“Safe weakrefs”, originally from pyDispatcher.
Provides a way to safely weakref any function, including bound methods (which aren’t handled by the core weakref module).
Bases: object
‘Safe’ and reusable weak references to instance methods.
BoundMethodWeakref objects provide a mechanism for referencing a bound method without requiring that the method object itself (which is normally a transient object) is kept alive. Instead, the BoundMethodWeakref object keeps weak references to both the object and the function which together define the instance method.
the identity key for the reference, calculated by the class’s calculate_key() method applied to the target instance method
sequence of callable objects taking single argument, a reference to this object which will be called when either the target object or target function is garbage collected (i.e. when this object becomes invalid). These are specified as the on_delete parameters of safe_ref() calls.
weak reference to the target object
weak reference to the target function
class attribute pointing to all live BoundMethodWeakref objects indexed by the class’s calculate_key(target) method applied to the target objects. This weak value dictionary is used to short-circuit creation so that multiple references to the same (object, function) pair produce the same BoundMethodWeakref instance.
Bases: thriftpool.utils.dispatch.saferef.BoundMethodWeakref
A specialized BoundMethodWeakref, for platforms where instance methods are not descriptors.
It assumes that the function name and the target attribute name are the same, instead of assuming that the function is a descriptor. This approach is equally fast, but not 100% reliable because functions can be stored on an attribute named differenty than the function’s name such as in:
>>> class A(object):
... pass
>>> def foo(self):
... return "foo"
>>> A.bar = foo
But this shouldn’t be a common use case. So, on platforms where methods aren’t descriptors (such as Jython) this implementation has the advantage of working in the most cases.
Instantiates the appropiate BoundMethodWeakRef, depending on the details of the underlying class method implementation.
Return a safe weak reference to a callable target
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Signal class.
Bases: object
Base class for all signals
Connect receiver to sender for signal.
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Disconnect receiver from sender for signal.
If weak references are used, disconnect need not be called. The receiver will be removed from dispatch automatically.
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Send signal from sender to all connected receivers.
If any receiver raises an error, the error propagates back through send, terminating the dispatch loop, so it is quite possible to not have all receivers called if a raises an error.
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Returns: | a list of tuple pairs: [(receiver, response), ... ]. |
Send signal from sender to all connected receivers catching errors.
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Returns: | a list of tuple pairs: [(receiver, response), ... ]. |
Raises DispatcherKeyError: | |
if any receiver raises an error (specifically any subclass of Exception), the error instance is returned as the result for that receiver.