LISTPTR(o))

     6 

     7 

     8 PyDoc_STRVAR(weakref_getweakrefcount__doc__,

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

    10 "to 'object'.");

    11 

    12 static PyObject *

    13 weakref_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 

    29 PyDoc_STRVAR(weakref_getweakrefs__doc__,

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

    31 "that point to 'object'.");

    32 

    33 static PyObject *

    34 weakref_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 

    60 PyDoc_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 

    65 static PyObject *

    66 weakref_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 

    79 static PyMethodDef

    80 weakref_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 

    91 PyMODINIT_FUNC

    92 init_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 }