Mercurial > repos > bcclaywell > argo_navis

comparison venv/lib/python2.7/_weakrefset.py @ 0:d67268158946 draft

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
planemo upload commit a3f181f5f126803c654b3a66dd4e83a48f7e203b
author bcclaywell
date Mon, 12 Oct 2015 17:43:33 -0400
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:d67268158946
1 # Access WeakSet through the weakref module.
2 # This code is separated-out because it is needed
3 # by abc.py to load everything else at startup.
4
5 from _weakref import ref
6
7 __all__ = ['WeakSet']
8
9
10 class _IterationGuard(object):
11 # This context manager registers itself in the current iterators of the
12 # weak container, such as to delay all removals until the context manager
13 # exits.
14 # This technique should be relatively thread-safe (since sets are).
15
16 def __init__(self, weakcontainer):
17 # Don't create cycles
18 self.weakcontainer = ref(weakcontainer)
19
20 def __enter__(self):
21 w = self.weakcontainer()
22 if w is not None:
23 w._iterating.add(self)
24 return self
25
26 def __exit__(self, e, t, b):
27 w = self.weakcontainer()
28 if w is not None:
29 s = w._iterating
30 s.remove(self)
31 if not s:
32 w._commit_removals()
33
34
35 class WeakSet(object):
36 def __init__(self, data=None):
37 self.data = set()
38 def _remove(item, selfref=ref(self)):
39 self = selfref()
40 if self is not None:
41 if self._iterating:
42 self._pending_removals.append(item)
43 else:
44 self.data.discard(item)
45 self._remove = _remove
46 # A list of keys to be removed
47 self._pending_removals = []
48 self._iterating = set()
49 if data is not None:
50 self.update(data)
51
52 def _commit_removals(self):
53 l = self._pending_removals
54 discard = self.data.discard
55 while l:
56 discard(l.pop())
57
58 def __iter__(self):
59 with _IterationGuard(self):
60 for itemref in self.data:
61 item = itemref()
62 if item is not None:
63 # Caveat: the iterator will keep a strong reference to
64 # `item` until it is resumed or closed.
65 yield item
66
67 def __len__(self):
68 return len(self.data) - len(self._pending_removals)
69
70 def __contains__(self, item):
71 try:
72 wr = ref(item)
73 except TypeError:
74 return False
75 return wr in self.data
76
77 def __reduce__(self):
78 return (self.__class__, (list(self),),
79 getattr(self, '__dict__', None))
80
81 __hash__ = None
82
83 def add(self, item):
84 if self._pending_removals:
85 self._commit_removals()
86 self.data.add(ref(item, self._remove))
87
88 def clear(self):
89 if self._pending_removals:
90 self._commit_removals()
91 self.data.clear()
92
93 def copy(self):
94 return self.__class__(self)
95
96 def pop(self):
97 if self._pending_removals:
98 self._commit_removals()
99 while True:
100 try:
101 itemref = self.data.pop()
102 except KeyError:
103 raise KeyError('pop from empty WeakSet')
104 item = itemref()
105 if item is not None:
106 return item
107
108 def remove(self, item):
109 if self._pending_removals:
110 self._commit_removals()
111 self.data.remove(ref(item))
112
113 def discard(self, item):
114 if self._pending_removals:
115 self._commit_removals()
116 self.data.discard(ref(item))
117
118 def update(self, other):
119 if self._pending_removals:
120 self._commit_removals()
121 for element in other:
122 self.add(element)
123
124 def __ior__(self, other):
125 self.update(other)
126 return self
127
128 def difference(self, other):
129 newset = self.copy()
130 newset.difference_update(other)
131 return newset
132 __sub__ = difference
133
134 def difference_update(self, other):
135 self.__isub__(other)
136 def __isub__(self, other):
137 if self._pending_removals:
138 self._commit_removals()
139 if self is other:
140 self.data.clear()
141 else:
142 self.data.difference_update(ref(item) for item in other)
143 return self
144
145 def intersection(self, other):
146 return self.__class__(item for item in other if item in self)
147 __and__ = intersection
148
149 def intersection_update(self, other):
150 self.__iand__(other)
151 def __iand__(self, other):
152 if self._pending_removals:
153 self._commit_removals()
154 self.data.intersection_update(ref(item) for item in other)
155 return self
156
157 def issubset(self, other):
158 return self.data.issubset(ref(item) for item in other)
159 __le__ = issubset
160
161 def __lt__(self, other):
162 return self.data < set(ref(item) for item in other)
163
164 def issuperset(self, other):
165 return self.data.issuperset(ref(item) for item in other)
166 __ge__ = issuperset
167
168 def __gt__(self, other):
169 return self.data > set(ref(item) for item in other)
170
171 def __eq__(self, other):
172 if not isinstance(other, self.__class__):
173 return NotImplemented
174 return self.data == set(ref(item) for item in other)
175
176 def __ne__(self, other):
177 opposite = self.__eq__(other)
178 if opposite is NotImplemented:
179 return NotImplemented
180 return not opposite
181
182 def symmetric_difference(self, other):
183 newset = self.copy()
184 newset.symmetric_difference_update(other)
185 return newset
186 __xor__ = symmetric_difference
187
188 def symmetric_difference_update(self, other):
189 self.__ixor__(other)
190 def __ixor__(self, other):
191 if self._pending_removals:
192 self._commit_removals()
193 if self is other:
194 self.data.clear()
195 else:
196 self.data.symmetric_difference_update(ref(item, self._remove) for item in other)
197 return self
198
199 def union(self, other):
200 return self.__class__(e for s in (self, other) for e in s)
201 __or__ = union
202
203 def isdisjoint(self, other):
204 return len(self.intersection(other)) == 0