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Variation of patch # 1624059 to speed up checking if an object is a subclass

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of some of the common builtin types.

Use a bit in tp_flags for each common builtin type.  Check the bit
to determine if any instance is a subclass of these common types.
The check avoids a function call and O(n) search of the base classes.
The check is done in the various Py*_Check macros rather than calling
PyType_IsSubtype().

All the bits are set in tp_flags when the type is declared
in the Objects/*object.c files because PyType_Ready() is not called
for all the types.  Should PyType_Ready() be called for all types?
If so and the change is made, the changes to the Objects/*object.c files
can be reverted (remove setting the tp_flags).  Objects/typeobject.c
would also have to be modified to add conditions
for Py*_CheckExact() in addition to each the PyType_IsSubtype check.
This commit is contained in:
Neal Norwitz 2007-02-25 19:44:48 +00:00
parent 5a3e812444
commit ee3a1b5244
18 changed files with 61 additions and 22 deletions
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22
Objects/typeobject.c
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@ -2288,7 +2288,7 @@ PyTypeObject PyType_Type = {
(setattrofunc)type_setattro, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_BASETYPE, /* tp_flags */
Py_TPFLAGS_BASETYPE | Py_TPFLAGS_TYPE_SUBCLASS, /* tp_flags */
type_doc, /* tp_doc */
(traverseproc)type_traverse, /* tp_traverse */
(inquiry)type_clear, /* tp_clear */
@ -2967,6 +2967,26 @@ inherit_special(PyTypeObject *type, PyTypeObject *base)
if (type->tp_flags & base->tp_flags & Py_TPFLAGS_HAVE_CLASS) {
COPYVAL(tp_dictoffset);
}
/* Setup fast subclass flags */
if (PyType_IsSubtype(base, (PyTypeObject*)PyExc_BaseException))
type->tp_flags |= Py_TPFLAGS_BASE_EXC_SUBCLASS;
else if (PyType_IsSubtype(base, &PyType_Type))
type->tp_flags |= Py_TPFLAGS_TYPE_SUBCLASS;
else if (PyType_IsSubtype(base, &PyInt_Type))
type->tp_flags |= Py_TPFLAGS_INT_SUBCLASS;
else if (PyType_IsSubtype(base, &PyLong_Type))
type->tp_flags |= Py_TPFLAGS_LONG_SUBCLASS;
else if (PyType_IsSubtype(base, &PyString_Type))
type->tp_flags |= Py_TPFLAGS_STRING_SUBCLASS;
else if (PyType_IsSubtype(base, &PyUnicode_Type))
type->tp_flags |= Py_TPFLAGS_UNICODE_SUBCLASS;
else if (PyType_IsSubtype(base, &PyTuple_Type))
type->tp_flags |= Py_TPFLAGS_TUPLE_SUBCLASS;
else if (PyType_IsSubtype(base, &PyList_Type))
type->tp_flags |= Py_TPFLAGS_LIST_SUBCLASS;
else if (PyType_IsSubtype(base, &PyDict_Type))
type->tp_flags |= Py_TPFLAGS_DICT_SUBCLASS;
}
static void