Re: man page rendering speed (was: Playground pager lsp(1))

[Ralph Corderoy <ralph@inputplus.co.uk>]

Hi Branden,

> You're referring to cat pages.  As far as I know, these are on their
> way out if not already gone.

catman must die.  It was never a good solution to the problem.  As well
as ignoring different TERMs, it also didn't handle a user's variations
to a terminal's definition.  I'm glad to see Colin is open to the idea,
though accept it's initial and on-going work for him.

> On my system, all groff man pages but one render in between a tenth and
> a fortieth of a second.

Colin made the point I was going to make: how long must my eyeballs wait
to be pleasured?

    $ strace -ttt -fe read,write -o /tmp/st man ffmpeg-all
    $ cat /tmp/st
 →  19788 1680952657.119429 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0  \0\0\0\0\0\0"..., 832) = 832
    ...
    19801 1680952658.350823 write(1, "FFMPEG-ALL(1)                   "..., 1023 <unfinished ...>
    19801 1680952658.352054 <... write resumed>) = 1023
    19801 1680952658.353074 write(1, "ified by a plain output url.\33[m\n"..., 1023 <unfinished ...>
    19801 1680952658.353357 <... write resumed>) = 1023
    19801 1680952658.354272 write(1, "e command line multiple times. E"..., 1023) = 1023
    19801 1680952658.357171 write(1, "aw input files.\33[m\n\33[m\n\33[1mDETAI"..., 1009) = 1009
    19801 1680952658.357478 read(0, "--- | encoded data | <----+\n    "..., 4096) = 4096
    19801 1680952658.358752 write(1, "               | output | <-----"..., 1023) = 1023
    19801 1680952658.359556 write(1, "peg\33[0m can process raw audio an"..., 574) = 574
 →  19801 1680952658.359735 read(3,  <unfinished ...>
    ...
    19801 1680952662.323859 <... read resumed>"q", 1) = 1
    ...
    $

    1680952658.359735 - 1680952657.119429 = 1.240306

strace adds a bit of overhead.

    $ PAGER=true time -p man ffmpeg-all
    real 0.99
    user 1.07
    sys 0.15
    $

Hard to find a slower CPU.

    $ grep name /proc/cpuinfo | uniq -c
          4 model name      : Intel(R) Atom(TM) CPU D525   @ 1.80GHz

-- 
Cheers, Ralph.