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dispatcher_nb.py

##   dispatcher_nb.py
##       based on dispatcher.py
##
##   Copyright (C) 2003-2005 Alexey "Snake" Nezhdanov
##       modified by Dimitur Kirov <dkirov@gmail.com>
##
##   This program 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; either version 2, or (at your option)
##   any later version.
##
##   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.

# $Id: dispatcher.py,v 1.40 2006/01/18 19:26:43 normanr Exp $

'''
Main xmpppy mechanism. Provides library with methods to assign different handlers
to different XMPP stanzas.
Contains one tunable attribute: DefaultTimeout (25 seconds by default). It defines time that 
Dispatcher.SendAndWaitForResponce method will wait for reply stanza before giving up.
'''

import simplexml, sys
from xml.parsers.expat import ExpatError
from protocol import *
from client import PlugIn

# default timeout to wait for response for our id
DEFAULT_TIMEOUT_SECONDS = 25
ID = 0

00035 class Dispatcher(PlugIn):
      ''' Ancestor of PlugIn class. Handles XMPP stream, i.e. aware of stream headers.
            Can be plugged out/in to restart these headers (used for SASL f.e.). '''
      def __init__(self):
            PlugIn.__init__(self)
            DBG_LINE='dispatcher'
            self.handlers={}
            self._expected={}
            self._defaultHandler=None
            self._pendingExceptions=[]
            self._eventHandler=None
            self._cycleHandlers=[]
            self._exported_methods=[self.RegisterHandler, self.RegisterDefaultHandler, \
            self.RegisterEventHandler, self.UnregisterCycleHandler, self.RegisterCycleHandler, \
            self.RegisterHandlerOnce, self.UnregisterHandler, self.RegisterProtocol, \
            self.SendAndWaitForResponse, self.send,self.disconnect, \
            self.SendAndCallForResponse, self.getAnID, self.Event]

      def getAnID(self):
            global ID
            ID += 1
            return `ID`

00058       def dumpHandlers(self):
            ''' Return set of user-registered callbacks in it's internal format.
                  Used within the library to carry user handlers set over Dispatcher replugins. '''
            return self.handlers
      
00063       def restoreHandlers(self, handlers):
            ''' Restores user-registered callbacks structure from dump previously obtained via dumpHandlers.
                  Used within the library to carry user handlers set over Dispatcher replugins. '''
            self.handlers = handlers

00068       def _init(self):
            ''' Registers default namespaces/protocols/handlers. Used internally.  '''
            self.RegisterNamespace('unknown')
            self.RegisterNamespace(NS_STREAMS)
            self.RegisterNamespace(self._owner.defaultNamespace)
            self.RegisterProtocol('iq', Iq)
            self.RegisterProtocol('presence', Presence)
            self.RegisterProtocol('message', Message)
            self.RegisterDefaultHandler(self.returnStanzaHandler)
            # Register Gajim's event handler as soon as dispatcher begins
            self.RegisterEventHandler(self._owner._caller._event_dispatcher)
            self.on_responses = {}
            
00081       def plugin(self, owner):
            ''' Plug the Dispatcher instance into Client class instance and send initial stream header. Used internally.'''
            self._init()
            self._owner.lastErrNode = None
            self._owner.lastErr = None
            self._owner.lastErrCode = None
            self.StreamInit()
      
00089       def plugout(self):
            ''' Prepares instance to be destructed. '''
            self.Stream.dispatch = None
            self.Stream.DEBUG = None
            self.Stream.features = None
            self.Stream.destroy()

00096       def StreamInit(self):
            ''' Send an initial stream header. '''
            self.Stream = simplexml.NodeBuilder()
            self.Stream._dispatch_depth = 2
            self.Stream.dispatch = self.dispatch
            self.Stream.stream_header_received = self._check_stream_start
            self._owner.debug_flags.append(simplexml.DBG_NODEBUILDER)
            self.Stream.DEBUG = self._owner.DEBUG
            self.Stream.features = None
            self._metastream = Node('stream:stream')
            self._metastream.setNamespace(self._owner.Namespace)
            self._metastream.setAttr('version', '1.0')
            self._metastream.setAttr('xmlns:stream', NS_STREAMS)
            self._metastream.setAttr('to', self._owner.Server)
            self._owner.send("<?xml version='1.0'?>%s>" % str(self._metastream)[:-2])

      def _check_stream_start(self, ns, tag, attrs):
            if ns<>NS_STREAMS or tag<>'stream':
                  raise ValueError('Incorrect stream start: (%s,%s). Terminating.' % (tag, ns))

00116       def ProcessNonBlocking(self, data=None):
            ''' Check incoming stream for data waiting. If "timeout" is positive - block for as max. this time.
                  Returns:
                  1) length of processed data if some data were processed;
                  2) '0' string if no data were processed but link is alive;
                  3) 0 (zero) if underlying connection is closed.'''
            for handler in self._cycleHandlers: 
                  handler(self)
            if len(self._pendingExceptions) > 0:
                  _pendingException = self._pendingExceptions.pop()
                  raise _pendingException[0], _pendingException[1], _pendingException[2]
            try:
                  self.Stream.Parse(data)
                  # end stream:stream tag received
                  if self.Stream._NodeBuilder__depth == 0:
                        self._owner.Connection.disconnect()
                        return 0
            except ExpatError:
                  sys.exc_clear()
                  self._owner.Connection.pollend()
                  return 0
            if len(self._pendingExceptions) > 0:
                   _pendingException = self._pendingExceptions.pop()
                   raise _pendingException[0], _pendingException[1], _pendingException[2]
            return len(data)
      
00142       def RegisterNamespace(self, xmlns, order='info'):
            ''' Creates internal structures for newly registered namespace.
                  You can register handlers for this namespace afterwards. By default one namespace
                  already registered (jabber:client or jabber:component:accept depending on context. '''
            self.DEBUG('Registering namespace "%s"' % xmlns, order)
            self.handlers[xmlns]={}
            self.RegisterProtocol('unknown', Protocol, xmlns=xmlns)
            self.RegisterProtocol('default', Protocol, xmlns=xmlns)

00151       def RegisterProtocol(self, tag_name, Proto, xmlns=None, order='info'):
            ''' Used to declare some top-level stanza name to dispatcher.
               Needed to start registering handlers for such stanzas.
               Iq, message and presence protocols are registered by default. '''
            if not xmlns: xmlns=self._owner.defaultNamespace
            self.DEBUG('Registering protocol "%s" as %s(%s)' %
                                                (tag_name, Proto, xmlns), order)
            self.handlers[xmlns][tag_name]={type:Proto, 'default':[]}

00160       def RegisterNamespaceHandler(self, xmlns, handler, typ='', ns='', makefirst=0, system=0):
            ''' Register handler for processing all stanzas for specified namespace. '''
            self.RegisterHandler('default', handler, typ, ns, xmlns, makefirst, system)

00164       def RegisterHandler(self, name, handler, typ='', ns='', xmlns=None, makefirst=0, system=0):
            '''Register user callback as stanzas handler of declared type. Callback must take
                  (if chained, see later) arguments: dispatcher instance (for replying), incomed
                  return of previous handlers.
                  The callback must raise xmpp.NodeProcessed just before return if it want preven
                  callbacks to be called with the same stanza as argument _and_, more importantly
                  library from returning stanza to sender with error set (to be enabled in 0.2 ve
                  Arguments:
                        "name" - name of stanza. F.e. "iq".
                        "handler" - user callback.
                        "typ" - value of stanza's "type" attribute. If not specified any value match
                        "ns" - namespace of child that stanza must contain.
                        "chained" - chain together output of several handlers.
                        "makefirst" - insert handler in the beginning of handlers list instead of
                        adding it to the end. Note that more common handlers (i.e. w/o "typ" and "
                        will be called first nevertheless.
                        "system" - call handler even if NodeProcessed Exception were raised already.
                  '''
            if not xmlns: 
                  xmlns=self._owner.defaultNamespace
            self.DEBUG('Registering handler %s for "%s" type->%s ns->%s(%s)' % 
                                                (handler, name, typ, ns, xmlns), 'info')
            if not typ and not ns: 
                  typ='default'
            if not self.handlers.has_key(xmlns): 
                  self.RegisterNamespace(xmlns,'warn')
            if not self.handlers[xmlns].has_key(name): 
                  self.RegisterProtocol(name,Protocol,xmlns,'warn')
            if not self.handlers[xmlns][name].has_key(typ+ns): 
                  self.handlers[xmlns][name][typ+ns]=[]
            if makefirst: 
                  self.handlers[xmlns][name][typ+ns].insert(0,{'func':handler,'system':system})
            else: 
                  self.handlers[xmlns][name][typ+ns].append({'func':handler,'system':system})

00199       def RegisterHandlerOnce(self,name,handler,typ='',ns='',xmlns=None,makefirst=0, system=0):
            ''' Unregister handler after first call (not implemented yet). '''
            if not xmlns: 
                  xmlns=self._owner.defaultNamespace
            self.RegisterHandler(name, handler, typ, ns, xmlns, makefirst, system)

00205       def UnregisterHandler(self, name, handler, typ='', ns='', xmlns=None):
            ''' Unregister handler. "typ" and "ns" must be specified exactly the same as with registering.'''
            if not xmlns: 
                  xmlns=self._owner.defaultNamespace
            if not typ and not ns: 
                  typ='default'
            if not self.handlers.has_key(xmlns):
                  return
            if not self.handlers[xmlns].has_key(name): 
                  return
            if not self.handlers[xmlns][name].has_key(typ+ns): 
                  return
            for pack in self.handlers[xmlns][name][typ+ns]:
                  if handler==pack['func']: 
                        break
            else: 
                  pack=None
            try: 
                  self.handlers[xmlns][name][typ+ns].remove(pack)
            except ValueError: 
                  pass

00227       def RegisterDefaultHandler(self,handler):
            ''' Specify the handler that will be used if no NodeProcessed exception were raised.
                  This is returnStanzaHandler by default. '''
            self._defaultHandler=handler

00232       def RegisterEventHandler(self,handler):
            ''' Register handler that will process events. F.e. "FILERECEIVED" event. '''
            self._eventHandler=handler

00236       def returnStanzaHandler(self,conn,stanza):
            ''' Return stanza back to the sender with <feature-not-implemennted/> error set. '''
            if stanza.getType() in ['get','set']:
                  conn.send(Error(stanza,ERR_FEATURE_NOT_IMPLEMENTED))

      def streamErrorHandler(self,conn,error):
            name,text='error',error.getData()
            for tag in error.getChildren():
                  if tag.getNamespace()==NS_XMPP_STREAMS:
                        if tag.getName()=='text': 
                              text=tag.getData()
                        else: 
                              name=tag.getName()
            if name in stream_exceptions.keys(): 
                  exc=stream_exceptions[name]
            else: 
                  exc=StreamError
            raise exc((name,text))

00255       def RegisterCycleHandler(self, handler):
            ''' Register handler that will be called on every Dispatcher.Process() call. '''
            if handler not in self._cycleHandlers: 
                  self._cycleHandlers.append(handler)

00260       def UnregisterCycleHandler(self, handler):
            ''' Unregister handler that will is called on every Dispatcher.Process() call.'''
            if handler in self._cycleHandlers: 
                  self._cycleHandlers.remove(handler)
      
00265       def Event(self, realm, event, data):
            ''' Raise some event. Takes three arguments:
                  1) "realm" - scope of event. Usually a namespace. 
                  2) "event" - the event itself. F.e. "SUCESSFULL SEND".
                  3) data that comes along with event. Depends on event.'''
            if self._eventHandler: self._eventHandler(realm,event,data)

00272       def dispatch(self, stanza, session=None, direct=0):
            ''' Main procedure that performs XMPP stanza recognition and calling apppropriate handlers for it.
                  Called internally. '''
            if not session: 
                  session = self
            session.Stream._mini_dom = None
            name = stanza.getName()

            if not direct and self._owner._component:
                  if name == 'route':
                        if stanza.getAttr('error') == None:
                              if len(stanza.getChildren()) == 1:
                                    stanza = stanza.getChildren()[0]
                                    name=stanza.getName()
                              else:
                                    for each in stanza.getChildren():
                                          self.dispatch(each,session,direct=1)
                                    return
                  elif name == 'presence':
                        return
                  elif name in ('features','bind'):
                        pass
                  else:
                        raise UnsupportedStanzaType(name)
            
            if name=='features': 
                  session.Stream.features=stanza
            
            xmlns=stanza.getNamespace()
            if not self.handlers.has_key(xmlns):
                  self.DEBUG("Unknown namespace: " + xmlns, 'warn')
                  xmlns='unknown'
            if not self.handlers[xmlns].has_key(name):
                  self.DEBUG("Unknown stanza: " + name, 'warn')
                  name='unknown'
            else:
                  self.DEBUG("Got %s/%s stanza" % (xmlns, name), 'ok')

            if stanza.__class__.__name__=='Node': 
                  stanza=self.handlers[xmlns][name][type](node=stanza)
            
            typ=stanza.getType()
            if not typ: typ=''
            stanza.props=stanza.getProperties()
            ID=stanza.getID()
            
            session.DEBUG("Dispatching %s stanza with type->%s props->%s id->%s"%(name,typ,stanza.props,ID),'ok')
            list=['default']                                                     # we will use all handlers:
            if self.handlers[xmlns][name].has_key(typ): list.append(typ)                # from very common...
            for prop in stanza.props:
                  if self.handlers[xmlns][name].has_key(prop): list.append(prop)
                  if typ and self.handlers[xmlns][name].has_key(typ+prop): list.append(typ+prop)  # ...to very particular
            
            chain=self.handlers[xmlns]['default']['default']
            for key in list:
                  if key: chain = chain + self.handlers[xmlns][name][key]
            
            output=''
            if session._expected.has_key(ID):
                  user=0
                  if type(session._expected[ID]) == type(()):
                        cb,args = session._expected[ID]
                        session.DEBUG("Expected stanza arrived. Callback %s(%s) found!" % (cb, args), 'ok')
                        try: 
                              cb(session,stanza,**args)
                        except Exception, typ:
                              if typ.__class__.__name__ <>'NodeProcessed': raise
                  else:
                        session.DEBUG("Expected stanza arrived!",'ok')
                        session._expected[ID]=stanza
            else: 
                  user=1
            for handler in chain:
                  if user or handler['system']:
                        try:
                              handler['func'](session,stanza)
                        except Exception, typ:
                              if typ.__class__.__name__ <> 'NodeProcessed':
                                    self._pendingExceptions.insert(0, sys.exc_info())
                                    return
                              user=0
            if user and self._defaultHandler: 
                  self._defaultHandler(session, stanza)
      
      def WaitForData(self, data):
            if data is None:
                  return
            res = self.ProcessNonBlocking(data)
            # 0 result indicates that we have closed the connection, e.g.
            # we have released dispatcher, so self._owner has no methods
            if not res:
                  return
            self._owner.remove_timeout()
            if self._expected[self._witid] is None:
                  return
            if self.on_responses.has_key(self._witid):
                  i = self._witid # copy id cause it can change in resp() call
                  self._owner.onreceive(None)
                  resp, args = self.on_responses[self._witid]
                  del(self.on_responses[self._witid])
                  if args is None:
                        resp(self._expected[self._witid])
                  else:
                        resp(self._owner, self._expected[self._witid], **args)
                  del self._expected[i]
      
00378       def SendAndWaitForResponse(self, stanza, timeout=None, func=None, args=None):
            ''' Put stanza on the wire and wait for recipient's response to it. '''
            if timeout is None: 
                  timeout = DEFAULT_TIMEOUT_SECONDS
            self._witid = self.send(stanza)
            if func:
                  self.on_responses[self._witid] = (func, args)
            if timeout:
                  self._owner.set_timeout(timeout)
            self._owner.onreceive(self.WaitForData)
            self._expected[self._witid] = None
            return self._witid
      
00391       def SendAndCallForResponse(self, stanza, func=None, args=None):
            ''' Put stanza on the wire and call back when recipient replies.
                  Additional callback arguments can be specified in args. '''
            self.SendAndWaitForResponse(stanza, 0, func, args)
      
00396       def send(self, stanza):
            ''' Serialise stanza and put it on the wire. Assign an unique ID to it before send.
                  Returns assigned ID.'''
            if type(stanza) in [type(''), type(u'')]: 
                  return self._owner.Connection.send(stanza)
            if not isinstance(stanza, Protocol): 
                  _ID=None
            elif not stanza.getID():
                  global ID
                  ID+=1
                  _ID=`ID`
                  stanza.setID(_ID)
            else: 
                  _ID=stanza.getID()
            if self._owner._registered_name and not stanza.getAttr('from'): 
                  stanza.setAttr('from', self._owner._registered_name)
            if self._owner._component and stanza.getName() != 'bind':
                  to=self._owner.Server
                  if stanza.getTo() and stanza.getTo().getDomain():
                        to=stanza.getTo().getDomain()
                  frm=stanza.getFrom()
                  if frm.getDomain():
                        frm=frm.getDomain()
                  route=Protocol('route', to=to, frm=frm, payload=[stanza])
                  stanza=route
            stanza.setNamespace(self._owner.Namespace)
            stanza.setParent(self._metastream)
            self._owner.Connection.send(stanza)
            return _ID
      
00426       def disconnect(self):
            ''' Send a stream terminator. '''
            self._owner.Connection.send('</stream:stream>')

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