141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake"""Weak reference support for Python. 241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred DrakeThis module is an implementation of PEP 205: 441deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 5ba08f072d29f2108503a97bf495315e072ae7787Alexandre Vassalottihttp://www.python.org/dev/peps/pep-0205/ 641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake""" 741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 8bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake# Naming convention: Variables named "wr" are weak reference objects; 9bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake# they are called this instead of "ref" to avoid name collisions with 10bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake# the module-global ref() function imported from _weakref. 11bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake 1241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drakeimport UserDict 1341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 1433ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchlingfrom _weakref import ( 1533ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling getweakrefcount, 1633ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling getweakrefs, 1733ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling ref, 1833ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling proxy, 1933ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling CallableProxyType, 2033ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling ProxyType, 2133ad28b68dd6caadc1e6cb8f917665d6270e7b25Andrew M. Kuchling ReferenceType) 2241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 23222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónssonfrom _weakrefset import WeakSet, _IterationGuard 24e6410c536c9dca5a3a7899888c071f41a1767291Michael Foord 25e029242d5cfb8a3879bdc7324db4449e6a8451cfFred Drakefrom exceptions import ReferenceError 26e029242d5cfb8a3879bdc7324db4449e6a8451cfFred Drake 27e029242d5cfb8a3879bdc7324db4449e6a8451cfFred Drake 2841deb1efc2f969b58e49af669cc20d15ccdb04c6Fred DrakeProxyTypes = (ProxyType, CallableProxyType) 2941deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 309a9d219f07656a9f1eb6f8beb2a9e2ee462b77f8Fred Drake__all__ = ["ref", "proxy", "getweakrefcount", "getweakrefs", 3188f801d40944960f5bc7e0b8631674371a100f90Brett Cannon "WeakKeyDictionary", "ReferenceError", "ReferenceType", "ProxyType", 32e6410c536c9dca5a3a7899888c071f41a1767291Michael Foord "CallableProxyType", "ProxyTypes", "WeakValueDictionary", 'WeakSet'] 3341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 34bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake 355e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwisclass WeakValueDictionary(UserDict.UserDict): 36bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake """Mapping class that references values weakly. 3741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 38bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake Entries in the dictionary will be discarded when no strong 39bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake reference to the value exists anymore 40bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake """ 4141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake # We inherit the constructor without worrying about the input 4241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake # dictionary; since it uses our .update() method, we get the right 439d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake # checks (if the other dictionary is a WeakValueDictionary, 449d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake # objects are unwrapped on the way out, and we always wrap on the 459d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake # way in). 4641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 47f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka def __init__(*args, **kw): 48f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka if not args: 49f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka raise TypeError("descriptor '__init__' of 'WeakValueDictionary' " 50f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka "object needs an argument") 51f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka self = args[0] 52f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka args = args[1:] 53f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka if len(args) > 1: 54f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka raise TypeError('expected at most 1 arguments, got %d' % len(args)) 550a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake def remove(wr, selfref=ref(self)): 560a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self = selfref() 570a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake if self is not None: 58222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._iterating: 59222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._pending_removals.append(wr.key) 60222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson else: 61222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson del self.data[wr.key] 620a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self._remove = remove 63222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # A list of keys to be removed 64222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._pending_removals = [] 65222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._iterating = set() 669166e1a24ac7b15776ffd38e436fa51a9b002674Georg Brandl UserDict.UserDict.__init__(self, *args, **kw) 670a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 68222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson def _commit_removals(self): 69222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson l = self._pending_removals 70222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson d = self.data 71222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # We shouldn't encounter any KeyError, because this method should 72222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # always be called *before* mutating the dict. 73222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson while l: 74222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson del d[l.pop()] 75222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson 7641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def __getitem__(self, key): 774fd06e0170aa75e4873b73f733bfd3f3de19d967Fred Drake o = self.data[key]() 7841deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is None: 7941deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake raise KeyError, key 8041deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake else: 8141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return o 8241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 83222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson def __delitem__(self, key): 84222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 85222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 86222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson del self.data[key] 87222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson 8861146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger def __contains__(self, key): 8961146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger try: 9061146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger o = self.data[key]() 9161146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger except KeyError: 9261146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger return False 9361146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger return o is not None 9461146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger 9561146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger def has_key(self, key): 9661146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger try: 9761146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger o = self.data[key]() 9861146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger except KeyError: 9961146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger return False 10061146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger return o is not None 10161146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger 10241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def __repr__(self): 1039d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake return "<WeakValueDictionary at %s>" % id(self) 10441deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 10541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def __setitem__(self, key, value): 106222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 107222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 1080a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self.data[key] = KeyedRef(value, self._remove, key) 10941deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 110222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson def clear(self): 111222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 112222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 113222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self.data.clear() 114222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson 11541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def copy(self): 1169d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake new = WeakValueDictionary() 117bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake for key, wr in self.data.items(): 118bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 11941deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is not None: 12041deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake new[key] = o 1219d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake return new 12241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 123775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou __copy__ = copy 124775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou 125775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou def __deepcopy__(self, memo): 126775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou from copy import deepcopy 127775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou new = self.__class__() 128775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou for key, wr in self.data.items(): 129775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou o = wr() 130775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou if o is not None: 131775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou new[deepcopy(key, memo)] = o 132775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou return new 133775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou 1341d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake def get(self, key, default=None): 13541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake try: 136bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake wr = self.data[key] 13741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake except KeyError: 13841deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return default 13941deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake else: 140bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 14141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is None: 14241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake # This should only happen 14341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return default 14441deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake else: 14541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return o 14641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 14741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def items(self): 148312a5dc539b583abcbbf006942a4ceead9b9172bFred Drake L = [] 149bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake for key, wr in self.data.items(): 150bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 15141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is not None: 152312a5dc539b583abcbbf006942a4ceead9b9172bFred Drake L.append((key, o)) 15341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return L 15441deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 155101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def iteritems(self): 156222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 157222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr in self.data.itervalues(): 158222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson value = wr() 159222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if value is not None: 160222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield wr.key, value 161101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 162101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def iterkeys(self): 163222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 164222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for k in self.data.iterkeys(): 165222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield k 16661146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger 167222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson __iter__ = iterkeys 168101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 169017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake def itervaluerefs(self): 170017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """Return an iterator that yields the weak references to the values. 171017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 172017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake The references are not guaranteed to be 'live' at the time 173017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake they are used, so the result of calling the references needs 174017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake to be checked before being used. This can be used to avoid 175017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake creating references that will cause the garbage collector to 176017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake keep the values around longer than needed. 177017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 178017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """ 179222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 180222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr in self.data.itervalues(): 181222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield wr 182017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 183101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def itervalues(self): 184222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 185222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr in self.data.itervalues(): 186222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson obj = wr() 187222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if obj is not None: 188222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield obj 189101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 19041deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def popitem(self): 191222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 192222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 19341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake while 1: 194bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake key, wr = self.data.popitem() 195bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 19641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is not None: 19741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return key, o 19841deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 1992c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger def pop(self, key, *args): 200222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 201222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 2022c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger try: 2032c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger o = self.data.pop(key)() 2042c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger except KeyError: 2052c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger if args: 2062c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger return args[0] 2072c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger raise 2082c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger if o is None: 2092c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger raise KeyError, key 2102c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger else: 2112c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger return o 2122c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger 21380ce6dd5642025f5cdf0ba5556f08df0803f5636Walter Dörwald def setdefault(self, key, default=None): 21441deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake try: 215bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake wr = self.data[key] 21641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake except KeyError: 217222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 218222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 2190a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self.data[key] = KeyedRef(default, self._remove, key) 22041deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return default 22141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake else: 222bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake return wr() 22341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 224f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka def update(*args, **kwargs): 225f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka if not args: 226f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka raise TypeError("descriptor 'update' of 'WeakValueDictionary' " 227f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka "object needs an argument") 228f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka self = args[0] 229f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka args = args[1:] 230f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka if len(args) > 1: 231f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka raise TypeError('expected at most 1 arguments, got %d' % len(args)) 232f522bbc9c27d5602b4d0a8287e6f383ba2399f51Serhiy Storchaka dict = args[0] if args else None 233222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._pending_removals: 234222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._commit_removals() 23541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake d = self.data 23631017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if dict is not None: 23731017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if not hasattr(dict, "items"): 23831017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger dict = type({})(dict) 23931017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger for key, o in dict.items(): 2400a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake d[key] = KeyedRef(o, self._remove, key) 24131017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if len(kwargs): 24231017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger self.update(kwargs) 24341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 244017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake def valuerefs(self): 245017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """Return a list of weak references to the values. 246017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 247017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake The references are not guaranteed to be 'live' at the time 248017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake they are used, so the result of calling the references needs 249017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake to be checked before being used. This can be used to avoid 250017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake creating references that will cause the garbage collector to 251017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake keep the values around longer than needed. 252017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 253017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """ 254017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake return self.data.values() 255017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 25641deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake def values(self): 25741deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake L = [] 258bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake for wr in self.data.values(): 259bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 26041deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake if o is not None: 26141deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake L.append(o) 26241deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake return L 26341deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 2640a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2650a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drakeclass KeyedRef(ref): 2660a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake """Specialized reference that includes a key corresponding to the value. 2670a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2680a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake This is used in the WeakValueDictionary to avoid having to create 2690a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake a function object for each key stored in the mapping. A shared 2700a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake callback object can use the 'key' attribute of a KeyedRef instead 2710a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake of getting a reference to the key from an enclosing scope. 2720a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2730a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake """ 2740a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2750a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake __slots__ = "key", 2760a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2770a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake def __new__(type, ob, callback, key): 2780a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self = ref.__new__(type, ob, callback) 2790a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake self.key = key 2800a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake return self 2810a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake 2820a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake def __init__(self, ob, callback, key): 2830a4dd390bf653128de8bc2e99da64967c8cdf86eFred Drake super(KeyedRef, self).__init__(ob, callback) 284746fe0fae5442403c64be34b87609601166e97c8Fred Drake 28541deb1efc2f969b58e49af669cc20d15ccdb04c6Fred Drake 2865e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwisclass WeakKeyDictionary(UserDict.UserDict): 287bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake """ Mapping class that references keys weakly. 288bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake 289bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake Entries in the dictionary will be discarded when there is no 290bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake longer a strong reference to the key. This can be used to 291bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake associate additional data with an object owned by other parts of 292bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake an application without adding attributes to those objects. This 293bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake can be especially useful with objects that override attribute 294bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake accesses. 295bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake """ 2965e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 2975e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def __init__(self, dict=None): 2985e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis self.data = {} 299746fe0fae5442403c64be34b87609601166e97c8Fred Drake def remove(k, selfref=ref(self)): 300746fe0fae5442403c64be34b87609601166e97c8Fred Drake self = selfref() 301746fe0fae5442403c64be34b87609601166e97c8Fred Drake if self is not None: 302222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if self._iterating: 303222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._pending_removals.append(k) 304222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson else: 305222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson del self.data[k] 3065e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis self._remove = remove 307222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # A list of dead weakrefs (keys to be removed) 308222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._pending_removals = [] 309222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self._iterating = set() 310222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if dict is not None: 311222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson self.update(dict) 312222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson 313222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson def _commit_removals(self): 314222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # NOTE: We don't need to call this method before mutating the dict, 315222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # because a dead weakref never compares equal to a live weakref, 316222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # even if they happened to refer to equal objects. 317222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson # However, it means keys may already have been removed. 318222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson l = self._pending_removals 319222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson d = self.data 320222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson while l: 321222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson try: 322222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson del d[l.pop()] 323222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson except KeyError: 324222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson pass 3255e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 326b663a2ccbdd9bbd9a13f0cea743af709c53ec0c1Fred Drake def __delitem__(self, key): 327886128f4f8b30b7e3623418eab063a3a8dd3495cTim Peters del self.data[ref(key)] 328b663a2ccbdd9bbd9a13f0cea743af709c53ec0c1Fred Drake 3295e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def __getitem__(self, key): 3305e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return self.data[ref(key)] 3315e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 3325e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def __repr__(self): 3335e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return "<WeakKeyDictionary at %s>" % id(self) 3345e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 3355e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def __setitem__(self, key, value): 3365e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis self.data[ref(key, self._remove)] = value 3375e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 3385e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def copy(self): 3395e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis new = WeakKeyDictionary() 3405e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis for key, value in self.data.items(): 3415e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis o = key() 3425e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis if o is not None: 3435e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis new[o] = value 3449d2c85dec7262475b83d45fdb53651c9c069e1cbFred Drake return new 3455e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 346775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou __copy__ = copy 347775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou 348775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou def __deepcopy__(self, memo): 349775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou from copy import deepcopy 350775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou new = self.__class__() 351775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou for key, value in self.data.items(): 352775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou o = key() 353775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou if o is not None: 354775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou new[o] = deepcopy(value, memo) 355775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou return new 356775fd66d7bd74cdedef536ff4f8c134ba718678fAntoine Pitrou 3571d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake def get(self, key, default=None): 3585e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return self.data.get(ref(key),default) 3595e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 3601d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake def has_key(self, key): 3613bae7ddf8e63889b185235f85a6695bc05d59059Fred Drake try: 3623bae7ddf8e63889b185235f85a6695bc05d59059Fred Drake wr = ref(key) 3633bae7ddf8e63889b185235f85a6695bc05d59059Fred Drake except TypeError: 3643bae7ddf8e63889b185235f85a6695bc05d59059Fred Drake return 0 36554f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger return wr in self.data 3661d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake 36754f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger def __contains__(self, key): 36854f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger try: 36954f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger wr = ref(key) 37054f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger except TypeError: 37154f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger return 0 37254f0222547b1e92cd018ef132307a6f793dc9505Raymond Hettinger return wr in self.data 373c411dbaeee29dba87d5432a92fe76ea65d8e25f0Tim Peters 3745e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def items(self): 3755e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis L = [] 3765e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis for key, value in self.data.items(): 3775e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis o = key() 3785e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis if o is not None: 3795e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis L.append((o, value)) 3805e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return L 3815e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 382101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def iteritems(self): 383222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 384222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr, value in self.data.iteritems(): 385222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson key = wr() 386222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if key is not None: 387222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield key, value 388101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 389017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake def iterkeyrefs(self): 390017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """Return an iterator that yields the weak references to the keys. 391017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 392017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake The references are not guaranteed to be 'live' at the time 393017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake they are used, so the result of calling the references needs 394017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake to be checked before being used. This can be used to avoid 395017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake creating references that will cause the garbage collector to 396017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake keep the keys around longer than needed. 397017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 398017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """ 399222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 400222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr in self.data.iterkeys(): 401222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield wr 402017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 403101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def iterkeys(self): 404222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 405222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for wr in self.data.iterkeys(): 406222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson obj = wr() 407222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson if obj is not None: 408222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield obj 40961146790992e0a00b76a6bf6ecc9e53289a1ecd7Raymond Hettinger 410222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson __iter__ = iterkeys 411101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 412101209d44ce063cd04fd6793d94991f8e6688428Fred Drake def itervalues(self): 413222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson with _IterationGuard(self): 414222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson for value in self.data.itervalues(): 415222b284911d1d4057f2034c41aa810693fc64f02Kristján Valur Jónsson yield value 416101209d44ce063cd04fd6793d94991f8e6688428Fred Drake 417017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake def keyrefs(self): 418017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """Return a list of weak references to the keys. 419017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 420017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake The references are not guaranteed to be 'live' at the time 421017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake they are used, so the result of calling the references needs 422017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake to be checked before being used. This can be used to avoid 423017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake creating references that will cause the garbage collector to 424017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake keep the keys around longer than needed. 425017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 426017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake """ 427017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake return self.data.keys() 428017e68c413be6262eb1e71b0f0c5676d6db33a43Fred Drake 4291d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake def keys(self): 4301d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake L = [] 431bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake for wr in self.data.keys(): 432bd7f818c508248e12f88e51198cb5e9b861dacbfFred Drake o = wr() 4331d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake if o is not None: 4341d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake L.append(o) 4351d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake return L 4361d9e4b7de3d15007d5b9e7ac4b38f5e158d3c840Fred Drake 4375e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis def popitem(self): 4385e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis while 1: 4395e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis key, value = self.data.popitem() 4405e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis o = key() 4415e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis if o is not None: 4425e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return o, value 4435e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 4442c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger def pop(self, key, *args): 4452c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger return self.data.pop(ref(key), *args) 4462c2d322884ee72077a256ec3cd0aa9ce3580eedcRaymond Hettinger 44780ce6dd5642025f5cdf0ba5556f08df0803f5636Walter Dörwald def setdefault(self, key, default=None): 4485e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis return self.data.setdefault(ref(key, self._remove),default) 4495e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis 45031017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger def update(self, dict=None, **kwargs): 4515e1633365d8a48e96dd4f42c4e7c8729bc62c26dMartin v. Löwis d = self.data 45231017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if dict is not None: 45331017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if not hasattr(dict, "items"): 45431017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger dict = type({})(dict) 45531017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger for key, value in dict.items(): 45631017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger d[ref(key, self._remove)] = value 45731017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger if len(kwargs): 45831017aed36a5c5b0e4b16ca58bea09c9ce360134Raymond Hettinger self.update(kwargs) 459