Objects/xxobject.c

   1
   2 /* Use this file as a template to start implementing a new object type.
   3    If your objects will be called foobar, start by copying this file to
   4    foobarobject.c, changing all occurrences of xx to foobar and all
   5    occurrences of Xx by Foobar.  You will probably want to delete all
   6    references to 'x_attr' and add your own types of attributes
   7    instead.  Maybe you want to name your local variables other than
   8    'xp'.  If your object type is needed in other files, you'll have to
   9    create a file "foobarobject.h"; see intobject.h for an example. */
  10
  11
  12 /* Xx objects */
  13
  14 #include "Python.h"
  15
  16 typedef struct {
  17         PyObject_HEAD
  18         PyObject        *x_attr;        /* Attributes dictionary */
  19 } xxobject;
  20
  21 staticforward PyTypeObject Xxtype;
  22
  23 #define is_xxobject(v)          ((v)->ob_type == &Xxtype)
  24
  25 static xxobject *
  26 newxxobject(PyObject *arg)
  27 {
  28         xxobject *xp;
  29         xp = PyObject_New(xxobject, &Xxtype);
  30         if (xp == NULL)
  31                 return NULL;
  32         xp->x_attr = NULL;
  33         return xp;
  34 }
  35
  36 /* Xx methods */
  37
  38 static void
  39 xx_dealloc(xxobject *xp)
  40 {
  41         Py_XDECREF(xp->x_attr);
  42         PyObject_Del(xp);
  43 }
  44
  45 static PyObject *
  46 xx_demo(xxobject *self, PyObject *args)
  47 {
  48         if (!PyArg_ParseTuple(args, ":demo"))
  49                 return NULL;
  50         Py_INCREF(Py_None);
  51         return Py_None;
  52 }
  53
  54 static PyMethodDef xx_methods[] = {
  55         {"demo",        (PyCFunction)xx_demo,   METH_VARARGS},
  56         {NULL,          NULL}           /* sentinel */
  57 };
  58
  59 static PyObject *
  60 xx_getattr(xxobject *xp, char *name)
  61 {
  62         if (xp->x_attr != NULL) {
  63                 PyObject *v = PyDict_GetItemString(xp->x_attr, name);
  64                 if (v != NULL) {
  65                         Py_INCREF(v);
  66                         return v;
  67                 }
  68         }
  69         return Py_FindMethod(xx_methods, (PyObject *)xp, name);
  70 }
  71
  72 static int
  73 xx_setattr(xxobject *xp, char *name, PyObject *v)
  74 {
  75         if (xp->x_attr == NULL) {
  76                 xp->x_attr = PyDict_New();
  77                 if (xp->x_attr == NULL)
  78                         return -1;
  79         }
  80         if (v == NULL) {
  81                 int rv = PyDict_DelItemString(xp->x_attr, name);
  82                 if (rv < 0)
  83                         PyErr_SetString(PyExc_AttributeError,
  84                                         "delete non-existing xx attribute");
  85                 return rv;
  86         }
  87         else
  88                 return PyDict_SetItemString(xp->x_attr, name, v);
  89 }
  90
  91 static PyTypeObject Xxtype = {
  92         PyObject_HEAD_INIT(&PyType_Type)
  93         0,                      /*ob_size*/
  94         "xx",                   /*tp_name*/
  95         sizeof(xxobject),       /*tp_basicsize*/
  96         0,                      /*tp_itemsize*/
  97         /* methods */
  98         (destructor)xx_dealloc, /*tp_dealloc*/
  99         0,                      /*tp_print*/
 100         (getattrfunc)xx_getattr, /*tp_getattr*/
 101         (setattrfunc)xx_setattr, /*tp_setattr*/
 102         0,                      /*tp_compare*/
 103         0,                      /*tp_repr*/
 104         0,                      /*tp_as_number*/
 105         0,                      /*tp_as_sequence*/
 106         0,                      /*tp_as_mapping*/
 107         0,                      /*tp_hash*/
 108 };