Class v.c.l.s.BoundMethodWeakref(object):

Part of vmc.contrib.louie.saferef View In Hierarchy

'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.

Attributes:

- ``key``: The identity key for the reference, calculated by the
  class's calculate_key method applied to the target instance method.

- ``deletion_methods``: 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_self``: Weak reference to the target object.

- ``weak_func``: Weak reference to the target function.

Class Attributes:
    
- ``_all_instances``: 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.

Method	__new__	Create new instance or return current instance.
Method	__init__	Return a weak-reference-like instance for a bound method.
Class Method	calculate_key	Calculate the reference key for this reference.
Method	__str__	Give a friendly representation of the object.
Method	__nonzero__	Whether we are still a valid reference.
Method	__cmp__	Compare with another reference.
Method	__call__	Return a strong reference to the bound method.

def __new__(cls, target, *arguments, on_delete=None, **named):

Create new instance or return current instance.

Basically this method of construction allows us to short-circuit creation of references to already- referenced instance methods. The key corresponding to the target is calculated, and if there is already an existing reference, that is returned, with its deletion_methods attribute updated. Otherwise the new instance is created and registered in the table of already-referenced methods.

def __init__(self, target, on_delete=None):

Return a weak-reference-like instance for a bound method.

- ``target``: The instance-method target for the weak reference,
  must have im_self and im_func attributes and be
  reconstructable via the following, which is true of built-in
  instance methods::
    
    target.im_func.__get__( target.im_self )

- ``on_delete``: Optional callback which will be called when
  this weak reference ceases to be valid (i.e. either the
  object or the function is garbage collected).  Should take a
  single argument, which will be passed a pointer to this
  object.

@classmethod
def calculate_key(cls, target):

Calculate the reference key for this reference.

Currently this is a two-tuple of the id()'s of the target object and the target function respectively.

def __str__(self):

Give a friendly representation of the object.

def __nonzero__(self):

Whether we are still a valid reference.

def __cmp__(self, other):

Compare with another reference.

def __call__(self):

Return a strong reference to the bound method.

If the target cannot be retrieved, then will return None, otherwise returns a bound instance method for our object and function.

Note: You may call this method any number of times, as it does not invalidate the reference.

API Documentation for vodafone-mobile-connect-card-driver-for-linux, generated by pydoctor at 2008-01-10 13:06:31.