Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/cachetools/keys.py: 42%

1"""Key functions for memoizing decorators.""" 

2 

3__all__ = ("hashkey", "methodkey", "typedkey") 

4 

5 

6class _HashedTuple(tuple): 

7 """A tuple that ensures that hash() will be called no more than once 

8 per element, since cache decorators will hash the key multiple 

9 times on a cache miss. See also _HashedSeq in the standard 

10 library functools implementation. 

11 

12 """ 

13 

14 __hashvalue = None 

15 

16 def __hash__(self, hash=tuple.__hash__): 

17 hashvalue = self.__hashvalue 

18 if hashvalue is None: 

19 self.__hashvalue = hashvalue = hash(self) 

20 return hashvalue 

21 

22 def __add__(self, other, add=tuple.__add__): 

23 return _HashedTuple(add(self, other)) 

24 

25 def __radd__(self, other, add=tuple.__add__): 

26 return _HashedTuple(add(other, self)) 

27 

28 def __getstate__(self): 

29 return {} 

30 

31 

32# used for separating keyword arguments; we do not use an object 

33# instance here so identity is preserved when pickling/unpickling 

34_kwmark = (_HashedTuple,) 

35 

36 

37def hashkey(*args, **kwargs): 

38 """Return a cache key for the specified hashable arguments.""" 

39 

40 if kwargs: 

41 return _HashedTuple(args + sum(sorted(kwargs.items()), _kwmark)) 

42 else: 

43 return _HashedTuple(args) 

44 

45 

46def methodkey(self, *args, **kwargs): 

47 """Return a cache key for use with cached methods.""" 

48 return hashkey(*args, **kwargs) 

49 

50 

51def typedkey(*args, **kwargs): 

52 """Return a typed cache key for the specified hashable arguments.""" 

53 

54 key = hashkey(*args, **kwargs) 

55 key += tuple(type(v) for v in args) 

56 key += tuple(type(v) for _, v in sorted(kwargs.items())) 

57 return key