From 91143069d1a40cefd997522d85cb2d8adf1681f7 Mon Sep 17 00:00:00 2001 From: Samuel Mendoza-Jonas Date: Wed, 4 Feb 2015 12:02:23 +1100 Subject: ui/ncurses: Reduce unnecessary calls to redrawwin All current *_post() methods in ui/ncurses call redrawwin() and wrefresh() together. wrefresh() updates any lines on the screen that have been marked as changed or invalid. However redrawwin() marks the entire screen as invalid unconditionally. We can reduce the amount of data written to the screen by avoiding calls to redrawwin(). Screen transitions are the primary use case of redrawwin(), where the whole screen must be invalidated to avoid stale data remaining on screen. All other 'in-screen' updates such as changes to widgets or changing focus do not require a call to redrawwin(). The most noticeable performance improvement is in nc-menu, which makes an unnecssary call to redrawwin() after every addition to the boot option menu. eg. The number of bytes written to STDOUT in the main menu: # Boot options | Before | After -------------------------------- 8 | 5488 | 1149 133 | 422454 | 4652 Signed-off-by: Samuel Mendoza-Jonas --- ui/ncurses/nc-add-url.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'ui/ncurses/nc-add-url.c') diff --git a/ui/ncurses/nc-add-url.c b/ui/ncurses/nc-add-url.c index 386d813..cf55b03 100644 --- a/ui/ncurses/nc-add-url.c +++ b/ui/ncurses/nc-add-url.c @@ -43,6 +43,7 @@ struct add_url_screen { bool exit; bool show_help; + bool need_redraw; void (*on_exit)(struct cui *); int label_x; @@ -93,6 +94,7 @@ static void add_url_screen_process_key(struct nc_scr *scr, int key) } else if (screen->show_help) { screen->show_help = false; + screen->need_redraw = true; cui_show_help(screen->cui, _("Retrieve Config"), &add_url_help_text); @@ -106,7 +108,10 @@ static int add_url_screen_post(struct nc_scr *scr) struct add_url_screen *screen = add_url_screen_from_scr(scr); widgetset_post(screen->widgetset); nc_scr_frame_draw(scr); - redrawwin(scr->main_ncw); + if (screen->need_redraw) { + redrawwin(scr->main_ncw); + screen->need_redraw = false; + } wrefresh(screen->scr.main_ncw); return 0; } @@ -224,6 +229,7 @@ struct add_url_screen *add_url_screen_init(struct cui *cui, screen->on_exit = on_exit; screen->label_x = 2; screen->field_x = 25; + screen->need_redraw = false; nc_scr_init(&screen->scr, pb_add_url_screen_sig, 0, cui, add_url_screen_process_key, -- cgit v1.2.1