February 2009 - saga-rg - lists.ogf.org

SAGA related talks at OGF
by Steve Fisher 27 Feb '09

27 Feb '09

Hi, For those attending the OGF next week there are two SAGA related talks in the Grid Programming session : http://www.ogf.org/gf/event_schedule/index.php?id=1640 on Tuesday morning. Steve

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Context and Session thoughts
by Steve Fisher 25 Feb '09

25 Feb '09

Hi, I am not very clear from the spec how to handle contexts - and it would appear that C++ and Java implementations have interpreted it differently. I will try to explain what I think should happen then you can all tell me why I am wrong. If I have omitted the session parameter to get a default session then I get a session with the default context. An implementation (which may or may be adapter based) has a set of contexts that it knows about - each with an implementation-defined type. An implementation-defined context type in turn defines a set of context attribute names that are meaningful to that type The implementation defines one of the contexts types that it knows about as a default type - so the default context is actually a context with the default type. If the default context needs to be modified by the user to be useful - e.g. storing a password - then there is no benefit in using the default context. So the default context should not be modifiable by the user. It may be implemented as a singleton. The user can also create a context with a type known to him and to the implementation. He may need to set attributes of this context before it can be used. The implementation must not modify any attributes - though the constructor may set attributes to sensible defaults which can then be modified by the user. The set_defaults call should *not* be in the spec - it is purely an implementation thing. Steve

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Context attributes
by Steve Fisher 20 Feb '09

20 Feb '09

Hi, I have been looking at the spec for details of the Context class. I don't understand why it has specific attributes defined when only "Type" is common to all contexts. Attributes such as "Server", "CertRepository" etc should not be there. The implementation can document which attributes are needed. Have I missed something? Steve

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