+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, tim 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, type([])):
+ raise TypeError, 'Not allowed to tuple-ize a list'
+ elif not isinstance(items, type(())):
+ 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 or tuple of words (though word could probably
+ be any kind of object, not just a string, but this has not been
+ tested). A tuple 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, type([])):
+ 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: <lambda> (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: <lambda> (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: <lambda> (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()
projects / wxWidgets.git / blobdiff