#8314 @memoize on methods should still allow garbage collection
Our @memoize works pretty similarly to @lru_cache and doesn't do what you might expect on a method (as opposed to a simple function). It creates a global class-level cache with self as one of the args and thus the self object is referenced forever and cannot be garbage collected. https://bugs.python.org/issue19859 describes the situation
db/8314 (branched off of [#8311] since it adds a requirement)
I looked into many off-the-shelf existing libraries but none worked:
@methodtools.lru_cache()is supposed to be exactly for this case of a method, but in my testing holds global cache still. Also has 3 more dependencies it pulls in.@cachedtools.cached(cache={})holds global cache@cachedtools.cached(cache=WeakValueDictionary())errors@cachedtools.cachedmethod(lambda self: self.cache, key=partial(hashkey, 'our_method_name'))requires a self.cache (or creating one on the fly) and knowing the method name to make a properly scoped key@pylru.lrudecorator()requires size param, holds global cache@ring.lru()ran into UnicodeEncodeError@memoized_methodfrom https://stackoverflow.com/a/33672499/ gets interference with Ming since it rewrites the attrDrop-ins for py3
functools.lru_cache(which wouldn't work either):@cachedtools.lru_cache()errors@repoze.lru.lru_cache()requires size param, holds global cache@functools32.lru_cache()holds global cache@backports.functools_lru_cacheholds global cacheRelated
Tickets:
#8311