# -*- test-case-name: twisted.test.test_cred -*-
# Twisted, the Framework of Your Internet
# Copyright (C) 2001 Matthew W. Lefkowitz
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
"""
This module is for domain-specific representations of users.
Stability: semi-stable
Future Plans: Errors may be changed to unify reporting in twisted.cred.
"""
from twisted.python import log,reflect
from twisted.cred import identity
import types
class Perspective:
"""I am an Identity's view onto a service.
I am the interface through which most 'external' code should
interact with a service; I represent the actions a user may
perform upon a service, and the state associated with that
user for that service.
"""
_service_cached = 0 # Has my service cached me from a loaded store, or do I live in memory usually?
def __init__(self, perspectiveName, identityName="Nobody"):
"""Create me.
I require a name for myself and a reference to the service
I participate in. (My identity name will be 'Nobody' by
default, which will normally not resolve.)
"""
if not isinstance(perspectiveName, types.StringType):
raise TypeError("Expected string, got %s."% perspectiveName)
if not isinstance(identityName, types.StringType):
raise TypeError("Expected string, got %s."% identityName)
self.perspectiveName = perspectiveName
self.identityName = identityName
def setIdentityName(self, name):
if not isinstance(name, types.StringType):
raise TypeError
self.identityName = name
def setIdentity(self, ident):
"""Determine which identity I connect to.
"""
if not isinstance(ident, identity.Identity):
raise TypeError
self.setIdentityName(ident.name)
def makeIdentity(self, password):
"""Make an identity from this perspective with a password.
This is a utility method, which can be used in circumstances
where the distinction between Perspective and Identity is weak,
such as single-Service servers.
"""
if not isinstance(password, types.StringType):
raise TypeError
ident = self.service.authorizer.createIdentity(self.perspectiveName)
# ident = identity.Identity(self.perspectiveName, self.service.application)
self.setIdentity(ident)
ident.setPassword(password)
ident.addKeyForPerspective(self)
ident.save()
return ident
def getPerspectiveName(self):
"""Return the unique name of this perspective.
This will return a value such that
self.service.getPerspectiveNamed(value) is self.
(XXX: That's assuming I have been addPerspective'd to my service.)
"""
return self.perspectiveName
def getService(self):
"""Return a service.
"""
return self.service
def setService(self, service):
"""Change what service I am a part of.
"""
self.service = service
def getIdentityRequest(self):
"""Request my identity.
"""
return (self.service.authorizer.
getIdentityRequest(self.identityName))
_attachedCount = 0
def attached(self, reference, identity):
"""Called when a remote reference is 'attached' to me.
After being authorized, a remote actor can attach to me
through its identity. This call will be made when that
happens, and the return value of this method will be used
as the _actual_ perspective to which I am attached.
Note that the symmetric call, detached, will be made on
whatever this method returns, _not_ on me. Therefore,
by default I return 'self'.
"""
log.msg('attached [%s]' % reflect.qual(self.__class__))
self._attachedCount = self._attachedCount + 1
if self._attachedCount == 1:
self.service.cachePerspective(self)
else:
log.msg(" (multiple references attached: %s)" % self._attachedCount)
return self
def detached(self, reference, identity):
"""Called when a broker is 'detached' from me.
See 'attached'.
When a remote actor disconnects (or times out, for example,
with HTTP), this is called in order to indicate that the
reference associated with that peer is no longer attached to
this perspective.
"""
log.msg('detached [%s]' % reflect.qual(self.__class__))
self._attachedCount = self._attachedCount - 1
if self._attachedCount <= 0:
self.service.uncachePerspective(self)
if self._attachedCount < 0:
log.msg(" (Weird stuff: attached count = %s)" % self._attachedCount)
else:
log.msg(" (multiple references attached: %s)" % self._attachedCount)
return self
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