https://github.com/python/cpython/commit/ffdf1c30ab6940a5efe6f33e61678021d9f... commit: ffdf1c30ab6940a5efe6f33e61678021d9fd14b6 branch: master author: Raymond Hettinger <rhettinger@users.noreply.github.com> committer: GitHub <noreply@github.com> date: 2019-01-31T15:03:38-08:00 summary: Consistently move the misses update to just before the user function call (GH-11715) files: M Lib/functools.py M Modules/_functoolsmodule.c diff --git a/Lib/functools.py b/Lib/functools.py index 6233c30c203e..fe47600caa1a 100644 --- a/Lib/functools.py +++ b/Lib/functools.py @@ -541,10 +541,10 @@ def _lru_cache_wrapper(user_function, maxsize, typed, _CacheInfo): if maxsize == 0: def wrapper(*args, **kwds): - # No caching -- just a statistics update after a successful call + # No caching -- just a statistics update nonlocal misses - result = user_function(*args, **kwds) misses += 1 + result = user_function(*args, **kwds) return result elif maxsize is None: @@ -557,9 +557,9 @@ def wrapper(*args, **kwds): if result is not sentinel: hits += 1 return result + misses += 1 result = user_function(*args, **kwds) cache[key] = result - misses += 1 return result else: diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c index 141210204ca5..d72aaff2b13c 100644 --- a/Modules/_functoolsmodule.c +++ b/Modules/_functoolsmodule.c @@ -796,10 +796,12 @@ lru_cache_make_key(PyObject *args, PyObject *kwds, int typed) static PyObject * uncached_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwds) { - PyObject *result = PyObject_Call(self->func, args, kwds); + PyObject *result; + + self->misses++; + result = PyObject_Call(self->func, args, kwds); if (!result) return NULL; - self->misses++; return result; } @@ -827,6 +829,7 @@ infinite_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwd Py_DECREF(key); return NULL; } + self->misses++; result = PyObject_Call(self->func, args, kwds); if (!result) { Py_DECREF(key); @@ -838,7 +841,6 @@ infinite_lru_cache_wrapper(lru_cache_object *self, PyObject *args, PyObject *kwd return NULL; } Py_DECREF(key); - self->misses++; return result; }