bug#31138: Native json slower than json.el

[Eli Zaretskii]

> From: yyoncho <yyoncho@gmail.com>
> Date: Mon, 25 Mar 2019 23:34:38 +0200
> Cc: Sébastien Chapuis <sebastien@chapu.is>, 
>       31138@debbugs.gnu.org
> 
> 3. Even in the best case scenario native parsing is not fast enough. In 
> lsp-mode, you might receive 3.5mb
> json as a server-side response while you are typing. E. g. I might type "abc" 
> and get 10.5 mb json.

What kind of throughput do you get with native JSON parsing when you
submit a 10MB JSON to it?  My testing indicates that decoding strings
by UTF-8 runs at about 50 msec per MByte for short strings, and about
4 times faster for very large strings.  How does this compare with the
overall time for processing a 10MB JSON?

> Alternatively, we (lsp-mode team) will be able to solve all these in a 
> dynamic module if emacs module
> mechanism is extended to allow creating emacs lisp structures efficiently. 

I think we should only consider this after we profile JSON parsing and
see which parts take the most processing time.