Append-only B+ Tree on Node.js
github.com
github.com
https://github.com/kevingadd/DataMangler
Of interest might be the fact that it's based on memory-mapped files, and it supports multithreaded querying. Insertion is single-threaded, though.
Unfortunately, it uses a regular old B-Tree. I should probably change it to a B+ Tree for better range queries... didn't even know about that data structure until seeing this HN post. :)
http://www.tarsnap.com/kivaloo.html
It's a specialized key value store. I'm reading through the C code for it. It will be fun to read your code along with that - thanks for putting it out there.
I don't mind you creating a wrapper by any means and you don't need my permission anyway; it's open-source.
NOTE: it doesn't do log-structuring or compaction atm so the file will just continue to grow.