[saga-rg] exceptions...

[Andre Merzky]

Hi Graeme, 

I updated the exception description in CVS today - I would
be grateful if you could give it a sanity check.

As for specifying the exceptions for each call: you are
right, we should try to define that as complete as possible.

However, I think that some of the exceptions might be
implementation defined.  For example:  an implmentation
might have attributes stored remotely, and might have
authorization attached.  So it should be able to throw
AurorizationFailed on attributes.  For other implementations
that might not make sense.

Similar considerations would probably lead to have almost
all exceptions on almost all method calls.  At least:

  IncorrectSession
  AuthentificationFailed
  AuthorizationFailed
  PermissionDenied
  BadParameter
  Timeout
  NoSuccess

are applicable to most operations I assume, depending on how
they are implemented (assume an implementation which
forwards _all_ SAGA calls to a web service, as could be done
on top of gLite for example).

Would it make sense to list these exceptions on all calls?
I think it is simplier to state that they can always be
thrown, and list only the few additional exceptions on the
calls.

What do you think?

Cheers, Andre.


Quoting [Graeme Pound] (Feb 20 2006):
> 
> Andre, Pascal,
> 
> >
> >>So, I/we _think_ the agreement was to have only one simple
> >>saga::exception class which gets thrown whenever something
> >>happens which violates the semantic contract of a saga call.
> >
> >The different implementation can always sub-class them to provide better 
> >exception semantic. A single saga::exception class is more then enough.
> >
> 
> This approach is fine. Within the Java I have been subclassing 
> exceptions with reference to the 'types' of exception described in the 
> details of the specification. Unfortunately this description is 
> incomplete at present.
> 
> It is important that the description of different types of exception 
> that may be thrown by each method is completed, and expanded where 
> appropriate.
> 
> Graeme



-- 
"So much time, so little to do..."  -- Garfield