Re: [PATCH 1/3] gitk: turn off undo manager in the text widget

> From e965e1deb9747bbc2b40dc2de95afb65aee9f7fd Mon Sep 17 00:00:00 2001
> From: Markus Hitter <mah@jump-ing.de>
> Date: Sun, 6 Nov 2016 20:38:03 +0100
> Subject: [PATCH 1/3] gitk: turn off undo manager in the text widget
>
> The diff text widget is read-only, so there's zero point in
> building an undo stack. This change reduces memory consumption of
> this widget by about 95%.
>
> Memory usage of the whole program for viewing a reference commit
> before; 579'692'744 bytes, after: 32'724'446 bytes.
>

> Test procedure:
>
>  - Choose a largish commit and check it out. In this case one with
>    90'802 lines, 5'006'902 bytes.
>
>  - Have a Tcl version with memory debugging enabled. This is,
>    build one with --enable-symbols=mem passed to configure.
>
>  - Instrument Gitk to regularly show a memory dump. E.g. by adding
>    these code lines at the very bottom:
>
>      proc memDump {} {
>          catch {
>              set output [memory info]
>              puts $output
>          }
>
>          after 3000 memDump
>      }
>
>      memDump
>
>  - Start Gitk, it'll load this largish commit into the diff text
>    field automatically (because it's the current commit).
>
>  - Wait until memory consumption levels out and note the numbers.
>
> Note that the numbers reported by [memory info] are much smaller
> than the ones reported in 'top' (1.75 GB vs. 105 MB in this case),
> likely due to all the instrumentation coming with the debug
> version of Tcl.
>

> Signed-off-by: Markus Hitter <mah@jump-ing.de>
> ---
>  gitk | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gitk b/gitk
> index 805a1c7..8654e29 100755
> --- a/gitk
> +++ b/gitk
> @@ -2403,7 +2403,7 @@ proc makewindow {} {
>
>      set ctext .bleft.bottom.ctext
>      text $ctext -background $bgcolor -foreground $fgcolor \
> -       -state disabled -font textfont \
> +       -state disabled -undo 0 -font textfont \
>         -yscrollcommand scrolltext -wrap none \
>         -xscrollcommand ".bleft.bottom.sbhorizontal set"
>      if {$have_tk85} {
> --
> 2.9.3
>