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# Twisted, the Framework of Your Internet
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# Copyright (C) 2001 Matthew W. Lefkowitz
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of version 2.1 of the GNU Lesser General Public
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# License as published by the Free Software Foundation.
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Lesser General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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from twisted.python import defer
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from perspective import Perspective
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"""I am a service that internet applications interact with.
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I represent a set of abstractions which users may interact with over a
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(See Also: twisted.spread.pb.Service)
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perspectiveClass = Perspective
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def __init__(self, serviceName, application=None):
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"""Create me, attached to the given application.
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Arguments: application, a twisted.internet.app.Application instance.
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if not isinstance(serviceName, types.StringType):
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self.serviceName = serviceName
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self.perspectives = {}
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self.setApplication(application)
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def cachePerspective(self, perspective):
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"""Cache a perspective loaded from an external data source.
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Perspectives that were 'loaded' from memory will not be uncached.
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if self.perspectives.has_key(perspective.perspectiveName):
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self.perspectives[perspective.perspectiveName] = perspective
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perspective._service_cached = 1
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def uncachePerspective(self, perspective):
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"""Uncache a perspective loaded from an external data source.
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Perspectives that were 'loaded' from memory will not be uncached.
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if self.perspectives.has_key(perspective.perspectiveName):
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if perspective._service_cached:
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del self.perspectives[perspective.perspectiveName]
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def setApplication(self, application):
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from twisted.internet import app
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if application and not isinstance(application, app.Application):
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if self.application and self.application is not application:
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raise RuntimeError, "Application already set!"
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self.application = application
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application.addService(self)
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def createPerspective(self, name):
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"""Create a perspective from self.perspectiveClass and add it to this service.
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p = self.perspectiveClass(name)
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self.perspectives[name] = p
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def addPerspective(self, perspective):
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"""Add a perspective to this Service.
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if not isinstance(perspective, Perspective):
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perspective.setService(self)
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self.perspectives[perspective.getPerspectiveName()] = perspective
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def getPerspectiveNamed(self, name):
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"""Return a perspective that represents a user for this service. (DEPRECATED)
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Raises a KeyError if no such user exists. Override this method to
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provide dynamic instantiation of perspectives.
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return self.perspectives[name]
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def loadPerspective(self, name):
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"""Load a perspective from an external data-source.
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If no such data-source exists, return None. Implement this if you want
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to load your perspectives from somewhere else (e.g. LDAP or a
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database). It is not recommended to call this directly, since
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getPerspectiveRequest provides management of caching perspectives.
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return defer.fail("No such perspective %s" % name)
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def getPerspectiveRequest(self, name):
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"""Return a Deferred which is a request for a perspective on this service.
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p = self.getPerspectiveNamed(name)
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return self.loadPerspective(name)
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return defer.succeed(p)
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def getServiceName(self):
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"""The name of this service.
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return self.serviceName or self.getServiceType()
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def getServiceType(self):
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"""Get a string describing the type of this service.
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return self.serviceType or str(self.__class__)
added
removed
twisted/cred/service.py
