Issue #18594: Fix the fast path for collections.Counter().

The path wasn't being taken due to an over-restrictive type check.
This commit is contained in:
Raymond Hettinger 2013-10-01 00:55:43 -07:00
parent 21b2933456
commit 2ff2190b62
4 changed files with 20 additions and 5 deletions

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@ -482,6 +482,7 @@ PyAPI_FUNC(PyObject *) PyType_GenericNew(PyTypeObject *,
PyObject *, PyObject *); PyObject *, PyObject *);
#ifndef Py_LIMITED_API #ifndef Py_LIMITED_API
PyAPI_FUNC(PyObject *) _PyType_Lookup(PyTypeObject *, PyObject *); PyAPI_FUNC(PyObject *) _PyType_Lookup(PyTypeObject *, PyObject *);
PyAPI_FUNC(PyObject *) _PyType_LookupId(PyTypeObject *, _Py_Identifier *);
PyAPI_FUNC(PyObject *) _PyObject_LookupSpecial(PyObject *, _Py_Identifier *); PyAPI_FUNC(PyObject *) _PyObject_LookupSpecial(PyObject *, _Py_Identifier *);
PyAPI_FUNC(PyTypeObject *) _PyType_CalculateMetaclass(PyTypeObject *, PyObject *); PyAPI_FUNC(PyTypeObject *) _PyType_CalculateMetaclass(PyTypeObject *, PyObject *);
#endif #endif

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@ -74,6 +74,9 @@ Library
- Issue #12641: Avoid passing "-mno-cygwin" to the mingw32 compiler, except - Issue #12641: Avoid passing "-mno-cygwin" to the mingw32 compiler, except
when necessary. Patch by Oscar Benjamin. when necessary. Patch by Oscar Benjamin.
- Issue #18594: The fast path for collections.Counter() was never taken
due to an over-restrictive type check.
- Properly initialize all fields of a SSL object after allocation. - Properly initialize all fields of a SSL object after allocation.
- Issue #4366: Fix building extensions on all platforms when --enable-shared - Issue #4366: Fix building extensions on all platforms when --enable-shared

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@ -1689,10 +1689,16 @@ Count elements in the iterable, updating the mappping");
static PyObject * static PyObject *
_count_elements(PyObject *self, PyObject *args) _count_elements(PyObject *self, PyObject *args)
{ {
_Py_IDENTIFIER(__getitem__);
_Py_IDENTIFIER(__setitem__);
PyObject *it, *iterable, *mapping, *oldval; PyObject *it, *iterable, *mapping, *oldval;
PyObject *newval = NULL; PyObject *newval = NULL;
PyObject *key = NULL; PyObject *key = NULL;
PyObject *one = NULL; PyObject *one = NULL;
PyObject *mapping_getitem;
PyObject *mapping_setitem;
PyObject *dict_getitem;
PyObject *dict_setitem;
if (!PyArg_UnpackTuple(args, "_count_elements", 2, 2, &mapping, &iterable)) if (!PyArg_UnpackTuple(args, "_count_elements", 2, 2, &mapping, &iterable))
return NULL; return NULL;
@ -1707,7 +1713,15 @@ _count_elements(PyObject *self, PyObject *args)
return NULL; return NULL;
} }
if (PyDict_CheckExact(mapping)) { mapping_getitem = _PyType_LookupId(Py_TYPE(mapping), &PyId___getitem__);
dict_getitem = _PyType_LookupId(&PyDict_Type, &PyId___getitem__);
mapping_setitem = _PyType_LookupId(Py_TYPE(mapping), &PyId___setitem__);
dict_setitem = _PyType_LookupId(&PyDict_Type, &PyId___setitem__);
if (mapping_getitem != NULL &&
mapping_getitem == dict_getitem &&
mapping_setitem != NULL &&
mapping_setitem == dict_setitem) {
while (1) { while (1) {
key = PyIter_Next(it); key = PyIter_Next(it);
if (key == NULL) if (key == NULL)

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@ -49,9 +49,6 @@ _Py_IDENTIFIER(__module__);
_Py_IDENTIFIER(__name__); _Py_IDENTIFIER(__name__);
_Py_IDENTIFIER(__new__); _Py_IDENTIFIER(__new__);
static PyObject *
_PyType_LookupId(PyTypeObject *type, struct _Py_Identifier *name);
static PyObject * static PyObject *
slot_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds); slot_tp_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
@ -2589,7 +2586,7 @@ _PyType_Lookup(PyTypeObject *type, PyObject *name)
return res; return res;
} }
static PyObject * PyObject *
_PyType_LookupId(PyTypeObject *type, struct _Py_Identifier *name) _PyType_LookupId(PyTypeObject *type, struct _Py_Identifier *name)
{ {
PyObject *oname; PyObject *oname;