Paul Alfille wrote: > Hmm... > > owlib is written in C, and needs a fixed data size (string size) for > floating point output. I arbitrarily used 12 characters and the %g > printf format to be most general. > > Currently type (floating point, integer...) and certainly precision > aren't part of the ownet messages. If we really want it, I'd create a > new ownet message type (extended_read perhaps) that carried more > information about it's data type. > > We are only using 7 of the 2^32 available message types > http://www.owfs.org/index.php?page=owserver-message-types > but any change would still leave issues with backwards compatibility. > > Paul Alfille > Paul,
You may hate this suggestion, but IMO the way to go is option negotiation. It's messy, adds all sorts of code, and is the only way I know off the slippery slope you propose. I've been involved in any number of these fire drills, and there are a couple ways I have seen it done, They all start with breaking the options down into areas, so known data types could be one area and composite sensors could be another... Then you modify the session start up to include the lowest common denominator selection process. Then you can either have each option have a defined name as you pass the string of known names for an area on startup. The other is to have a version number for each area, and each version has a known set of capabilities. The version number is much simpler if there is not 10 different groups writing different implementations of the protocol. The string set is more general and used in many RFCs because of the interoperability desire. jerry ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
