bug#31138: Native json slower than json.el

[Dmitry Gutov]

On 24.04.2019 19:21, Eli Zaretskii wrote:

> Please point me to examples of this, I don't think I understand what
> you have in mind.

Buffers with output from a process. In this example, the process is a 
network connection. Not sure it applies, though. Since output arrives 
piece-by-piece, maybe it gets decoded with *-string routines 
(mm-decode-string uses that).

> > > We could perhaps try
> > > a similar optimization for UTF-8 instead of just ASCII.
> >
> > I think so.
>
> Turns out we already do, I just missed that.

OK.

> What does libjansson do if it receives strings with bytes it cannot
> interpret?  Like raw bytes or UTF-8 sequences whose length is more
> than 4 bytes?

One could test that directly, but its API docs list different kinds of 
errors, including:

  json_error_invalid_utf8
  json_error_null_character
  json_error_null_byte_in_key

And we check for error status in functions that use the encoded values.

Reading the sources, there are several places where the first error is 
signaled.