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| <== Date ==> | <== Thread ==> |
|---|
| Subject: | Re: [EXTERNAL] Re: Change PVA structure dynamically during IOC operation |
| From: | "Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov> |
| To: | "Johnson, Andrew N." <anj at anl.gov>, "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>, "Alnajjar, Dawood" <dnajjar at slac.stanford.edu> |
| Date: | Wed, 28 Sep 2022 18:38:46 +0000 |
|
You're right, I missed the Any type.
It does encode the structure description with each update, so missing out the efficiency usually offered in the protocol.
Yes, union would be better. It describes all options once, then sends updates with just the index of the option that's being used.
From: Andrew Johnson <anj at anl.gov>
PVA does support unions though, and an "any" type, so assuming you can design all the versions of the structure that you will need up front (and that the pvxs implementation supports them) you should be able to use them
to make changes to your PVA structure without having to withdraw and re-add the PV. I believe a union will be more efficient than using an "any".
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