From c5b1fa9411300725ea78964db8af995fdf7af7da Mon Sep 17 00:00:00 2001
From: Nicholas Marriott <nicholas.marriott@gmail.com>
Date: Mon, 26 Nov 2007 22:18:57 +0000
Subject: [PATCH] Shift history up by 10% at a time.

---
 CHANGES          |  4 +++-
 screen-display.c | 43 ++++++++++++++++++++++---------------------
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/CHANGES b/CHANGES
index a067866e..b7c41ad2 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,7 @@
 26 November 2007
 
+* Rather than shifting up one line at a time once the history is full,
+  shift by 10% of the history each time. This is faster.
 * Add ^A and ^E to copy mode to move to start-of-line/end-of-line.
 
 24 November 2007
@@ -271,4 +273,4 @@
   (including mutt, emacs). No status bar yet and no key remapping or other
   customisation.
 
-$Id: CHANGES,v 1.85 2007-11-26 20:36:30 nicm Exp $
+$Id: CHANGES,v 1.86 2007-11-26 22:18:57 nicm Exp $
diff --git a/screen-display.c b/screen-display.c
index 9d4dee0c..1fb137d9 100644
--- a/screen-display.c
+++ b/screen-display.c
@@ -1,4 +1,4 @@
-/* $Id: screen-display.c,v 1.7 2007-11-24 13:26:42 nicm Exp $ */
+/* $Id: screen-display.c,v 1.8 2007-11-26 22:18:57 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -166,35 +166,36 @@ screen_display_cursor_down(struct screen *s)
 void
 screen_display_scroll_region_up(struct screen *s)
 {
-	u_int	sy;
+	u_int	ny, sy;
 	
 	/*
 	 * If the region is the entire screen, this is easy-peasy. Allocate
 	 * a new line and adjust the history size.
-	 * XXX1 should this be done somewhere else?
+	 * XXX should this be done somewhere else?
 	 */
-	if (s->rupper == 0 && s->rlower == screen_last_y(s)) {
+	if (s->rupper == 0 && s->rlower == screen_last_y(s)) {	
 		sy = screen_size_y(s) + s->hsize;
-
 		if (s->hsize == s->hlimit) {
-			/*
-			 * If the limit is hit, free the first and shift
-			 * the whole thing up.
-			 */
-			screen_free_lines(s, 0, 1);
-			screen_move_lines(s, 0, 1, sy - 1);
-		} else {
-			s->hsize++;
+			/* If the limit is hit, free 10% and shift up. */
+			ny = s->hlimit / 10;
+			if (ny < 1)
+				ny = 1;
+			screen_free_lines(s, 0, ny);
+			screen_move_lines(s, 0, ny, sy - ny);
 
-			s->grid_data = xrealloc(
-			    s->grid_data, sy + 1, sizeof *s->grid_data);
-			s->grid_attr = xrealloc(
-			    s->grid_attr, sy + 1, sizeof *s->grid_attr);
-			s->grid_colr = xrealloc(
-			    s->grid_colr, sy + 1, sizeof *s->grid_colr);
-			s->grid_size = xrealloc(
-			    s->grid_size, sy + 1, sizeof *s->grid_size);
+			s->hsize -= ny;
+			sy -= ny;
 		}
+		s->hsize++;
+
+		s->grid_data = xrealloc(
+		    s->grid_data, sy + 1, sizeof *s->grid_data);
+		s->grid_attr = xrealloc(
+		    s->grid_attr, sy + 1, sizeof *s->grid_attr);
+		s->grid_colr = xrealloc(
+		    s->grid_colr, sy + 1, sizeof *s->grid_colr);
+		s->grid_size = xrealloc(
+		    s->grid_size, sy + 1, sizeof *s->grid_size);
 		screen_display_make_lines(s, screen_last_y(s), 1);
 		return;
 	}