pickle.loads 不返回相同的数据转储

Question

PolicyModule is a class created by me.

When I try to dump/load an instance of it I do not get in return the same data:

module = PolicyModule(new.name,new.domain,decomposed_module[switch][port])
module.install()
modules[new.name] = module
print 'POLICY TO DUMP'
print modules[new.name].isInstalled()
print modules[new.name].name
print modules[new.name].domain
print modules[new.name].action
print modules[new.name].policy  
print '\n'
msg = pickle.dumps(modules[new.name],-1)
x = pickle.loads(msg)
print 'POLICY LOADED'
print x.isInstalled()
print x.name
print x.domain
print x.action
print x.policy 
print '\n'

This is what is printed:

POLICY TO DUMP
True
routing
match: ('dstip', 10.0.0.1)
parallel:
    sequential:
        match: ('switch', 2) ('dstip', 10.0.0.2)
        fwd 1
    sequential:
        match: ('switch', 2) ('dstip', 10.0.0.3)
        fwd 2
sequential:
    match: ('dstip', 10.0.0.1)
    parallel:
        sequential:
            match: ('switch', 2) ('dstip', 10.0.0.2)
            fwd 1
        sequential:
            match: ('switch', 2) ('dstip', 10.0.0.3)
            fwd 2

POLICY LOADED
True
routing
match: ('dstip', 10.0.0.1)
drop
identity

Note well : match, sequential, fwd and parallel are instances of others classes.

For each class, I set the setstate and getstate methods as following:

def __getstate__(self):
    odict = self.__dict__.copy() # copy the dict since we change it
    return odict

def __setstate__(self, dict):
    self.__dict__.update(dict)

It think that the problem is here:

class sequential(CombinatorPolicy):

def __new__(self, policies=[]):
    if len(policies) == 0:
        return identity
    else:
        rv = super(sequential, self).__new__(sequential, policies)
        rv.__init__(policies)
        return rv

and here:

class parallel(CombinatorPolicy):

def __new__(self, policies=[]):
    # Hackety hack.
    if len(policies) == 0:
        return drop
    else:
        rv = super(parallel, self).__new__(parallel, policies)
        rv.__init__(policies)
        return rv

because I always get a drop instead of a parallel instance, and an identity instead of a sequential . It's like the setdate method passes an empty list to the new method.

Answer 1

I found the solution myself.

I just forgot to define getnewargs methods in both parallel and sequential classes.

More info here .