Source Code for Module Products.ZenUtils.PBUtil

  1  ########################################################################### 
  2  # 
  3  # This program is part of Zenoss Core, an open source monitoring platform. 
  4  # Copyright (C) 2007, Zenoss Inc. 
  5  # 
  6  # This program is free software; you can redistribute it and/or modify it 
  7  # under the terms of the GNU General Public License version 2 as published by 
  8  # the Free Software Foundation. 
  9  # 
 10  # For complete information please visit: http://www.zenoss.com/oss/ 
 11  # 
 12  ########################################################################### 
 13   
 14  # taken from r1.10 of buildbot.sf.net/buildbot/pbutil.py 
 15   
 16  # flumotion has nearly the same code 
 17   
 18  __doc__ = """PBUtil 
 19  Base classes handy for use with PB clients. 
 20  """ 
 21   
 22  from twisted.spread import pb 
 23   
 24  from twisted.spread.pb import PBClientFactory 
 25  from twisted.internet import protocol 
 26  from twisted.python import log 
 27   
 28 -class ReconnectingPBClientFactory(PBClientFactory, 
 29                                    protocol.ReconnectingClientFactory): 
 30      """Reconnecting client factory for PB brokers. 
 31   
 32      Like PBClientFactory, but if the connection fails or is lost, the factory 
 33      will attempt to reconnect. 
 34   
 35      Instead of using f.getRootObject (which gives a Deferred that can only 
 36      be fired once), override the gotRootObject method. 
 37   
 38      Instead of using the newcred f.login (which is also one-shot), call 
 39      f.startLogin() with the credentials and client, and override the 
 40      gotPerspective method. 
 41   
 42      Instead of using the oldcred f.getPerspective (also one-shot), call 
 43      f.startGettingPerspective() with the same arguments, and override 
 44      gotPerspective. 
 45   
 46      gotRootObject and gotPerspective will be called each time the object is 
 47      received (once per successful connection attempt). You will probably want 
 48      to use obj.notifyOnDisconnect to find out when the connection is lost. 
 49   
 50      If an authorization error occurs, failedToGetPerspective() will be 
 51      invoked. 
 52   
 53      To use me, subclass, then hand an instance to a connector (like 
 54      TCPClient). 
 55      """ 
 56      __pychecker__='no-override' 
 57   
 58      # maxDelay(secs) set to 5 minute maximum delay before attempting to 
 59      # reconnect 
 60      maxDelay = 300 
 61   
 62 -    def __init__(self): 
 63          PBClientFactory.__init__(self) 
 64          self._doingLogin = False 
 65          self._doingGetPerspective = False 
 66   
 67 -    def clientConnectionFailed(self, connector, reason): 
 68          PBClientFactory.clientConnectionFailed(self, connector, reason) 
 69          # Twisted-1.3 erroneously abandons the connection on non-UserErrors. 
 70          # To avoid this bug, don't upcall, and implement the correct version 
 71          # of the method here. 
 72          if self.continueTrying: 
 73              self.connector = connector 
 74              self.retry() 
 75   
 76 -    def clientConnectionLost(self, connector, reason, reconnecting=1): 
 77          PBClientFactory.clientConnectionLost(self, connector, reason, 
 78                                               reconnecting=reconnecting) 
 79          RCF = protocol.ReconnectingClientFactory 
 80          RCF.clientConnectionLost(self, connector, reason) 
 81   
 82 -    def clientConnectionMade(self, broker): 
 83          self.resetDelay() 
 84          PBClientFactory.clientConnectionMade(self, broker) 
 85          if self._doingLogin: 
 86              self.doLogin(self._root) 
 87          if self._doingGetPerspective: 
 88              self.doGetPerspective(self._root) 
 89          self.gotRootObject(self._root) 
 90   
 91 -    def __getstate__(self): 
 92          # this should get folded into ReconnectingClientFactory 
 93          d = self.__dict__.copy() 
 94          d['connector'] = None 
 95          d['_callID'] = None 
 96          return d 
 97   
 98      # oldcred methods 
 99   
100 -    def getPerspective(self, *args): 
101          raise RuntimeError( "getPerspective is one-shot: use startGettingPerspective instead" ) 
102   
103 -    def startGettingPerspective(self, username, password, serviceName, 
104                                  perspectiveName=None, client=None): 
105          self._doingGetPerspective = True 
106          if perspectiveName == None: 
107              perspectiveName = username 
108          self._oldcredArgs = (username, password, serviceName, 
109                               perspectiveName, client) 
110   
111 -    def doGetPerspective(self, root): 
112          # oldcred getPerspective() 
113          (username, password, 
114           serviceName, perspectiveName, client) = self._oldcredArgs 
115          d = self._cbAuthIdentity(root, username, password) 
116          d.addCallback(self._cbGetPerspective, 
117                        serviceName, perspectiveName, client) 
118          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective) 
119   
120   
121      # newcred methods 
122   
123 -    def login(self, credentials, client=None): 
124          from Products.ZenUtils.Utils import unused 
125          unused(credentials, client) 
126          raise RuntimeError( "Login is one-shot: use startLogin instead" ) 
127   
128 -    def startLogin(self, credentials, client=None): 
129          self._credentials = credentials 
130          self._client = client 
131          self._doingLogin = True 
132   
133 -    def doLogin(self, root): 
134          # newcred login() 
135          d = self._cbSendUsername(root, self._credentials.username, 
136                                   self._credentials.password, self._client) 
137          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective) 
138          return d 
139   
140   
141      # methods to override 
142   
143 -    def gotPerspective(self, perspective): 
144          """The remote avatar or perspective (obtained each time this factory 
145          connects) is now available.""" 
146          pass 
147   
148 -    def gotRootObject(self, root): 
149          """The remote root object (obtained each time this factory connects) 
150          is now available. This method will be called each time the connection 
151          is established and the object reference is retrieved.""" 
152          pass 
153   
154 -    def failedToGetPerspective(self, why): 
155          """The login process failed, most likely because of an authorization 
156          failure (bad password), but it is also possible that we lost the new 
157          connection before we managed to send our credentials. 
158          """ 
159          log.msg("ReconnectingPBClientFactory.failedToGetPerspective") 
160          if why.check(pb.PBConnectionLost): 
161              log.msg("we lost the brand-new connection") 
162              # retrying might help here, let clientConnectionLost decide 
163              return 
164          # probably authorization 
165          self.stopTrying() # logging in harder won't help 
166          log.err(why) 
167