"""Base classes handy for use with PB clients.
"""
from twisted.spread import pb
from twisted.spread.pb import PBClientFactory
from twisted.internet import protocol
from twisted.python import log
class NewCredPerspective(pb.Avatar):
def attached(self, mind):
return self
def detached(self, mind):
pass
class ReconnectingPBClientFactory(PBClientFactory,
protocol.ReconnectingClientFactory):
"""Reconnecting client factory for PB brokers.
Like PBClientFactory, but if the connection fails or is lost, the factory
will attempt to reconnect.
Instead of using f.getRootObject (which gives a Deferred that can only
be fired once), override the gotRootObject method.
Instead of using the newcred f.login (which is also one-shot), call
f.startLogin() with the credentials and client, and override the
gotPerspective method.
Instead of using the oldcred f.getPerspective (also one-shot), call
f.startGettingPerspective() with the same arguments, and override
gotPerspective.
gotRootObject and gotPerspective will be called each time the object is
received (once per successful connection attempt). You will probably want
to use obj.notifyOnDisconnect to find out when the connection is lost.
If an authorization error occurs, failedToGetPerspective() will be
invoked.
To use me, subclass, then hand an instance to a connector (like
TCPClient).
"""
def __init__(self):
PBClientFactory.__init__(self)
self._doingLogin = False
self._doingGetPerspective = False
def clientConnectionFailed(self, connector, reason):
PBClientFactory.clientConnectionFailed(self, connector, reason)
# Twisted-1.3 erroneously abandons the connection on non-UserErrors.
# To avoid this bug, don't upcall, and implement the correct version
# of the method here.
if self.continueTrying:
self.connector = connector
self.retry()
def clientConnectionLost(self, connector, reason):
PBClientFactory.clientConnectionLost(self, connector, reason,
reconnecting=True)
RCF = protocol.ReconnectingClientFactory
RCF.clientConnectionLost(self, connector, reason)
def clientConnectionMade(self, broker):
self.resetDelay()
PBClientFactory.clientConnectionMade(self, broker)
if self._doingLogin:
self.doLogin(self._root)
if self._doingGetPerspective:
self.doGetPerspective(self._root)
self.gotRootObject(self._root)
# oldcred methods
def getPerspective(self, *args):
raise RuntimeError, "getPerspective is one-shot: use startGettingPerspective instead"
def startGettingPerspective(self, username, password, serviceName,
perspectiveName=None, client=None):
self._doingGetPerspective = True
if perspectiveName == None:
perspectiveName = username
self._oldcredArgs = (username, password, serviceName,
perspectiveName, client)
def doGetPerspective(self, root):
# oldcred getPerspective()
(username, password,
serviceName, perspectiveName, client) = self._oldcredArgs
d = self._cbAuthIdentity(root, username, password)
d.addCallback(self._cbGetPerspective,
serviceName, perspectiveName, client)
d.addCallbacks(self.gotPerspective, self.failedToGetPerspective)
# newcred methods
def login(self, *args):
raise RuntimeError, "login is one-shot: use startLogin instead"
def startLogin(self, credentials, client=None):
self._credentials = credentials
self._client = client
self._doingLogin = True
def doLogin(self, root):
# newcred login()
d = self._cbSendUsername(root, self._credentials.username,
self._credentials.password, self._client)
d.addCallbacks(self.gotPerspective, self.failedToGetPerspective)
# methods to override
def gotPerspective(self, perspective):
"""The remote avatar or perspective (obtained each time this factory
connects) is now available."""
pass
def gotRootObject(self, root):
"""The remote root object (obtained each time this factory connects)
is now available. This method will be called each time the connection
is established and the object reference is retrieved."""
pass
def failedToGetPerspective(self, why):
"""The login process failed, most likely because of an authorization
failure (bad password), but it is also possible that we lost the new
connection before we managed to send our credentials.
"""
log.msg("ReconnectingPBClientFactory.failedToGetPerspective")
if why.check(pb.PBConnectionLost):
log.msg("we lost the brand-new connection")
# retrying might help here, let clientConnectionLost decide
return
# probably authorization
self.stopTrying() # logging in harder won't help
log.err(why)
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