Cache

class surfalize.cache.CachedInstance

Bases: object

Mixin class that provides the basic facilities necessary for the cache decorator as well as a method to clear the cache.

Methods

clear_cache()	Clears the cache for the entire instance.
create_cache_entry(method, entry, args, kwargs)	Manually creates a cache entry for the specified method.

clear_cache()

Clears the cache for the entire instance.

Returns:

None

create_cache_entry(method, entry, args, kwargs)

Manually creates a cache entry for the specified method.

Parameters:

methodfunction pointer

method to cache.

entryany

return value that will be cached

args

arguments to the method call for which to create the cache entry

kwargs

keyword arguments to the method call for which to create the cache entry

Returns:

None

surfalize.cache.cache(method)

Decorator that enables caching on class instance without creating memory leaks. This is accomplished by relying on a cache inside the instance. Classes that want to use this decorator must implement a dictionary called ‘_method_cache’ or inherit from CachedInstance. This approach is necessary because functools.lru_cache keeps references to the class instance that prevent it from being garbage collected indefinitely, thus leaking a substantial amount of memory. See https://bugs.python.org/issue19859 for more details.

This implementation will not work on methods with unhashable arguments.

Parameters:

methodmethod

method to be decorated.

Returns:

wrapped_method