1134566 - Improve the performance of the source-map library by rewriting parts of it in asm.js.

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P4)

Description

[Eddy Bruel [:ejpbruel]]

Parsing source maps is a significant performance bottleneck for the devtools. The parser implementation is written in JS and is already optimized to the point where we don't expect to get any big wins there.

The only way to get better performance at this point would be to rewrite the parser in either C++ or asm.js. Since the source-map library is used by people outside of Mozilla as well, asm.js seems the best option here.

Comment 1

[Tom Tromey :tromey]

Rust is the new hotness.
https://github.com/tromey/vlq

Though it seems to me that this is less important now that the decoding is done in a worker.
Marking it P4, the forgotten P.

Comment 2

[:Harald Kirschner :digitarald]

Tom, didn't this happen?

Comment 3

[Tom Tromey :tromey]

(In reply to :Harald Kirschner :digitarald from comment #2)
> Tom, didn't this happen?

Yes, but it hasn't landed in devtools-core yet (https://github.com/devtools-html/devtools-core/pull/995)
or been landed in M-C yet (note that M-C has two copies of the source map library).

Comment 4

[Jason Laster [:jlast]]

The sourcemap library uses wasm now.