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_New(PyCellObject, &PyCell_Type);
  11         op->ob_ref = obj;
  12         Py_XINCREF(obj);
  13
  14         PyObject_GC_Init(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_Fini(op);
  46         Py_XDECREF(op->ob_ref);
  47         PyObject_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         char buf[256];
  66
  67         if (op->ob_ref == NULL)
  68                 sprintf(buf, "<cell at %p: empty>", op);
  69         else
  70                 sprintf(buf, "<cell at %p: %.80s object at %p>",
  71                         op, op->ob_ref->ob_type->tp_name, op->ob_ref);
  72         return PyString_FromString(buf);
  73 }
  74
  75 static int
  76 cell_traverse(PyCellObject *op, visitproc visit, void *arg)
  77 {
  78         if (op->ob_ref)
  79                 return visit(op->ob_ref, arg);
  80         return 0;
  81 }
  82
  83 static int
  84 cell_clear(PyCellObject *op)
  85 {
  86         Py_XDECREF(op->ob_ref);
  87         op->ob_ref = NULL;
  88         return 0;
  89 }
  90
  91 PyTypeObject PyCell_Type = {
  92         PyObject_HEAD_INIT(&PyType_Type)
  93         0,
  94         "cell",
  95         sizeof(PyCellObject) + PyGC_HEAD_SIZE,
  96         0,
  97         (destructor)cell_dealloc,               /* tp_dealloc */
  98         0,                                      /* tp_print */
  99         0,                                      /* tp_getattr */
 100         0,                                      /* tp_setattr */
 101         (cmpfunc)cell_compare,                  /* tp_compare */
 102         (reprfunc)cell_repr,                    /* tp_repr */
 103         0,                                      /* tp_as_number */
 104         0,                                      /* tp_as_sequence */
 105         0,                                      /* tp_as_mapping */
 106         0,                                      /* tp_hash */
 107         0,                                      /* tp_call */
 108         0,                                      /* tp_str */
 109         0,                                      /* tp_getattro */
 110         0,                                      /* tp_setattro */
 111         0,                                      /* tp_as_buffer */
 112         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_GC,     /* tp_flags */
 113         0,                                      /* tp_doc */
 114         (traverseproc)cell_traverse,            /* tp_traverse */
 115         (inquiry)cell_clear,                    /* tp_clear */
 116 };