Re: Understanding filter function calls

[Karthik Chikmagalur <karthikchikmagalur@gmail.com>]

> It does not take any longer for the filter function to run on each
> invocation.  The problem is that The filter in Emacs is called with
> about 4KB of new text every time, and these calls are spaced out evenly
> in time, so Emacs takes longer to get around to parsing the stdout with
> TeXLive 2023.
>
> The dvisvgm process is thus bottlenecked by Emacs.  I can imagine a few
> different ways to fix this, but I don't know how to do them:

I can confirm this after some benchmarking:

| dvisvgm version | Run in shell (s) | Run via Emacs (s) | Difference |
|-----------------+------------------+-------------------+------------|
| TeXLive 2022    |            1.427 |             1.786 |        25% |
| TeXLive 2023    |            1.481 |             2.202 |        48% |

The variances are small and have been omitted.  So TeXLive 2023's
dvisvgm is about 48% slower when called from Emacs because it's waiting
on Emacs to pick up the process output.  Using a larger stream buffer
(if possible) should fix this issue.

Karthik