1 /* Cell object implementation */
2
3 #include "Python.h"
4
5 PyObject *
PyCell_New(PyObject * obj)6 PyCell_New(PyObject *obj)
7 {
8 PyCellObject *op;
9
10 op = (PyCellObject *)PyObject_GC_New(PyCellObject, &PyCell_Type);
11 if (op == NULL)
12 return NULL;
13 op->ob_ref = obj;
14 Py_XINCREF(obj);
15
16 _PyObject_GC_TRACK(op);
17 return (PyObject *)op;
18 }
19
20 PyObject *
PyCell_Get(PyObject * op)21 PyCell_Get(PyObject *op)
22 {
23 if (!PyCell_Check(op)) {
24 PyErr_BadInternalCall();
25 return NULL;
26 }
27 Py_XINCREF(((PyCellObject*)op)->ob_ref);
28 return PyCell_GET(op);
29 }
30
31 int
PyCell_Set(PyObject * op,PyObject * obj)32 PyCell_Set(PyObject *op, PyObject *obj)
33 {
34 PyObject* oldobj;
35 if (!PyCell_Check(op)) {
36 PyErr_BadInternalCall();
37 return -1;
38 }
39 oldobj = PyCell_GET(op);
40 Py_XINCREF(obj);
41 PyCell_SET(op, obj);
42 Py_XDECREF(oldobj);
43 return 0;
44 }
45
46 static void
cell_dealloc(PyCellObject * op)47 cell_dealloc(PyCellObject *op)
48 {
49 _PyObject_GC_UNTRACK(op);
50 Py_XDECREF(op->ob_ref);
51 PyObject_GC_Del(op);
52 }
53
54 static int
cell_compare(PyCellObject * a,PyCellObject * b)55 cell_compare(PyCellObject *a, PyCellObject *b)
56 {
57 /* Py3K warning for comparisons */
58 if (PyErr_WarnPy3k("cell comparisons not supported in 3.x",
59 1) < 0) {
60 return -2;
61 }
62
63 if (a->ob_ref == NULL) {
64 if (b->ob_ref == NULL)
65 return 0;
66 return -1;
67 } else if (b->ob_ref == NULL)
68 return 1;
69 return PyObject_Compare(a->ob_ref, b->ob_ref);
70 }
71
72 static PyObject *
cell_repr(PyCellObject * op)73 cell_repr(PyCellObject *op)
74 {
75 if (op->ob_ref == NULL)
76 return PyString_FromFormat("<cell at %p: empty>", op);
77
78 return PyString_FromFormat("<cell at %p: %.80s object at %p>",
79 op, op->ob_ref->ob_type->tp_name,
80 op->ob_ref);
81 }
82
83 static int
cell_traverse(PyCellObject * op,visitproc visit,void * arg)84 cell_traverse(PyCellObject *op, visitproc visit, void *arg)
85 {
86 Py_VISIT(op->ob_ref);
87 return 0;
88 }
89
90 static int
cell_clear(PyCellObject * op)91 cell_clear(PyCellObject *op)
92 {
93 Py_CLEAR(op->ob_ref);
94 return 0;
95 }
96
97 static PyObject *
cell_get_contents(PyCellObject * op,void * closure)98 cell_get_contents(PyCellObject *op, void *closure)
99 {
100 if (op->ob_ref == NULL)
101 {
102 PyErr_SetString(PyExc_ValueError, "Cell is empty");
103 return NULL;
104 }
105 Py_INCREF(op->ob_ref);
106 return op->ob_ref;
107 }
108
109 static PyGetSetDef cell_getsetlist[] = {
110 {"cell_contents", (getter)cell_get_contents, NULL},
111 {NULL} /* sentinel */
112 };
113
114 PyTypeObject PyCell_Type = {
115 PyVarObject_HEAD_INIT(&PyType_Type, 0)
116 "cell",
117 sizeof(PyCellObject),
118 0,
119 (destructor)cell_dealloc, /* tp_dealloc */
120 0, /* tp_print */
121 0, /* tp_getattr */
122 0, /* tp_setattr */
123 (cmpfunc)cell_compare, /* tp_compare */
124 (reprfunc)cell_repr, /* tp_repr */
125 0, /* tp_as_number */
126 0, /* tp_as_sequence */
127 0, /* tp_as_mapping */
128 0, /* tp_hash */
129 0, /* tp_call */
130 0, /* tp_str */
131 PyObject_GenericGetAttr, /* tp_getattro */
132 0, /* tp_setattro */
133 0, /* tp_as_buffer */
134 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
135 0, /* tp_doc */
136 (traverseproc)cell_traverse, /* tp_traverse */
137 (inquiry)cell_clear, /* tp_clear */
138 0, /* tp_richcompare */
139 0, /* tp_weaklistoffset */
140 0, /* tp_iter */
141 0, /* tp_iternext */
142 0, /* tp_methods */
143 0, /* tp_members */
144 cell_getsetlist, /* tp_getset */
145 };
146