Re: lib/58282: Sysinst terminal output size increased because curses

[Andreas Gustafsson <gson%gson.org@localhost>]

The following reply was made to PR lib/58282; it has been noted by GNATS.

From: Andreas Gustafsson <gson%gson.org@localhost>
To: Brett Lymn <blymn%internode.on.net@localhost>
Cc: gnats-bugs%netbsd.org@localhost
Subject: Re: lib/58282: Sysinst terminal output size increased because curses
Date: Tue, 9 Jul 2024 13:06:41 +0300

 Brett Lymn wrote:
 > >  Why can't this be optimized to a single instance of ^[[37m^[[44m
 > >  followed multiple spaces?
 > 
 > Please try the attached patch, see if this helps.
 
 It helps with the specific issue where the color is being set before
 every space character during the intial clearing of the screen when
 sysinst is first started.  This part is now much faster, which should
 help give new users on serial consoles a much better first impression.
 
 Unfortunately, that's not the only issue that appeared with the curses
 changes of April 2022.  They also changed the way the screen is
 cleared between the subsequent pages of the sysinst UI (after the
 initial startup) from clearing a line at a time using ^[[K to clearing
 a character at a time using spaces (but thankfully it was not setting
 the color before each space like it did with the initial screen).  It
 looks like this latter change actually accounted for the bulk of the
 output size growth, but it's not as noticeable to the user because the
 added delay does not happen all at once at the very beginning, but is
 divided among many screens.
 
 Here are the two links from the original PR again, now with the
 corresponding file sizes:
 
   https://www.gson.org/netbsd/bugs/curses/2022.04.11.21.23.07-install.log           74365
   https://www.gson.org/netbsd/bugs/curses/2022.04.12.07.03.29-install.log          164936
 
 And here is the output from a current build with and without your patch,
 with sizes:
 
   https://www.gson.org/netbsd/bugs/curses/2024.07.06.11.09.17-install.log          250499
   https://www.gson.org/netbsd/bugs/curses/2024.07.06.11.09.17-install-patched.log  226238
 
 -- 
 Andreas Gustafsson, gson%gson.org@localhost