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