[FS} Speed of functions defined in versioned document versus same document

George_Anderson

Is there a reason to expect a performance boost when calling a function from an imported versioned document as opposed to importing from another file in the same document?

As an example, I copied a low-level function (`project`) from the FS stdlib into my document and renamed it 'local_project'. The profiler shows that calling 'local_project' is nearly twice as slow as calling the one in stdlib, despite no modifications. Is there a reason to expect this, and does it imply that I could get better performance by refactoring code into separate documents?

ilya_baran

There should be no difference (at least in functions like this).  I expect what you're seeing is due to variance in the profiling, especially for small time intervals -- you have to run 'project' a lot of times before you get a reliable performance estimate. 

George_Anderson

@ilya_baran Here's a document demonstrating the problem (speed difference solidly verified by 1000 calls, or you can increase it).

https://cad.onshape.com/documents/fc0c21d7adb92e6906adc991/w/e277f19123deb82b34708ec1/e/7e35b1da4119fae5f3d2bb2a

It turns out it has something to do with imported stdlib versions. I have two featurescript tabs -- if the stdlib version I import is different in the two tabs (e.g. I used 1549 and 1540, but any two different versions in either tab seems to demonstrate the problem), then the version "locally imported" from the library tab is about 40% slower, while the direct import from the library and a locally defined copy in the same tab don't change speed.

ilya_baran

Interesting -- there is clearly an effect from mixing different std versions.  Without profiling the internals, I can't immediately explain it, though I have some guesses.  Regardless, not mixing stds has performance benefits outside what is measured during execution, so that remains the recommendation.