"""Module that defines all needed classes and functions for caching facility."""
from functools import lru_cache, wraps
from datetime import datetime, timedelta
# found on https://bit.ly/39vlEXs
# thanks https://realpython.com/team/svaldarrama/ for your awsome article about caching in python
# has been adapted by us to meet our requirements
[docs]def timed_lru_cache(lifetime: int = 3600, maxsize: int = 128):
"""Provide cache with a given lifetime.
This function has to be used as decorator.
Each time the the cache will be accessed the decorator checks current date is past experation date.
If so, the cache will cleared and the new expiration data will be recomputed. If not the cache entry
will be delivered.
:param lifetime: The lifetime of cache in seconds, defaults to 3600
:type lifetime: int, optional
:param maxsize: The maximum number of cache items, defaults to 128
:type maxsize: int, optional
"""
def wrapper_cache(func):
func = lru_cache(maxsize=maxsize)(func)
func.lifetime = timedelta(seconds=lifetime)
func.expiration = datetime.utcnow() + func.lifetime
@wraps(func)
def wrapped_func(*args, **kwargs):
if datetime.utcnow() >= func.expiration:
func.cache_clear()
func.expiration = datetime.utcnow() + func.lifetime
return func(*args, **kwargs)
return wrapped_func
return wrapper_cache