diff options
Diffstat (limited to 'AppPkg/Applications/Python/Python-2.7.10/Lib/_weakrefset.py')
| -rw-r--r-- | AppPkg/Applications/Python/Python-2.7.10/Lib/_weakrefset.py | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/AppPkg/Applications/Python/Python-2.7.10/Lib/_weakrefset.py b/AppPkg/Applications/Python/Python-2.7.10/Lib/_weakrefset.py new file mode 100644 index 0000000000..9cd1857731 --- /dev/null +++ b/AppPkg/Applications/Python/Python-2.7.10/Lib/_weakrefset.py @@ -0,0 +1,204 @@ +# 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(object):
+ # 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(object):
+ 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:
+ # Caveat: the iterator will keep a strong reference to
+ # `item` until it is resumed or closed.
+ 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))
+
+ __hash__ = 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 __ne__(self, other):
+ opposite = self.__eq__(other)
+ if opposite is NotImplemented:
+ return NotImplemented
+ return not opposite
+
+ 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
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