Optimizing tty display update (was: Implementing image support for kitty terminal)

[Stefan Monnier]

> BTW, do you have a slow connection you could use to test larger stream
> buffer sizes with, at least anecdotally?

No, sorry, I can't remember the last time I had a connection for which
optimizing the amount of data sent to the terminal to update the screen
could have made a difference.

The closest I can remember is a discussion around `baud-rate` and
`isearch-slow-terminal-mode`:

    https://lists.gnu.org/archive/html/emacs-devel/2020-10/msg01639.html

> If we remove the flushes, except at the end of the update, and give
> the output stream a large buffer (setvbuf, or something), we could at
> least get some impression if that may benefit users.

I can't think of any reason why it would make the behavior worse and it
would simplify the code, so I'm all for it.


        Stefan