54 lines
2.0 KiB
Python
54 lines
2.0 KiB
Python
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class NameplateListingMachine(object):
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m = MethodicalMachine()
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def __init__(self):
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self._list_nameplate_waiters = []
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# Ideally, each API request would spawn a new "list_nameplates" message
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# to the server, so the response would be maximally fresh, but that would
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# require correlating server request+response messages, and the protocol
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# is intended to be less stateful than that. So we offer a weaker
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# freshness property: if no server requests are in flight, then a new API
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# request will provoke a new server request, and the result will be
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# fresh. But if a server request is already in flight when a second API
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# request arrives, both requests will be satisfied by the same response.
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@m.state(initial=True)
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def idle(self): pass
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@m.state()
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def requesting(self): pass
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@m.input()
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def list_nameplates(self): pass # returns Deferred
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@m.input()
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def response(self, message): pass
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@m.output()
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def add_deferred(self):
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d = defer.Deferred()
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self._list_nameplate_waiters.append(d)
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return d
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@m.output()
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def send_request(self):
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self._connection.send_command("list")
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@m.output()
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def distribute_response(self, message):
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nameplates = parse(message)
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waiters = self._list_nameplate_waiters
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self._list_nameplate_waiters = []
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for d in waiters:
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d.callback(nameplates)
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idle.upon(list_nameplates, enter=requesting,
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outputs=[add_deferred, send_request],
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collector=lambda outs: outs[0])
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idle.upon(response, enter=idle, outputs=[])
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requesting.upon(list_nameplates, enter=requesting,
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outputs=[add_deferred],
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collector=lambda outs: outs[0])
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requesting.upon(response, enter=idle, outputs=[distribute_response])
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# nlm._connection = c = Connection(ws)
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# nlm.list_nameplates().addCallback(display_completions)
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# c.register_dispatch("nameplates", nlm.response)
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