[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#57266: Acknowledgement (Maintaining the base_line_number cache)
From: |
Stefan Monnier |
Subject: |
bug#57266: Acknowledgement (Maintaining the base_line_number cache) |
Date: |
Wed, 17 Aug 2022 17:39:51 -0400 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/29.0.50 (gnu/linux) |
Hmm... there was some serious thinko in my BASE_LINE_NUMBER_VALID_P.
Adjusted patch below,
Stefan
diff --git a/src/window.c b/src/window.c
index c8fcb3a607f..436d4e342d7 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4093,6 +4093,8 @@ set_window_buffer (Lisp_Object window, Lisp_Object buffer,
buffer);
w->start_at_line_beg = false;
w->force_start = false;
+ /* Flush the base_line cache since it applied to another buffer. */
+ w->base_line_number = 0;
}
wset_redisplay (w);
diff --git a/src/xdisp.c b/src/xdisp.c
index 03c43be5bc0..902cd276a43 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -18341,6 +18341,14 @@ cursor_row_fully_visible_p (struct window *w, bool
force_p,
`scroll-conservatively' and the Emacs manual. */
#define SCROLL_LIMIT 100
+/* The freshness of the w->base_line_number cache is only ensured at every
+ redisplay cycle, so the cache can be used only if there's been
+ no relevant changes to the buffer since the last redisplay. */
+#define BASE_LINE_NUMBER_VALID_P(w) \
+ (eassert (current_buffer == XBUFFER ((w)->contents)), \
+ !current_buffer->clip_changed \
+ && BEG_UNCHANGED >= (w)->base_line_pos)
+
static int
try_scrolling (Lisp_Object window, bool just_this_one_p,
intmax_t arg_scroll_conservatively, intmax_t scroll_step,
@@ -18640,9 +18648,10 @@ try_scrolling (Lisp_Object window, bool
just_this_one_p,
else
{
/* Maybe forget recorded base line for line number display. */
- if (!just_this_one_p
- || current_buffer->clip_changed
- || BEG_UNCHANGED < CHARPOS (startp))
+ /* FIXME: Why do we need this? `try_scrolling` can only be called from
+ `redisplay_window` which should have flushed this cache already when
+ eeded. */
+ if (!BASE_LINE_NUMBER_VALID_P (w))
w->base_line_number = 0;
/* If cursor ends up on a partially visible line,
@@ -19404,9 +19413,6 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
/* Record it now because it's overwritten. */
bool current_matrix_up_to_date_p = false;
bool used_current_matrix_p = false;
- /* This is less strict than current_matrix_up_to_date_p.
- It indicates that the buffer contents and narrowing are unchanged. */
- bool buffer_unchanged_p = false;
bool temp_scroll_step = false;
specpdl_ref count = SPECPDL_INDEX ();
int rc;
@@ -19505,11 +19511,6 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
specbind (Qinhibit_point_motion_hooks, Qt);
- buffer_unchanged_p
- = (w->window_end_valid
- && !current_buffer->clip_changed
- && !window_outdated (w));
-
/* When windows_or_buffers_changed is non-zero, we can't rely
on the window end being valid, so set it to zero there. */
if (windows_or_buffers_changed)
@@ -19648,6 +19649,10 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
}
}
+ if (!BASE_LINE_NUMBER_VALID_P (w))
+ /* Forget any recorded base line for line number display. */
+ w->base_line_number = 0;
+
force_start:
/* Handle case where place to start displaying has been specified,
@@ -19668,10 +19673,6 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
w->preserve_vscroll_p = false;
w->window_end_valid = false;
- /* Forget any recorded base line for line number display. */
- if (!buffer_unchanged_p)
- w->base_line_number = 0;
-
/* Redisplay the mode line. Select the buffer properly for that.
Also, run the hook window-scroll-functions
because we have scrolled. */
@@ -20000,12 +20001,6 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
if (w->cursor.vpos >= 0)
{
- if (!just_this_one_p
- || current_buffer->clip_changed
- || BEG_UNCHANGED < CHARPOS (startp))
- /* Forget any recorded base line for line number display. */
- w->base_line_number = 0;
-
if (!cursor_row_fully_visible_p (w, true, false, false))
{
clear_glyph_matrix (w->desired_matrix);
@@ -20076,10 +20071,6 @@ redisplay_window (Lisp_Object window, bool
just_this_one_p)
debug_method_add (w, "recenter");
#endif
- /* Forget any previously recorded base line for line number display. */
- if (!buffer_unchanged_p)
- w->base_line_number = 0;
-
/* Determine the window start relative to point. */
init_iterator (&it, w, PT, PT_BYTE, NULL, DEFAULT_FACE_ID);
it.current_y = it.last_visible_y;
@@ -24211,6 +24202,13 @@ maybe_produce_line_number (struct it *it)
if (!last_line)
{
/* If possible, reuse data cached by line-number-mode. */
+ /* NOTE: We use `base_line_number` without checking
+ BASE_LINE_NUMBER_VALID_P because we assume that `redisplay_window`
+ has already flushed this cache for us when needed.
+ NOTEĀ²: IIUC checking BASE_LINE_NUMBER_VALID_P here would be
+ overly pessimistic because it might say that the cache
+ was invalid before entering `redisplay_window` yet the
+ value has just been refreshed. */
if (it->w->base_line_number > 0
&& it->w->base_line_pos > 0
&& it->w->base_line_pos <= IT_CHARPOS (*it)
@@ -27949,6 +27947,17 @@ decode_mode_spec (struct window *w, register int c,
int field_width,
startpos = marker_position (w->start);
startpos_byte = marker_byte_position (w->start);
height = WINDOW_TOTAL_LINES (w);
+
+ if (!BASE_LINE_NUMBER_VALID_P (w))
+ /* NOTE: This check is necessary when we're called from
+ `format-mode-line` but not when we're called from
+ `redisplay_window`.
+ FIXME: It's usually harmless in that case, except if you have
+ several `%l` in your modeline, in which case it will cause the
+ cache to to be recomputed as many times when it's out of
+ date :-( */
+ w->base_line_number = 0;
+
/* We cannot cope with w->start being outside of the
accessible portion of the buffer; in particular,
display_count_lines call below might infloop if called with
@@ -27962,8 +27971,6 @@ decode_mode_spec (struct window *w, register int c, int
field_width,
{
startpos = BUF_BEGV (b);
startpos_byte = BUF_BEGV_BYTE (b);
- w->base_line_pos = 0;
- w->base_line_number = 0;
}
/* If we decided that this buffer isn't suitable for line numbers,
@@ -28044,6 +28051,12 @@ decode_mode_spec (struct window *w, register int c,
int field_width,
goto no_value;
}
+ /* NOTE: if current_buffer->clip_changed is set or
+ if BEG_UNCHANGED is < position, this new cached value
+ may be unusable, because we can't reset BEG_UNCHANGED
+ or `clip_changed` from here (since they reflect the
+ changes since the last redisplay do they can only be reset
+ from `mark_window_display_accurate_1`). */
w->base_line_number = topline - nlines;
w->base_line_pos = BYTE_TO_CHAR (position);
}
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/17
- Message not available
- bug#57266: Acknowledgement (Maintaining the base_line_number cache),
Stefan Monnier <=
- bug#57266: Maintaining the base_line_number cache, Eli Zaretskii, 2022/08/18
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Eli Zaretskii, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Eli Zaretskii, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Eli Zaretskii, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Eli Zaretskii, 2022/08/22
- bug#57266: Maintaining the base_line_number cache, Stefan Monnier, 2022/08/22