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Viewing changes to doc/howto/listings/pclients/multiple.py

  • Committer: Bazaar Package Importer
  • Author(s): Matthias Klose
  • Date: 2004-06-21 22:01:11 UTC
  • mto: (2.2.3 sid)
  • mto: This revision was merged to the branch mainline in revision 3.
  • Revision ID: james.westby@ubuntu.com-20040621220111-vkf909euqnyrp3nr
Tags: upstream-1.3.0
Import upstream version 1.3.0

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doc/howto/listings/pclients/multiple.py
 
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from twisted.spread import pb
 
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class MultipleClientPerspective(pb.Perspective):
 
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    """Many clients may use this Perspective at once."""
 
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    # This example is from twisted.manhole.service.Perspective.
 
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    def __init__(self, perspectiveName, identityName="Nobody"):
 
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        pb.Perspective.__init__(self, perspectiveName, identityName)
 
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        self.clients = {}
 
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    def attached(self, client, identity):
 
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        # The clients dictionary is really only used as a set and not as a
 
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        # mapping, but we go ahead and throw the Identity into the value slot
 
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        # because hey, it's there.
 
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        self.clients[client] = identity
 
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        return self
 
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    def detached(self, client, identity):
 
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        try:
 
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            del self.clients[client]
 
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        except KeyError:
 
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            # This is probably something as benign as the client being removed
 
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            # by a DeadReferenceError in sendMessage and again when the broker
 
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            # formally closes down.  No big deal.
 
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            pass
 
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    def sendMessage(self, message):
 
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        """Pass a message to my clients' console.
 
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        """
 
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        for client in self.clients.keys():
 
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            try:
 
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                client.callRemote('message', message)
 
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            except pb.DeadReferenceError:
 
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                # Stale broker.  This is the error you get if in the process
 
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                # of doing the callRemote, the broker finds out the transport
 
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                # just died, or something along those lines.  So remove that
 
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                # client from our list.
 
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                self.detached(client, None)
 
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    def __getstate__(self):
 
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        state = styles.Versioned.__getstate__(self)
 
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        state['clients'] = {}
 
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        return state