Instead of storing all UTF-8 characters in the extended cell which means

that 14 bytes are wasted for each character in the BMP, only store
characters of three bytes or less in the cell itself and store others
(outside the BMP or with combining characters) in a separate global
tree. Can reduce grid memory use for heavy Unicode users by around 30%.

1 files changed, 23 insertions, 5 deletions

diff --git a/window-copy.c b/window-copy.c
index e572eaa8..1efe01d0 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -2551,23 +2551,33 @@ window_copy_search_rl_regex(struct grid *gd, u_int *ppx, u_int *psx, u_int py,
 }
 
 static const char *
-window_copy_cellstring(const struct grid_line *gl, u_int px, size_t *size)
+window_copy_cellstring(const struct grid_line *gl, u_int px, size_t *size,
+    int *allocated)
 {
+	static struct utf8_data	 ud;
 	struct grid_cell_entry	*gce;
+	char			*copy;
 
 	if (px >= gl->cellsize) {
 		*size = 1;
+		*allocated = 0;
 		return (" ");
 	}
 
 	gce = &gl->celldata[px];
 	if (~gce->flags & GRID_FLAG_EXTENDED) {
 		*size = 1;
+		*allocated = 0;
 		return (&gce->data.data);
 	}
 
-	*size = gl->extddata[gce->offset].data.size;
-	return (gl->extddata[gce->offset].data.data);
+	utf8_get_big(gl->extddata[gce->offset].data, &ud);
+	*size = ud.size;
+	*allocated = 1;
+
+	copy = xmalloc(ud.size);
+	memcpy(copy, ud.data, ud.size);
+	return (copy);
 }
 
 /* Find last match in given range. */
@@ -2630,6 +2640,7 @@ window_copy_stringify(struct grid *gd, u_int py, u_int first, u_int last,
 	const struct grid_line	*gl;
 	const char		*d;
 	size_t			 bufsize = 1024, dlen;
+	int			 allocated;
 
 	while (bufsize < newsize)
 		bufsize *= 2;
@@ -2638,7 +2649,7 @@ window_copy_stringify(struct grid *gd, u_int py, u_int first, u_int last,
 	gl = grid_peek_line(gd, py);
 	bx = *size - 1;
 	for (ax = first; ax < last; ax++) {
-		d = window_copy_cellstring(gl, ax, &dlen);
+		d = window_copy_cellstring(gl, ax, &dlen, &allocated);
 		newsize += dlen;
 		while (bufsize < newsize) {
 			bufsize *= 2;
@@ -2650,6 +2661,8 @@ window_copy_stringify(struct grid *gd, u_int py, u_int first, u_int last,
 			memcpy(buf + bx, d, dlen);
 			bx += dlen;
 		}
+		if (allocated)
+			free((void *)d);
 	}
 	buf[newsize - 1] = '\0';
 
@@ -2670,6 +2683,7 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 	struct {
 		const char	*d;
 		size_t		 dlen;
+		int		 allocated;
 	} *cells;
 
 	/* Populate the array of cell data. */
@@ -2680,7 +2694,7 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 	gl = grid_peek_line(gd, pywrap);
 	while (cell < ncells) {
 		cells[cell].d = window_copy_cellstring(gl, px,
-		    &cells[cell].dlen);
+		    &cells[cell].dlen, &cells[cell].allocated);
 		cell++;
 		px++;
 		if (px == gd->sx) {
@@ -2738,6 +2752,10 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 	*ppy = pywrap;
 
 	/* Free cell data. */
+	for (cell = 0; cell < ncells; cell++) {
+		if (cells[cell].allocated)
+			free((void *)cells[cell].d);
+	}
 	free(cells);
 }