commit 0e9bef3429e92e9d9c6a087f741828b35329f242
parent 34238dc1199b9bd1bf94c4bc59e4bad744d0d698
Author: Benno Schulenberg <bensberg@telfort.nl>
Date: Sun, 17 Jul 2022 08:56:29 +0200
display: remember text and column positions when softwrapping a line
This adjusts the main softwrapping routine so that it remembers the
reached point in a line's text and the corresponding column. This
avoids having to scan the line from the beginning for each iterative
call, and thus saves a substantial amount of time when softwrapping
very long lines.
This mitigates https://savannah.gnu.org/bugs/?62442.
Reported-by: Devin Hussey <husseydevin@gmail.com>
Original-patch-by: Devin Hussey <husseydevin@gmail.com>
Diffstat:
3 files changed, 29 insertions(+), 12 deletions(-)
diff --git a/src/move.c b/src/move.c
@@ -472,10 +472,11 @@ void do_end(void)
#ifndef NANO_TINY
if (ISSET(SOFTWRAP)) {
+ bool kickoff = TRUE;
bool last_chunk = FALSE;
size_t leftedge = leftedge_for(was_column, openfile->current);
size_t rightedge = get_softwrap_breakpoint(openfile->current->data,
- leftedge, &last_chunk);
+ leftedge, &kickoff, &last_chunk);
size_t rightedge_x;
/* If we're on the last chunk, we're already at the end of the line.
diff --git a/src/prototypes.h b/src/prototypes.h
@@ -607,8 +607,8 @@ int go_forward_chunks(int nrows, linestruct **line, size_t *leftedge);
bool less_than_a_screenful(size_t was_lineno, size_t was_leftedge);
void edit_scroll(bool direction);
#ifndef NANO_TINY
-size_t get_softwrap_breakpoint(const char *text, size_t leftedge,
- bool *end_of_line);
+size_t get_softwrap_breakpoint(const char *linedata, size_t leftedge,
+ bool *kickoff, bool *end_of_line);
size_t get_chunk_and_edge(size_t column, linestruct *line, size_t *leftedge);
size_t chunk_for(size_t column, linestruct *line);
size_t leftedge_for(size_t column, linestruct *line);
diff --git a/src/winio.c b/src/winio.c
@@ -2825,6 +2825,8 @@ int update_softwrapped_line(linestruct *line)
/* The end column of the current chunk. */
char *converted;
/* The data of the chunk with tabs and control characters expanded. */
+ bool kickoff = TRUE;
+ /* This tells the softwrapping routine to start at beginning-of-line. */
bool end_of_line = FALSE;
/* Becomes TRUE when the last chunk of the line has been reached. */
@@ -2849,7 +2851,7 @@ int update_softwrapped_line(linestruct *line)
starting_row = row;
while (!end_of_line && row < editwinrows) {
- to_col = get_softwrap_breakpoint(line->data, from_col, &end_of_line);
+ to_col = get_softwrap_breakpoint(line->data, from_col, &kickoff, &end_of_line);
sequel_column = (end_of_line) ? 0 : to_col;
@@ -2930,13 +2932,14 @@ int go_forward_chunks(int nrows, linestruct **line, size_t *leftedge)
#ifndef NANO_TINY
if (ISSET(SOFTWRAP)) {
size_t current_leftedge = *leftedge;
+ bool kickoff = TRUE;
/* Advance through the requested number of chunks. */
for (i = nrows; i > 0; i--) {
bool end_of_line = FALSE;
current_leftedge = get_softwrap_breakpoint((*line)->data,
- current_leftedge, &end_of_line);
+ current_leftedge, &kickoff, &end_of_line);
if (!end_of_line)
continue;
@@ -2946,6 +2949,7 @@ int go_forward_chunks(int nrows, linestruct **line, size_t *leftedge)
*line = (*line)->next;
current_leftedge = 0;
+ kickoff = TRUE;
}
/* Only change leftedge when we actually could move. */
@@ -3071,20 +3075,29 @@ void edit_scroll(bool direction)
* return it. This will always be editwincols or less after leftedge. Set
* end_of_line to TRUE if we reach the end of the line while searching the
* text. Assume leftedge is the leftmost column of a softwrapped chunk. */
-size_t get_softwrap_breakpoint(const char *text, size_t leftedge,
- bool *end_of_line)
+size_t get_softwrap_breakpoint(const char *linedata, size_t leftedge,
+ bool *kickoff, bool *end_of_line)
{
+ static const char *text;
+ /* Pointer at the current character in this line's data. */
+ static size_t column;
+ /* Column position that corresponds to the above pointer. */
size_t goal_column = leftedge + editwincols;
/* The place at or before which text must be broken. */
size_t breaking_col = goal_column;
/* The column where text can be broken, when there's no better. */
- size_t column = 0;
- /* Current column position in text. */
size_t last_blank_col = 0;
/* The column position of the last seen whitespace character. */
const char *farthest_blank = NULL;
/* A pointer to the last seen whitespace character in text. */
+ /* Initialize the static variables when it's another line. */
+ if (*kickoff) {
+ text = linedata;
+ column = 0;
+ *kickoff = FALSE;
+ }
+
/* First find the place in text where the current chunk starts. */
while (*text != '\0' && column < leftedge)
text += advance_over(text, &column);
@@ -3132,9 +3145,10 @@ size_t get_chunk_and_edge(size_t column, linestruct *line, size_t *leftedge)
{
size_t current_chunk = 0, start_col = 0, end_col;
bool end_of_line = FALSE;
+ bool kickoff = TRUE;
while (TRUE) {
- end_col = get_softwrap_breakpoint(line->data, start_col, &end_of_line);
+ end_col = get_softwrap_breakpoint(line->data, start_col, &kickoff, &end_of_line);
/* We reached the end of the line and/or found column, so get out. */
if (end_of_line || (start_col <= column && column < end_col)) {
@@ -3196,9 +3210,10 @@ size_t actual_last_column(size_t leftedge, size_t column)
{
#ifndef NANO_TINY
if (ISSET(SOFTWRAP)) {
+ bool kickoff = TRUE;
bool last_chunk = FALSE;
size_t end_col = get_softwrap_breakpoint(openfile->current->data,
- leftedge, &last_chunk) - leftedge;
+ leftedge, &kickoff, &last_chunk) - leftedge;
/* If we're not on the last chunk, we're one column past the end of
* the row. Shifting back one column might put us in the middle of
@@ -3476,6 +3491,7 @@ void spotlight_softwrapped(size_t from_col, size_t to_col)
size_t leftedge = leftedge_for(from_col, openfile->current);
size_t break_col;
bool end_of_line = FALSE;
+ bool kickoff = TRUE;
char *word;
place_the_cursor();
@@ -3483,7 +3499,7 @@ void spotlight_softwrapped(size_t from_col, size_t to_col)
while (row < editwinrows) {
break_col = get_softwrap_breakpoint(openfile->current->data,
- leftedge, &end_of_line);
+ leftedge, &kickoff, &end_of_line);
/* If the highlighting ends on this chunk, we can stop after it. */
if (break_col >= to_col) {
