| Index: third_party/twisted_8_1/twisted/words/xish/utility.py
|
| diff --git a/third_party/twisted_8_1/twisted/words/xish/utility.py b/third_party/twisted_8_1/twisted/words/xish/utility.py
|
| deleted file mode 100644
|
| index 48a610f0967c97d2f5a02b5f752e1dad84124fda..0000000000000000000000000000000000000000
|
| --- a/third_party/twisted_8_1/twisted/words/xish/utility.py
|
| +++ /dev/null
|
| @@ -1,335 +0,0 @@
|
| -# -*- test-case-name: twisted.words.test.test_xishutil -*-
|
| -#
|
| -# Copyright (c) 2001-2008 Twisted Matrix Laboratories.
|
| -# See LICENSE for details.
|
| -
|
| -"""
|
| -Event Dispatching and Callback utilities.
|
| -"""
|
| -
|
| -from twisted.python import log
|
| -from twisted.words.xish import xpath
|
| -
|
| -class _MethodWrapper(object):
|
| - """
|
| - Internal class for tracking method calls.
|
| - """
|
| - def __init__(self, method, *args, **kwargs):
|
| - self.method = method
|
| - self.args = args
|
| - self.kwargs = kwargs
|
| -
|
| -
|
| - def __call__(self, *args, **kwargs):
|
| - nargs = self.args + args
|
| - nkwargs = self.kwargs.copy()
|
| - nkwargs.update(kwargs)
|
| - self.method(*nargs, **nkwargs)
|
| -
|
| -
|
| -class CallbackList:
|
| - """
|
| - Container for callbacks.
|
| -
|
| - Event queries are linked to lists of callables. When a matching event
|
| - occurs, these callables are called in sequence. One-time callbacks
|
| - are removed from the list after the first time the event was triggered.
|
| -
|
| - Arguments to callbacks are split spread across two sets. The first set,
|
| - callback specific, is passed to C{addCallback} and is used for all
|
| - subsequent event triggers. The second set is passed to C{callback} and is
|
| - event specific. Positional arguments in the second set come after the
|
| - positional arguments of the first set. Keyword arguments in the second set
|
| - override those in the first set.
|
| -
|
| - @ivar callbacks: The registered callbacks as mapping from the callable to a
|
| - tuple of a wrapper for that callable that keeps the
|
| - callback specific arguments and a boolean that signifies
|
| - if it is to be called only once.
|
| - @type callbacks: C{dict}
|
| - """
|
| -
|
| - def __init__(self):
|
| - self.callbacks = {}
|
| -
|
| -
|
| - def addCallback(self, onetime, method, *args, **kwargs):
|
| - """
|
| - Add callback.
|
| -
|
| - The arguments passed are used as callback specific arguments.
|
| -
|
| - @param onetime: If C{True}, this callback is called at most once.
|
| - @type onetime: C{bool}
|
| - @param method: The callback callable to be added.
|
| - @param args: Positional arguments to the callable.
|
| - @type args: C{list}
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| - @param kwargs: Keyword arguments to the callable.
|
| - @type kwargs: C{dict}
|
| - """
|
| -
|
| - if not method in self.callbacks:
|
| - self.callbacks[method] = (_MethodWrapper(method, *args, **kwargs),
|
| - onetime)
|
| -
|
| -
|
| - def removeCallback(self, method):
|
| - """
|
| - Remove callback.
|
| -
|
| - @param method: The callable to be removed.
|
| - """
|
| -
|
| - if method in self.callbacks:
|
| - del self.callbacks[method]
|
| -
|
| -
|
| - def callback(self, *args, **kwargs):
|
| - """
|
| - Call all registered callbacks.
|
| -
|
| - The passed arguments are event specific and augment and override
|
| - the callback specific arguments as described above.
|
| -
|
| - @note: Exceptions raised by callbacks are trapped and logged. They will
|
| - not propagate up to make sure other callbacks will still be
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| - called, and the event dispatching allways succeeds.
|
| -
|
| - @param args: Positional arguments to the callable.
|
| - @type args: C{list}
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| - @param kwargs: Keyword arguments to the callable.
|
| - @type kwargs: C{dict}
|
| - """
|
| -
|
| - for key, (methodwrapper, onetime) in self.callbacks.items():
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| - try:
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| - methodwrapper(*args, **kwargs)
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| - except:
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| - log.err()
|
| -
|
| - if onetime:
|
| - del self.callbacks[key]
|
| -
|
| -
|
| - def isEmpty(self):
|
| - """
|
| - Return if list of registered callbacks is empty.
|
| -
|
| - @rtype: C{bool}
|
| - """
|
| -
|
| - return len(self.callbacks) == 0
|
| -
|
| -
|
| -
|
| -class EventDispatcher:
|
| - """
|
| - Event dispatching service.
|
| -
|
| - The C{EventDispatcher} allows observers to be registered for certain events
|
| - that are dispatched. There are two types of events: XPath events and Named
|
| - events.
|
| -
|
| - Every dispatch is triggered by calling L{dispatch} with a data object and,
|
| - for named events, the name of the event.
|
| -
|
| - When an XPath type event is dispatched, the associated object is assumed to
|
| - be an L{Element<twisted.words.xish.domish.Element>} instance, which is
|
| - matched against all registered XPath queries. For every match, the
|
| - respective observer will be called with the data object.
|
| -
|
| - A named event will simply call each registered observer for that particular
|
| - event name, with the data object. Unlike XPath type events, the data object
|
| - is not restricted to L{Element<twisted.words.xish.domish.Element>}, but can
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| - be anything.
|
| -
|
| - When registering observers, the event that is to be observed is specified
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| - using an L{xpath.XPathQuery} instance or a string. In the latter case, the
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| - string can also contain the string representation of an XPath expression.
|
| - To distinguish these from named events, each named event should start with
|
| - a special prefix that is stored in C{self.prefix}. It defaults to
|
| - C{//event/}.
|
| -
|
| - Observers registered using L{addObserver} are persistent: after the
|
| - observer has been triggered by a dispatch, it remains registered for a
|
| - possible next dispatch. If instead L{addOnetimeObserver} was used to
|
| - observe an event, the observer is removed from the list of observers after
|
| - the first observed event.
|
| -
|
| - Obsevers can also prioritized, by providing an optional C{priority}
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| - parameter to the L{addObserver} and L{addOnetimeObserver} methods. Higher
|
| - priority observers are then called before lower priority observers.
|
| -
|
| - Finally, observers can be unregistered by using L{removeObserver}.
|
| - """
|
| -
|
| - def __init__(self, eventprefix="//event/"):
|
| - self.prefix = eventprefix
|
| - self._eventObservers = {}
|
| - self._xpathObservers = {}
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| - self._dispatchDepth = 0 # Flag indicating levels of dispatching
|
| - # in progress
|
| - self._updateQueue = [] # Queued updates for observer ops
|
| -
|
| -
|
| - def _getEventAndObservers(self, event):
|
| - if isinstance(event, xpath.XPathQuery):
|
| - # Treat as xpath
|
| - observers = self._xpathObservers
|
| - else:
|
| - if self.prefix == event[:len(self.prefix)]:
|
| - # Treat as event
|
| - observers = self._eventObservers
|
| - else:
|
| - # Treat as xpath
|
| - event = xpath.internQuery(event)
|
| - observers = self._xpathObservers
|
| -
|
| - return event, observers
|
| -
|
| -
|
| - def addOnetimeObserver(self, event, observerfn, priority=0, *args, **kwargs):
|
| - """
|
| - Register a one-time observer for an event.
|
| -
|
| - Like L{addObserver}, but is only triggered at most once. See there
|
| - for a description of the parameters.
|
| - """
|
| - self._addObserver(True, event, observerfn, priority, *args, **kwargs)
|
| -
|
| -
|
| - def addObserver(self, event, observerfn, priority=0, *args, **kwargs):
|
| - """
|
| - Register an observer for an event.
|
| -
|
| - Each observer will be registered with a certain priority. Higher
|
| - priority observers get called before lower priority observers.
|
| -
|
| - @param event: Name or XPath query for the event to be monitored.
|
| - @type event: C{str} or L{xpath.XPathQuery}.
|
| - @param observerfn: Function to be called when the specified event
|
| - has been triggered. This callable takes
|
| - one parameter: the data object that triggered
|
| - the event. When specified, the C{*args} and
|
| - C{**kwargs} parameters to addObserver are being used
|
| - as additional parameters to the registered observer
|
| - callable.
|
| - @param priority: (Optional) priority of this observer in relation to
|
| - other observer that match the same event. Defaults to
|
| - C{0}.
|
| - @type priority: C{int}
|
| - """
|
| - self._addObserver(False, event, observerfn, priority, *args, **kwargs)
|
| -
|
| -
|
| - def _addObserver(self, onetime, event, observerfn, priority, *args, **kwargs):
|
| - # If this is happening in the middle of the dispatch, queue
|
| - # it up for processing after the dispatch completes
|
| - if self._dispatchDepth > 0:
|
| - self._updateQueue.append(lambda:self._addObserver(onetime, event, observerfn, priority, *args, **kwargs))
|
| - return
|
| -
|
| - event, observers = self._getEventAndObservers(event)
|
| -
|
| - if priority not in observers:
|
| - cbl = CallbackList()
|
| - observers[priority] = {event: cbl}
|
| - else:
|
| - priorityObservers = observers[priority]
|
| - if event not in priorityObservers:
|
| - cbl = CallbackList()
|
| - observers[priority][event] = cbl
|
| - else:
|
| - cbl = priorityObservers[event]
|
| -
|
| - cbl.addCallback(onetime, observerfn, *args, **kwargs)
|
| -
|
| -
|
| - def removeObserver(self, event, observerfn):
|
| - """
|
| - Remove callable as observer for an event.
|
| -
|
| - The observer callable is removed for all priority levels for the
|
| - specified event.
|
| -
|
| - @param event: Event for which the observer callable was registered.
|
| - @type event: C{str} or L{xpath.XPathQuery}
|
| - @param observerfn: Observer callable to be unregistered.
|
| - """
|
| -
|
| - # If this is happening in the middle of the dispatch, queue
|
| - # it up for processing after the dispatch completes
|
| - if self._dispatchDepth > 0:
|
| - self._updateQueue.append(lambda:self.removeObserver(event, observerfn))
|
| - return
|
| -
|
| - event, observers = self._getEventAndObservers(event)
|
| -
|
| - emptyLists = []
|
| - for priority, priorityObservers in observers.iteritems():
|
| - for query, callbacklist in priorityObservers.iteritems():
|
| - if event == query:
|
| - callbacklist.removeCallback(observerfn)
|
| - if callbacklist.isEmpty():
|
| - emptyLists.append((priority, query))
|
| -
|
| - for priority, query in emptyLists:
|
| - del observers[priority][query]
|
| -
|
| -
|
| - def dispatch(self, obj, event=None):
|
| - """
|
| - Dispatch an event.
|
| -
|
| - When C{event} is C{None}, an XPath type event is triggered, and
|
| - C{obj} is assumed to be an instance of
|
| - L{Element<twisted.words.xish.domish.Element>}. Otherwise, C{event}
|
| - holds the name of the named event being triggered. In the latter case,
|
| - C{obj} can be anything.
|
| -
|
| - @param obj: The object to be dispatched.
|
| - @param event: Optional event name.
|
| - @type event: C{str}
|
| - """
|
| -
|
| - foundTarget = False
|
| -
|
| - self._dispatchDepth += 1
|
| -
|
| - if event != None:
|
| - # Named event
|
| - observers = self._eventObservers
|
| - match = lambda query, obj: query == event
|
| - else:
|
| - # XPath event
|
| - observers = self._xpathObservers
|
| - match = lambda query, obj: query.matches(obj)
|
| -
|
| - priorities = observers.keys()
|
| - priorities.sort()
|
| - priorities.reverse()
|
| -
|
| - emptyLists = []
|
| - for priority in priorities:
|
| - for query, callbacklist in observers[priority].iteritems():
|
| - if match(query, obj):
|
| - callbacklist.callback(obj)
|
| - foundTarget = True
|
| - if callbacklist.isEmpty():
|
| - emptyLists.append((priority, query))
|
| -
|
| - for priority, query in emptyLists:
|
| - del observers[priority][query]
|
| -
|
| - self._dispatchDepth -= 1
|
| -
|
| - # If this is a dispatch within a dispatch, don't
|
| - # do anything with the updateQueue -- it needs to
|
| - # wait until we've back all the way out of the stack
|
| - if self._dispatchDepth == 0:
|
| - # Deal with pending update operations
|
| - for f in self._updateQueue:
|
| - f()
|
| - self._updateQueue = []
|
| -
|
| - return foundTarget
|
|
|