faster ways to get repo status?

[jyn514]

I have the following code in my shell prompt:

# if there's an error here, we'll see it because we don't redirect stderr.
jj_desc() {
	rev=$1; color=$2
	desc=$(jj log --ignore-working-copy --no-graph -T description -r "$rev" | head -n1)
	if [ -n "$desc" ]; then
		printf %s "(${color}jj: $desc)"
		return 0
	fi
	return 1
}

if jj_desc @ "$FAINT_RED"; then exit 0; fi
if [ "$(jj diff --ignore-working-copy --name-only | wc -l)" = 0 ]; then
	color="$FAINT_GREEN"
else
	color="$FAINT_RED"
fi
jj_desc @- || printf %s "${color}jj"

This takes about .15 seconds to execute on a medium-large repo (~3.4 million git objects):

; bash -x jj-info 2>&1| ts -s %.S
00.000004 + '[' -n '' ']'
00.000451 ++ ansi_escape '\033[2;31m'
00.000464 ++ command printf '\01\033[2;31m\02'
00.000471 ++ printf '\01\033[2;31m\02'
00.000477 + FAINT_RED=''
00.000482 ++ ansi_escape '\033[2;32m'
00.000488 ++ command printf '\01\033[2;32m\02'
00.000493 ++ printf '\01\033[2;32m\02'
00.000498 + FAINT_GREEN=''
00.000503 ++ ansi_escape '\033[2;37m'
00.000508 ++ command printf '\01\033[2;37m\02'
00.000513 ++ printf '\01\033[2;37m\02'
00.000517 + FAINT_WHITE=''
00.000522 + jj_desc @ ''
00.000527 + rev=@
00.000532 + color=''
00.000537 ++ jj log --ignore-working-copy --no-graph -T description -r @
00.000542 ++ head -n1
00.054314 + desc=
00.054344 + '[' -n '' ']'
00.054351 + return 1
00.054839 ++ jj diff --ignore-working-copy --name-only
00.054936 ++ wc -l
00.132591 + '[' '       0' = 0 ']'
00.132622 + color=''
00.132630 + jj_desc @-
00.132636 + rev=@-
00.132641 + color=
00.133152 ++ jj log --ignore-working-copy --no-graph -T description -r @-
00.133230 ++ head -n1
00.191103 + desc='fix some tests, support async closures'
00.191132 + '[' -n 'fix some tests, support async closures' ']'
00.191139 + printf %s '(jj: fix some tests, support async closures)'
00.191145 (jj: fix some tests, support async closures)

As you can see, the longest bits are jj log --ignore-working-copy --no-graph -T description -r @ and jj diff --ignore-working-copy --name-only. Is there any way to speed these up? I understand why diff might be slow, but I really don't know why log -T description should take 50 milliseconds to execute ...

[jyn514]

I did find a way to combine all these into a single invocation of jj, which is fast enough for my needs:

info=$(jj log -T 'empty++":"++description++"\n"' -r '@-|@' --no-graph --ignore-working-copy)

color=$FAINT_RED
if [ "$(echo "$info" | head -n1 | cut -d : -f1)" = true ]; then
	color=$FAINT_GREEN
fi
desc=$(echo "$info" | tail -n+2 | cut -d : -f2-)

[jyn514]

I also found that jj was spending time spawning less -F, which is possible to disable with --config ui.paginate=never. that wasn't most of the time, though.