Performance improvements for regex searching, most notably:

- Use the grid data directly instead of copying it.

- Special case the most typical one byte character cells and use memcmp
  for multiple bytes instead of a handrolled loop.

- Hoist regcomp out of the loop into the calling functions.

GitHub issue 2143.

Also a man page from from jmc@.

1 files changed, 6 insertions, 11 deletions

diff --git a/window-copy.c b/window-copy.c
index 8c226a92..57228273 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -2523,9 +2523,8 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 		cells[cell].d = window_copy_cellstring(gl, px,
 		    &cells[cell].dlen);
 		cell++;
-		px++;
-		if (px == gd->sx) {
-			px = 0;
+		px = (px + 1) % gd->sx;
+		if (px == 0) {
 			pywrap++;
 			gl = grid_peek_line(gd, pywrap);
 		}
@@ -2714,27 +2713,23 @@ window_copy_search(struct window_mode_entry *wme, int direction, int regex)
 	struct screen			*s = data->backing, ss;
 	struct screen_write_ctx		 ctx;
 	struct grid			*gd = s->grid;
-	const char			*str = data->searchstr;
 	u_int				 fx, fy, endline;
 	int				 wrapflag, cis, found;
 
-	if (regex && str[strcspn(str, "^$*+()?[].\\")] == '\0')
-		regex = 0;
-
 	free(wp->searchstr);
-	wp->searchstr = xstrdup(str);
+	wp->searchstr = xstrdup(data->searchstr);
 	wp->searchregex = regex;
 
 	fx = data->cx;
 	fy = screen_hsize(data->backing) - data->oy + data->cy;
 
-	screen_init(&ss, screen_write_strlen("%s", str), 1, 0);
+	screen_init(&ss, screen_write_strlen("%s", data->searchstr), 1, 0);
 	screen_write_start(&ctx, NULL, &ss);
-	screen_write_nputs(&ctx, -1, &grid_default_cell, "%s", str);
+	screen_write_nputs(&ctx, -1, &grid_default_cell, "%s", data->searchstr);
 	screen_write_stop(&ctx);
 
 	wrapflag = options_get_number(wp->window->options, "wrap-search");
-	cis = window_copy_is_lowercase(str);
+	cis = window_copy_is_lowercase(data->searchstr);
 
 	if (direction) {
 		window_copy_move_right(s, &fx, &fy, wrapflag);