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1 from twisted.application import service |
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2 from twisted.python import components, failure |
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3 from twisted.internet import defer, reactor |
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4 |
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5 class IBackendService(components.Interface): |
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6 """ Interface to a backend service of a pubsub service """ |
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7 |
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8 class BackendException(Exception): |
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9 def __init__(self, msg = ''): |
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10 self.msg = msg |
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11 |
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12 def __str__(self): |
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13 return self.msg |
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14 |
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15 class NodeNotFound(BackendException): |
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16 #def __init__(self, msg = 'Node not found'): |
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17 # BackendException.__init__(self, msg) |
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18 pass |
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19 |
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20 class NotAuthorized(BackendException): |
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21 pass |
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22 |
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23 class MemoryBackendService(service.Service): |
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24 |
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25 __implements__ = IBackendService, |
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26 |
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27 def __init__(self): |
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28 self.nodes = {"ralphm/test": 'test'} |
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29 self.subscribers = {"ralphm/test": ["ralphm@ik.nu", "intosi@ik.nu"] } |
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30 self.affiliations = {"ralphm/test": { "ralphm@ik.nu": "owner", "ralphm@se-135.se.wtb.tue.nl": 'publisher' } } |
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31 |
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32 def do_publish(self, node, publisher, item): |
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33 try: |
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34 try: |
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35 result = self.nodes[node] |
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36 except KeyError: |
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37 raise NodeNotFound |
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38 |
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39 try: |
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40 affiliation = self.affiliations[node][publisher] |
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41 if affiliation not in ['owner', 'publisher']: |
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42 raise NotAuthorized |
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43 except KeyError: |
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44 raise NotAuthorized() |
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45 print "publish by %s to %s" % (publisher, node) |
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46 return defer.succeed(result) |
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47 except: |
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48 f = failure.Failure() |
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49 return defer.fail(f) |
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50 |
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51 def get_subscribers(self, node): |
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52 d = defer.Deferred() |
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53 try: |
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54 result = self.subscribers[node] |
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55 except: |
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56 f = failure.Failure() |
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57 reactor.callLater(0, d.errback, f) |
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58 else: |
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59 reactor.callLater(0, d.callback, result) |
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60 |
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61 return d |
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62 |
