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| author | Eli Zaretskii <eliz@gnu.org> | 2017-07-09 17:37:23 +0300 |
|---|---|---|
| committer | Eli Zaretskii <eliz@gnu.org> | 2017-07-09 17:37:23 +0300 |
| commit | 83218cf4c34c3593b4d58bd68d1f280cb3e6634b (patch) | |
| tree | bd380cdba83ecd2995dfcd1fc9ea80b2db21c522 | |
| parent | b2aef8122ad1404854728615ca03a7f3cd3f93a3 (diff) | |
| download | emacs-83218cf4c34c3593b4d58bd68d1f280cb3e6634b.tar.gz | |
Speed up display of line numbers for very large buffers
* src/xdisp.c (maybe_produce_line_number): Speed up line counting
using values cached by mode-line display of line numbers.
(Bug#27622)
| -rw-r--r-- | src/xdisp.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/src/xdisp.c b/src/xdisp.c index 5df2dd18311..28ed7685236 100644 --- a/src/xdisp.c +++ b/src/xdisp.c @@ -20823,7 +20823,6 @@ maybe_produce_line_number (struct it *it) ptrdiff_t start_from, bytepos; ptrdiff_t this_line; bool first_time = false; - ptrdiff_t beg = display_line_numbers_widen ? BEG : BEGV; ptrdiff_t beg_byte = display_line_numbers_widen ? BEG_BYTE : BEGV_BYTE; ptrdiff_t z_byte = display_line_numbers_widen ? Z_BYTE : ZV_BYTE; void *itdata = bidi_shelve_cache (); @@ -20834,8 +20833,21 @@ maybe_produce_line_number (struct it *it) { if (!last_line) { - /* FIXME: Maybe reuse the data in it->w->base_line_number. */ - start_from = beg; + /* If possible, reuse data cached by line-number-mode. */ + if (it->w->base_line_number > 0 + && it->w->base_line_pos > 0 + && it->w->base_line_pos <= IT_CHARPOS (*it) + /* line-number-mode always displays narrowed line + numbers, so we cannot use its data if the user wants + line numbers that disregard narrowing. */ + && !(display_line_numbers_widen + && (BEG_BYTE != BEGV_BYTE || Z_BYTE != ZV_BYTE))) + { + start_from = CHAR_TO_BYTE (it->w->base_line_pos); + last_line = it->w->base_line_number - 1; + } + else + start_from = beg_byte; if (!it->lnum_bytepos) first_time = true; } @@ -20845,7 +20857,7 @@ maybe_produce_line_number (struct it *it) /* Paranoia: what if someone changes the narrowing since the last time display_line was called? Shouldn't really happen, but who knows what some crazy Lisp invoked by :eval could do? */ - if (!(beg_byte <= start_from && start_from < z_byte)) + if (!(beg_byte <= start_from && start_from <= z_byte)) { last_line = 0; start_from = beg_byte; |