Fabio Erculiani
74 lines
1.7 KiB
Python
74 lines
1.7 KiB
Python
# -*- coding: utf-8 -*-
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"""
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@author: Fabio Erculiani <lxnay@sabayon.org>
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@contact: lxnay@sabayon.org
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@copyright: Fabio Erculiani
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@license: GPL-2
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I{EntropyRepository} caching interface.
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"""
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import weakref
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from entropy.core import Singleton
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class EntropyRepositoryCacher(Singleton):
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"""
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Tiny singleton-based helper class used by EntropyRepository in order
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to keep cached items in RAM.
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"""
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def init_singleton(self):
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self.__live_cache = {}
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def clear(self):
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"""
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Clear all the cached items
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"""
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self.__live_cache.clear()
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def clear_key(self, key):
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"""
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Clear just the cached item at key (hash table).
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"""
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try:
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del self.__live_cache[key]
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except KeyError:
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pass
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def keys(self):
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"""
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Return a list of available cache keys
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"""
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return list(self.__live_cache.keys())
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def discard(self, key):
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"""
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Discard all the cache items with hash table key starting with "key".
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"""
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for dkey in tuple(self.__live_cache.keys()):
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if dkey.startswith(key):
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try:
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self.__live_cache.pop(dkey)
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except KeyError:
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pass
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def get(self, key):
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"""
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Get the cached item, if exists.
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"""
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obj = self.__live_cache.get(key)
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if isinstance(obj, weakref.ref):
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return obj()
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return obj
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def set(self, key, value):
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"""
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Set item in cache.
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"""
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if isinstance(value, (set, frozenset)):
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self.__live_cache[key] = weakref.ref(value)
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else:
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self.__live_cache[key] = value
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