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Diffstat (limited to '')
-rw-r--r-- | src/pybind/mgr/dashboard/plugins/lru_cache.py | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/src/pybind/mgr/dashboard/plugins/lru_cache.py b/src/pybind/mgr/dashboard/plugins/lru_cache.py new file mode 100644 index 000000000..4d8fc27b3 --- /dev/null +++ b/src/pybind/mgr/dashboard/plugins/lru_cache.py @@ -0,0 +1,43 @@ +# -*- coding: utf-8 -*- +""" +This is a minimal implementation of lru_cache function. + +Based on Python 3 functools and backports.functools_lru_cache. +""" + +from collections import OrderedDict +from functools import wraps +from threading import RLock + + +def lru_cache(maxsize=128, typed=False): + if typed is not False: + raise NotImplementedError("typed caching not supported") + + def decorating_function(function): + cache = OrderedDict() + stats = [0, 0] + rlock = RLock() + setattr(function, 'cache_info', lambda: + "hits={}, misses={}, maxsize={}, currsize={}".format( + stats[0], stats[1], maxsize, len(cache))) + + @wraps(function) + def wrapper(*args, **kwargs): + key = args + tuple(kwargs.items()) + with rlock: + if key in cache: + ret = cache[key] + del cache[key] + cache[key] = ret + stats[0] += 1 + else: + ret = function(*args, **kwargs) + if len(cache) == maxsize: + cache.popitem(last=False) + cache[key] = ret + stats[1] += 1 + return ret + + return wrapper + return decorating_function |