http://docs.python.org/faq/programming.html#how-do-i-get-a-list-of-all-instances-of-a-given-class
6b2e6521a33d693200360d70d2a03e48eceb4dfe On Wed, Mar 13, 2013 at 01:29:19PM +0900, YAMAMOTO Takashi wrote: > will be used by management code > > Signed-off-by: YAMAMOTO Takashi <yamam...@valinux.co.jp> > --- > ryu/instance_registry.py | 94 > ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 94 insertions(+) > create mode 100644 ryu/instance_registry.py > > diff --git a/ryu/instance_registry.py b/ryu/instance_registry.py > new file mode 100644 > index 0000000..a98bc75 > --- /dev/null > +++ b/ryu/instance_registry.py > @@ -0,0 +1,94 @@ > +# Copyright (C) 2013 Nippon Telegraph and Telephone Corporation. > +# Copyright (C) 2013 YAMAMOTO Takashi <yamamoto at valinux co jp> > +# > +# Licensed under the Apache License, Version 2.0 (the "License"); > +# you may not use this file except in compliance with the License. > +# You may obtain a copy of the License at > +# > +# http://www.apache.org/licenses/LICENSE-2.0 > +# > +# Unless required by applicable law or agreed to in writing, software > +# distributed under the License is distributed on an "AS IS" BASIS, > +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or > +# implied. > +# See the License for the specific language governing permissions and > +# limitations under the License. > + > +import weakref > + > + > +class InstanceRegistry(type): > + def __new__(cls, name, bases, dict): > + def unregister(self): > + for i, r in enumerate(self._instances): > + v = r() > + if v is None or v is self: > + self._instances.pop(i) > + if v is self: > + break > + dict['_instances'] = [] WeakValueDictionary can be used. something like w_v_d[id(self)] = self. WeakSet is more suitable, but it's not available in python 2.6 unfortunately. > + dict['instance_registry_unregister'] = unregister > + return type.__new__(cls, name, bases, dict) > + > + def __call__(self, *args): > + i = type.__call__(self, *args) > + self._instances.append(weakref.ref(i)) > + return i > + > + def __iter__(self): > + class Iter(object): > + def __init__(self, iter): > + self.iter = iter > + > + def __iter__(self): > + return self > + > + def next(self): > + while True: > + r = self.iter.next() > + v = r() > + if not v is None: > + break > + return v > + > + return Iter(iter(self._instances)) > + > + > +if __name__ == '__main__': > + class A(object): > + __metaclass__ = InstanceRegistry > + > + def __init__(self, name): > + self.name = name > + > + def __repr__(self): > + return self.name > + > + class B(A): > + pass > + > + a = A("a1") > + b = B("b1") > + > + print a, b > + > + print "iterate A" > + for i in A: > + print i > + print "iterate B" > + for i in B: > + print i > + > +# del a > +# del b > +# del i > +# import gc > +# gc.collect() > + > + a.instance_registry_unregister() > + print "iterate A" > + for i in A: > + print i > + print "iterate B" > + for i in B: > + print i > -- > 1.8.0.1 > > > ------------------------------------------------------------------------------ > Everyone hates slow websites. So do we. > Make your web apps faster with AppDynamics > Download AppDynamics Lite for free today: > http://p.sf.net/sfu/appdyn_d2d_mar > _______________________________________________ > Ryu-devel mailing list > Ryu-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/ryu-devel > -- yamahata ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar _______________________________________________ Ryu-devel mailing list Ryu-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ryu-devel
