From: Carcassi, G. <car...@bn...> - 2010-09-07 15:15:48
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Hi Marty, Didn't we already have this discussion when we were all here? >Thus pvManager present all data via a single interface. But instead of >proving 3456 interfaces it provides just 8 interfaces. It does this by >limiting choices are follows: > >The value data types supported are int32, float64, string, and enum. I got this from both Kay and Bob independently: while there is a difference on the wire, the client is not going to care that much about the difference among different integers or floats. >For each a scalar or array is supported. >For each data type all of alarm, timeStamp, and display are included. Again, this was decided during the discussion, to keep things simple. Right now we are shooting for getting everything, but we can always scale back if we find problems. >I believe that it will be very hard to provide an efficient >implementations for either V3 CA or for pvAccess. Why? Because we are limiting the options to get everything or nothing? Again, don't confuse the pvManager client interfaces with what goes on the wire: these are two different things. The fact that the data type defines all the elements does not mean that they always have to be present and returned. You can still return null or throw an UnsupportedOperationException. They are methods: they can do whatever we need them to do. Gabriele |