Source Code for Module 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 = 5 
 59   
 60 -    def __init__(self): 
 61          PBClientFactory.__init__(self) 
 62          self._doingLogin = False 
 63          self._doingGetPerspective = False 
 64   
 65 -    def clientConnectionFailed(self, connector, reason): 
 66          PBClientFactory.clientConnectionFailed(self, connector, reason) 
 67          # Twisted-1.3 erroneously abandons the connection on non-UserErrors. 
 68          # To avoid this bug, don't upcall, and implement the correct version 
 69          # of the method here. 
 70          if self.continueTrying: 
 71              self.connector = connector 
 72              self.retry() 
 73   
 74 -    def clientConnectionLost(self, connector, reason, reconnecting=1): 
 75          PBClientFactory.clientConnectionLost(self, connector, reason, 
 76                                               reconnecting=reconnecting) 
 77          RCF = protocol.ReconnectingClientFactory 
 78          RCF.clientConnectionLost(self, connector, reason) 
 79   
 80 -    def clientConnectionMade(self, broker): 
 81          self.resetDelay() 
 82          PBClientFactory.clientConnectionMade(self, broker) 
 83          if self._doingLogin: 
 84              self.doLogin(self._root) 
 85          if self._doingGetPerspective: 
 86              self.doGetPerspective(self._root) 
 87          self.gotRootObject(self._root) 
 88   
 89 -    def __getstate__(self): 
 90          # this should get folded into ReconnectingClientFactory 
 91          d = self.__dict__.copy() 
 92          d['connector'] = None 
 93          d['_callID'] = None 
 94          return d 
 95   
 96      # oldcred methods 
 97   
 98 -    def getPerspective(self, *args): 
 99          raise RuntimeError( "getPerspective is one-shot: use startGettingPerspective instead" ) 
100   
101 -    def startGettingPerspective(self, username, password, serviceName, 
102                                  perspectiveName=None, client=None): 
103          self._doingGetPerspective = True 
104          if perspectiveName == None: 
105              perspectiveName = username 
106          self._oldcredArgs = (username, password, serviceName, 
107                               perspectiveName, client) 
108   
109 -    def doGetPerspective(self, root): 
110          # oldcred getPerspective() 
111          (username, password, 
112           serviceName, perspectiveName, client) = self._oldcredArgs 
113          d = self._cbAuthIdentity(root, username, password) 
114          d.addCallback(self._cbGetPerspective, 
115                        serviceName, perspectiveName, client) 
116          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective) 
117   
118   
119      # newcred methods 
120   
121 -    def login(self, credentials, client=None): 
122          from Products.ZenUtils.Utils import unused 
123          unused(credentials, client) 
124          raise RuntimeError( "Login is one-shot: use startLogin instead" ) 
125   
126 -    def startLogin(self, credentials, client=None): 
127          self._credentials = credentials 
128          self._client = client 
129          self._doingLogin = True 
130   
131 -    def doLogin(self, root): 
132          # newcred login() 
133          d = self._cbSendUsername(root, self._credentials.username, 
134                                   self._credentials.password, self._client) 
135          d.addCallbacks(self.gotPerspective, self.failedToGetPerspective) 
136          return d 
137   
138   
139      # methods to override 
140   
141 -    def gotPerspective(self, perspective): 
142          """The remote avatar or perspective (obtained each time this factory 
143          connects) is now available.""" 
144          pass 
145   
146 -    def gotRootObject(self, root): 
147          """The remote root object (obtained each time this factory connects) 
148          is now available. This method will be called each time the connection 
149          is established and the object reference is retrieved.""" 
150          pass 
151   
152 -    def failedToGetPerspective(self, why): 
153          """The login process failed, most likely because of an authorization 
154          failure (bad password), but it is also possible that we lost the new 
155          connection before we managed to send our credentials. 
156          """ 
157          log.msg("ReconnectingPBClientFactory.failedToGetPerspective") 
158          if why.check(pb.PBConnectionLost): 
159              log.msg("we lost the brand-new connection") 
160              # retrying might help here, let clientConnectionLost decide 
161              return 
162          # probably authorization 
163          self.stopTrying() # logging in harder won't help 
164          log.err(why) 
165