Pure gold kyle! Thanks stacks for such a detailed explanation.
forgive my top-posting
-aW
0n Tue, May 27, 2008 at 10:49:29PM -0500, Kyle Wheeler wrote:
On Wednesday, May 28 at 09:56 AM, quoth Wilkinson, Alex:
Ok so in the manual time_inc says:
this variable controls the frequency with which progress updates
are displayed. It suppresses updates less than ``time_inc''
milliseconds apart. This can improve throughput on systems with
slow terminals, or when running mutt on a remote system.
Ok so what is meant by progress updates ?
Whenever mutt does something that can take a while (such as download a
large message, open a very large mailbox, send a large message, etc.),
it displays status information about that task at the bottom of the
terminal. That status information is a progress update.
I'm still trying to work out what time_inc gives me :(
time_inc is a solution to a problem that some people have had. Here's
how things used to work:
Progress updates used to be on a once every N things basis (this is
the $read_inc setting). For example, when opening a large mailbox, you
could tell mutt to post a new progress update every 10 messages (ten
is the default, but it could be any number). Thus, after parsing ten
messages, mutt would change the message at the bottom of the terminal
(update it) to tell you that another ten messages had been parsed.
Now, generally speaking, mutt can read messages out of a mailbox
pretty darn fast. Let's say, just for discussion purposes, that on you
computer, mutt can read 1000 messages every second. With a $read_inc
setting of 10, that means mutt will attempt to update the terminal's
contents 100 times per second, or once every 1/100th of a second.
That's pretty darn fast---you can't even read that fast---and some
terminals just aren't that fast. If your terminal is slow and can't
change it's display that quickly, you're spending a lot of time
(comparatively speaking) updating your terminal and you aren't even
getting anything useful out of it because the terminal can't display
updates that quickly. It can even slow down how quickly mutt opens a
mailbox, because mutt can't change the display until the previous
display has finished. If your terminal has a reaction time of 1/25th
of a second, that means updating the terminal 100 times takes 4
seconds! That's no good, because that forces mutt to take four times
as long to open a 1000 message mailbox (which it could have opened in
1 second, if it didn't have to wait for the terminal). With me so far?
Previously, to compensate, you would do something like increase the
read_inc setting to, say, 100. Thus, mutt would attempt to update the
terminal's contents only 10 times per second. That's still plenty
fast, on your 1/25th second terminal, it only takes 0.4 seconds, which
means mutt can easily meet its deadline of opening the 1000 message
mailbox in 1 second.
But now imagine that in addition to opening a local mailbox, which
mutt can open quickly, you also want to open a remote IMAP mailbox,
which mutt can only pull down much more slowly. Let's say, just for
argument's sake, that mutt can only read 20 IMAP messages every
second. If your $read_inc setting is 100, that means mutt has to read
100 messages before it tells you how far along it is, which means that
in the IMAP situation, it'll only tell you what it's doing every five
seconds. That's annoying! It's also very imprecise! You don't know if
mutt is just chugging along, or if there's one really big message
that's causing a problem, or quite what's going on. What you'd really
like mutt to do is to tell you what it's up to every so often, so that
you know it's still alive, but at a pace that doesn't slow down its
operation. That's where $time_inc comes in. You can set $read_inc to
something absurdly small, like 1, and then set $time_inc to something
reasonable, like 250. That means that it'll update the terminal to
tell you what it's up to 4 times per second, NO MATTER how quickly or
slowly it's doing its job. That way you can ensure that mutt keeps you
informed (even if the task is really slow) without slowing itself down
(even if the task is really fast).
Does that make sense?
AFAICT with time_inc=10 included in my $HOME/.mutt/settings I see no
change, yet I see people on this list raving about it ? What am I
missing ?
A $time_inc=10 setting is absurdly low. That's telling mutt that you
need updates every 1/100th of a second. You can't read that fast, and
your terminal can't update that fast. The real joy of $time_inc is
that you can make your increments (read_inc and
