Viewing file:  scoped_cache.py (1.34 KB) -rw-r--r--
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"""
This is a simple wrapper around lru_cache which allows
us to enable caching only within some scope defined by contextmanager
It makes it easier to cache some functions e.g. only inside wpos-user get
scope and still be able to get fresh data in wpos-user enable
where cached commands might return different results because of outside
"""
from contextlib import contextmanager
from functools import lru_cache
_CACHED_FUNCTIONS = {}
CACHING_ENABLED = False
@contextmanager
def enable_caching():
"""
This context manager sets global marker
which enables caching
"""
global CACHING_ENABLED
if CACHING_ENABLED:
raise RuntimeError('nested scopes are not supported')
try:
CACHING_ENABLED = True
yield
finally:
_clear_cache()
CACHING_ENABLED = False
def _clear_cache():
"""
Clear cache of all registered functions
"""
for func in _CACHED_FUNCTIONS.values():
func.cache_clear()
def cached_in_scope(func):
"""
Primary code which decides should we return cached
result or fresh
"""
def _wrapper(*args, **kwargs):
if CACHING_ENABLED:
return _CACHED_FUNCTIONS[func.__name__](*args, **kwargs)
return func(*args, **kwargs)
cached_func = lru_cache()(func)
_CACHED_FUNCTIONS[func.__name__] = cached_func
return _wrapper
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