| | """Key functions for memoizing decorators.""" |
| |
|
| | __all__ = ("hashkey", "methodkey", "typedkey", "typedmethodkey") |
| |
|
| |
|
| | class _HashedTuple(tuple): |
| | """A tuple that ensures that hash() will be called no more than once |
| | per element, since cache decorators will hash the key multiple |
| | times on a cache miss. See also _HashedSeq in the standard |
| | library functools implementation. |
| | |
| | """ |
| |
|
| | __hashvalue = None |
| |
|
| | def __hash__(self, hash=tuple.__hash__): |
| | hashvalue = self.__hashvalue |
| | if hashvalue is None: |
| | self.__hashvalue = hashvalue = hash(self) |
| | return hashvalue |
| |
|
| | def __add__(self, other, add=tuple.__add__): |
| | return _HashedTuple(add(self, other)) |
| |
|
| | def __radd__(self, other, add=tuple.__add__): |
| | return _HashedTuple(add(other, self)) |
| |
|
| | def __getstate__(self): |
| | return {} |
| |
|
| |
|
| | |
| | |
| | _kwmark = (_HashedTuple,) |
| |
|
| |
|
| | def hashkey(*args, **kwargs): |
| | """Return a cache key for the specified hashable arguments.""" |
| |
|
| | if kwargs: |
| | return _HashedTuple(args + sum(sorted(kwargs.items()), _kwmark)) |
| | else: |
| | return _HashedTuple(args) |
| |
|
| |
|
| | def methodkey(self, *args, **kwargs): |
| | """Return a cache key for use with cached methods.""" |
| | return hashkey(*args, **kwargs) |
| |
|
| |
|
| | def typedkey(*args, **kwargs): |
| | """Return a typed cache key for the specified hashable arguments.""" |
| |
|
| | key = hashkey(*args, **kwargs) |
| | key += tuple(type(v) for v in args) |
| | key += tuple(type(v) for _, v in sorted(kwargs.items())) |
| | return key |
| |
|
| |
|
| | def typedmethodkey(self, *args, **kwargs): |
| | """Return a typed cache key for use with cached methods.""" |
| | return typedkey(*args, **kwargs) |
| |
|