U ku f @sdZddlmZddlmZddlmZmZmZddl Z ddl m Z er\ddl m Z mZmZedZde je jfd d d d d ddZdS)z2 Helpers related to (dynamic) resource retrieval. ) annotations lru_cache) TYPE_CHECKINGCallableTypeVarN)Resource)URIDRetrieve_Tz+Callable[[Retrieve[D]], Retrieve[D]] | NonezCallable[[_T], D]zCallable[[D], Resource[D]]z,Callable[[Callable[[URI], _T]], Retrieve[D]])cacheloads from_contentsreturncs,dkrtddddfdd }|S)aG Create a retriever which caches its return values from a simpler callable. Takes a function which returns things like serialized JSON (strings) and returns something suitable for passing to `Registry` as a retrieve function. This decorator both reduces a small bit of boilerplate for a common case (deserializing JSON from strings and creating `Resource` objects from the result) as well as makes the probable need for caching a bit easier. Retrievers which otherwise do expensive operations (like hitting the network) might otherwise be called repeatedly. Examples -------- .. testcode:: from referencing import Registry from referencing.typing import URI import referencing.retrieval @referencing.retrieval.to_cached_resource() def retrieve(uri: URI): print(f"Retrieved {uri}") # Normally, go get some expensive JSON from the network, a file ... return ''' { "$schema": "https://json-schema.org/draft/2020-12/schema", "foo": "bar" } ''' one = Registry(retrieve=retrieve).get_or_retrieve("urn:example:foo") print(one.value.contents["foo"]) # Retrieving the same URI again reuses the same value (and thus doesn't # print another retrieval message here) two = Registry(retrieve=retrieve).get_or_retrieve("urn:example:foo") print(two.value.contents["foo"]) .. testoutput:: Retrieved urn:example:foo bar bar N)maxsizezCallable[[URI], _T]retrievecsddfdd }|S)Nr )urics|}|}|S)N)rresponsecontents)rrrr9/tmp/pip-unpacked-wheel-g5oy8ly_/referencing/retrieval.pycached_retrieveOsz>to_cached_resource..decorator..cached_retriever)rrr rrrr decoratorNsz%to_cached_resource..decoratorr)r rrrrrrto_cached_resources7  r)__doc__ __future__r functoolsrtypingrrrjsonZ referencingrZreferencing.typingr r r r rrrrrrrs