diff options
Diffstat (limited to 'Lib/functools.py')
| -rw-r--r-- | Lib/functools.py | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/Lib/functools.py b/Lib/functools.py index 9d8cea9..815386b 100644 --- a/Lib/functools.py +++ b/Lib/functools.py @@ -15,6 +15,10 @@ from _functools import partial, reduce from collections import OrderedDict, Counter from heapq import nsmallest from operator import itemgetter +try: + from _thread import allocate_lock as Lock +except: + from _dummy_thread import allocate_lock as Lock # update_wrapper() and wraps() are tools to help write # wrapper functions that can handle naive introspection @@ -115,37 +119,42 @@ def lfu_cache(maxsize=100): http://en.wikipedia.org/wiki/Cache_algorithms#Least-Frequently_Used """ - def decorating_function(user_function): + def decorating_function(user_function, tuple=tuple, sorted=sorted, len=len): cache = {} # mapping of args to results use_count = Counter() # times each key has been accessed kwd_mark = object() # separate positional and keyword args + lock = Lock() @wraps(user_function) def wrapper(*args, **kwds): key = args if kwds: key += (kwd_mark,) + tuple(sorted(kwds.items())) - use_count[key] += 1 # count a use of this key try: - result = cache[key] - wrapper.hits += 1 + with lock: + use_count[key] += 1 # count a use of this key + result = cache[key] + wrapper.hits += 1 except KeyError: result = user_function(*args, **kwds) - cache[key] = result - wrapper.misses += 1 - if len(cache) > maxsize: - # purge the 10% least frequently used entries - for key, _ in nsmallest(maxsize // 10, - use_count.items(), - key=itemgetter(1)): - del cache[key], use_count[key] + with lock: + use_count[key] += 1 # count a use of this key + cache[key] = result + wrapper.misses += 1 + if len(cache) > maxsize: + # purge the 10% least frequently used entries + for key, _ in nsmallest(maxsize // 10, + use_count.items(), + key=itemgetter(1)): + del cache[key], use_count[key] return result def clear(): """Clear the cache and cache statistics""" - cache.clear() - use_count.clear() - wrapper.hits = wrapper.misses = 0 + with lock: + cache.clear() + use_count.clear() + wrapper.hits = wrapper.misses = 0 wrapper.hits = wrapper.misses = 0 wrapper.clear = clear @@ -161,9 +170,10 @@ def lru_cache(maxsize=100): http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used """ - def decorating_function(user_function): + def decorating_function(user_function, tuple=tuple, sorted=sorted, len=len): cache = OrderedDict() # ordered least recent to most recent kwd_mark = object() # separate positional and keyword args + lock = Lock() @wraps(user_function) def wrapper(*args, **kwds): @@ -171,20 +181,25 @@ def lru_cache(maxsize=100): if kwds: key += (kwd_mark,) + tuple(sorted(kwds.items())) try: - result = cache.pop(key) - wrapper.hits += 1 + with lock: + result = cache[key] + del cache[key] + cache[key] = result # record recent use of this key + wrapper.hits += 1 except KeyError: result = user_function(*args, **kwds) - wrapper.misses += 1 - if len(cache) >= maxsize: - cache.popitem(0) # purge least recently used cache entry - cache[key] = result # record recent use of this key + with lock: + cache[key] = result # record recent use of this key + wrapper.misses += 1 + if len(cache) > maxsize: + cache.popitem(0) # purge least recently used cache entry return result def clear(): """Clear the cache and cache statistics""" - cache.clear() - wrapper.hits = wrapper.misses = 0 + with lock: + cache.clear() + wrapper.hits = wrapper.misses = 0 wrapper.hits = wrapper.misses = 0 wrapper.clear = clear |