Merge performance improvements into upstream

[richardartoul]

Hello!

My team has been maintaining a forked branch of vellum with some performance pooling improvements. These changes have significantly reduced memory allocations and memory consumption of the FST building process in our timeseries database.

I know a previous teammate of mine (who is unfortunately on leave of absence) had begun contributing some code back to upstream. Are you open to me opening P.Rs to contribute the remaining performance improvements back? We'd love to not maintain our own fork, as well as contribute back to the library that saved us a ton of work :)

Thanks again for open sourcing such a great library.

[abhinavdangeti]

Absolutely, we welcome all valuable contributions. Here's instructions on how you could contribute back to the library ..

https://github.com/couchbase/vellum/blob/master/CONTRIBUTING.md

[richardartoul]

Great! Here is the first P.R #27

Please pardon my ignorance, but I'm having trouble signing the CLA. I went to here but couldn't figure out where to go from there.

Also C.I is failing, but I don't think its anything related to my build. Appears to be having trouble installing the errcheck linter

[richardartoul]

Second P.R: #28 (rebased off the previous one to avoid conflicts, we can try and merge the other one first then this one)

Also I believe you can close #22 as its redundant with #28

[richardartoul]

@abhinavdangeti Just pinging to see if you got a chance to review!

[abhinavdangeti]

Hey @richardartoul, thanks for the contributions. Haven't had a chance to look into them yet. One of us here on the team will take a look as soon as we are able.

[richardartoul]

Sounds good, thanks!

[richardartoul]

Sorry for the spam, just wondering if you'd had a chance to take a look? The performance improvements are quite substantial and we hate to maintain our own fork