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Commit Description:
Merge pull request #17 from nattee/master...
Commit Description:
Merge pull request #17 from nattee/master
upgrade to current working snapshot
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lib/assets/Lib/_weakrefset.py
| 194 lines
| 5.6 KiB
| text/x-python
| PythonLexer
|
| r584 | # Access WeakSet through the weakref module. | |||
| # This code is separated-out because it is needed | ||||
| # by abc.py to load everything else at startup. | ||||
| from _weakref import ref | ||||
| __all__ = ['WeakSet'] | ||||
| class _IterationGuard: | ||||
| # This context manager registers itself in the current iterators of the | ||||
| # weak container, such as to delay all removals until the context manager | ||||
| # exits. | ||||
| # This technique should be relatively thread-safe (since sets are). | ||||
| def __init__(self, weakcontainer): | ||||
| # Don't create cycles | ||||
| self.weakcontainer = ref(weakcontainer) | ||||
| def __enter__(self): | ||||
| w = self.weakcontainer() | ||||
| if w is not None: | ||||
| w._iterating.add(self) | ||||
| return self | ||||
| def __exit__(self, e, t, b): | ||||
| w = self.weakcontainer() | ||||
| if w is not None: | ||||
| s = w._iterating | ||||
| s.remove(self) | ||||
| if not s: | ||||
| w._commit_removals() | ||||
| class WeakSet: | ||||
| def __init__(self, data=None): | ||||
| self.data = set() | ||||
| def _remove(item, selfref=ref(self)): | ||||
| self = selfref() | ||||
| if self is not None: | ||||
| if self._iterating: | ||||
| self._pending_removals.append(item) | ||||
| else: | ||||
| self.data.discard(item) | ||||
| self._remove = _remove | ||||
| # A list of keys to be removed | ||||
| self._pending_removals = [] | ||||
| self._iterating = set() | ||||
| if data is not None: | ||||
| self.update(data) | ||||
| def _commit_removals(self): | ||||
| l = self._pending_removals | ||||
| discard = self.data.discard | ||||
| while l: | ||||
| discard(l.pop()) | ||||
| def __iter__(self): | ||||
| with _IterationGuard(self): | ||||
| for itemref in self.data: | ||||
| item = itemref() | ||||
| if item is not None: | ||||
| yield item | ||||
| def __len__(self): | ||||
| return len(self.data) - len(self._pending_removals) | ||||
| def __contains__(self, item): | ||||
| try: | ||||
| wr = ref(item) | ||||
| except TypeError: | ||||
| return False | ||||
| return wr in self.data | ||||
| def __reduce__(self): | ||||
| return (self.__class__, (list(self),), | ||||
| getattr(self, '__dict__', None)) | ||||
| def add(self, item): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| self.data.add(ref(item, self._remove)) | ||||
| def clear(self): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| self.data.clear() | ||||
| def copy(self): | ||||
| return self.__class__(self) | ||||
| def pop(self): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| while True: | ||||
| try: | ||||
| itemref = self.data.pop() | ||||
| except KeyError: | ||||
| raise KeyError('pop from empty WeakSet') | ||||
| item = itemref() | ||||
| if item is not None: | ||||
| return item | ||||
| def remove(self, item): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| self.data.remove(ref(item)) | ||||
| def discard(self, item): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| self.data.discard(ref(item)) | ||||
| def update(self, other): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| for element in other: | ||||
| self.add(element) | ||||
| def __ior__(self, other): | ||||
| self.update(other) | ||||
| return self | ||||
| def difference(self, other): | ||||
| newset = self.copy() | ||||
| newset.difference_update(other) | ||||
| return newset | ||||
| __sub__ = difference | ||||
| def difference_update(self, other): | ||||
| self.__isub__(other) | ||||
| def __isub__(self, other): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| if self is other: | ||||
| self.data.clear() | ||||
| else: | ||||
| self.data.difference_update(ref(item) for item in other) | ||||
| return self | ||||
| def intersection(self, other): | ||||
| return self.__class__(item for item in other if item in self) | ||||
| __and__ = intersection | ||||
| def intersection_update(self, other): | ||||
| self.__iand__(other) | ||||
| def __iand__(self, other): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| self.data.intersection_update(ref(item) for item in other) | ||||
| return self | ||||
| def issubset(self, other): | ||||
| return self.data.issubset(ref(item) for item in other) | ||||
| __le__ = issubset | ||||
| def __lt__(self, other): | ||||
| return self.data < set(ref(item) for item in other) | ||||
| def issuperset(self, other): | ||||
| return self.data.issuperset(ref(item) for item in other) | ||||
| __ge__ = issuperset | ||||
| def __gt__(self, other): | ||||
| return self.data > set(ref(item) for item in other) | ||||
| def __eq__(self, other): | ||||
| if not isinstance(other, self.__class__): | ||||
| return NotImplemented | ||||
| return self.data == set(ref(item) for item in other) | ||||
| def symmetric_difference(self, other): | ||||
| newset = self.copy() | ||||
| newset.symmetric_difference_update(other) | ||||
| return newset | ||||
| __xor__ = symmetric_difference | ||||
| def symmetric_difference_update(self, other): | ||||
| self.__ixor__(other) | ||||
| def __ixor__(self, other): | ||||
| if self._pending_removals: | ||||
| self._commit_removals() | ||||
| if self is other: | ||||
| self.data.clear() | ||||
| else: | ||||
| self.data.symmetric_difference_update(ref(item, self._remove) for item in other) | ||||
| return self | ||||
| def union(self, other): | ||||
| return self.__class__(e for s in (self, other) for e in s) | ||||
| __or__ = union | ||||
| def isdisjoint(self, other): | ||||
| return len(self.intersection(other)) == 0 | ||||