Objects/cellobject.c

   1 /* Cell object implementation */
   2
   3 #include "Python.h"
   4
   5 PyObject *
   6 PyCell_New(PyObject *obj)
   7 {
   8         PyCellObject *op;
   9
  10         op = (PyCellObject *)PyObject_GC_New(PyCellObject, &PyCell_Type);
  11         op->ob_ref = obj;
  12         Py_XINCREF(obj);
  13
  14         _PyObject_GC_TRACK(op);
  15         return (PyObject *)op;
  16 }
  17
  18 PyObject *
  19 PyCell_Get(PyObject *op)
  20 {
  21         if (!PyCell_Check(op)) {
  22                 PyErr_BadInternalCall();
  23                 return NULL;
  24         }
  25         Py_XINCREF(((PyCellObject*)op)->ob_ref);
  26         return PyCell_GET(op);
  27 }
  28
  29 int
  30 PyCell_Set(PyObject *op, PyObject *obj)
  31 {
  32         if (!PyCell_Check(op)) {
  33                 PyErr_BadInternalCall();
  34                 return -1;
  35         }
  36         Py_XDECREF(((PyCellObject*)op)->ob_ref);
  37         Py_XINCREF(obj);
  38         PyCell_SET(op, obj);
  39         return 0;
  40 }
  41
  42 static void
  43 cell_dealloc(PyCellObject *op)
  44 {
  45         _PyObject_GC_UNTRACK(op);
  46         Py_XDECREF(op->ob_ref);
  47         PyObject_GC_Del(op);
  48 }
  49
  50 static int
  51 cell_compare(PyCellObject *a, PyCellObject *b)
  52 {
  53         if (a->ob_ref == NULL) {
  54                 if (b->ob_ref == NULL)
  55                         return 0;
  56                 return -1;
  57         } else if (b->ob_ref == NULL)
  58                 return 1;
  59         return PyObject_Compare(a->ob_ref, b->ob_ref);
  60 }
  61
  62 static PyObject *
  63 cell_repr(PyCellObject *op)
  64 {
  65         if (op->ob_ref == NULL)
  66                 return PyString_FromFormat("<cell at %p: empty>", op);
  67
  68         return PyString_FromFormat("<cell at %p: %.80s object at %p>",
  69                                    op, op->ob_ref->ob_type->tp_name,
  70                                    op->ob_ref);
  71 }
  72
  73 static int
  74 cell_traverse(PyCellObject *op, visitproc visit, void *arg)
  75 {
  76         if (op->ob_ref)
  77                 return visit(op->ob_ref, arg);
  78         return 0;
  79 }
  80
  81 static int
  82 cell_clear(PyCellObject *op)
  83 {
  84         Py_XDECREF(op->ob_ref);
  85         op->ob_ref = NULL;
  86         return 0;
  87 }
  88
  89 static PyObject *
  90 cell_get_contents(PyCellObject *op, void *closure)
  91 {
  92         Py_XINCREF(op->ob_ref);
  93         return op->ob_ref;
  94 }
  95
  96 static PyGetSetDef cell_getsetlist[] = {
  97         {"cell_contents", (getter)cell_get_contents, NULL},
  98         {NULL} /* sentinel */
  99 };
 100
 101 PyTypeObject PyCell_Type = {
 102         PyObject_HEAD_INIT(&PyType_Type)
 103         0,
 104         "cell",
 105         sizeof(PyCellObject),
 106         0,
 107         (destructor)cell_dealloc,               /* tp_dealloc */
 108         0,                                      /* tp_print */
 109         0,                                      /* tp_getattr */
 110         0,                                      /* tp_setattr */
 111         (cmpfunc)cell_compare,                  /* tp_compare */
 112         (reprfunc)cell_repr,                    /* tp_repr */
 113         0,                                      /* tp_as_number */
 114         0,                                      /* tp_as_sequence */
 115         0,                                      /* tp_as_mapping */
 116         0,                                      /* tp_hash */
 117         0,                                      /* tp_call */
 118         0,                                      /* tp_str */
 119         PyObject_GenericGetAttr,                /* tp_getattro */
 120         0,                                      /* tp_setattro */
 121         0,                                      /* tp_as_buffer */
 122         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
 123         0,                                      /* tp_doc */
 124         (traverseproc)cell_traverse,            /* tp_traverse */
 125         (inquiry)cell_clear,                    /* tp_clear */
 126         0,                                      /* tp_richcompare */
 127         0,                                      /* tp_weaklistoffset */
 128         0,                                      /* tp_iter */
 129         0,                                      /* tp_iternext */
 130         0,                                      /* tp_methods */
 131         0,                                      /* tp_members */
 132         cell_getsetlist,                        /* tp_getset */
 133 };