krpc.py

   1 ## Copyright 2002-2003 Andrew Loewenstern, All Rights Reserved
   2 # see LICENSE.txt for license information
   3
   4 import airhook
   5 from twisted.internet.defer import Deferred
   6 from twisted.protocols import basic
   7 from bencode import bencode, bdecode
   8 from twisted.internet import reactor
   9 import time
  10
  11 import hash
  12
  13 KRPC_TIMEOUT = 60
  14
  15 KRPC_ERROR = 1
  16 KRPC_ERROR_METHOD_UNKNOWN = 2
  17 KRPC_ERROR_RECEIVED_UNKNOWN = 3
  18 KRPC_ERROR_TIMEOUT = 4
  19
  20 class KRPC(basic.NetstringReceiver):
  21     noisy = 1
  22     def __init__(self):
  23         self.tids = {}
  24
  25
  26     def dataRecieved(self, data):
  27         basic.NetstringReceiver(self, data)
  28         if self.brokenPeer:
  29             self.resetConnection()
  30
  31     def resetConnection(self):
  32         self.brokenPeer = 0
  33         self._readerState = basic.LENGTH
  34         self._readerLength = 0
  35
  36     def stringReceived(self, str):
  37         # bdecode
  38         try:
  39             msg = bdecode(str)
  40         except Exception, e:
  41             if self.naisy:
  42                 print "response decode error: " + `e`
  43             self.d.errback()
  44         else:
  45             # look at msg type
  46             if msg['typ']  == 'req':
  47                 ilen = len(str)
  48                 # if request
  49                 #       tell factory to handle
  50                 f = getattr(self.factory ,"krpc_" + msg['req'], None)
  51                 if f and callable(f):
  52                     msg['arg']['_krpc_sender'] =  self.transport.addr
  53                     try:
  54                         ret = apply(f, (), msg['arg'])
  55                     except Exception, e:
  56                         ## send error
  57                         out = bencode({'tid':msg['tid'], 'typ':'err', 'err' :`e`})
  58                         olen = len(out)
  59                         self.sendString(out)
  60                     else:
  61                         if ret:
  62                             #   make response
  63                             out = bencode({'tid' : msg['tid'], 'typ' : 'rsp', 'rsp' : ret})
  64                         else:
  65                             out = bencode({'tid' : msg['tid'], 'typ' : 'rsp', 'rsp' : {}})
  66                         #       send response
  67                         olen = len(out)
  68                         self.sendString(out)
  69
  70                 else:
  71                     if self.noisy:
  72                         print "don't know about method %s" % msg['req']
  73                     # unknown method
  74                     out = bencode({'tid':msg['tid'], 'typ':'err', 'err' : KRPC_ERROR_METHOD_UNKNOWN})
  75                     olen = len(out)
  76                     self.sendString(out)
  77                 if self.noisy:
  78                     print "%s %s >>> %s - %s %s %s" % (time.asctime(), self.transport.addr, self.factory.node.port,
  79                                                     ilen, msg['req'], olen)
  80             elif msg['typ'] == 'rsp':
  81                 # if response
  82                 #       lookup tid
  83                 if self.tids.has_key(msg['tid']):
  84                     df = self.tids[msg['tid']]
  85                     #   callback
  86                     del(self.tids[msg['tid']])
  87                     df.callback({'rsp' : msg['rsp'], '_krpc_sender': self.transport.addr})
  88                 else:
  89                     print 'timeout ' + `msg['rsp']['sender']`
  90                     # no tid, this transaction timed out already...
  91             elif msg['typ'] == 'err':
  92                 # if error
  93                 #       lookup tid
  94                 df = self.tids[msg['tid']]
  95                 #       callback
  96                 df.errback(msg['err'])
  97                 del(self.tids[msg['tid']])
  98             else:
  99                 print "unknown message type " + `msg`
 100                 # unknown message type
 101                 df = self.tids[msg['tid']]
 102                 #       callback
 103                 df.errback(KRPC_ERROR_RECEIVED_UNKNOWN)
 104                 del(self.tids[msg['tid']])
 105
 106     def sendRequest(self, method, args):
 107         # make message
 108         # send it
 109         msg = {'tid' : hash.newID(), 'typ' : 'req',  'req' : method, 'arg' : args}
 110         str = bencode(msg)
 111         d = Deferred()
 112         self.tids[msg['tid']] = d
 113         def timeOut(tids = self.tids, id = msg['tid']):
 114             if tids.has_key(id):
 115                 df = tids[id]
 116                 del(tids[id])
 117                 print ">>>>>> KRPC_ERROR_TIMEOUT"
 118                 df.errback(KRPC_ERROR_TIMEOUT)
 119         reactor.callLater(KRPC_TIMEOUT, timeOut)
 120         self.sendString(str)
 121         return d
 122