xref: /third_party/python/Doc/includes/custom3.c (revision 7db96d56) 
1#define PY_SSIZE_T_CLEAN
2#include <Python.h>
3#include "structmember.h"
4
5typedef struct {
6    PyObject_HEAD
7    PyObject *first; /* first name */
8    PyObject *last;  /* last name */
9    int number;
10} CustomObject;
11
12static void
13Custom_dealloc(CustomObject *self)
14{
15    Py_XDECREF(self->first);
16    Py_XDECREF(self->last);
17    Py_TYPE(self)->tp_free((PyObject *) self);
18}
19
20static PyObject *
21Custom_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
22{
23    CustomObject *self;
24    self = (CustomObject *) type->tp_alloc(type, 0);
25    if (self != NULL) {
26        self->first = PyUnicode_FromString("");
27        if (self->first == NULL) {
28            Py_DECREF(self);
29            return NULL;
30        }
31        self->last = PyUnicode_FromString("");
32        if (self->last == NULL) {
33            Py_DECREF(self);
34            return NULL;
35        }
36        self->number = 0;
37    }
38    return (PyObject *) self;
39}
40
41static int
42Custom_init(CustomObject *self, PyObject *args, PyObject *kwds)
43{
44    static char *kwlist[] = {"first", "last", "number", NULL};
45    PyObject *first = NULL, *last = NULL, *tmp;
46
47    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|UUi", kwlist,
48                                     &first, &last,
49                                     &self->number))
50        return -1;
51
52    if (first) {
53        tmp = self->first;
54        Py_INCREF(first);
55        self->first = first;
56        Py_DECREF(tmp);
57    }
58    if (last) {
59        tmp = self->last;
60        Py_INCREF(last);
61        self->last = last;
62        Py_DECREF(tmp);
63    }
64    return 0;
65}
66
67static PyMemberDef Custom_members[] = {
68    {"number", T_INT, offsetof(CustomObject, number), 0,
69     "custom number"},
70    {NULL}  /* Sentinel */
71};
72
73static PyObject *
74Custom_getfirst(CustomObject *self, void *closure)
75{
76    Py_INCREF(self->first);
77    return self->first;
78}
79
80static int
81Custom_setfirst(CustomObject *self, PyObject *value, void *closure)
82{
83    PyObject *tmp;
84    if (value == NULL) {
85        PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute");
86        return -1;
87    }
88    if (!PyUnicode_Check(value)) {
89        PyErr_SetString(PyExc_TypeError,
90                        "The first attribute value must be a string");
91        return -1;
92    }
93    tmp = self->first;
94    Py_INCREF(value);
95    self->first = value;
96    Py_DECREF(tmp);
97    return 0;
98}
99
100static PyObject *
101Custom_getlast(CustomObject *self, void *closure)
102{
103    Py_INCREF(self->last);
104    return self->last;
105}
106
107static int
108Custom_setlast(CustomObject *self, PyObject *value, void *closure)
109{
110    PyObject *tmp;
111    if (value == NULL) {
112        PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute");
113        return -1;
114    }
115    if (!PyUnicode_Check(value)) {
116        PyErr_SetString(PyExc_TypeError,
117                        "The last attribute value must be a string");
118        return -1;
119    }
120    tmp = self->last;
121    Py_INCREF(value);
122    self->last = value;
123    Py_DECREF(tmp);
124    return 0;
125}
126
127static PyGetSetDef Custom_getsetters[] = {
128    {"first", (getter) Custom_getfirst, (setter) Custom_setfirst,
129     "first name", NULL},
130    {"last", (getter) Custom_getlast, (setter) Custom_setlast,
131     "last name", NULL},
132    {NULL}  /* Sentinel */
133};
134
135static PyObject *
136Custom_name(CustomObject *self, PyObject *Py_UNUSED(ignored))
137{
138    return PyUnicode_FromFormat("%S %S", self->first, self->last);
139}
140
141static PyMethodDef Custom_methods[] = {
142    {"name", (PyCFunction) Custom_name, METH_NOARGS,
143     "Return the name, combining the first and last name"
144    },
145    {NULL}  /* Sentinel */
146};
147
148static PyTypeObject CustomType = {
149    PyVarObject_HEAD_INIT(NULL, 0)
150    .tp_name = "custom3.Custom",
151    .tp_doc = PyDoc_STR("Custom objects"),
152    .tp_basicsize = sizeof(CustomObject),
153    .tp_itemsize = 0,
154    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
155    .tp_new = Custom_new,
156    .tp_init = (initproc) Custom_init,
157    .tp_dealloc = (destructor) Custom_dealloc,
158    .tp_members = Custom_members,
159    .tp_methods = Custom_methods,
160    .tp_getset = Custom_getsetters,
161};
162
163static PyModuleDef custommodule = {
164    PyModuleDef_HEAD_INIT,
165    .m_name = "custom3",
166    .m_doc = "Example module that creates an extension type.",
167    .m_size = -1,
168};
169
170PyMODINIT_FUNC
171PyInit_custom3(void)
172{
173    PyObject *m;
174    if (PyType_Ready(&CustomType) < 0)
175        return NULL;
176
177    m = PyModule_Create(&custommodule);
178    if (m == NULL)
179        return NULL;
180
181    Py_INCREF(&CustomType);
182    if (PyModule_AddObject(m, "Custom", (PyObject *) &CustomType) < 0) {
183        Py_DECREF(&CustomType);
184        Py_DECREF(m);
185        return NULL;
186    }
187
188    return m;
189}
190