rexy712/nano-linefolding
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

painting: stop coloring an extremely long line after 2000 bytes

Browse Source 
Especially when softwrapping and when multiline regexes are involved,
colorizing takes roughly exponential time relative to the line length.
To avoid bogging down, stop colorizing a line beyond a certain point.

This mitigates https://savannah.gnu.org/bugs/?61799.
Reported-by: Devin Hussey <husseydevin@gmail.com>
This commit is contained in:
Benno Schulenberg 2022-04-01 16:52:45 +02:00
parent df7b0a6d97
commit fe42eb7a1a
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
src/winio.c
View File

@ -2475,6 +2475,9 @@ void place_the_cursor(void)
openfile->current_y = row;
}
/* The number of bytes after which to stop painting, to avoid major slowdowns. */
#define PAINT_LIMIT 2000
/* Draw the given text on the given row of the edit window. line is the
* line to be drawn, and converted is the actual string to be written with
* tabs and control characters replaced by strings of regular characters.
@ -2548,7 +2551,7 @@ void draw_row(int row, const char *converted, linestruct *line, size_t from_col)
/* First case: varnish is a single-line expression. */
if (varnish->end == NULL) {
while (index < till_x) {
while (index < PAINT_LIMIT && index < till_x) {
/* If there is no match, go on to the next line. */
if (regexec(varnish->start, &line->data[index], 1,
&match, (index == 0) ? 0 : REG_NOTBOL) != 0)
@ -2629,8 +2632,8 @@ void draw_row(int row, const char *converted, linestruct *line, size_t from_col)
* looking only after an end match, if there is one. */
index = (paintlen == 0) ? 0 : endmatch.rm_eo;
while (regexec(varnish->start, line->data + index, 1, &startmatch,
(index == 0) ? 0 : REG_NOTBOL) == 0) {
while (index < PAINT_LIMIT && regexec(varnish->start, line->data + index,
1, &startmatch, (index == 0) ? 0 : REG_NOTBOL) == 0) {
/* Make the match relative to the beginning of the line. */
startmatch.rm_so += index;
startmatch.rm_eo += index;