Long overdue change to the way we store cells in the grid: now, instead

of storing a full grid_cell with UTF-8 data and everything, store a new
type grid_cell_entry. This can either be the cell itself (for ASCII
cells), or an offset into an extended array (per line) for UTF-8
data.

This avoid a large (8 byte) overhead on non-UTF-8 cells (by far the
majority for most users) without the complexity of the shadow array we
had before. Grid memory without any UTF-8 is about half.

The disadvantage that cells can no longer be modified in place and need
to be copied out of the grid and back but it turned out to be lot less
complicated than I expected.

1 files changed, 15 insertions, 24 deletions

diff --git a/usr.bin/tmux/tty.c b/usr.bin/tmux/tty.c
index 99d5a1efb8e..cb7ede09f03 100644
--- a/usr.bin/tmux/tty.c
+++ b/usr.bin/tmux/tty.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty.c,v 1.192 2015/10/31 13:12:03 nicm Exp $ */
+/* $OpenBSD: tty.c,v 1.193 2015/11/13 08:09:28 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -656,10 +656,8 @@ void
 tty_draw_line(struct tty *tty, const struct window_pane *wp,
     struct screen *s, u_int py, u_int ox, u_int oy)
 {
-	const struct grid_cell	*gc;
+	struct grid_cell	 gc;
 	struct grid_line	*gl;
-	struct grid_cell	 tmpgc;
-	struct utf8_data	 ud;
 	u_int			 i, sx;
 	int			 flags;
 
@@ -686,18 +684,13 @@ tty_draw_line(struct tty *tty, const struct window_pane *wp,
 		tty_cursor(tty, ox, oy + py);
 
 	for (i = 0; i < sx; i++) {
-		gc = grid_view_peek_cell(s->grid, i, py);
+		grid_view_get_cell(s->grid, i, py, &gc);
 		if (screen_check_selection(s, i, py)) {
-			memcpy(&tmpgc, &s->sel.cell, sizeof tmpgc);
-			grid_cell_get(gc, &ud);
-			grid_cell_set(&tmpgc, &ud);
-			tmpgc.flags = gc->flags &
-			    ~(GRID_FLAG_FG256|GRID_FLAG_BG256);
-			tmpgc.flags |= s->sel.cell.flags &
+			gc.flags &= ~(GRID_FLAG_FG256|GRID_FLAG_BG256);
+			gc.flags |= s->sel.cell.flags &
 			    (GRID_FLAG_FG256|GRID_FLAG_BG256);
-			tty_cell(tty, &tmpgc, wp);
-		} else
-			tty_cell(tty, gc, wp);
+		}
+		tty_cell(tty, &gc, wp);
 	}
 
 	if (sx < tty->sx) {
@@ -1078,7 +1071,7 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 	tty_region_pane(tty, ctx, ctx->orupper, ctx->orlower);
 
 	/* Is the cursor in the very last position? */
-	width = grid_cell_width(ctx->cell);
+	width = ctx->cell->data.width;
 	if (ctx->ocx > wp->sx - width) {
 		if (ctx->xoff != 0 || wp->sx != tty->sx) {
 			/*
@@ -1095,7 +1088,7 @@ tty_cmd_cell(struct tty *tty, const struct tty_ctx *ctx)
 			 * move as far left as possible and redraw the last
 			 * cell to move into the last position.
 			 */
-			cx = screen_size_x(s) - grid_cell_width(&ctx->last_cell);
+			cx = screen_size_x(s) - ctx->last_cell.data.width;
 			tty_cursor_pane(tty, ctx, cx, ctx->ocy);
 			tty_cell(tty, &ctx->last_cell, wp);
 		}
@@ -1155,8 +1148,7 @@ void
 tty_cell(struct tty *tty, const struct grid_cell *gc,
     const struct window_pane *wp)
 {
-	struct utf8_data	ud;
-	u_int			i;
+	u_int	i;
 
 	/* Skip last character if terminal is stupid. */
 	if (tty->term->flags & TERM_EARLYWRAP &&
@@ -1171,23 +1163,22 @@ tty_cell(struct tty *tty, const struct grid_cell *gc,
 	tty_attributes(tty, gc, wp);
 
 	/* Get the cell and if ASCII write with putc to do ACS translation. */
-	grid_cell_get(gc, &ud);
-	if (ud.size == 1) {
-		if (*ud.data < 0x20 || *ud.data == 0x7f)
+	if (gc->data.size == 1) {
+		if (*gc->data.data < 0x20 || *gc->data.data == 0x7f)
 			return;
-		tty_putc(tty, *ud.data);
+		tty_putc(tty, *gc->data.data);
 		return;
 	}
 
 	/* If not UTF-8, write _. */
 	if (!(tty->flags & TTY_UTF8)) {
-		for (i = 0; i < ud.width; i++)
+		for (i = 0; i < gc->data.width; i++)
 			tty_putc(tty, '_');
 		return;
 	}
 
 	/* Write the data. */
-	tty_putn(tty, ud.data, ud.size, ud.width);
+	tty_putn(tty, gc->data.data, gc->data.size, gc->data.width);
 }
 
 void