WebAssembly WIP plus fix for edge case in decoding.

[krisselden]

[vlascik]

So does this help, how faster is it so far? Btw, have you seen https://medium.com/@david.aurelio/medium-fast-source-map-generation-for-react-native-ea5549007c18 ? A write-up on how React got their sourcemap generation down from 3s to 0.5s. Seems like it could be useful.

[krisselden]

@vlascik there are benchmarks, the current js version goes from 5 seconds for source-map to .5 for the 15mb of mappings in that scala sourcemap example. The webassembly version didn't see much improvement for node 8 but on the nightly v8 integration it cut it down to ~250ms from 500ms.

Thanks for the article you can see if you look at the history of this project I'm aware of the allocation issues and how slow the Mozilla sourcemap library is. I have further notes for speeding up concat in a build pipeline and other ideas but just have had a limited amount of time.

[vlascik]

5s -> 250ms is pretty awesome, great job. I just realized fast-sourcemap-concat still uses Mozilla's source-map for some reason... that's a shame, fixing sourcemaps could really help with Ember's rebuilds. I'll take a look if I'd be able to change that, but I'm afraid getting up to speed on the subject won't be that trivial. Hope you'll find some spare cycles soon.

[stefanpenner]

I'll take a look if I'd be able to change that, but I'm afraid getting up to speed on the subject won't be that trivial. Hope you'll find some spare cycles soon.

Ya the goal of this project is to eventually replace the one in broccoli-concat. If you have cycles to help, we would love the help :)