On my slow laptop (P3 600MHz), system-wide bash completions take
too much time to load (> 2s), and a significant fraction of this
time is spent loading git-completion.bash:
$ time bash -c ". ./git-completion.bash" # hot cache, before this patch
real 0m0.509s
user 0m0.310s
sys 0m0.180s
Kirill tracked down that the most time is spent warming up
merge_strategy, all_command & porcelain_command caches.
Since git is not used in each and every interactive xterm, it
seems best to load completion support with cold caches, and then
load each needed thing lazily. This has most of the speed
advantage of pre-generating everything at build time, without the
complication of figuring out at build time what commands will be
available at run time.
The result is that loading completion is significantly faster
now:
$ time bash -c ". ./git-completion.bash" # cold cache, after this patch
real 0m0.171s
user 0m0.060s
sys 0m0.040s
Suggested-by: Kirill Smelkov <kirr@xxxxxxxxxx>
Cc: Shawn O. Pearce <spearce@xxxxxxxxxxx>
Cc: Stephen Boyd <bebarino@xxxxxxxxx>
Cc: Sverre Rabbelier <srabbelier@xxxxxxxxx>
Cc: Junio C Hamano <junio@xxxxxxxxx>
Signed-off-by: Jonathan Nieder <jrnieder@xxxxxxxxx>
---
Stephen Boyd wrote:
> Ah ok. I think this proves even more that pregenerating the
> completion is a bad idea. With dynamic population we don't have
> these problems and it only takes 250ms more to load on a P3 700Mhz.
Hmm, 250 ms is a lot.
Strictly speaking, even with the existing completion script, it might
be nice to provide a "hash -r"-like command to bring the caches up to
date. Such a function could be:
git-completion-rehash ()
{
__git_compute_all_commands
__git_compute_merge_strategies
__git_compute_porcelain_commands
}
But that is a separate topic.
contrib/completion/git-completion.bash | 35 +++++++++++++++++--------------
1 files changed, 19 insertions(+), 16 deletions(-)
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 9e8b607..7088ec7 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -330,10 +330,9 @@ __git_list_merge_strategies ()
}'
}
-__git_merge_strategies ()
+__git_compute_merge_strategies ()
{
- : ${__git_merge_strategylist:=$(__git_list_merge_strategies)}
- echo "$__git_merge_strategylist"
+ : ${__git_merge_strategies=$(__git_list_merge_strategies)}
}
__git_complete_file ()
@@ -468,15 +467,16 @@ __git_complete_remote_or_refspec ()
__git_complete_strategy ()
{
+ __git_compute_merge_strategies
case "${COMP_WORDS[COMP_CWORD-1]}" in
-s|--strategy)
- __gitcomp "$(__git_merge_strategies)"
+ __gitcomp "$__git_merge_strategies"
return 0
esac
local cur="${COMP_WORDS[COMP_CWORD]}"
case "$cur" in
--strategy=*)
- __gitcomp "$(__git_merge_strategies)" "" "${cur##--strategy=}"
+ __gitcomp "$__git_merge_strategies" "" "${cur##--strategy=}"
return 0
;;
esac
@@ -495,16 +495,16 @@ __git_list_all_commands ()
done
}
-__git_all_commands ()
+__git_compute_all_commands ()
{
- : ${__git_all_commandlist:=$(__git_list_all_commands)}
- echo "$__git_all_commandlist"
+ : ${__git_all_commands=$(__git_list_all_commands)}
}
__git_list_porcelain_commands ()
{
local i IFS=" "$'\n'
- for i in "help" $(__git_all_commands)
+ __git_compute_all_commands
+ for i in "help" $__git_all_commands
do
case $i in
*--*) : helper pattern;;
@@ -586,10 +586,9 @@ __git_list_porcelain_commands ()
done
}
-__git_porcelain_commands ()
+__git_compute_porcelain_commands ()
{
- : ${__git_porcelain_commandlist:=$(__git_list_porcelain_commands)}
- echo "$__git_porcelain_commandlist"
+ : ${__git_porcelain_commands=$(__git_list_porcelain_commands)}
}
__git_aliases ()
@@ -1082,7 +1081,8 @@ _git_help ()
return
;;
esac
- __gitcomp "$(__git_all_commands)
+ __git_compute_all_commands
+ __gitcomp "__git_all_commands
attributes cli core-tutorial cvs-migration
diffcore gitk glossary hooks ignore modules
repository-layout tutorial tutorial-2
@@ -1438,7 +1438,8 @@ _git_config ()
return
;;
pull.twohead|pull.octopus)
- __gitcomp "$(__git_merge_strategies)"
+ __git_compute_merge_strategies
+ __gitcomp "$__git_merge_strategies"
return
;;
color.branch|color.diff|color.interactive|\
@@ -1539,7 +1540,8 @@ _git_config ()
pager.*)
local pfx="${cur%.*}."
cur="${cur#*.}"
- __gitcomp "$(__git_all_commands)" "$pfx" "$cur"
+ __git_compute_all_commands
+ __gitcomp "__git_all_commands" "$pfx" "$cur"
return
;;
remote.*.*)
@@ -2136,7 +2138,8 @@ _git ()
--help
"
;;
- *) __gitcomp "$(__git_porcelain_commands) $(__git_aliases)" ;;
+ *) __git_compute_porcelain_commands
+ __gitcomp "$__git_porcelain_commands $(__git_aliases)" ;;
esac
return
fi
--
1.6.5.2
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