[vte] Add _vte_ring_resize()

[Behdad Esfahbod <behdad src gnome org>]

commit 031a653d791248c51df12af1b59d169179330b55
Author: Behdad Esfahbod <behdad behdad org>
Date:   Fri Aug 21 14:09:44 2009 -0400

    Add _vte_ring_resize()
    
    Avoids creating a new ring when changing scrollback lines.

 src/ring.c |   43 +++++++++++++++++++++++++++++++++----------
 src/ring.h |   16 ++++++++--------
 src/vte.c  |   36 ++++--------------------------------
 3 files changed, 45 insertions(+), 50 deletions(-)
---
diff --git a/src/ring.c b/src/ring.c
index a3c4859..454a82f 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -66,19 +66,42 @@ _vte_ring_new(glong max_elements)
 {
 	VteRing *ret = g_slice_new0(VteRing);
 	ret->max = MAX(max_elements, 2);
-	ret->array = g_malloc0(sizeof(gpointer) * ret->max);
+	ret->array = g_malloc0(sizeof(VteRowData *) * ret->max);
 	return ret;
 }
 
-VteRing *
-_vte_ring_new_with_delta(glong max_elements, glong delta)
+void
+_vte_ring_resize(VteRing *ring, glong max_elements)
 {
-	VteRing *ret;
-	ret = _vte_ring_new(max_elements);
-	ret->delta = delta;
-	return ret;
+	glong position, end, old_max;
+	VteRowData **old_array;
+
+	max_elements = MAX(max_elements, 2);
+
+	if (ring->max == max_elements)
+		return;
+
+	old_max = ring->max;
+	old_array = ring->array;
+
+	ring->max = max_elements;
+	ring->array = g_malloc0(sizeof(VteRowData *) * ring->max);
+
+	end = ring->delta + ring->length;
+	for (position = ring->delta; position < end; position++) {
+		_vte_free_row_data (ring->array[position % ring->max]);
+		ring->array[position % ring->max] = old_array[position % old_max];
+	}
+
+	if (ring->length > ring->max) {
+	  ring->length = ring->max;
+	  ring->delta = end - ring->max;
+	}
+
+	g_free (old_array);
 }
 
+
 /**
  * _vte_ring_insert:
  * @ring: a #VteRing
@@ -91,7 +114,7 @@ _vte_ring_new_with_delta(glong max_elements, glong delta)
  *
  */
 void
-_vte_ring_insert(VteRing * ring, long position, gpointer data)
+_vte_ring_insert(VteRing * ring, long position, VteRowData * data)
 {
 	long point, i;
 
@@ -174,7 +197,7 @@ _vte_ring_insert(VteRing * ring, long position, gpointer data)
  *
  */
 void
-_vte_ring_insert_preserve(VteRing * ring, long position, gpointer data)
+_vte_ring_insert_preserve(VteRing * ring, long position, VteRowData * data)
 {
 	long point, i;
 	VteRowData **tmp;
@@ -272,7 +295,7 @@ _vte_ring_remove(VteRing * ring, long position, gboolean free_element)
  *
  */
 void
-_vte_ring_append(VteRing * ring, gpointer data)
+_vte_ring_append(VteRing * ring, VteRowData * data)
 {
 	g_assert(data != NULL);
 	_vte_ring_insert(ring, ring->delta + ring->length, data);
diff --git a/src/ring.h b/src/ring.h
index 55d7c18..23456d0 100644
--- a/src/ring.h
+++ b/src/ring.h
@@ -41,10 +41,10 @@ struct _VteRing {
 #define _vte_ring_contains(__ring, __position) \
 	(((__position) >= (__ring)->delta) && \
 	 ((__position) < (__ring)->delta + (__ring)->length))
-#define _vte_ring_delta(__ring) ((__ring)->delta)
-#define _vte_ring_length(__ring) ((__ring)->length)
+#define _vte_ring_delta(__ring) ((__ring)->delta + 0)
+#define _vte_ring_length(__ring) ((__ring)->length /* + 0 XXX */)
 #define _vte_ring_next(__ring) ((__ring)->delta + (__ring)->length)
-#define _vte_ring_max(__ring) ((__ring)->max)
+#define _vte_ring_max(__ring) ((__ring)->max + 0)
 #ifdef VTE_DEBUG
 #define _vte_ring_index(__ring, __position) \
 	((__ring)->array[(__position) % (__ring)->max] ? \
@@ -54,18 +54,18 @@ struct _VteRing {
 		  (__position), (__position) % (__ring)->max, \
 		  (__ring)->delta, (__ring)->length, (__ring)->max, \
 		  (__ring)->delta + (__ring)->length, \
-		  __LINE__), (gpointer) NULL))
+		  __LINE__), (VteRowData *) NULL))
 #else
 #define _vte_ring_index(__ring, __position) \
 	((__ring)->array[(__position) % (__ring)->max])
 #endif
 
 VteRing *_vte_ring_new(glong max_elements);
-VteRing *_vte_ring_new_with_delta(glong max_elements, glong delta);
-void _vte_ring_insert(VteRing *ring, glong position, gpointer data);
-void _vte_ring_insert_preserve(VteRing *ring, glong position, gpointer data);
+void _vte_ring_resize(VteRing *ring, glong max_elements);
+void _vte_ring_insert(VteRing *ring, glong position, VteRowData * data);
+void _vte_ring_insert_preserve(VteRing *ring, glong position, VteRowData * data);
 void _vte_ring_remove(VteRing *ring, glong position, gboolean free_element);
-void _vte_ring_append(VteRing *ring, gpointer data);
+void _vte_ring_append(VteRing *ring, VteRowData * data);
 void _vte_ring_free(VteRing *ring, gboolean free_elements);
 
 G_END_DECLS
diff --git a/src/vte.c b/src/vte.c
index a55c748..7bd002a 100644
--- a/src/vte.c
+++ b/src/vte.c
@@ -7914,31 +7914,6 @@ vte_terminal_set_termcap(VteTerminal *terminal, const char *path,
 }
 
 static void
-vte_terminal_reset_rowdata(VteTerminal *terminal, VteRing **ring, glong lines)
-{
-	VteRing *new_ring;
-	VteRowData *row;
-	long i, next;
-
-	_vte_debug_print(VTE_DEBUG_MISC,
-			"Sizing scrollback buffer to %ld lines.\n",
-			lines);
-	if (*ring && (_vte_ring_max(*ring) == lines)) {
-		return;
-	}
-	new_ring = _vte_ring_new_with_delta(lines, *ring ? _vte_ring_delta(*ring) : 0);
-	if (*ring) {
-		next = _vte_ring_next(*ring);
-		for (i = _vte_ring_delta(*ring); i < next; i++) {
-			row = _vte_ring_index(*ring, i);
-			_vte_ring_append(new_ring, row);
-		}
-		_vte_ring_free(*ring, FALSE);
-	}
-	*ring = new_ring;
-}
-
-static void
 _vte_terminal_codeset_changed_cb(struct _vte_iso2022_state *state, gpointer p)
 {
 	vte_terminal_set_encoding(p, _vte_iso2022_state_get_codeset(state));
@@ -8012,15 +7987,13 @@ vte_terminal_init(VteTerminal *terminal)
         pvt->child_exit_status = 0;
 
 	/* Initialize the screens and histories. */
-	vte_terminal_reset_rowdata(terminal, &pvt->alternate_screen.row_data,
-				   VTE_SCROLLBACK_INIT);
+	pvt->alternate_screen.row_data = _vte_ring_new (VTE_SCROLLBACK_INIT);
 	pvt->alternate_screen.sendrecv_mode = TRUE;
 	pvt->alternate_screen.status_line_contents = g_string_new(NULL);
 	pvt->screen = &terminal->pvt->alternate_screen;
 	_vte_terminal_set_default_attributes(terminal);
 
-	vte_terminal_reset_rowdata(terminal, &pvt->normal_screen.row_data,
-				   VTE_SCROLLBACK_INIT);
+	pvt->normal_screen.row_data = _vte_ring_new (VTE_SCROLLBACK_INIT);
 	pvt->normal_screen.sendrecv_mode = TRUE;
 	pvt->normal_screen.status_line_contents = g_string_new(NULL);
 	pvt->screen = &terminal->pvt->normal_screen;
@@ -13129,7 +13102,7 @@ vte_terminal_set_scrollback_lines(VteTerminal *terminal, glong lines)
 		lines = MAX (lines, terminal->row_count);
 		next = MAX (screen->cursor_current.row + 1,
 				_vte_ring_next (screen->row_data));
-		vte_terminal_reset_rowdata (terminal, &screen->row_data, lines);
+		_vte_ring_resize (screen->row_data, lines);
 		low = _vte_ring_delta (screen->row_data);
 		high = low + lines - terminal->row_count + 1;
 		screen->insert_delta = CLAMP (screen->insert_delta, low, high);
@@ -13139,8 +13112,7 @@ vte_terminal_set_scrollback_lines(VteTerminal *terminal, glong lines)
 			_vte_ring_length (screen->row_data) = next - low;
 		}
 	} else {
-		vte_terminal_reset_rowdata (terminal, &screen->row_data,
-				terminal->row_count);
+		_vte_ring_resize (screen->row_data, terminal->row_count);
 		scroll_delta = _vte_ring_delta (screen->row_data);
 		screen->insert_delta = _vte_ring_delta (screen->row_data);
 		if (_vte_ring_next (screen->row_data) > screen->insert_delta + terminal->row_count){