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Wildly varying regen times with instantiate

joshtargo
joshtargo Member Posts: 655 EDU
in FeatureScript

I've got a feature that instantiates configured geometry from Part Studios in previous Version of the same doc. Three addInstance calls into one instantiator, then a single instantiate.

Regen times swing by roughly 8x and I haven't been able to find a repeatable pattern.

What I'm seeing

Regen lands at either ~200ms or ~25ms, with very little in between. The same feature producing identical geometry will sit at one number or the other depending on what I did immediately before, and I can't predict which.

Some things that seem to matter, though none of them hold consistently:

  • Scrubbing the numeric inputs around and returning to a value often drops the time to the low number, but not always.
  • Committing the feature and reopening tends to help, but not always.
  • Suppressing and unsuppressing seems to reliably drop it to ~25ms without touching any input.

That last one is the part I find strangest — same parameters, nothing edited, and the cost disappears. So whatever the expensive work is, the re-entry path skips it and the first-touch path doesn't.

There's clearly some caching involved, but I've had trouble characterizing its scope. It isn't global across documents — a set of values that's fast in one document costs full price in a fresh one. Within a document it's shared between multiple instances of the feature. Beyond that I've had results that contradict each other.

What I've ruled out

  • Not my authoring workspace. Same behavior in a clean document with the feature inserted normally.
  • Not the dialog. Times are the same whether the dialog is open or committed.
  • Not document reload or tab switching. Neither changes anything.

Questions

  1. Is cost like this expected for instantiate against a configured source studio, or does 200ms suggest something inefficient on my end?
  2. What actually gets cached, and at what scope? I'd like to understand what a real user experiences versus what I see while iterating.
  3. Would opMergeContexts behave differently, or is the cost in regenerating the source studio at the configuration — in which case the transfer mechanism wouldn't matter?
  4. Anything I can do from the feature side to reduce first-hit cost?

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