From e3359f8349cf972052604c089b5bab71f5e33095 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 24 Sep 2019 20:44:58 +0000
Subject: [PATCH] Some minor performance improvements - most notably, don't
 search the input state table if the next character matches the same state as
 before.

---
 grid.c         | 22 ++++++++++++----------
 input.c        | 27 +++++++++++++++++----------
 log.c          |  3 +++
 screen-write.c |  6 ++----
 4 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/grid.c b/grid.c
index 2f1e9b59..a016dc12 100644
--- a/grid.c
+++ b/grid.c
@@ -186,17 +186,19 @@ grid_clear_cell(struct grid *gd, u_int px, u_int py, u_int bg)
 	struct grid_cell	*gc;
 
 	memcpy(gce, &grid_cleared_entry, sizeof *gce);
-	if (bg & COLOUR_FLAG_RGB) {
-		grid_get_extended_cell(gl, gce, gce->flags);
-		gl->flags |= GRID_LINE_EXTENDED;
+	if (bg != 8) {
+		if (bg & COLOUR_FLAG_RGB) {
+			grid_get_extended_cell(gl, gce, gce->flags);
+			gl->flags |= GRID_LINE_EXTENDED;
 
-		gc = &gl->extddata[gce->offset];
-		memcpy(gc, &grid_cleared_cell, sizeof *gc);
-		gc->bg = bg;
-	} else {
-		if (bg & COLOUR_FLAG_256)
-			gce->flags |= GRID_FLAG_BG256;
-		gce->data.bg = bg;
+			gc = &gl->extddata[gce->offset];
+			memcpy(gc, &grid_cleared_cell, sizeof *gc);
+			gc->bg = bg;
+		} else {
+			if (bg & COLOUR_FLAG_256)
+				gce->flags |= GRID_FLAG_BG256;
+			gce->data.bg = bg;
+		}
 	}
 }
 
diff --git a/input.c b/input.c
index f37f8fd8..2ff7a65d 100644
--- a/input.c
+++ b/input.c
@@ -888,7 +888,8 @@ input_parse_buffer(struct window_pane *wp, u_char *buf, size_t len)
 {
 	struct input_ctx		*ictx = wp->ictx;
 	struct screen_write_ctx		*sctx = &ictx->ctx;
-	const struct input_transition	*itr;
+	const struct input_state	*state = NULL;
+	const struct input_transition	*itr = NULL;
 	size_t				 off = 0;
 
 	if (len == 0)
@@ -916,16 +917,22 @@ input_parse_buffer(struct window_pane *wp, u_char *buf, size_t len)
 		ictx->ch = buf[off++];
 
 		/* Find the transition. */
-		itr = ictx->state->transitions;
-		while (itr->first != -1 && itr->last != -1) {
-			if (ictx->ch >= itr->first && ictx->ch <= itr->last)
-				break;
-			itr++;
-		}
-		if (itr->first == -1 || itr->last == -1) {
-			/* No transition? Eh? */
-			fatalx("no transition from state");
+		if (ictx->state != state ||
+		    itr == NULL ||
+		    ictx->ch < itr->first ||
+		    ictx->ch > itr->last) {
+			itr = ictx->state->transitions;
+			while (itr->first != -1 && itr->last != -1) {
+				if (ictx->ch >= itr->first && ictx->ch <= itr->last)
+					break;
+				itr++;
+			}
+			if (itr->first == -1 || itr->last == -1) {
+				/* No transition? Eh? */
+				fatalx("no transition from state");
+			}
 		}
+		state = ictx->state;
 
 		/*
 		 * Any state except print stops the current collection. This is
diff --git a/log.c b/log.c
index c002663e..44b24c67 100644
--- a/log.c
+++ b/log.c
@@ -131,6 +131,9 @@ log_debug(const char *msg, ...)
 {
 	va_list	ap;
 
+	if (log_file == NULL)
+		return;
+
 	va_start(ap, msg);
 	log_vwrite(msg, ap);
 	va_end(ap);
diff --git a/screen-write.c b/screen-write.c
index 6c509e2c..34d16ee8 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -1326,8 +1326,7 @@ screen_write_collect_end(struct screen_write_ctx *ctx)
 		}
 	}
 
-	memcpy(&gc, &ci->gc, sizeof gc);
-	grid_view_set_cells(s->grid, s->cx, s->cy, &gc, ci->data, ci->used);
+	grid_view_set_cells(s->grid, s->cx, s->cy, &ci->gc, ci->data, ci->used);
 	screen_write_set_cursor(ctx, s->cx + ci->used, -1);
 
 	for (xx = s->cx; xx < screen_size_x(s); xx++) {
@@ -1351,8 +1350,7 @@ screen_write_collect_add(struct screen_write_ctx *ctx,
 	/*
 	 * Don't need to check that the attributes and whatnot are still the
 	 * same - input_parse will end the collection when anything that isn't
-	 * a plain character is encountered. Also nothing should make it here
-	 * that isn't a single ASCII character.
+	 * a plain character is encountered.
 	 */
 
 	collect = 1;