Modules/xxsubtype.c

   1 #include "Python.h"
   2 #include "structmember.h"
   3
   4 /* Examples showing how to subtype the builtin list and dict types from C. */
   5
   6 /* spamlist -- a list subtype */
   7
   8 typedef struct {
   9         PyListObject list;
  10         int state;
  11 } spamlistobject;
  12
  13 static PyObject *
  14 spamlist_getstate(spamlistobject *self, PyObject *args)
  15 {
  16         if (!PyArg_ParseTuple(args, ":getstate"))
  17                 return NULL;
  18         return PyInt_FromLong(self->state);
  19 }
  20
  21 static PyObject *
  22 spamlist_setstate(spamlistobject *self, PyObject *args)
  23 {
  24         int state;
  25
  26         if (!PyArg_ParseTuple(args, "i:setstate", &state))
  27                 return NULL;
  28         self->state = state;
  29         Py_INCREF(Py_None);
  30         return Py_None;
  31 }
  32
  33 static PyMethodDef spamlist_methods[] = {
  34         {"getstate", (PyCFunction)spamlist_getstate, METH_VARARGS,
  35                 "getstate() -> state"},
  36         {"setstate", (PyCFunction)spamlist_setstate, METH_VARARGS,
  37                 "setstate(state)"},
  38         {NULL,  NULL},
  39 };
  40
  41 staticforward PyTypeObject spamlist_type;
  42
  43 static int
  44 spamlist_init(spamlistobject *self, PyObject *args, PyObject *kwds)
  45 {
  46         if (PyList_Type.tp_init((PyObject *)self, args, kwds) < 0)
  47                 return -1;
  48         self->state = 0;
  49         return 0;
  50 }
  51
  52 static PyObject *
  53 spamlist_state_get(spamlistobject *self)
  54 {
  55         return PyInt_FromLong(self->state);
  56 }
  57
  58 static PyGetSetDef spamlist_getsets[] = {
  59         {"state", (getter)spamlist_state_get, NULL,
  60          "an int variable for demonstration purposes"},
  61         {0}
  62 };
  63
  64 static PyTypeObject spamlist_type = {
  65         PyObject_HEAD_INIT(&PyType_Type)
  66         0,
  67         "xxsubtype.spamlist",
  68         sizeof(spamlistobject),
  69         0,
  70         0,                                      /* tp_dealloc */
  71         0,                                      /* tp_print */
  72         0,                                      /* tp_getattr */
  73         0,                                      /* tp_setattr */
  74         0,                                      /* tp_compare */
  75         0,                                      /* tp_repr */
  76         0,                                      /* tp_as_number */
  77         0,                                      /* tp_as_sequence */
  78         0,                                      /* tp_as_mapping */
  79         0,                                      /* tp_hash */
  80         0,                                      /* tp_call */
  81         0,                                      /* tp_str */
  82         0,                                      /* tp_getattro */
  83         0,                                      /* tp_setattro */
  84         0,                                      /* tp_as_buffer */
  85         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
  86         0,                                      /* tp_doc */
  87         0,                                      /* tp_traverse */
  88         0,                                      /* tp_clear */
  89         0,                                      /* tp_richcompare */
  90         0,                                      /* tp_weaklistoffset */
  91         0,                                      /* tp_iter */
  92         0,                                      /* tp_iternext */
  93         spamlist_methods,                       /* tp_methods */
  94         0,                                      /* tp_members */
  95         spamlist_getsets,                       /* tp_getset */
  96         &PyList_Type,                           /* tp_base */
  97         0,                                      /* tp_dict */
  98         0,                                      /* tp_descr_get */
  99         0,                                      /* tp_descr_set */
 100         0,                                      /* tp_dictoffset */
 101         (initproc)spamlist_init,                /* tp_init */
 102         0,                                      /* tp_alloc */
 103         0,                                      /* tp_new */
 104 };
 105
 106 /* spamdict -- a dict subtype */
 107
 108 typedef struct {
 109         PyDictObject dict;
 110         int state;
 111 } spamdictobject;
 112
 113 static PyObject *
 114 spamdict_getstate(spamdictobject *self, PyObject *args)
 115 {
 116         if (!PyArg_ParseTuple(args, ":getstate"))
 117                 return NULL;
 118         return PyInt_FromLong(self->state);
 119 }
 120
 121 static PyObject *
 122 spamdict_setstate(spamdictobject *self, PyObject *args)
 123 {
 124         int state;
 125
 126         if (!PyArg_ParseTuple(args, "i:setstate", &state))
 127                 return NULL;
 128         self->state = state;
 129         Py_INCREF(Py_None);
 130         return Py_None;
 131 }
 132
 133 static PyMethodDef spamdict_methods[] = {
 134         {"getstate", (PyCFunction)spamdict_getstate, METH_VARARGS,
 135                 "getstate() -> state"},
 136         {"setstate", (PyCFunction)spamdict_setstate, METH_VARARGS,
 137                 "setstate(state)"},
 138         {NULL,  NULL},
 139 };
 140
 141 staticforward PyTypeObject spamdict_type;
 142
 143 static int
 144 spamdict_init(spamdictobject *self, PyObject *args, PyObject *kwds)
 145 {
 146         if (PyDict_Type.tp_init((PyObject *)self, args, kwds) < 0)
 147                 return -1;
 148         self->state = 0;
 149         return 0;
 150 }
 151
 152 static PyMemberDef spamdict_members[] = {
 153         {"state", T_INT, offsetof(spamdictobject, state), READONLY,
 154          "an int variable for demonstration purposes"},
 155         {0}
 156 };
 157
 158 static PyTypeObject spamdict_type = {
 159         PyObject_HEAD_INIT(&PyType_Type)
 160         0,
 161         "xxsubtype.spamdict",
 162         sizeof(spamdictobject),
 163         0,
 164         0,                                      /* tp_dealloc */
 165         0,                                      /* tp_print */
 166         0,                                      /* tp_getattr */
 167         0,                                      /* tp_setattr */
 168         0,                                      /* tp_compare */
 169         0,                                      /* tp_repr */
 170         0,                                      /* tp_as_number */
 171         0,                                      /* tp_as_sequence */
 172         0,                                      /* tp_as_mapping */
 173         0,                                      /* tp_hash */
 174         0,                                      /* tp_call */
 175         0,                                      /* tp_str */
 176         0,                                      /* tp_getattro */
 177         0,                                      /* tp_setattro */
 178         0,                                      /* tp_as_buffer */
 179         Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
 180         0,                                      /* tp_doc */
 181         0,                                      /* tp_traverse */
 182         0,                                      /* tp_clear */
 183         0,                                      /* tp_richcompare */
 184         0,                                      /* tp_weaklistoffset */
 185         0,                                      /* tp_iter */
 186         0,                                      /* tp_iternext */
 187         spamdict_methods,                       /* tp_methods */
 188         spamdict_members,                       /* tp_members */
 189         0,                                      /* tp_getset */
 190         &PyDict_Type,                           /* tp_base */
 191         0,                                      /* tp_dict */
 192         0,                                      /* tp_descr_get */
 193         0,                                      /* tp_descr_set */
 194         0,                                      /* tp_dictoffset */
 195         (initproc)spamdict_init,                /* tp_init */
 196         0,                                      /* tp_alloc */
 197         0,                                      /* tp_new */
 198 };
 199
 200 PyObject *
 201 spam_bench(PyObject *self, PyObject *args)
 202 {
 203         PyObject *obj, *name, *res;
 204         int n = 1000;
 205         time_t t0, t1;
 206
 207         if (!PyArg_ParseTuple(args, "OS|i", &obj, &name, &n))
 208                 return NULL;
 209         t0 = clock();
 210         while (--n >= 0) {
 211                 res = PyObject_GetAttr(obj, name);
 212                 if (res == NULL)
 213                         return NULL;
 214                 Py_DECREF(res);
 215         }
 216         t1 = clock();
 217         return PyFloat_FromDouble((double)(t1-t0) / CLOCKS_PER_SEC);
 218 }
 219
 220 static PyMethodDef xxsubtype_functions[] = {
 221         {"bench",       spam_bench,     METH_VARARGS},
 222         {NULL,          NULL}           /* sentinel */
 223 };
 224
 225 DL_EXPORT(void)
 226 initxxsubtype(void)
 227 {
 228         PyObject *m, *d;
 229
 230         m = Py_InitModule("xxsubtype", xxsubtype_functions);
 231         if (m == NULL)
 232                 return;
 233
 234         if (PyType_Ready(&spamlist_type) < 0)
 235                 return;
 236         if (PyType_Ready(&spamdict_type) < 0)
 237                 return;
 238
 239         d = PyModule_GetDict(m);
 240         if (d == NULL)
 241                 return;
 242
 243         Py_INCREF(&spamlist_type);
 244         if (PyDict_SetItemString(d, "spamlist",
 245                                  (PyObject *) &spamlist_type) < 0)
 246                 return;
 247
 248         Py_INCREF(&spamdict_type);
 249         if (PyDict_SetItemString(d, "spamdict",
 250                                  (PyObject *) &spamdict_type) < 0)
 251                 return;
 252 }