#--------------------------------------------------------------------------- """ This module provides a publish-subscribe component that allows listeners to subcribe to messages of a given topic. Contrary to the original wxPython.lib.pubsub module, which it is based on, it uses weak referencing to the subscribers so the subscribers are not kept alive by the Publisher. Also, callable objects can be used in addition to functions and bound methods. See Publisher class docs for more details. Thanks to Robb Shecter and Robin Dunn for having provided the basis for this module (which now shares most of the concepts but very little design or implementation with the original wxPython.lib.pubsub). :Author: Oliver Schoenborn :Since: Apr 2004 :Version: $Id$ :Copyright: \(c) 2004 Oliver Schoenborn :License: wxWidgets Implementation notes -------------------- In class Publisher, I represent the topics-listener set as a tree where each node is a topic, and contains a list of listeners of that topic, and a dictionary of subtopics of that topic. When the Publisher is told to send a message for a given topic, it traverses the tree down to the topic for which a message is being generated, all listeners on the way get sent the message. Publisher currently uses a weak listener topic tree to store the topics for each listener, and if a listener dies before being unsubscribed, the tree is notified, and the tree eliminates the listener from itself. Ideally, _TopicTreeNode would be a generic _TreeNode with named subnodes, and _TopicTreeRoot would be a generic _Tree with named nodes, and Publisher would store listeners in each node and a topic tuple would be converted to a path in the tree. This would lead to a much cleaner separation of concerns. But time is over, time to move on. """ #--------------------------------------------------------------------------- # for function and method parameter counting: from types import InstanceType from inspect import getargspec, ismethod, isfunction # for weakly bound methods: from new import instancemethod as InstanceMethod from weakref import ref as WeakRef # ----------------------------------------------------------------------------- def _isbound(method): """Return true if method is a bound method, false otherwise""" assert ismethod(method) return method.im_self is not None def _paramMinCountFunc(function): """Given a function, return pair (min,d) where min is minimum # of args required, and d is number of default arguments.""" assert isfunction(function) (args, va, kwa, dflt) = getargspec(function) lenDef = len(dflt or ()) return (len(args or ()) - lenDef, lenDef) def _paramMinCount(callableObject): """ Given a callable object (function, method or callable instance), return pair (min,d) where min is minimum # of args required, and d is number of default arguments. The 'self' parameter, in the case of methods, is not counted. """ if type(callableObject) is InstanceType: min, d = _paramMinCountFunc(callableObject.__call__.im_func) return min-1, d elif ismethod(callableObject): min, d = _paramMinCountFunc(callableObject.im_func) return min-1, d elif isfunction(callableObject): return _paramMinCountFunc(callableObject) else: raise 'Cannot determine type of callable: '+repr(callableObject) def _tupleize(items): """Convert items to tuple if not already one, so items must be a list, tuple or non-sequence""" if isinstance(items, list): raise TypeError, 'Not allowed to tuple-ize a list' elif isinstance(items, (str, unicode)) and items.find('.') != -1: items = tuple(items.split('.')) elif not isinstance(items, tuple): items = (items,) return items def _getCallableName(callable): """Get name for a callable, ie function, bound method or callable instance""" if ismethod(callable): return '%s.%s ' % (callable.im_self, callable.im_func.func_name) elif isfunction(callable): return '%s ' % callable.__name__ else: return '%s ' % callable def _removeItem(item, fromList): """Attempt to remove item from fromList, return true if successful, false otherwise.""" try: fromList.remove(item) return True except ValueError: return False # ----------------------------------------------------------------------------- class _WeakMethod: """Represent a weak bound method, i.e. a method doesn't keep alive the object that it is bound to. It uses WeakRef which, used on its own, produces weak methods that are dead on creation, not very useful. Typically, you will use the getRef() function instead of using this class directly. """ def __init__(self, method, notifyDead = None): """The method must be bound. notifyDead will be called when object that method is bound to dies. """ assert ismethod(method) if method.im_self is None: raise ValueError, "We need a bound method!" if notifyDead is None: self.objRef = WeakRef(method.im_self) else: self.objRef = WeakRef(method.im_self, notifyDead) self.fun = method.im_func self.cls = method.im_class def __call__(self): """Returns a new.instancemethod if object for method still alive. Otherwise return None. Note that instancemethod causes a strong reference to object to be created, so shouldn't save the return value of this call. Note also that this __call__ is required only for compatibility with WeakRef.ref(), otherwise there would be more efficient ways of providing this functionality.""" if self.objRef() is None: return None else: return InstanceMethod(self.fun, self.objRef(), self.cls) def __cmp__(self, method2): """Two _WeakMethod objects compare equal if they refer to the same method of the same instance.""" return hash(self) - hash(method2) def __hash__(self): """Hash must depend on WeakRef of object, and on method, so that separate methods, bound to same object, can be distinguished. I'm not sure how robust this hash function is, any feedback welcome.""" return hash(self.fun)/2 + hash(self.objRef)/2 def __repr__(self): dead = '' if self.objRef() is None: dead = '; DEAD' obj = '<%s at %s%s>' % (self.__class__, id(self), dead) return obj def refs(self, weakRef): """Return true if we are storing same object referred to by weakRef.""" return self.objRef == weakRef def _getWeakRef(obj, notifyDead=None): """Get a weak reference to obj. If obj is a bound method, a _WeakMethod object, that behaves like a WeakRef, is returned, if it is anything else a WeakRef is returned. If obj is an unbound method, a ValueError will be raised.""" if ismethod(obj): createRef = _WeakMethod else: createRef = WeakRef if notifyDead is None: return createRef(obj) else: return createRef(obj, notifyDead) # ----------------------------------------------------------------------------- def getStrAllTopics(): """Function to call if, for whatever reason, you need to know explicitely what is the string to use to indicate 'all topics'.""" return '' # alias, easier to see where used ALL_TOPICS = getStrAllTopics() # ----------------------------------------------------------------------------- class _NodeCallback: """Encapsulate a weak reference to a method of a TopicTreeNode in such a way that the method can be called, if the node is still alive, but the callback does not *keep* the node alive. Also, define two methods, preNotify() and noNotify(), which can be redefined to something else, very useful for testing. """ def __init__(self, obj): self.objRef = _getWeakRef(obj) def __call__(self, weakCB): notify = self.objRef() if notify is not None: self.preNotify(weakCB) notify(weakCB) else: self.noNotify() def preNotify(self, dead): """'Gets called just before our callback (self.objRef) is called""" pass def noNotify(self): """Gets called if the TopicTreeNode for this callback is dead""" pass class _TopicTreeNode: """A node in the topic tree. This contains a list of callables that are interested in the topic that this node is associated with, and contains a dictionary of subtopics, whose associated values are other _TopicTreeNodes. The topic of a node is not stored in the node, so that the tree can be implemented as a dictionary rather than a list, for ease of use (and, likely, performance). Note that it uses _NodeCallback to encapsulate a callback for when a registered listener dies, possible thanks to WeakRef. Whenever this callback is called, the onDeadListener() function, passed in at construction time, is called (unless it is None). """ def __init__(self, topicPath, onDeadListenerWeakCB): self.__subtopics = {} self.__callables = [] self.__topicPath = topicPath self.__onDeadListenerWeakCB = onDeadListenerWeakCB def getPathname(self): """The complete node path to us, ie., the topic tuple that would lead to us""" return self.__topicPath def createSubtopic(self, subtopic, topicPath): """Create a child node for subtopic""" return self.__subtopics.setdefault(subtopic, _TopicTreeNode(topicPath, self.__onDeadListenerWeakCB)) def hasSubtopic(self, subtopic): """Return true only if topic string is one of subtopics of this node""" return self.__subtopics.has_key(subtopic) def getNode(self, subtopic): """Return ref to node associated with subtopic""" return self.__subtopics[subtopic] def addCallable(self, callable): """Add a callable to list of callables for this topic node""" try: id = self.__callables.index(_getWeakRef(callable)) return self.__callables[id] except ValueError: wrCall = _getWeakRef(callable, _NodeCallback(self.__notifyDead)) self.__callables.append(wrCall) return wrCall def getCallables(self): """Get callables associated with this topic node""" return [cb() for cb in self.__callables if cb() is not None] def hasCallable(self, callable): """Return true if callable in this node""" try: self.__callables.index(_getWeakRef(callable)) return True except ValueError: return False def sendMessage(self, message): """Send a message to our callables""" deliveryCount = 0 for cb in self.__callables: listener = cb() if listener is not None: listener(message) deliveryCount += 1 return deliveryCount def removeCallable(self, callable): """Remove weak callable from our node (and return True). Does nothing if not here (and returns False).""" try: self.__callables.remove(_getWeakRef(callable)) return True except ValueError: return False def clearCallables(self): """Abandon list of callables to caller. We no longer have any callables after this method is called.""" tmpList = [cb for cb in self.__callables if cb() is not None] self.__callables = [] return tmpList def __notifyDead(self, dead): """Gets called when a listener dies, thanks to WeakRef""" #print 'TreeNODE', `self`, 'received death certificate for ', dead self.__cleanupDead() if self.__onDeadListenerWeakCB is not None: cb = self.__onDeadListenerWeakCB() if cb is not None: cb(dead) def __cleanupDead(self): """Remove all dead objects from list of callables""" self.__callables = [cb for cb in self.__callables if cb() is not None] def __str__(self): """Print us in a not-so-friendly, but readable way, good for debugging.""" strVal = [] for callable in self.getCallables(): strVal.append(_getCallableName(callable)) for topic, node in self.__subtopics.iteritems(): strVal.append(' (%s: %s)' %(topic, node)) return ''.join(strVal) class _TopicTreeRoot(_TopicTreeNode): """ The root of the tree knows how to access other node of the tree and is the gateway of the tree user to the tree nodes. It can create topics, and and remove callbacks, etc. For efficiency, it stores a dictionary of listener-topics, so that unsubscribing a listener just requires finding the topics associated to a listener, and finding the corresponding nodes of the tree. Without it, unsubscribing would require that we search the whole tree for all nodes that contain given listener. Since Publisher is a singleton, it will contain all topics in the system so it is likely to be a large tree. However, it is possible that in some runs, unsubscribe() is called very little by the user, in which case most unsubscriptions are automatic, ie caused by the listeners dying. In this case, a flag is set to indicate that the dictionary should be cleaned up at the next opportunity. This is not necessary, it is just an optimization. """ def __init__(self): self.__callbackDict = {} self.__callbackDictCleanup = 0 # all child nodes will call our __rootNotifyDead method # when one of their registered listeners dies _TopicTreeNode.__init__(self, (ALL_TOPICS,), _getWeakRef(self.__rootNotifyDead)) def addTopic(self, topic, listener): """Add topic to tree if doesnt exist, and add listener to topic node""" assert isinstance(topic, tuple) topicNode = self.__getTreeNode(topic, make=True) weakCB = topicNode.addCallable(listener) assert topicNode.hasCallable(listener) theList = self.__callbackDict.setdefault(weakCB, []) assert self.__callbackDict.has_key(weakCB) # add it only if we don't already have it try: weakTopicNode = WeakRef(topicNode) theList.index(weakTopicNode) except ValueError: theList.append(weakTopicNode) assert self.__callbackDict[weakCB].index(weakTopicNode) >= 0 def getTopics(self, listener): """Return the list of topics for given listener""" weakNodes = self.__callbackDict.get(_getWeakRef(listener), []) return [weakNode().getPathname() for weakNode in weakNodes if weakNode() is not None] def isSubscribed(self, listener, topic=None): """Return true if listener is registered for topic specified. If no topic specified, return true if subscribed to something. Use topic=getStrAllTopics() to determine if a listener will receive messages for all topics.""" weakCB = _getWeakRef(listener) if topic is None: return self.__callbackDict.has_key(weakCB) else: topicPath = _tupleize(topic) for weakNode in self.__callbackDict[weakCB]: if topicPath == weakNode().getPathname(): return True return False def unsubscribe(self, listener, topicList): """Remove listener from given list of topics. If topicList doesn't have any topics for which listener has subscribed, the onNotSubscribed callback, if not None, will be called, as onNotSubscribed(listener, topic).""" weakCB = _getWeakRef(listener) if not self.__callbackDict.has_key(weakCB): return cbNodes = self.__callbackDict[weakCB] if topicList is None: for weakNode in cbNodes: weakNode().removeCallable(listener) del self.__callbackDict[weakCB] return for weakNode in cbNodes: node = weakNode() if node is not None and node.getPathname() in topicList: success = node.removeCallable(listener) assert success == True cbNodes.remove(weakNode) assert not self.isSubscribed(listener, node.getPathname()) def unsubAll(self, topicList, onNoSuchTopic): """Unsubscribe all listeners registered for any topic in topicList. If a topic in the list does not exist, and onNoSuchTopic is not None, a call to onNoSuchTopic(topic) is done for that topic.""" for topic in topicList: node = self.__getTreeNode(topic) if node is not None: weakCallables = node.clearCallables() for callable in weakCallables: weakNodes = self.__callbackDict[callable] success = _removeItem(WeakRef(node), weakNodes) assert success == True if weakNodes == []: del self.__callbackDict[callable] elif onNoSuchTopic is not None: onNoSuchTopic(topic) def sendMessage(self, topic, message, onTopicNeverCreated): """Send a message for given topic to all registered listeners. If topic doesn't exist, call onTopicNeverCreated(topic).""" # send to the all-toipcs listeners deliveryCount = _TopicTreeNode.sendMessage(self, message) # send to those who listen to given topic or any of its supertopics node = self for topicItem in topic: assert topicItem != '' if node.hasSubtopic(topicItem): node = node.getNode(topicItem) deliveryCount += node.sendMessage(message) else: # topic never created, don't bother continuing if onTopicNeverCreated is not None: onTopicNeverCreated(aTopic) break return deliveryCount def numListeners(self): """Return a pair (live, dead) with count of live and dead listeners in tree""" dead, live = 0, 0 for cb in self.__callbackDict: if cb() is None: dead += 1 else: live += 1 return live, dead # clean up the callback dictionary after how many dead listeners callbackDeadLimit = 10 def __rootNotifyDead(self, dead): #print 'TreeROOT received death certificate for ', dead self.__callbackDictCleanup += 1 if self.__callbackDictCleanup > _TopicTreeRoot.callbackDeadLimit: self.__callbackDictCleanup = 0 oldDict = self.__callbackDict self.__callbackDict = {} for weakCB, weakNodes in oldDict.iteritems(): if weakCB() is not None: self.__callbackDict[weakCB] = weakNodes def __getTreeNode(self, topic, make=False): """Return the tree node for 'topic' from the topic tree. If it doesnt exist and make=True, create it first.""" # if the all-topics, give root; if topic == (ALL_TOPICS,): return self # not root, so traverse tree node = self path = () for topicItem in topic: path += (topicItem,) if topicItem == ALL_TOPICS: raise ValueError, 'Topic tuple must not contain ""' if make: node = node.createSubtopic(topicItem, path) elif node.hasSubtopic(topicItem): node = node.getNode(topicItem) else: return None # done return node def printCallbacks(self): strVal = ['Callbacks:\n'] for listener, weakTopicNodes in self.__callbackDict.iteritems(): topics = [topic() for topic in weakTopicNodes if topic() is not None] strVal.append(' %s: %s\n' % (_getCallableName(listener()), topics)) return ''.join(strVal) def __str__(self): return 'all: %s' % _TopicTreeNode.__str__(self) # ----------------------------------------------------------------------------- class Publisher: """ The publish/subscribe manager. It keeps track of which listeners are interested in which topics (see subscribe()), and sends a Message for a given topic to listeners that have subscribed to that topic, with optional user data (see sendMessage()). The three important concepts for Publisher are: - listener: a function, bound method or callable object that can be called with only one parameter (not counting 'self' in the case of methods). The parameter will be a reference to a Message object. E.g., these listeners are ok:: class Foo: def __call__(self, a, b=1): pass # can be called with only one arg def meth(self, a): pass # takes only one arg def meth2(self, a=2, b=''): pass # can be called with one arg def func(a, b=''): pass Foo foo Publisher().subscribe(foo) # functor Publisher().subscribe(foo.meth) # bound method Publisher().subscribe(foo.meth2) # bound method Publisher().subscribe(func) # function The three types of callables all have arguments that allow a call with only one argument. In every case, the parameter 'a' will contain the message. - topic: a single word, a tuple of words, or a string containing a set of words separated by dots, for example: 'sports.baseball'. A tuple or a dotted notation string denotes a hierarchy of topics from most general to least. For example, a listener of this topic:: ('sports','baseball') would receive messages for these topics:: ('sports', 'baseball') # because same ('sports', 'baseball', 'highscores') # because more specific but not these:: 'sports' # because more general ('sports',) # because more general () or ('') # because only for those listening to 'all' topics ('news') # because different topic - message: this is an instance of Message, containing the topic for which the message was sent, and any data the sender specified. :note: This class is visible to importers of pubsub only as a Singleton. I.e., every time you execute 'Publisher()', it's actually the same instance of publisher that is returned. So to use, just do 'Publisher().method()'. """ __ALL_TOPICS_TPL = (ALL_TOPICS, ) def __init__(self): self.__messageCount = 0 self.__deliveryCount = 0 self.__topicTree = _TopicTreeRoot() # # Public API # def getDeliveryCount(self): """How many listeners have received a message since beginning of run""" return self.__deliveryCount def getMessageCount(self): """How many times sendMessage() was called since beginning of run""" return self.__messageCount def subscribe(self, listener, topic = ALL_TOPICS): """ Subscribe listener for given topic. If topic is not specified, listener will be subscribed for all topics (that listener will receive a Message for any topic for which a message is generated). This method may be called multiple times for one listener, registering it with many topics. It can also be invoked many times for a particular topic, each time with a different listener. See the class doc for requirements on listener and topic. :note: Calling this method for the same listener, with two topics in the same branch of the topic hierarchy, will cause the listener to be notified twice when a message for the deepest topic is sent. E.g. subscribe(listener, 't1') and then subscribe(listener, ('t1','t2')) means that when calling sendMessage('t1'), listener gets one message, but when calling sendMessage(('t1','t2')), listener gets message twice. This effect could be eliminated but it would not be safe to do so: how do we know what topic to give the listener? Answer appears trivial at first but is far from obvious. It is best to rely on the user to be careful about who registers for what topics. """ self.validate(listener) if topic is None: raise TypeError, 'Topic must be either a word, tuple of '\ 'words, or getStrAllTopics()' self.__topicTree.addTopic(_tupleize(topic), listener) def isSubscribed(self, listener, topic=None): """Return true if listener has subscribed to topic specified. If no topic specified, return true if subscribed to something. Use getStrAllTopics() to determine if a listener will receive messages for all topics.""" return self.__topicTree.isSubscribed(listener, topic) def validate(self, listener): """Similar to isValid(), but raises a TypeError exception if not valid""" # check callable if not callable(listener): raise TypeError, 'Listener '+`listener`+' must be a '\ 'function, bound method or instance.' # ok, callable, but if method, is it bound: elif ismethod(listener) and not _isbound(listener): raise TypeError, 'Listener '+`listener`+\ ' is a method but it is unbound!' # check that it takes the right number of parameters min, d = _paramMinCount(listener) if min > 1: raise TypeError, 'Listener '+`listener`+" can't"\ ' require more than one parameter!' if min <= 0 and d == 0: raise TypeError, 'Listener '+`listener`+' lacking arguments!' assert (min == 0 and d>0) or (min == 1) def isValid(self, listener): """Return true only if listener will be able to subscribe to Publisher.""" try: self.validate(listener) return True except TypeError: return False def unsubAll(self, topics=None, onNoSuchTopic=None): """Unsubscribe all listeners subscribed for topics. Topics can be a single topic (string or tuple) or a list of topics (ie list containing strings and/or tuples). If topics is not specified, all listeners for all topics will be unsubscribed, ie. the Publisher singleton will have no topics and no listeners left. If topics was specified and is not found among contained topics, the onNoSuchTopic, if specified, will be called, with the name of the topic.""" if topics is None: del self.__topicTree self.__topicTree = _TopicTreeRoot() return # make sure every topics are in tuple form if isinstance(topics, list): topicList = [_tupleize(x) for x in topics] else: topicList = [_tupleize(topics)] # unsub every listener of topics self.__topicTree.unsubAll(topicList, onNoSuchTopic) def unsubscribe(self, listener, topics=None): """Unsubscribe listener. If topics not specified, listener is completely unsubscribed. Otherwise, it is unsubscribed only for the topic (the usual tuple) or list of topics (ie a list of tuples) specified. In this case, if listener is not actually subscribed for (one of) the topics, the optional onNotSubscribed callback will be called, as onNotSubscribed(listener, missingTopic). Note that if listener subscribed for two topics (a,b) and (a,c), then unsubscribing for topic (a) will do nothing. You must use getAssociatedTopics(listener) and give unsubscribe() the returned list (or a subset thereof). """ self.validate(listener) topicList = None if topics is not None: if isinstance(topics, list): topicList = [_tupleize(x) for x in topics] else: topicList = [_tupleize(topics)] self.__topicTree.unsubscribe(listener, topicList) def getAssociatedTopics(self, listener): """Return a list of topics the given listener is registered with. Returns [] if listener never subscribed. :attention: when using the return of this method to compare to expected list of topics, remember that topics that are not in the form of a tuple appear as a one-tuple in the return. E.g. if you have subscribed a listener to 'topic1' and ('topic2','subtopic2'), this method returns:: associatedTopics = [('topic1',), ('topic2','subtopic2')] """ return self.__topicTree.getTopics(listener) def sendMessage(self, topic=ALL_TOPICS, data=None, onTopicNeverCreated=None): """Send a message for given topic, with optional data, to subscribed listeners. If topic is not specified, only the listeners that are interested in all topics will receive message. The onTopicNeverCreated is an optional callback of your choice that will be called if the topic given was never created (i.e. it, or one of its subtopics, was never subscribed to). The callback must be of the form f(a).""" aTopic = _tupleize(topic) message = Message(aTopic, data) self.__messageCount += 1 # send to those who listen to all topics self.__deliveryCount += \ self.__topicTree.sendMessage(aTopic, message, onTopicNeverCreated) # # Private methods # def __call__(self): """Allows for singleton""" return self def __str__(self): return str(self.__topicTree) # Create an instance with the same name as the class, effectivly # hiding the class object so it can't be instantiated any more. From # this point forward any calls to Publisher() will invoke the __call__ # of this instance which just returns itself. # # The only flaw with this approach is that you can't derive a new # class from Publisher without jumping through hoops. If this ever # becomes an issue then a new Singleton implementaion will need to be # employed. Publisher = Publisher() #--------------------------------------------------------------------------- class Message: """ A simple container object for the two components of a message; the topic and the user data. """ def __init__(self, topic, data): self.topic = topic self.data = data def __str__(self): return '[Topic: '+`self.topic`+', Data: '+`self.data`+']' #--------------------------------------------------------------------------- # # Code for a simple command-line test # def test(): def done(funcName): print '----------- Done %s -----------' % funcName def testParam(): def testFunc(a,b,c=1): pass class Foo: def testMeth(self,a,b): pass def __call__(self, a): pass foo = Foo() assert _paramMinCount(testFunc)==(2,1) assert _paramMinCount(Foo.testMeth)==(2,0) assert _paramMinCount(foo.testMeth)==(2,0) assert _paramMinCount(foo)==(1,0) done('testParam') testParam() #------------------------ _NodeCallback.notified = 0 def testPreNotifyNode(self, dead): _NodeCallback.notified += 1 print 'testPreNotifyNODE heard notification of', `dead` _NodeCallback.preNotify = testPreNotifyNode def testTreeNode(): class WS: def __init__(self, s): self.s = s def __call__(self, msg): print 'WS#', self.s, ' received msg ', msg def __str__(self): return self.s def testPreNotifyRoot(dead): print 'testPreNotifyROOT heard notification of', `dead` node = _TopicTreeNode((ALL_TOPICS,), WeakRef(testPreNotifyRoot)) boo, baz, bid = WS('boo'), WS('baz'), WS('bid') node.addCallable(boo) node.addCallable(baz) node.addCallable(boo) assert node.getCallables() == [boo,baz] assert node.hasCallable(boo) node.removeCallable(bid) # no-op assert node.hasCallable(baz) assert node.getCallables() == [boo,baz] node.removeCallable(boo) assert node.getCallables() == [baz] assert node.hasCallable(baz) assert not node.hasCallable(boo) node.removeCallable(baz) assert node.getCallables() == [] assert not node.hasCallable(baz) node2 = node.createSubtopic('st1', ('st1',)) node3 = node.createSubtopic('st2', ('st2',)) cb1, cb2, cb = WS('st1_cb1'), WS('st1_cb2'), WS('st2_cb') node2.addCallable(cb1) node2.addCallable(cb2) node3.addCallable(cb) node2.createSubtopic('st3', ('st1','st3')) node2.createSubtopic('st4', ('st1','st4')) print str(node) assert str(node) == ' (st1: st1_cb1 st1_cb2 (st4: ) (st3: )) (st2: st2_cb )' # verify send message, and that a dead listener does not get sent one delivered = node2.sendMessage('hello') assert delivered == 2 del cb1 delivered = node2.sendMessage('hello') assert delivered == 1 assert _NodeCallback.notified == 1 done('testTreeNode') testTreeNode() #------------------------ def testValidate(): class Foo: def __call__(self, a): pass def fun(self, b): pass def fun2(self, b=1): pass def fun3(self, a, b=2): pass def badFun(self): pass def badFun2(): pass def badFun3(self, a, b): pass server = Publisher() foo = Foo() server.validate(foo) server.validate(foo.fun) server.validate(foo.fun2) server.validate(foo.fun3) assert not server.isValid(foo.badFun) assert not server.isValid(foo.badFun2) assert not server.isValid(foo.badFun3) done('testValidate') testValidate() #------------------------ class SimpleListener: def __init__(self, number): self.number = number def __call__(self, message = ''): print 'Callable #%s got the message "%s"' %(self.number, message) def notify(self, message): print '%s.notify() got the message "%s"' %(self.number, message) def __str__(self): return "SimpleListener_%s" % self.number def testSubscribe(): publisher = Publisher() topic1 = 'politics' topic2 = ('history','middle age') topic3 = ('politics','UN') topic4 = ('politics','NATO') topic5 = ('politics','NATO','US') lisnr1 = SimpleListener(1) lisnr2 = SimpleListener(2) def func(message, a=1): print 'Func received message "%s"' % message lisnr3 = func lisnr4 = lambda x: 'Lambda received message "%s"' % x assert not publisher.isSubscribed(lisnr1) assert not publisher.isSubscribed(lisnr2) assert not publisher.isSubscribed(lisnr3) assert not publisher.isSubscribed(lisnr4) publisher.subscribe(lisnr1, topic1) assert publisher.getAssociatedTopics(lisnr1) == [(topic1,)] publisher.subscribe(lisnr1, topic2) publisher.subscribe(lisnr1, topic1) # do it again, should be no-op assert publisher.getAssociatedTopics(lisnr1) == [(topic1,),topic2] publisher.subscribe(lisnr2.notify, topic3) assert publisher.getAssociatedTopics(lisnr2.notify) == [topic3] assert publisher.getAssociatedTopics(lisnr1) == [(topic1,),topic2] publisher.subscribe(lisnr3, topic5) assert publisher.getAssociatedTopics(lisnr3) == [topic5] assert publisher.getAssociatedTopics(lisnr2.notify) == [topic3] assert publisher.getAssociatedTopics(lisnr1) == [(topic1,),topic2] publisher.subscribe(lisnr4) print "Publisher tree: ", publisher assert publisher.isSubscribed(lisnr1) assert publisher.isSubscribed(lisnr1, topic1) assert publisher.isSubscribed(lisnr1, topic2) assert publisher.isSubscribed(lisnr2.notify) assert publisher.isSubscribed(lisnr3, topic5) assert publisher.isSubscribed(lisnr4, ALL_TOPICS) expectTopicTree = 'all: (politics: SimpleListener_1 (UN: SimpleListener_2.notify ) (NATO: (US: func ))) (history: (middle age: SimpleListener_1 ))' print "Publisher tree: ", publisher assert str(publisher) == expectTopicTree publisher.unsubscribe(lisnr1, 'booboo') # should do nothing assert publisher.getAssociatedTopics(lisnr1) == [(topic1,),topic2] assert publisher.getAssociatedTopics(lisnr2.notify) == [topic3] assert publisher.getAssociatedTopics(lisnr3) == [topic5] publisher.unsubscribe(lisnr1, topic1) assert publisher.getAssociatedTopics(lisnr1) == [topic2] assert publisher.getAssociatedTopics(lisnr2.notify) == [topic3] assert publisher.getAssociatedTopics(lisnr3) == [topic5] publisher.unsubscribe(lisnr1, topic2) publisher.unsubscribe(lisnr1, topic2) publisher.unsubscribe(lisnr2.notify, topic3) publisher.unsubscribe(lisnr3, topic5) assert publisher.getAssociatedTopics(lisnr1) == [] assert publisher.getAssociatedTopics(lisnr2.notify) == [] assert publisher.getAssociatedTopics(lisnr3) == [] publisher.unsubscribe(lisnr4) expectTopicTree = 'all: (politics: (UN: ) (NATO: (US: ))) (history: (middle age: ))' print "Publisher tree: ", publisher assert str(publisher) == expectTopicTree assert publisher.getDeliveryCount() == 0 assert publisher.getMessageCount() == 0 publisher.unsubAll() assert str(publisher) == 'all: ' done('testSubscribe') testSubscribe() #------------------------ def testUnsubAll(): publisher = Publisher() topic1 = 'politics' topic2 = ('history','middle age') topic3 = ('politics','UN') topic4 = ('politics','NATO') topic5 = ('politics','NATO','US') lisnr1 = SimpleListener(1) lisnr2 = SimpleListener(2) def func(message, a=1): print 'Func received message "%s"' % message lisnr3 = func lisnr4 = lambda x: 'Lambda received message "%s"' % x publisher.subscribe(lisnr1, topic1) publisher.subscribe(lisnr1, topic2) publisher.subscribe(lisnr2.notify, topic3) publisher.subscribe(lisnr3, topic2) publisher.subscribe(lisnr3, topic5) publisher.subscribe(lisnr4) expectTopicTree = 'all: (politics: SimpleListener_1 (UN: SimpleListener_2.notify ) (NATO: (US: func ))) (history: (middle age: SimpleListener_1 func ))' print "Publisher tree: ", publisher assert str(publisher) == expectTopicTree publisher.unsubAll(topic1) assert publisher.getAssociatedTopics(lisnr1) == [topic2] assert not publisher.isSubscribed(lisnr1, topic1) publisher.unsubAll(topic2) print publisher assert publisher.getAssociatedTopics(lisnr1) == [] assert publisher.getAssociatedTopics(lisnr3) == [topic5] assert not publisher.isSubscribed(lisnr1) assert publisher.isSubscribed(lisnr3, topic5) #print "Publisher tree: ", publisher expectTopicTree = 'all: (politics: (UN: SimpleListener_2.notify ) (NATO: (US: func ))) (history: (middle age: ))' assert str(publisher) == expectTopicTree publisher.unsubAll(ALL_TOPICS) #print "Publisher tree: ", publisher expectTopicTree = 'all: (politics: (UN: SimpleListener_2.notify ) (NATO: (US: func ))) (history: (middle age: ))' assert str(publisher) == expectTopicTree publisher.unsubAll() done('testUnsubAll') testUnsubAll() #------------------------ def testSend(): publisher = Publisher() called = [] class TestListener: def __init__(self, num): self.number = num def __call__(self, b): called.append( 'TL%scb' % self.number ) def notify(self, b): called.append( 'TL%sm' % self.number ) def funcListener(b): called.append('func') lisnr1 = TestListener(1) lisnr2 = TestListener(2) lisnr3 = funcListener lisnr4 = lambda x: called.append('lambda') topic1 = 'politics' topic2 = 'history' topic3 = ('politics','UN') topic4 = ('politics','NATO','US') topic5 = ('politics','NATO') publisher.subscribe(lisnr1, topic1) publisher.subscribe(lisnr2, topic2) publisher.subscribe(lisnr2.notify, topic2) publisher.subscribe(lisnr3, topic4) publisher.subscribe(lisnr4) print publisher # setup ok, now test send/receipt publisher.sendMessage(topic1) assert called == ['lambda','TL1cb'] called = [] publisher.sendMessage(topic2) assert called == ['lambda','TL2cb','TL2m'] called = [] publisher.sendMessage(topic3) assert called == ['lambda','TL1cb'] called = [] publisher.sendMessage(topic4) assert called == ['lambda','TL1cb','func'] called = [] publisher.sendMessage(topic5) assert called == ['lambda','TL1cb'] assert publisher.getDeliveryCount() == 12 assert publisher.getMessageCount() == 5 # test weak referencing works: _NodeCallback.notified = 0 del lisnr2 called = [] publisher.sendMessage(topic2) assert called == ['lambda'] assert _NodeCallback.notified == 2 done('testSend') testSend() assert _NodeCallback.notified == 5 def testDead(): # verify if weak references work as expected print '------ Starting testDead ----------' node = _TopicTreeNode('t1', None) lisnr1 = SimpleListener(1) lisnr2 = SimpleListener(2) lisnr3 = SimpleListener(3) lisnr4 = SimpleListener(4) node.addCallable(lisnr1) node.addCallable(lisnr2) node.addCallable(lisnr3) node.addCallable(lisnr4) print 'Deleting listeners first' _NodeCallback.notified = 0 del lisnr1 del lisnr2 assert _NodeCallback.notified == 2 print 'Deleting node first' _NodeCallback.notified = 0 del node del lisnr3 del lisnr4 assert _NodeCallback.notified == 0 lisnr1 = SimpleListener(1) lisnr2 = SimpleListener(2) lisnr3 = SimpleListener(3) lisnr4 = SimpleListener(4) # try same with root of tree node = _TopicTreeRoot() node.addTopic(('',), lisnr1) node.addTopic(('',), lisnr2) node.addTopic(('',), lisnr3) node.addTopic(('',), lisnr4) # add objects that will die immediately to see if cleanup occurs # this must be done visually as it is a low-level detail _NodeCallback.notified = 0 _TopicTreeRoot.callbackDeadLimit = 3 node.addTopic(('',), SimpleListener(5)) node.addTopic(('',), SimpleListener(6)) node.addTopic(('',), SimpleListener(7)) print node.numListeners() assert node.numListeners() == (4, 3) node.addTopic(('',), SimpleListener(8)) assert node.numListeners() == (4, 0) assert _NodeCallback.notified == 4 print 'Deleting listeners first' _NodeCallback.notified = 0 del lisnr1 del lisnr2 assert _NodeCallback.notified == 2 print 'Deleting node first' _NodeCallback.notified = 0 del node del lisnr3 del lisnr4 assert _NodeCallback.notified == 0 done('testDead') testDead() print 'Exiting tests' #--------------------------------------------------------------------------- if __name__ == '__main__': test()