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#!/usr/bin/env python
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
from twisted.spread import pb, jelly
from twisted.python import log
from twisted.internet import reactor
class MyException(pb.Error): pass
class MyOtherException(pb.Error): pass
class ScaryObject:
# not safe for serialization
pass
def worksLike(obj):
# the callback/errback sequence in class One works just like an
# asynchronous version of the following:
try:
response = obj.callMethod(name, arg)
except pb.DeadReferenceError:
print " stale reference: the client disconnected or crashed"
except jelly.InsecureJelly:
print " InsecureJelly: you tried to send something unsafe to them"
except (MyException, MyOtherException):
print " remote raised a MyException" # or MyOtherException
except:
print " something else happened"
else:
print " method successful, response:", response
class One:
def worked(self, response):
print " method successful, response:", response
def check_InsecureJelly(self, failure):
failure.trap(jelly.InsecureJelly)
print " InsecureJelly: you tried to send something unsafe to them"
return None
def check_MyException(self, failure):
which = failure.trap(MyException, MyOtherException)
if which == MyException:
print " remote raised a MyException"
else:
print " remote raised a MyOtherException"
return None
def catch_everythingElse(self, failure):
print " something else happened"
log.err(failure)
return None
def doCall(self, explanation, arg):
print explanation
try:
deferred = self.remote.callRemote("fooMethod", arg)
deferred.addCallback(self.worked)
deferred.addErrback(self.check_InsecureJelly)
deferred.addErrback(self.check_MyException)
deferred.addErrback(self.catch_everythingElse)
except pb.DeadReferenceError:
print " stale reference: the client disconnected or crashed"
def callOne(self):
self.doCall("callOne: call with safe object", "safe string")
def callTwo(self):
self.doCall("callTwo: call with dangerous object", ScaryObject())
def callThree(self):
self.doCall("callThree: call that raises remote exception", "panic!")
def callShutdown(self):
print "telling them to shut down"
self.remote.callRemote("shutdown")
def callFour(self):
self.doCall("callFour: call on stale reference", "dummy")
def got_obj(self, obj):
self.remote = obj
reactor.callLater(1, self.callOne)
reactor.callLater(2, self.callTwo)
reactor.callLater(3, self.callThree)
reactor.callLater(4, self.callShutdown)
reactor.callLater(5, self.callFour)
reactor.callLater(6, reactor.stop)
factory = pb.PBClientFactory()
reactor.connectTCP("localhost", 8800, factory)
deferred = factory.getRootObject()
deferred.addCallback(One().got_obj)
reactor.run()
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