Source Code for Module bzProtocol

  1  ##bzProtocol.py handles BZoo protocol. 
  2  ##Copyright (C) 2006  Jean-Baptiste PERIN 
  3  ## 
  4  ##This program is free software; you can redistribute it and/or 
  5  ##modify it under the terms of the GNU General Public License 
  6  ##as published by the Free Software Foundation; either version 2 
  7  ##of the License, or (at your option) any later version. 
  8  ## 
  9  ##This program is distributed in the hope that it will be useful, 
 10  ##but WITHOUT ANY WARRANTY; without even the implied warranty of 
 11  ##MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 12  ##GNU General Public License for more details. 
 13  ## 
 14  ##You should have received a copy of the GNU General Public License 
 15  ##along with this program; if not, write to the Free Software 
 16  ##Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
 17  """ 
 18   This module contains classes involved in dialogue handling between clients and server. 
 19  """ 
 20   
 21  # TODO: Faire en sorte de gerer une taille max de packet client/serveur et serveur client 
 22  # TODO: mettre en place la transmission de "gros pacquets" en tache de fond 
 23   
 24  import struct 
 25  import bzMessage 
 26   
 27 -class bzProtocol: 
 28      """ 
 29      This class provides BZoo applications with message packing and unpacking services. 
 30   
 31      Exemple:: 
 32          import bzMessage 
 33           
 34          def myHandlerFct(values): 
 35              messages = values 
 36              print "I've just received message(s): ", messages 
 37                       
 38                    
 39          # initialisation of protocol and message list 
 40          aProtocol = bzProtocol()    
 41          message_queue = [] 
 42          message_queue.append(bzMessage.SayMessage("Hello World")) 
 43           
 44          # setup a handler on reception of message 
 45          self.aProtocol(bzMessage.CLIENTS_MESSAGES_MESSAGE,myHandlerFct) 
 46   
 47          # prepare raw data to send from current list of message 
 48          data2send = aProtocol.getNextDataMessage(message_queue, 1024) 
 49                         
 50          SendData (data2send) 
 51   
 52          # process incoming message 
 53          data = ReceiveData () 
 54          if (data is not None): 
 55              aProtocol.processDataMessage(data) 
 56       
 57      @ivar MessageTable: 
 58      @type MessageTable: 
 59      @ivar HandlerTable: gives the functions to  
 60      @type HandlerTable: list of list of handler function 
 61      """ 
 62   
 63 -    def __init__ (self,): 
 64           
 65          self.MessageTable = [ None for i in bzMessage.msgid] 
 66          #TODO: Put this table in bzMessage Module so that bzProtocol has nothing to do with messages types 
 67          self.MessageTable[bzMessage.POSITION_REPORT_MESSAGE] = bzMessage.PositionReport () 
 68          self.MessageTable[bzMessage.SITUATION_REPORT_MESSAGE] = bzMessage.ClientsSituationReport () 
 69          self.MessageTable[bzMessage.SAY_MESSAGE] = bzMessage.SayMessage () 
 70          self.MessageTable[bzMessage.CLIENTS_MESSAGES_MESSAGE] = bzMessage.ClientsMessages () 
 71          self.MessageTable[bzMessage.PRIVATE_SAY_MESSAGE] = bzMessage.PrivateSayMessage () 
 72          self.MessageTable[bzMessage.WELCOME_MESSAGE] = bzMessage.WelcomeMessage () 
 73          self.MessageTable[bzMessage.INIT_INVENTORY_MESSAGE] = bzMessage.InitInventory () 
 74          self.MessageTable[bzMessage.GRAB_OBJECT_MESSAGE] = bzMessage.GrabObject () 
 75          self.MessageTable[bzMessage.VANISH_OBJECT_MESSAGE] = bzMessage.VanishObject () 
 76          self.MessageTable[bzMessage.INVENTORY_ADD_MESSAGE] = bzMessage.InventoryAdd () 
 77          self.MessageTable[bzMessage.INSTANCIATE_OBJECT_MESSAGE] = bzMessage.InstanciateObject () 
 78          self.MessageTable[bzMessage.ACTIVATE_OBJECT_MESSAGE] = bzMessage.ActivateObject () 
 79          self.MessageTable[bzMessage.RELEASE_OBJECT_MESSAGE] = bzMessage.ReleaseObject () 
 80          self.MessageTable[bzMessage.RELEASE_OBJECT_MESSAGE] = bzMessage.ReleaseObject () 
 81          self.MessageTable[bzMessage.STORE_AVATAR_MESSAGE] = bzMessage.StoreAvatar () 
 82          self.MessageTable[bzMessage.DECLARE_VAR_MESSAGE] = bzMessage.DeclareVar () 
 83   
 84          self.HandlerTable = [ [] for i in bzMessage.msgid] 
 85           
 86   
 87          #self.state = 0 
 88       
 89 -    def __repr__ (self): 
 90          return "" 
 91   
 92 -    def addHandler (self, msgType, fct): 
 93          """ 
 94          Add a handler on reception of a peculiar message 
 95          @param msgType: the type of the message to attach the handler to  
 96          @type msgType: integer. 
 97          @param fct: the handler function.  
 98          @type fct: function. 
 99          """ 
100          self.HandlerTable[msgType].append(fct) 
101   
102       
103 -    def getNextDataMessage(self, msg_list, max_size): 
104          """ 
105          Build a packed data block  
106          @param msg_list: The server hostname or IP adress  
107          @type msg_list: String. 
108          @param max_size: the maximum size of the data packet to produce  
109          @type max_size: Integer 
110          @return: the next packed data block to send. 
111          @rtype: byte array. 
112          """ 
113          current_size = 0 
114          data = '' 
115          while len(msg_list) != 0: 
116              msg = msg_list.pop(0) 
117              data = data + msg.Encode() 
118          return data 
119   
120   
121   
122 -    def processDataMessage(self, data): 
123          """ 
124          Unpack received data into messages and call associated handler. 
125          @param data: A packed data block  
126          @type data: byte array. 
127          """ 
128   
129         
130          idx_byte = 0 
131          while (idx_byte < len(data)): 
132              try: 
133   
134                  [msgType] = struct.unpack('B', data[idx_byte]) 
135                  nb_byte, values = self.MessageTable[msgType].Decode(data[idx_byte:len(data)]) 
136                  for hdlr in self.HandlerTable[msgType]: 
137                      hdlr(values) 
138              except struct.error: 
139                  print "ERROR: Unable to unpack data" 
140                  break 
141                   
142              idx_byte = idx_byte + nb_byte 
143   
144  if __name__ == "__main__": 
145   
146       
147      aProtocol = bzProtocol() 
148       
149      aPR = bzMessage.PositionReport (position = [0.0, 0.0, 0.0], orientation = [[1.0, 0.0, 0.0],[0.0, 1.0, 0.0],[0.0, 0.0, 1.0]], action = 0) 
150       
151      del aProtocol 
152