Package flumotion :: Package common :: Module signals
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Source Code for Module flumotion.common.signals

 1  # -*- Mode: Python; test-case-name: flumotion.test.test_common_signals -*- 
 2  # vi:si:et:sw=4:sts=4:ts=4 
 3  # 
 4  # Flumotion - a streaming media server 
 5  # Copyright (C) 2007 Fluendo, S.L. (www.fluendo.com). 
 6  # All rights reserved. 
 7   
 8  # This file may be distributed and/or modified under the terms of 
 9  # the GNU General Public License version 2 as published by 
10  # the Free Software Foundation. 
11  # This file is distributed without any warranty; without even the implied 
12  # warranty of merchantability or fitness for a particular purpose. 
13  # See "LICENSE.GPL" in the source distribution for more information. 
14   
15  # Licensees having purchased or holding a valid Flumotion Advanced 
16  # Streaming Server license may use this file in accordance with the 
17  # Flumotion Advanced Streaming Server Commercial License Agreement. 
18  # See "LICENSE.Flumotion" in the source distribution for more information. 
19   
20  # Headers in this file shall remain intact. 
21   
22  from flumotion.common import log 
23   
24 -class SignalMixin(object):
25 __signals__ = () 26 27 __signalConnections = None 28 __signalId = 0 29
30 - def __ensureSignals(self):
31 if self.__signalConnections is None: 32 self.__signalConnections = {}
33
34 - def connect(self, signalName, proc, *args, **kwargs):
35 self.__ensureSignals() 36 37 if signalName not in self.__signals__: 38 raise ValueError('Unknown signal for object of type %r: %s' 39 % (type(self), signalName)) 40 41 sid = self.__signalId 42 self.__signalConnections[sid] = (signalName, proc, args, kwargs) 43 self.__signalId += 1 44 return sid
45
46 - def disconnect(self, signalId):
47 self.__ensureSignals() 48 49 if signalId not in self.__signalConnections: 50 raise ValueError('Unknown signal ID: %s' % (signalId,)) 51 52 del self.__signalConnections[signalId]
53
54 - def emit(self, signalName, *args):
55 self.__ensureSignals() 56 if signalName not in self.__signals__: 57 raise ValueError('Emitting unknown signal %s' % signalName) 58 59 connections = self.__signalConnections 60 for name, proc, pargs, pkwargs in connections.values(): 61 if name == signalName: 62 try: 63 proc(self, *(args + pargs), **pkwargs) 64 except Exception, e: 65 log.warning("signalmixin", "Exception calling " 66 "signal handler %r: %s", proc, 67 log.getExceptionMessage(e))
68