[Python-checkins] cpython (3.3): Issue #18594: Fix the fallback path in collections.Counter().
raymond.hettinger
python-checkins at python.org
Wed Oct 2 06:38:49 CEST 2013
http://hg.python.org/cpython/rev/1ee6f8a96fb9
changeset: 85916:1ee6f8a96fb9
branch: 3.3
parent: 85911:423736775f6b
user: Raymond Hettinger <python at rcn.com>
date: Tue Oct 01 21:36:09 2013 -0700
summary:
Issue #18594: Fix the fallback path in collections.Counter().
files:
Misc/NEWS | 3 +-
Modules/_collectionsmodule.c | 41 +++++++++++++----------
2 files changed, 25 insertions(+), 19 deletions(-)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -79,7 +79,8 @@
when necessary. Patch by Oscar Benjamin.
- Issue #18594: The fast path for collections.Counter() was never taken
- due to an over-restrictive type check.
+ due to an over-restrictive type check. And the fallback path did
+ not implement the same algorithm as the pure python code.
- Properly initialize all fields of a SSL object after allocation.
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -1694,7 +1694,9 @@
PyObject *it, *iterable, *mapping, *oldval;
PyObject *newval = NULL;
PyObject *key = NULL;
+ PyObject *zero = NULL;
PyObject *one = NULL;
+ PyObject *mapping_get = NULL;
PyObject *mapping_getitem;
PyObject *mapping_setitem;
PyObject *dict_getitem;
@@ -1708,10 +1710,8 @@
return NULL;
one = PyLong_FromLong(1);
- if (one == NULL) {
- Py_DECREF(it);
- return NULL;
- }
+ if (one == NULL)
+ goto done;
mapping_getitem = _PyType_LookupId(Py_TYPE(mapping), &PyId___getitem__);
dict_getitem = _PyType_LookupId(&PyDict_Type, &PyId___getitem__);
@@ -1741,23 +1741,25 @@
Py_DECREF(key);
}
} else {
+ mapping_get = PyObject_GetAttrString(mapping, "get");
+ if (mapping_get == NULL)
+ goto done;
+
+ zero = PyLong_FromLong(0);
+ if (zero == NULL)
+ goto done;
+
while (1) {
key = PyIter_Next(it);
if (key == NULL)
break;
- oldval = PyObject_GetItem(mapping, key);
- if (oldval == NULL) {
- if (!PyErr_Occurred() || !PyErr_ExceptionMatches(PyExc_KeyError))
- break;
- PyErr_Clear();
- Py_INCREF(one);
- newval = one;
- } else {
- newval = PyNumber_Add(oldval, one);
- Py_DECREF(oldval);
- if (newval == NULL)
- break;
- }
+ oldval = PyObject_CallFunctionObjArgs(mapping_get, key, zero, NULL);
+ if (oldval == NULL)
+ break;
+ newval = PyNumber_Add(oldval, one);
+ Py_DECREF(oldval);
+ if (newval == NULL)
+ break;
if (PyObject_SetItem(mapping, key, newval) == -1)
break;
Py_CLEAR(newval);
@@ -1765,10 +1767,13 @@
}
}
+done:
Py_DECREF(it);
Py_XDECREF(key);
Py_XDECREF(newval);
- Py_DECREF(one);
+ Py_XDECREF(mapping_get);
+ Py_XDECREF(zero);
+ Py_XDECREF(one);
if (PyErr_Occurred())
return NULL;
Py_RETURN_NONE;
--
Repository URL: http://hg.python.org/cpython
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