patch 9.1.1385: inefficient loop for 'nosmoothscroll' scrolling
Problem: Loop that ensures "w_skipcol" is zero with 'nosmoothscroll'
for (half)-page scrolling is inefficient.
Solution: Calculate the required "count" instead of looping until
"w_skipcol" is zero (Luuk van Baal).
fixes: #17301
closes: #17306
Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/move.c b/src/move.c
index f4bce40..1c1edde 100644
--- a/src/move.c
+++ b/src/move.c
@@ -3212,12 +3212,15 @@
// extra for scrolling backward so that consuming skipcol is symmetric.
if (labs(curwin->w_topline - prev_topline) > (dir == BACKWARD))
fixdir = dir * -1;
- while (curwin->w_skipcol > 0
- && curwin->w_topline < curbuf->b_ml.ml_line_count)
- {
- scroll_redraw(fixdir == FORWARD, 1);
- *curscount += (fixdir == dir ? 1 : -1);
- }
+
+ int width1 = curwin->w_width - curwin_col_off();
+ int width2 = width1 + curwin_col_off2();
+ count = 1 + (curwin->w_skipcol - width1) / width2;
+ if (fixdir == FORWARD)
+ count = 2 + (linetabsize_eol(curwin, curwin->w_topline)
+ - curwin->w_skipcol - width1) / width2;
+ scroll_redraw(fixdir == FORWARD, count);
+ *curscount += count * (fixdir == dir ? 1 : -1);
}
curwin->w_p_sms = prev_sms;
diff --git a/src/testdir/test_normal.vim b/src/testdir/test_normal.vim
index aa24bce..7f4f909 100644
--- a/src/testdir/test_normal.vim
+++ b/src/testdir/test_normal.vim
@@ -4345,4 +4345,13 @@
bwipe!
endfunc
+" Benchmark test for Ctrl-F with 'nosmoothscroll'
+func Test_scroll_longline_benchmark()
+ call setline(1, ['foo'->repeat(20000)] + [''])
+ let start = reltime()
+ exe "normal! \<C-F>"
+ call assert_inrange(0, 0.1, reltimefloat(reltime(start)))
+ bwipe!
+endfunc
+
" vim: shiftwidth=2 sts=2 expandtab nofoldenable
diff --git a/src/version.c b/src/version.c
index 55860d2..a2cfb00 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 1385,
+/**/
1384,
/**/
1383,