40 lines
1.1 KiB
Python
40 lines
1.1 KiB
Python
# vim:fileencoding=utf-8:noet
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from functools import wraps
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from powerline.lib.monotonic import monotonic
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def default_cache_key(**kwargs):
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return frozenset(kwargs.items())
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class memoize(object):
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'''Memoization decorator with timeout.'''
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def __init__(self, timeout, cache_key=default_cache_key, cache_reg_func=None):
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self.timeout = timeout
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self.cache_key = cache_key
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self.cache = {}
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self.cache_reg_func = cache_reg_func
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def __call__(self, func):
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@wraps(func)
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def decorated_function(**kwargs):
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if self.cache_reg_func:
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self.cache_reg_func(self.cache)
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self.cache_reg_func = None
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key = self.cache_key(**kwargs)
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try:
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cached = self.cache.get(key, None)
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except TypeError:
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return func(**kwargs)
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# Handle case when time() appears to be less then cached['time'] due
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# to clock updates. Not applicable for monotonic clock, but this
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# case is currently rare.
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if cached is None or not (cached['time'] < monotonic() < cached['time'] + self.timeout):
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cached = self.cache[key] = {
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'result': func(**kwargs),
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'time': monotonic(),
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}
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return cached['result']
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return decorated_function
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