##language:zh
'''
Finger演化：使用Perspective Broker对Twisted客户端进行支持

The Evolution of Finger: Twisted client support using Perspective Broker
'''
-- dreamingk [<<DateTime(2004-08-09T02:13:28Z)>>]
<<TableOfContents>>
== 介绍(Introduction) ==
这是Twisted教程(Twisted入门 - Finger演化)的第七部分。

This is the seventh part of the Twisted tutorial Twisted from Scratch, or The Evolution of Finger.

在这一部分，我们会向finger应用增加一个Perspective Broker服务，以便Twisted客户端可以访问finger服务器。

In this part, we add a Perspective Broker service to the finger application so that Twisted clients can access the finger server.

== 使用Perspectivev Broker(Use Perspective Broker) ==
我们增加对perspective broker的支持，它是Twisted的本地远程对象协议。现在，Twisted客户端不再需要通过象XML-RPC化的曲折的方法来得到用户的信息。

We add support for perspective broker, Twisted's native remote object protocol. Now, Twisted clients will not have to go through XML-RPCish contortions to get information about users.

{{{
#!python
# Do everything properly, and componentize
from twisted.application import internet, service
from twisted.internet import protocol, reactor, defer
from twisted.protocols import basic, irc
from twisted.python import components
from twisted.web import resource, server, static, xmlrpc, microdom
from twisted.web.woven import page, model, interfaces
from twisted.spread import pb
import cgi

class IFingerService(components.Interface):

    def getUser(self, user):
        """Return a deferred returning a string"""

    def getUsers(self):
        """Return a deferred returning a list of strings"""

class IFingerSetterService(components.Interface):

    def setUser(self, user, status):
        """Set the user's status to something"""

def catchError(err):
    return "Internal error in server"

class FingerProtocol(basic.LineReceiver):

    def lineReceived(self, user):
        d = self.factory.getUser(user)
        d.addErrback(catchError)
        def writeValue(value):
            self.transport.write(value+'\n')
            self.transport.loseConnection()
        d.addCallback(writeValue)


class IFingerFactory(components.Interface):

    def getUser(self, user):
        """Return a deferred returning a string"""

    def buildProtocol(self, addr):
        """Return a protocol returning a string"""


class FingerFactoryFromService(protocol.ServerFactory):

    __implements__ = IFingerFactory,

    protocol = FingerProtocol

    def __init__(self, service):
        self.service = service

    def getUser(self, user):
        return self.service.getUser(user)

components.registerAdapter(FingerFactoryFromService,
                           IFingerService,
                           IFingerFactory)

class FingerSetterProtocol(basic.LineReceiver):

    def connectionMade(self):
        self.lines = []

    def lineReceived(self, line):
        self.lines.append(line)

    def connectionLost(self, reason):
        if len(self.lines) == 2:
            self.factory.setUser(*self.lines)


class IFingerSetterFactory(components.Interface):

    def setUser(self, user, status):
        """Return a deferred returning a string"""

    def buildProtocol(self, addr):
        """Return a protocol returning a string"""


class FingerSetterFactoryFromService(protocol.ServerFactory):

    __implements__ = IFingerSetterFactory,

    protocol = FingerSetterProtocol

    def __init__(self, service):
        self.service = service

    def setUser(self, user, status):
        self.service.setUser(user, status)


components.registerAdapter(FingerSetterFactoryFromService,
                           IFingerSetterService,
                           IFingerSetterFactory)

class IRCReplyBot(irc.IRCClient):

    def connectionMade(self):
        self.nickname = self.factory.nickname
        irc.IRCClient.connectionMade(self)

    def privmsg(self, user, channel, msg):
        user = user.split('!')[0]
        if self.nickname.lower() == channel.lower():
            d = self.factory.getUser(msg)
            d.addErrback(catchError)
            d.addCallback(lambda m: "Status of %s: %s" % (msg, m))
            d.addCallback(lambda m: self.msg(user, m))


class IIRCClientFactory(components.Interface):

    """
    @ivar nickname
    """       

    def getUser(self, user):
        """Return a deferred returning a string"""

    def buildProtocol(self, addr):
        """Return a protocol"""


class IRCClientFactoryFromService(protocol.ClientFactory):

    __implements__ = IIRCClientFactory,

    protocol = IRCReplyBot
    nickname = None

    def __init__(self, service):
        self.service = service

    def getUser(self, user):
        return self.service.getUser(user)

components.registerAdapter(IRCClientFactoryFromService,
                           IFingerService,
                           IIRCClientFactory)

class UsersModel(model.MethodModel):

    def initialize(self, *args, **kwargs):
        self.service=args[0]

    def wmfactory_users(self, request):
        return self.service.getUsers()

components.registerAdapter(UsersModel, IFingerService, interfaces.IModel)

class UserStatusTree(page.Page):

    template = """<html><head><title>Users</title></head><body>
    <h1>Users</h1>
    <ul model="users" view="List">
    <li pattern="listItem"><a view="Anchor" /></li>
    </ul></body></html>"""                          

    def initialize(self, *args, **kwargs):
        self.service=args[0]

    def getDynamicChild(self, path, request):
        return UserStatus(user=path, service=self.service)

    def wchild_RPC2 (self, request):
        return UserStatusXR(self.service)

components.registerAdapter(UserStatusTree, IFingerService, resource.IResource)


class UserStatus(page.Page):

    template='''<html><head><title view="Text" model="user"/></head>
    <body><h1 view="Text" model="user"/>
    <p model="status" view="Text" />
    </body></html>'''                     

    def initialize(self, **kwargs):
        self.user = kwargs['user']
        self.service = kwargs['service']

    def wmfactory_user(self, request):
        return self.user

    def wmfactory_status(self, request):
        return self.service.getUser(self.user)


class UserStatusXR(xmlrpc.XMLRPC):

    def __init__(self, service):
        xmlrpc.XMLRPC.__init__(self)
        self.service = service

    def xmlrpc_getUser(self, user):
        return self.service.getUser(user)

    def xmlrpc_getUsers(self):
        return self.service.getUsers()


class IPerspectiveFinger(components.Interface):

    def remote_getUser(self, username):
        """return a user's status"""

    def remote_getUsers(self):
        """return a user's status"""

class PerspectiveFingerFromService(pb.Root):

    __implements__ = pb.Root.__implements__, IPerspectiveFinger

    def __init__(self, service):
        self.service = service

    def remote_getUser(self, username):
        return self.service.getUser(username)

    def remote_getUsers(self):
        return self.service.getUsers()

components.registerAdapter(PerspectiveFingerFromService,
                           IFingerService,
                           IPerspectiveFinger)


class FingerService(service.Service):

    __implements__ = IFingerService,

    def __init__(self, filename):
        self.filename = filename
        self._read()

    def _read(self):
        self.users = {}
        for line in file(self.filename):
            user, status = line.split(':', 1)
            user = user.strip()
            status = status.strip()
            self.users[user] = status
        self.call = reactor.callLater(30, self._read)

    def getUser(self, user):
        return defer.succeed(self.users.get(user, "No such user"))

    def getUsers(self):
        return defer.succeed(self.users.keys())


application = service.Application('finger', uid=1, gid=1)
f = FingerService('/etc/users')
serviceCollection = service.IServiceCollection(application)
internet.TCPServer(79, IFingerFactory(f)
                   ).setServiceParent(serviceCollection)
internet.TCPServer(8000, server.Site(resource.IResource(f))
                   ).setServiceParent(serviceCollection)
i = IIRCClientFactory(f)
i.nickname = 'fingerbot'
internet.TCPClient('irc.freenode.org', 6667, i
                   ).setServiceParent(serviceCollection)
internet.TCPServer(8889, pb.PBServerFactory(IPerspectiveFinger(f))
                   ).setServiceParent(serviceCollection)

Source listing - listings/finger/finger21.py
A simple client to test the perspective broker finger:

# test the PB finger on port 8889
# this code is essentially the same as
# the first example in howto/pb-usage

from twisted.spread import pb
from twisted.internet import reactor

def gotObject(object):
    print "got object:", object
    object.callRemote("getUser","moshez").addCallback(gotData)
# or
#   object.callRemote("getUsers").addCallback(gotData)

def gotData(data):
    print 'server sent:', data
    reactor.stop()

def gotNoObject(reason):
    print "no object:",reason
    reactor.stop()

factory = pb.PBClientFactory()
reactor.connectTCP("127.0.0.1",8889, factory)
factory.getRootObject().addCallbacks(gotObject,gotNoObject)
reactor.run()




}}}

Source listing - listings/finger/fingerPBclient.py

return index-->[[TwistedTUT]]

Version: 1.3.0