Source Code for Module buildslave.pbutil

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 14  # Copyright Buildbot Team Members 
 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  from twisted.cred import error 
 26   
 27 -class ReconnectingPBClientFactory(PBClientFactory, 
 28                                    protocol.ReconnectingClientFactory): 
 29      """Reconnecting client factory for PB brokers. 
 30   
 31      Like PBClientFactory, but if the connection fails or is lost, the factory 
 32      will attempt to reconnect. 
 33   
 34      Instead of using f.getRootObject (which gives a Deferred that can only 
 35      be fired once), override the gotRootObject method. 
 36   
 37      Instead of using the newcred f.login (which is also one-shot), call 
 38      f.startLogin() with the credentials and client, and override the 
 39      gotPerspective method. 
 40   
 41      gotRootObject and gotPerspective will be called each time the object is 
 42      received (once per successful connection attempt). You will probably want 
 43      to use obj.notifyOnDisconnect to find out when the connection is lost. 
 44   
 45      If an authorization error occurs, failedToGetPerspective() will be 
 46      invoked. 
 47   
 48      To use me, subclass, then hand an instance to a connector (like 
 49      TCPClient). 
 50      """ 
 51   
 52      # hung connections wait for a relatively long time, since a busy master may 
 53      # take a while to get back to us. 
 54      hungConnectionTimer = None 
 55      HUNG_CONNECTION_TIMEOUT = 120 
 56   
 57 -    def clientConnectionFailed(self, connector, reason): 
 58          PBClientFactory.clientConnectionFailed(self, connector, reason) 
 59          if self.continueTrying: 
 60              self.connector = connector 
 61              self.retry() 
 62   
 63 -    def clientConnectionLost(self, connector, reason): 
 64          PBClientFactory.clientConnectionLost(self, connector, reason, 
 65                                               reconnecting=True) 
 66          RCF = protocol.ReconnectingClientFactory 
 67          RCF.clientConnectionLost(self, connector, reason) 
 68   
 69 -    def startedConnecting(self, connector): 
 70          self.startHungConnectionTimer(connector) 
 71   
 72 -    def clientConnectionMade(self, broker): 
 73          self.resetDelay() 
 74          PBClientFactory.clientConnectionMade(self, broker) 
 75          self.doLogin(self._root, broker) 
 76          self.gotRootObject(self._root) 
 77   
 78      # newcred methods 
 79   
 80 -    def login(self, *args): 
 81          raise RuntimeError, "login is one-shot: use startLogin instead" 
 82   
 83 -    def startLogin(self, credentials, client=None): 
 84          self._credentials = credentials 
 85          self._client = client 
 86   
 87 -    def doLogin(self, root, broker): 
 88          # newcred login() 
 89          d = self._cbSendUsername(root, self._credentials.username, 
 90                                   self._credentials.password, self._client) 
 91          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective, 
 92                  errbackArgs=(broker,)) 
 93   
 94      # timer for hung connections 
 95   
 96 -    def startHungConnectionTimer(self, connector): 
 97          self.stopHungConnectionTimer() 
 98          def hungConnection(): 
 99              log.msg("connection attempt timed out (is the port number correct?)") 
100              self.hungConnectionTimer = None 
101              connector.disconnect() 
102              # (this will trigger the retry) 
103          self.hungConnectionTimer = reactor.callLater(self.HUNG_CONNECTION_TIMEOUT, hungConnection) 
104   
105 -    def stopHungConnectionTimer(self): 
106          if self.hungConnectionTimer: 
107              self.hungConnectionTimer.cancel() 
108          self.hungConnectionTimer = None 
109   
110      # methods to override 
111   
112 -    def gotPerspective(self, perspective): 
113          """The remote avatar or perspective (obtained each time this factory 
114          connects) is now available.""" 
115          self.stopHungConnectionTimer() 
116   
117 -    def gotRootObject(self, root): 
118          """The remote root object (obtained each time this factory connects) 
119          is now available. This method will be called each time the connection 
120          is established and the object reference is retrieved.""" 
121          self.stopHungConnectionTimer() 
122   
123 -    def failedToGetPerspective(self, why, broker): 
124          """The login process failed, most likely because of an authorization 
125          failure (bad password), but it is also possible that we lost the new 
126          connection before we managed to send our credentials. 
127          """ 
128          log.msg("ReconnectingPBClientFactory.failedToGetPerspective") 
129          self.stopHungConnectionTimer() 
130          # put something useful in the logs 
131          if why.check(pb.PBConnectionLost): 
132              log.msg("we lost the brand-new connection") 
133              # fall through 
134          elif why.check(error.UnauthorizedLogin): 
135              log.msg("unauthorized login; check slave name and password") 
136              # fall through 
137          else: 
138              log.err(why, 'While trying to connect:') 
139              self.stopTrying() 
140              reactor.stop() 
141              return 
142   
143          # lose the current connection, which will trigger a retry 
144          broker.transport.loseConnection() 
145