Source Code for Module buildslave.pbutil

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 15   
 16   
 17  """Base classes handy for use with PB clients. 
 18  """ 
 19   
 20  from twisted.spread import pb 
 21   
 22  from twisted.spread.pb import PBClientFactory 
 23  from twisted.internet import protocol, reactor 
 24  from twisted.python import log 
 25   
 26 -class ReconnectingPBClientFactory(PBClientFactory, 
 27                                    protocol.ReconnectingClientFactory): 
 28      """Reconnecting client factory for PB brokers. 
 29   
 30      Like PBClientFactory, but if the connection fails or is lost, the factory 
 31      will attempt to reconnect. 
 32   
 33      Instead of using f.getRootObject (which gives a Deferred that can only 
 34      be fired once), override the gotRootObject method. 
 35   
 36      Instead of using the newcred f.login (which is also one-shot), call 
 37      f.startLogin() with the credentials and client, and override the 
 38      gotPerspective method. 
 39   
 40      gotRootObject and gotPerspective will be called each time the object is 
 41      received (once per successful connection attempt). You will probably want 
 42      to use obj.notifyOnDisconnect to find out when the connection is lost. 
 43   
 44      If an authorization error occurs, failedToGetPerspective() will be 
 45      invoked. 
 46   
 47      To use me, subclass, then hand an instance to a connector (like 
 48      TCPClient). 
 49      """ 
 50   
 51      # hung connections wait for a relatively long time, since a busy master may 
 52      # take a while to get back to us. 
 53      hungConnectionTimer = None 
 54      HUNG_CONNECTION_TIMEOUT = 120 
 55   
 56 -    def clientConnectionFailed(self, connector, reason): 
 57          PBClientFactory.clientConnectionFailed(self, connector, reason) 
 58          if self.continueTrying: 
 59              self.connector = connector 
 60              self.retry() 
 61   
 62 -    def clientConnectionLost(self, connector, reason): 
 63          PBClientFactory.clientConnectionLost(self, connector, reason, 
 64                                               reconnecting=True) 
 65          RCF = protocol.ReconnectingClientFactory 
 66          RCF.clientConnectionLost(self, connector, reason) 
 67   
 68 -    def startedConnecting(self, connector): 
 69          self.startHungConnectionTimer(connector) 
 70   
 71 -    def clientConnectionMade(self, broker): 
 72          self.resetDelay() 
 73          PBClientFactory.clientConnectionMade(self, broker) 
 74          self.doLogin(self._root) 
 75          self.gotRootObject(self._root) 
 76   
 77      # newcred methods 
 78   
 79 -    def login(self, *args): 
 80          raise RuntimeError, "login is one-shot: use startLogin instead" 
 81   
 82 -    def startLogin(self, credentials, client=None): 
 83          self._credentials = credentials 
 84          self._client = client 
 85   
 86 -    def doLogin(self, root): 
 87          # newcred login() 
 88          d = self._cbSendUsername(root, self._credentials.username, 
 89                                   self._credentials.password, self._client) 
 90          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective) 
 91   
 92      # timer for hung connections 
 93   
 94 -    def startHungConnectionTimer(self, connector): 
 95          self.stopHungConnectionTimer() 
 96          def hungConnection(): 
 97              log.msg("connection attempt timed out (is the port number correct?)") 
 98              self.hungConnectionTimer = None 
 99              connector.disconnect() 
100              # (this will trigger the retry) 
101          self.hungConnectionTimer = reactor.callLater(self.HUNG_CONNECTION_TIMEOUT, hungConnection) 
102   
103 -    def stopHungConnectionTimer(self): 
104          if self.hungConnectionTimer: 
105              self.hungConnectionTimer.cancel() 
106          self.hungConnectionTimer = None 
107   
108      # methods to override 
109   
110 -    def gotPerspective(self, perspective): 
111          """The remote avatar or perspective (obtained each time this factory 
112          connects) is now available.""" 
113          self.stopHungConnectionTimer() 
114   
115 -    def gotRootObject(self, root): 
116          """The remote root object (obtained each time this factory connects) 
117          is now available. This method will be called each time the connection 
118          is established and the object reference is retrieved.""" 
119          self.stopHungConnectionTimer() 
120   
121 -    def failedToGetPerspective(self, why): 
122          """The login process failed, most likely because of an authorization 
123          failure (bad password), but it is also possible that we lost the new 
124          connection before we managed to send our credentials. 
125          """ 
126          log.msg("ReconnectingPBClientFactory.failedToGetPerspective") 
127          self.stopHungConnectionTimer() 
128          if why.check(pb.PBConnectionLost): 
129              log.msg("we lost the brand-new connection") 
130              # retrying might help here, let clientConnectionLost decide 
131              return 
132          # probably authorization 
133          self.stopTrying() # logging in harder won't help 
134          log.err(why) 
135          reactor.stop() 
136