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/Objects/methodobject.c

https://github.com/albertz/CPython
C | 333 lines | 276 code | 41 blank | 16 comment | 46 complexity | d64e3f1bfde74e2487dcb6b0e13b81a0 MD5 | raw file
  1
  2/* Method object implementation */
  3
  4#include "Python.h"
  5#include "internal/mem.h"
  6#include "internal/pystate.h"
  7#include "structmember.h"
  8
  9/* Free list for method objects to safe malloc/free overhead
 10 * The m_self element is used to chain the objects.
 11 */
 12static PyCFunctionObject *free_list = NULL;
 13static int numfree = 0;
 14#ifndef PyCFunction_MAXFREELIST
 15#define PyCFunction_MAXFREELIST 256
 16#endif
 17
 18/* undefine macro trampoline to PyCFunction_NewEx */
 19#undef PyCFunction_New
 20
 21PyAPI_FUNC(PyObject *)
 22PyCFunction_New(PyMethodDef *ml, PyObject *self)
 23{
 24    return PyCFunction_NewEx(ml, self, NULL);
 25}
 26
 27PyObject *
 28PyCFunction_NewEx(PyMethodDef *ml, PyObject *self, PyObject *module)
 29{
 30    PyCFunctionObject *op;
 31    op = free_list;
 32    if (op != NULL) {
 33        free_list = (PyCFunctionObject *)(op->m_self);
 34        (void)PyObject_INIT(op, &PyCFunction_Type);
 35        numfree--;
 36    }
 37    else {
 38        op = PyObject_GC_New(PyCFunctionObject, &PyCFunction_Type);
 39        if (op == NULL)
 40            return NULL;
 41    }
 42    op->m_weakreflist = NULL;
 43    op->m_ml = ml;
 44    Py_XINCREF(self);
 45    op->m_self = self;
 46    Py_XINCREF(module);
 47    op->m_module = module;
 48    _PyObject_GC_TRACK(op);
 49    return (PyObject *)op;
 50}
 51
 52PyCFunction
 53PyCFunction_GetFunction(PyObject *op)
 54{
 55    if (!PyCFunction_Check(op)) {
 56        PyErr_BadInternalCall();
 57        return NULL;
 58    }
 59    return PyCFunction_GET_FUNCTION(op);
 60}
 61
 62PyObject *
 63PyCFunction_GetSelf(PyObject *op)
 64{
 65    if (!PyCFunction_Check(op)) {
 66        PyErr_BadInternalCall();
 67        return NULL;
 68    }
 69    return PyCFunction_GET_SELF(op);
 70}
 71
 72int
 73PyCFunction_GetFlags(PyObject *op)
 74{
 75    if (!PyCFunction_Check(op)) {
 76        PyErr_BadInternalCall();
 77        return -1;
 78    }
 79    return PyCFunction_GET_FLAGS(op);
 80}
 81
 82/* Methods (the standard built-in methods, that is) */
 83
 84static void
 85meth_dealloc(PyCFunctionObject *m)
 86{
 87    _PyObject_GC_UNTRACK(m);
 88    if (m->m_weakreflist != NULL) {
 89        PyObject_ClearWeakRefs((PyObject*) m);
 90    }
 91    Py_XDECREF(m->m_self);
 92    Py_XDECREF(m->m_module);
 93    if (numfree < PyCFunction_MAXFREELIST) {
 94        m->m_self = (PyObject *)free_list;
 95        free_list = m;
 96        numfree++;
 97    }
 98    else {
 99        PyObject_GC_Del(m);
100    }
101}
102
103static PyObject *
104meth_reduce(PyCFunctionObject *m)
105{
106    _Py_IDENTIFIER(getattr);
107
108    if (m->m_self == NULL || PyModule_Check(m->m_self))
109        return PyUnicode_FromString(m->m_ml->ml_name);
110
111    return Py_BuildValue("N(Os)", _PyEval_GetBuiltinId(&PyId_getattr),
112                         m->m_self, m->m_ml->ml_name);
113}
114
115static PyMethodDef meth_methods[] = {
116    {"__reduce__", (PyCFunction)meth_reduce, METH_NOARGS, NULL},
117    {NULL, NULL}
118};
119
120static PyObject *
121meth_get__text_signature__(PyCFunctionObject *m, void *closure)
122{
123    return _PyType_GetTextSignatureFromInternalDoc(m->m_ml->ml_name, m->m_ml->ml_doc);
124}
125
126static PyObject *
127meth_get__doc__(PyCFunctionObject *m, void *closure)
128{
129    return _PyType_GetDocFromInternalDoc(m->m_ml->ml_name, m->m_ml->ml_doc);
130}
131
132static PyObject *
133meth_get__name__(PyCFunctionObject *m, void *closure)
134{
135    return PyUnicode_FromString(m->m_ml->ml_name);
136}
137
138static PyObject *
139meth_get__qualname__(PyCFunctionObject *m, void *closure)
140{
141    /* If __self__ is a module or NULL, return m.__name__
142       (e.g. len.__qualname__ == 'len')
143
144       If __self__ is a type, return m.__self__.__qualname__ + '.' + m.__name__
145       (e.g. dict.fromkeys.__qualname__ == 'dict.fromkeys')
146
147       Otherwise return type(m.__self__).__qualname__ + '.' + m.__name__
148       (e.g. [].append.__qualname__ == 'list.append') */
149    PyObject *type, *type_qualname, *res;
150    _Py_IDENTIFIER(__qualname__);
151
152    if (m->m_self == NULL || PyModule_Check(m->m_self))
153        return PyUnicode_FromString(m->m_ml->ml_name);
154
155    type = PyType_Check(m->m_self) ? m->m_self : (PyObject*)Py_TYPE(m->m_self);
156
157    type_qualname = _PyObject_GetAttrId(type, &PyId___qualname__);
158    if (type_qualname == NULL)
159        return NULL;
160
161    if (!PyUnicode_Check(type_qualname)) {
162        PyErr_SetString(PyExc_TypeError, "<method>.__class__."
163                        "__qualname__ is not a unicode object");
164        Py_XDECREF(type_qualname);
165        return NULL;
166    }
167
168    res = PyUnicode_FromFormat("%S.%s", type_qualname, m->m_ml->ml_name);
169    Py_DECREF(type_qualname);
170    return res;
171}
172
173static int
174meth_traverse(PyCFunctionObject *m, visitproc visit, void *arg)
175{
176    Py_VISIT(m->m_self);
177    Py_VISIT(m->m_module);
178    return 0;
179}
180
181static PyObject *
182meth_get__self__(PyCFunctionObject *m, void *closure)
183{
184    PyObject *self;
185
186    self = PyCFunction_GET_SELF(m);
187    if (self == NULL)
188        self = Py_None;
189    Py_INCREF(self);
190    return self;
191}
192
193static PyGetSetDef meth_getsets [] = {
194    {"__doc__",  (getter)meth_get__doc__,  NULL, NULL},
195    {"__name__", (getter)meth_get__name__, NULL, NULL},
196    {"__qualname__", (getter)meth_get__qualname__, NULL, NULL},
197    {"__self__", (getter)meth_get__self__, NULL, NULL},
198    {"__text_signature__", (getter)meth_get__text_signature__, NULL, NULL},
199    {0}
200};
201
202#define OFF(x) offsetof(PyCFunctionObject, x)
203
204static PyMemberDef meth_members[] = {
205    {"__module__",    T_OBJECT,     OFF(m_module), PY_WRITE_RESTRICTED},
206    {NULL}
207};
208
209static PyObject *
210meth_repr(PyCFunctionObject *m)
211{
212    if (m->m_self == NULL || PyModule_Check(m->m_self))
213        return PyUnicode_FromFormat("<built-in function %s>",
214                                   m->m_ml->ml_name);
215    return PyUnicode_FromFormat("<built-in method %s of %s object at %p>",
216                               m->m_ml->ml_name,
217                               m->m_self->ob_type->tp_name,
218                               m->m_self);
219}
220
221static PyObject *
222meth_richcompare(PyObject *self, PyObject *other, int op)
223{
224    PyCFunctionObject *a, *b;
225    PyObject *res;
226    int eq;
227
228    if ((op != Py_EQ && op != Py_NE) ||
229        !PyCFunction_Check(self) ||
230        !PyCFunction_Check(other))
231    {
232        Py_RETURN_NOTIMPLEMENTED;
233    }
234    a = (PyCFunctionObject *)self;
235    b = (PyCFunctionObject *)other;
236    eq = a->m_self == b->m_self;
237    if (eq)
238        eq = a->m_ml->ml_meth == b->m_ml->ml_meth;
239    if (op == Py_EQ)
240        res = eq ? Py_True : Py_False;
241    else
242        res = eq ? Py_False : Py_True;
243    Py_INCREF(res);
244    return res;
245}
246
247static Py_hash_t
248meth_hash(PyCFunctionObject *a)
249{
250    Py_hash_t x, y;
251    if (a->m_self == NULL)
252        x = 0;
253    else {
254        x = PyObject_Hash(a->m_self);
255        if (x == -1)
256            return -1;
257    }
258    y = _Py_HashPointer((void*)(a->m_ml->ml_meth));
259    if (y == -1)
260        return -1;
261    x ^= y;
262    if (x == -1)
263        x = -2;
264    return x;
265}
266
267
268PyTypeObject PyCFunction_Type = {
269    PyVarObject_HEAD_INIT(&PyType_Type, 0)
270    "builtin_function_or_method",
271    sizeof(PyCFunctionObject),
272    0,
273    (destructor)meth_dealloc,                   /* tp_dealloc */
274    0,                                          /* tp_print */
275    0,                                          /* tp_getattr */
276    0,                                          /* tp_setattr */
277    0,                                          /* tp_reserved */
278    (reprfunc)meth_repr,                        /* tp_repr */
279    0,                                          /* tp_as_number */
280    0,                                          /* tp_as_sequence */
281    0,                                          /* tp_as_mapping */
282    (hashfunc)meth_hash,                        /* tp_hash */
283    PyCFunction_Call,                           /* tp_call */
284    0,                                          /* tp_str */
285    PyObject_GenericGetAttr,                    /* tp_getattro */
286    0,                                          /* tp_setattro */
287    0,                                          /* tp_as_buffer */
288    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
289    0,                                          /* tp_doc */
290    (traverseproc)meth_traverse,                /* tp_traverse */
291    0,                                          /* tp_clear */
292    meth_richcompare,                           /* tp_richcompare */
293    offsetof(PyCFunctionObject, m_weakreflist), /* tp_weaklistoffset */
294    0,                                          /* tp_iter */
295    0,                                          /* tp_iternext */
296    meth_methods,                               /* tp_methods */
297    meth_members,                               /* tp_members */
298    meth_getsets,                               /* tp_getset */
299    0,                                          /* tp_base */
300    0,                                          /* tp_dict */
301};
302
303/* Clear out the free list */
304
305int
306PyCFunction_ClearFreeList(void)
307{
308    int freelist_size = numfree;
309
310    while (free_list) {
311        PyCFunctionObject *v = free_list;
312        free_list = (PyCFunctionObject *)(v->m_self);
313        PyObject_GC_Del(v);
314        numfree--;
315    }
316    assert(numfree == 0);
317    return freelist_size;
318}
319
320void
321PyCFunction_Fini(void)
322{
323    (void)PyCFunction_ClearFreeList();
324}
325
326/* Print summary info about the state of the optimized allocator */
327void
328_PyCFunction_DebugMallocStats(FILE *out)
329{
330    _PyDebugAllocatorStats(out,
331                           "free PyCFunctionObject",
332                           numfree, sizeof(PyCFunctionObject));
333}