From 1ff50df8bc4048f72bc770372968da2f262cb58e Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Fri, 30 Mar 2012 13:15:48 -0700 Subject: [PATCH] Minor cleanup: add whitespace, add comments, bring function attribute updates together. --- Lib/functools.py | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/Lib/functools.py b/Lib/functools.py index 331da3c0c31..299e9d8bf19 100644 --- a/Lib/functools.py +++ b/Lib/functools.py @@ -161,6 +161,7 @@ def lru_cache(maxsize=100, typed=False): See: http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used """ + # Users should only access the lru_cache through its public API: # cache_info, cache_clear, and f.__wrapped__ # The internals of the lru_cache are encapsulated for thread safety and @@ -192,7 +193,6 @@ def lru_cache(maxsize=100, typed=False): if maxsize == 0: - @wraps(user_function) def wrapper(*args, **kwds): # no caching, just do a statistics update after a successful call nonlocal misses @@ -202,7 +202,6 @@ def lru_cache(maxsize=100, typed=False): elif maxsize is None: - @wraps(user_function) def wrapper(*args, **kwds): # simple caching without ordering or size limit nonlocal hits, misses @@ -218,7 +217,6 @@ def lru_cache(maxsize=100, typed=False): else: - @wraps(user_function) def wrapper(*args, **kwds): # size limited caching that tracks accesses by recency nonlocal hits, misses @@ -238,11 +236,12 @@ def lru_cache(maxsize=100, typed=False): return result result = user_function(*args, **kwds) with lock: + # put result in a new link at the front of the list last = root[PREV] link = [last, root, key, result] cache[key] = last[NEXT] = root[PREV] = link if _len(cache) > maxsize: - # purge least recently used cache entry + # purge the least recently used cache entry old_prev, old_next, old_key, old_result = root[NEXT] root[NEXT] = old_next old_next[PREV] = root @@ -265,6 +264,6 @@ def lru_cache(maxsize=100, typed=False): wrapper.cache_info = cache_info wrapper.cache_clear = cache_clear - return wrapper + return update_wrapper(wrapper, user_function) return decorating_function