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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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15
Include/object.h
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@ -376,7 +376,8 @@ PyAPI_DATA(PyTypeObject) PyType_Type; /* built-in 'type' */
PyAPI_DATA(PyTypeObject) PyBaseObject_Type; /* built-in 'object' */
PyAPI_DATA(PyTypeObject) PySuper_Type; /* built-in 'super' */
#define PyType_Check(op) PyObject_TypeCheck(op, &PyType_Type)
#define PyType_Check(op) \
PyType_FastSubclass((op)->ob_type, Py_TPFLAGS_TYPE_SUBCLASS)
#define PyType_CheckExact(op) ((op)->ob_type == &PyType_Type)
PyAPI_FUNC(int) PyType_Ready(PyTypeObject *);
@ -517,6 +518,17 @@ given type object has a specified feature.
/* Objects support nb_index in PyNumberMethods */
#define Py_TPFLAGS_HAVE_INDEX (1L<<17)
/* These flags are used to determine if a type is a subclass. */
#define Py_TPFLAGS_INT_SUBCLASS (1L<<23)
#define Py_TPFLAGS_LONG_SUBCLASS (1L<<24)
#define Py_TPFLAGS_LIST_SUBCLASS (1L<<25)
#define Py_TPFLAGS_TUPLE_SUBCLASS (1L<<26)
#define Py_TPFLAGS_STRING_SUBCLASS (1L<<27)
#define Py_TPFLAGS_UNICODE_SUBCLASS (1L<<28)
#define Py_TPFLAGS_DICT_SUBCLASS (1L<<29)
#define Py_TPFLAGS_BASE_EXC_SUBCLASS (1L<<30)
#define Py_TPFLAGS_TYPE_SUBCLASS (1L<<31)
#define Py_TPFLAGS_DEFAULT ( \
Py_TPFLAGS_HAVE_GETCHARBUFFER | \
Py_TPFLAGS_HAVE_SEQUENCE_IN | \
@ -530,6 +542,7 @@ given type object has a specified feature.
0)
#define PyType_HasFeature(t,f) (((t)->tp_flags & (f)) != 0)
#define PyType_FastSubclass(t,f) PyType_HasFeature(t,f)
/*