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# This file is part of Buildbot. Buildbot is free software: you can
# redistribute it and/or modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation, version 2.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc., 51
# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Copyright Buildbot Team Members
"""Base classes handy for use with PB clients.
"""
from twisted.spread import pb
from twisted.spread.pb import PBClientFactory
from twisted.internet import protocol, reactor
from twisted.python import log
from twisted.cred import error
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.
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).
"""
# hung connections wait for a relatively long time, since a busy master may
# take a while to get back to us.
hungConnectionTimer = None
HUNG_CONNECTION_TIMEOUT = 120
def clientConnectionFailed(self, connector, reason):
PBClientFactory.clientConnectionFailed(self, connector, reason)
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 startedConnecting(self, connector):
self.startHungConnectionTimer(connector)
def clientConnectionMade(self, broker):
self.resetDelay()
PBClientFactory.clientConnectionMade(self, broker)
self.doLogin(self._root, broker)
self.gotRootObject(self._root)
# 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
def doLogin(self, root, broker):
# newcred login()
d = self._cbSendUsername(root, self._credentials.username,
self._credentials.password, self._client)
d.addCallbacks(self.gotPerspective, self.failedToGetPerspective,
errbackArgs=(broker,))
# timer for hung connections
def startHungConnectionTimer(self, connector):
self.stopHungConnectionTimer()
def hungConnection():
log.msg("connection attempt timed out (is the port number correct?)")
self.hungConnectionTimer = None
connector.disconnect()
# (this will trigger the retry)
self.hungConnectionTimer = reactor.callLater(self.HUNG_CONNECTION_TIMEOUT, hungConnection)
def stopHungConnectionTimer(self):
if self.hungConnectionTimer:
self.hungConnectionTimer.cancel()
self.hungConnectionTimer = None
# methods to override
def gotPerspective(self, perspective):
"""The remote avatar or perspective (obtained each time this factory
connects) is now available."""
self.stopHungConnectionTimer()
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."""
self.stopHungConnectionTimer()
def failedToGetPerspective(self, why, broker):
"""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")
self.stopHungConnectionTimer()
# put something useful in the logs
if why.check(pb.PBConnectionLost):
log.msg("we lost the brand-new connection")
# fall through
elif why.check(error.UnauthorizedLogin):
log.msg("unauthorized login; check slave name and password")
# fall through
else:
log.err(why, 'While trying to connect:')
self.stopTrying()
reactor.stop()
return
# lose the current connection, which will trigger a retry
broker.transport.loseConnection()
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