From 5e6a8177e55a8e30e0cd67c7ee3039aa22ff1c0e Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Fri, 3 Feb 2017 21:01:02 +0000
Subject: [PATCH] Cache status line position to reduce option lookups during
 output.

---
 cmd-set-option.c |  2 ++
 resize.c         |  2 ++
 session.c        |  2 ++
 status.c         | 19 ++++++++++++++-----
 tmux.h           |  4 +++-
 5 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/cmd-set-option.c b/cmd-set-option.c
index c7cef42c..cc8b7570 100644
--- a/cmd-set-option.c
+++ b/cmd-set-option.c
@@ -248,6 +248,8 @@ cmd_set_option_exec(struct cmd *self, struct cmdq_item *item)
 		RB_FOREACH(w, windows, &windows)
 			layout_fix_panes(w, w->sx, w->sy);
 	}
+	RB_FOREACH (s, sessions, &sessions)
+		status_update_saved(s);
 
 	/*
 	 * Update sizes and redraw. May not always be necessary but do it
diff --git a/resize.c b/resize.c
index 2d3f02cc..ba8078bc 100644
--- a/resize.c
+++ b/resize.c
@@ -89,6 +89,8 @@ recalculate_sizes(void)
 
 		s->sx = ssx;
 		s->sy = ssy;
+
+		status_update_saved(s);
 	}
 
 	RB_FOREACH(w, windows, &windows) {
diff --git a/session.c b/session.c
index 19a6f139..09c2dc26 100644
--- a/session.c
+++ b/session.c
@@ -131,6 +131,8 @@ session_create(const char *name, int argc, char **argv, const char *path,
 	s->options = options_create(global_s_options);
 	s->hooks = hooks_create(global_hooks);
 
+	status_update_saved(s);
+
 	s->tio = NULL;
 	if (tio != NULL) {
 		s->tio = xmalloc(sizeof *s->tio);
diff --git a/status.c b/status.c
index c4f79050..6cc1ee37 100644
--- a/status.c
+++ b/status.c
@@ -192,17 +192,26 @@ status_timer_start_all(void)
 		status_timer_start(c);
 }
 
+/* Update status cache. */
+void
+status_update_saved(struct session *s)
+{
+	if (!options_get_number(s->options, "status"))
+		s->statusat = -1;
+	else if (options_get_number(s->options, "status-position") == 0)
+		s->statusat = 0;
+	else
+		s->statusat = 1;
+}
+
 /* Get screen line of status line. -1 means off. */
 int
 status_at_line(struct client *c)
 {
 	struct session	*s = c->session;
 
-	if (!options_get_number(s->options, "status"))
-		return (-1);
-
-	if (options_get_number(s->options, "status-position") == 0)
-		return (0);
+	if (s->statusat != 1)
+		return (s->statusat);
 	return (c->tty.sy - 1);
 }
 
diff --git a/tmux.h b/tmux.h
index 533a5476..c980f9bb 100644
--- a/tmux.h
+++ b/tmux.h
@@ -545,7 +545,6 @@ struct grid_cell {
 	int			fg;
 	int			bg;
 	struct utf8_data	data;
-
 };
 struct grid_cell_entry {
 	u_char			flags;
@@ -936,6 +935,8 @@ struct session {
 	struct winlink_stack lastw;
 	struct winlinks	 windows;
 
+	int		 statusat;
+
 	struct hooks	*hooks;
 	struct options	*options;
 
@@ -1864,6 +1865,7 @@ void	 server_unzoom_window(struct window *);
 /* status.c */
 void	 status_timer_start(struct client *);
 void	 status_timer_start_all(void);
+void	 status_update_saved(struct session *s);
 int	 status_at_line(struct client *);
 struct window *status_get_window_at(struct client *, u_int);
 int	 status_redraw(struct client *);