9f4cc34f37
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39667 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
1244 lines
47 KiB
Python
1244 lines
47 KiB
Python
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#---------------------------------------------------------------------------
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"""
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This module provides a publish-subscribe component that allows
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listeners to subcribe to messages of a given topic. Contrary to the
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original wxPython.lib.pubsub module (which it is based on), it uses
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weak referencing to the subscribers so the lifetime of subscribers
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is not affected by Publisher. Also, callable objects can be used in
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addition to functions and bound methods. See Publisher class docs for
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more details.
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Thanks to Robb Shecter and Robin Dunn for having provided
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the basis for this module (which now shares most of the concepts but
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very little design or implementation with the original
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wxPython.lib.pubsub).
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The publisher is a singleton instance of the PublisherClass class. You
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access the instance via the Publisher object available from the module::
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from wx.lib.pubsub import Publisher
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Publisher().subscribe(...)
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Publisher().sendMessage(...)
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...
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:Author: Oliver Schoenborn
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:Since: Apr 2004
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:Version: $Id$
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:Copyright: \(c) 2004 Oliver Schoenborn
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:License: wxWidgets
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"""
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_implNotes = """
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Implementation notes
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--------------------
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In class Publisher, I represent the topics-listener set as a tree
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where each node is a topic, and contains a list of listeners of that
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topic, and a dictionary of subtopics of that topic. When the Publisher
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is told to send a message for a given topic, it traverses the tree
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down to the topic for which a message is being generated, all
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listeners on the way get sent the message.
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Publisher currently uses a weak listener topic tree to store the
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topics for each listener, and if a listener dies before being
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unsubscribed, the tree is notified, and the tree eliminates the
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listener from itself.
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Ideally, _TopicTreeNode would be a generic _TreeNode with named
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subnodes, and _TopicTreeRoot would be a generic _Tree with named
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nodes, and Publisher would store listeners in each node and a topic
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tuple would be converted to a path in the tree. This would lead to a
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much cleaner separation of concerns. But time is over, time to move on.
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"""
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#---------------------------------------------------------------------------
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# for function and method parameter counting:
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from types import InstanceType
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from inspect import getargspec, ismethod, isfunction
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# for weakly bound methods:
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from new import instancemethod as InstanceMethod
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from weakref import ref as WeakRef
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# -----------------------------------------------------------------------------
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def _isbound(method):
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"""Return true if method is a bound method, false otherwise"""
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assert ismethod(method)
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return method.im_self is not None
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def _paramMinCountFunc(function):
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"""Given a function, return pair (min,d) where min is minimum # of
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args required, and d is number of default arguments."""
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assert isfunction(function)
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(args, va, kwa, dflt) = getargspec(function)
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lenDef = len(dflt or ())
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lenArgs = len(args or ())
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lenVA = int(va is not None)
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return (lenArgs - lenDef + lenVA, lenDef)
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def _paramMinCount(callableObject):
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"""
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Given a callable object (function, method or callable instance),
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return pair (min,d) where min is minimum # of args required, and d
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is number of default arguments. The 'self' parameter, in the case
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of methods, is not counted.
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"""
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if type(callableObject) is InstanceType:
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min, d = _paramMinCountFunc(callableObject.__call__.im_func)
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return min-1, d
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elif ismethod(callableObject):
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min, d = _paramMinCountFunc(callableObject.im_func)
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return min-1, d
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elif isfunction(callableObject):
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return _paramMinCountFunc(callableObject)
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else:
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raise 'Cannot determine type of callable: '+repr(callableObject)
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def _tupleize(items):
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"""Convert items to tuple if not already one,
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so items must be a list, tuple or non-sequence"""
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if isinstance(items, list):
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raise TypeError, 'Not allowed to tuple-ize a list'
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elif isinstance(items, (str, unicode)) and items.find('.') != -1:
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items = tuple(items.split('.'))
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elif not isinstance(items, tuple):
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items = (items,)
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return items
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def _getCallableName(callable):
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"""Get name for a callable, ie function, bound
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method or callable instance"""
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if ismethod(callable):
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return '%s.%s ' % (callable.im_self, callable.im_func.func_name)
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elif isfunction(callable):
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return '%s ' % callable.__name__
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else:
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return '%s ' % callable
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def _removeItem(item, fromList):
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"""Attempt to remove item from fromList, return true
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if successful, false otherwise."""
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try:
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fromList.remove(item)
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return True
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except ValueError:
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return False
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# -----------------------------------------------------------------------------
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class _WeakMethod:
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"""Represent a weak bound method, i.e. a method doesn't keep alive the
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object that it is bound to. It uses WeakRef which, used on its own,
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produces weak methods that are dead on creation, not very useful.
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Typically, you will use the getRef() function instead of using
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this class directly. """
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def __init__(self, method, notifyDead = None):
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"""The method must be bound. notifyDead will be called when
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object that method is bound to dies. """
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assert ismethod(method)
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if method.im_self is None:
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raise ValueError, "We need a bound method!"
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if notifyDead is None:
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self.objRef = WeakRef(method.im_self)
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else:
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self.objRef = WeakRef(method.im_self, notifyDead)
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self.fun = method.im_func
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self.cls = method.im_class
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def __call__(self):
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"""Returns a new.instancemethod if object for method still alive.
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Otherwise return None. Note that instancemethod causes a
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strong reference to object to be created, so shouldn't save
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the return value of this call. Note also that this __call__
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is required only for compatibility with WeakRef.ref(), otherwise
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there would be more efficient ways of providing this functionality."""
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if self.objRef() is None:
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return None
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else:
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return InstanceMethod(self.fun, self.objRef(), self.cls)
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def __eq__(self, method2):
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"""Two WeakMethod objects compare equal if they refer to the same method
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of the same instance. Thanks to Josiah Carlson for patch and clarifications
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on how dict uses eq/cmp and hashing. """
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if not isinstance(method2, _WeakMethod):
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return False
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return self.fun is method2.fun \
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and self.objRef() is method2.objRef() \
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and self.objRef() is not None
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def __hash__(self):
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"""Hash is an optimization for dict searches, it need not
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return different numbers for every different object. Some objects
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are not hashable (eg objects of classes derived from dict) so no
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hash(objRef()) in there, and hash(self.cls) would only be useful
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in the rare case where instance method was rebound. """
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return hash(self.fun)
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def __repr__(self):
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dead = ''
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if self.objRef() is None:
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dead = '; DEAD'
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obj = '<%s at %s%s>' % (self.__class__, id(self), dead)
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return obj
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def refs(self, weakRef):
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"""Return true if we are storing same object referred to by weakRef."""
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return self.objRef == weakRef
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def _getWeakRef(obj, notifyDead=None):
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"""Get a weak reference to obj. If obj is a bound method, a _WeakMethod
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object, that behaves like a WeakRef, is returned, if it is
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anything else a WeakRef is returned. If obj is an unbound method,
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a ValueError will be raised."""
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if ismethod(obj):
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createRef = _WeakMethod
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else:
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createRef = WeakRef
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if notifyDead is None:
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return createRef(obj)
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else:
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return createRef(obj, notifyDead)
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# -----------------------------------------------------------------------------
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def getStrAllTopics():
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"""Function to call if, for whatever reason, you need to know
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explicitely what is the string to use to indicate 'all topics'."""
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return ''
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# alias, easier to see where used
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ALL_TOPICS = getStrAllTopics()
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# -----------------------------------------------------------------------------
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class _NodeCallback:
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"""Encapsulate a weak reference to a method of a TopicTreeNode
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in such a way that the method can be called, if the node is
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still alive, but the callback does not *keep* the node alive.
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Also, define two methods, preNotify() and noNotify(), which can
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be redefined to something else, very useful for testing.
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"""
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def __init__(self, obj):
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self.objRef = _getWeakRef(obj)
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def __call__(self, weakCB):
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notify = self.objRef()
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if notify is not None:
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self.preNotify(weakCB)
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notify(weakCB)
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else:
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self.noNotify()
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def preNotify(self, dead):
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"""'Gets called just before our callback (self.objRef) is called"""
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pass
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def noNotify(self):
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"""Gets called if the TopicTreeNode for this callback is dead"""
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pass
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class _TopicTreeNode:
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"""A node in the topic tree. This contains a list of callables
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that are interested in the topic that this node is associated
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with, and contains a dictionary of subtopics, whose associated
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values are other _TopicTreeNodes. The topic of a node is not stored
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in the node, so that the tree can be implemented as a dictionary
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rather than a list, for ease of use (and, likely, performance).
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Note that it uses _NodeCallback to encapsulate a callback for
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when a registered listener dies, possible thanks to WeakRef.
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Whenever this callback is called, the onDeadListener() function,
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passed in at construction time, is called (unless it is None).
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"""
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def __init__(self, topicPath, onDeadListenerWeakCB):
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self.__subtopics = {}
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self.__callables = []
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self.__topicPath = topicPath
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self.__onDeadListenerWeakCB = onDeadListenerWeakCB
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def getPathname(self):
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"""The complete node path to us, ie., the topic tuple that would lead to us"""
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return self.__topicPath
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def createSubtopic(self, subtopic, topicPath):
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"""Create a child node for subtopic"""
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return self.__subtopics.setdefault(subtopic,
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_TopicTreeNode(topicPath, self.__onDeadListenerWeakCB))
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def hasSubtopic(self, subtopic):
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"""Return true only if topic string is one of subtopics of this node"""
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return self.__subtopics.has_key(subtopic)
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def getNode(self, subtopic):
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"""Return ref to node associated with subtopic"""
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return self.__subtopics[subtopic]
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def addCallable(self, callable):
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"""Add a callable to list of callables for this topic node"""
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try:
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id = self.__callables.index(_getWeakRef(callable))
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return self.__callables[id]
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except ValueError:
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wrCall = _getWeakRef(callable, _NodeCallback(self.__notifyDead))
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self.__callables.append(wrCall)
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return wrCall
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def getCallables(self):
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"""Get callables associated with this topic node"""
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return [cb() for cb in self.__callables if cb() is not None]
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def hasCallable(self, callable):
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"""Return true if callable in this node"""
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try:
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self.__callables.index(_getWeakRef(callable))
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return True
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except ValueError:
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return False
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def sendMessage(self, message):
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"""Send a message to our callables"""
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deliveryCount = 0
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for cb in self.__callables:
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listener = cb()
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if listener is not None:
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listener(message)
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deliveryCount += 1
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return deliveryCount
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def removeCallable(self, callable):
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"""Remove weak callable from our node (and return True).
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Does nothing if not here (and returns False)."""
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try:
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self.__callables.remove(_getWeakRef(callable))
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return True
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except ValueError:
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return False
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def clearCallables(self):
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"""Abandon list of callables to caller. We no longer have
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any callables after this method is called."""
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tmpList = [cb for cb in self.__callables if cb() is not None]
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self.__callables = []
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return tmpList
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def __notifyDead(self, dead):
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"""Gets called when a listener dies, thanks to WeakRef"""
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#print 'TreeNODE', `self`, 'received death certificate for ', dead
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self.__cleanupDead()
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if self.__onDeadListenerWeakCB is not None:
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cb = self.__onDeadListenerWeakCB()
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if cb is not None:
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cb(dead)
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def __cleanupDead(self):
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"""Remove all dead objects from list of callables"""
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self.__callables = [cb for cb in self.__callables if cb() is not None]
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def __str__(self):
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"""Print us in a not-so-friendly, but readable way, good for debugging."""
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strVal = []
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for callable in self.getCallables():
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strVal.append(_getCallableName(callable))
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for topic, node in self.__subtopics.iteritems():
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strVal.append(' (%s: %s)' %(topic, node))
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return ''.join(strVal)
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class _TopicTreeRoot(_TopicTreeNode):
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"""
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The root of the tree knows how to access other node of the
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tree and is the gateway of the tree user to the tree nodes.
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It can create topics, and and remove callbacks, etc.
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For efficiency, it stores a dictionary of listener-topics,
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so that unsubscribing a listener just requires finding the
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topics associated to a listener, and finding the corresponding
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nodes of the tree. Without it, unsubscribing would require
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that we search the whole tree for all nodes that contain
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given listener. Since Publisher is a singleton, it will
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contain all topics in the system so it is likely to be a large
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tree. However, it is possible that in some runs, unsubscribe()
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is called very little by the user, in which case most unsubscriptions
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are automatic, ie caused by the listeners dying. In this case,
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a flag is set to indicate that the dictionary should be cleaned up
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at the next opportunity. This is not necessary, it is just an
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optimization.
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"""
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def __init__(self):
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self.__callbackDict = {}
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self.__callbackDictCleanup = 0
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# all child nodes will call our __rootNotifyDead method
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# when one of their registered listeners dies
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_TopicTreeNode.__init__(self, (ALL_TOPICS,),
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_getWeakRef(self.__rootNotifyDead))
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def addTopic(self, topic, listener):
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"""Add topic to tree if doesnt exist, and add listener to topic node"""
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assert isinstance(topic, tuple)
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topicNode = self.__getTreeNode(topic, make=True)
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weakCB = topicNode.addCallable(listener)
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assert topicNode.hasCallable(listener)
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theList = self.__callbackDict.setdefault(weakCB, [])
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assert self.__callbackDict.has_key(weakCB)
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# add it only if we don't already have it
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try:
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weakTopicNode = WeakRef(topicNode)
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theList.index(weakTopicNode)
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except ValueError:
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theList.append(weakTopicNode)
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assert self.__callbackDict[weakCB].index(weakTopicNode) >= 0
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|
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def getTopics(self, listener):
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"""Return the list of topics for given listener"""
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weakNodes = self.__callbackDict.get(_getWeakRef(listener), [])
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return [weakNode().getPathname() for weakNode in weakNodes
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if weakNode() is not None]
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|
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def isSubscribed(self, listener, topic=None):
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"""Return true if listener is registered for topic specified.
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If no topic specified, return true if subscribed to something.
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Use topic=getStrAllTopics() to determine if a listener will receive
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messages for all topics."""
|
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weakCB = _getWeakRef(listener)
|
|
if topic is None:
|
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return self.__callbackDict.has_key(weakCB)
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|
else:
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|
topicPath = _tupleize(topic)
|
|
for weakNode in self.__callbackDict[weakCB]:
|
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if topicPath == weakNode().getPathname():
|
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return True
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return False
|
|
|
|
def unsubscribe(self, listener, topicList):
|
|
"""Remove listener from given list of topics. If topicList
|
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doesn't have any topics for which listener has subscribed,
|
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nothing happens."""
|
|
weakCB = _getWeakRef(listener)
|
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if not self.__callbackDict.has_key(weakCB):
|
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return
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|
|
|
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)
|
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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(topic)
|
|
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 _SingletonKey: pass
|
|
|
|
class PublisherClass:
|
|
"""
|
|
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 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 PublisherClass that is
|
|
returned. So to use, just do'Publisher().method()'.
|
|
|
|
"""
|
|
|
|
__ALL_TOPICS_TPL = (ALL_TOPICS, )
|
|
|
|
def __init__(self, singletonKey):
|
|
"""Construct a Publisher. This can only be done by the pubsub
|
|
module. You just use pubsub.Publisher()."""
|
|
if not isinstance(singletonKey, _SingletonKey):
|
|
raise invalid_argument("Use Publisher() to get access to singleton")
|
|
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: The listener is held by Publisher() only by *weak*
|
|
reference. This means you must ensure you have at
|
|
least one strong reference to listener, otherwise it
|
|
will be DOA ("dead on arrival"). This is particularly
|
|
easy to forget when wrapping a listener method in a
|
|
proxy object (e.g. to bind some of its parameters),
|
|
e.g.::
|
|
|
|
class Foo:
|
|
def listener(self, event): pass
|
|
class Wrapper:
|
|
def __init__(self, fun): self.fun = fun
|
|
def __call__(self, *args): self.fun(*args)
|
|
foo = Foo()
|
|
Publisher().subscribe( Wrapper(foo.listener) ) # whoops: DOA!
|
|
wrapper = Wrapper(foo.listener)
|
|
Publisher().subscribe(wrapper) # good!
|
|
|
|
: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.
|
|
|
|
"""
|
|
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 topic=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 onNoSuchTopic is given, it will be called as
|
|
onNoSuchTopic(topic) for each topic that is unknown.
|
|
"""
|
|
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. Nothing happens if listener is not actually
|
|
subscribed to any of the topics.
|
|
|
|
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 by any listener).
|
|
It will be called as onTopicNeverCreated(topic)."""
|
|
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 the Publisher singleton. We prevent users from (inadvertently)
|
|
# instantiating more than one object, by requiring a key that is
|
|
# accessible only to module. 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.
|
|
_key = _SingletonKey()
|
|
Publisher = PublisherClass(_key)
|
|
|
|
|
|
#---------------------------------------------------------------------------
|
|
|
|
class Message:
|
|
"""
|
|
A simple container object for the two components of a message: the
|
|
topic and the user data. An instance of Message is given to your
|
|
listener when called by Publisher().sendMessage(topic) (if your
|
|
listener callback was registered for that topic).
|
|
"""
|
|
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 testFunc00(): pass
|
|
def testFunc21(a,b,c=1): pass
|
|
def testFuncA(*args): pass
|
|
def testFuncAK(*args,**kwds): pass
|
|
def testFuncK(**kwds): pass
|
|
|
|
class Foo:
|
|
def testMeth(self,a,b): pass
|
|
def __call__(self, a): pass
|
|
class Foo2:
|
|
def __call__(self, *args): pass
|
|
|
|
assert _paramMinCount(testFunc00)==(0,0)
|
|
assert _paramMinCount(testFunc21)==(2,1)
|
|
assert _paramMinCount(testFuncA) ==(1,0)
|
|
assert _paramMinCount(testFuncAK)==(1,0)
|
|
assert _paramMinCount(testFuncK) ==(0,0)
|
|
foo = Foo()
|
|
assert _paramMinCount(Foo.testMeth)==(2,0)
|
|
assert _paramMinCount(foo.testMeth)==(2,0)
|
|
assert _paramMinCount(foo)==(1,0)
|
|
assert _paramMinCount(Foo2())==(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()
|