\f
/* The newline cache: remembering which sections of text have no newlines. */
-/* If the user has requested newline caching, make sure it's on.
+/* If the user has requested the long scans caching, make sure it's on.
Otherwise, make sure it's off.
This is our cheezy way of associating an action with the change of
state of a buffer-local variable. */
static void
newline_cache_on_off (struct buffer *buf)
{
- if (NILP (BVAR (buf, cache_long_line_scans)))
+ if (NILP (BVAR (buf, cache_long_scans)))
{
/* It should be off. */
if (buf->newline_cache)
{
/* The termination address of the dumb loop. */
- register unsigned char *ceiling_addr
- = BYTE_POS_ADDR (ceiling_byte) + 1;
- register unsigned char *cursor
- = BYTE_POS_ADDR (start_byte);
- unsigned char *base = cursor;
+ unsigned char *lim_addr = BYTE_POS_ADDR (ceiling_byte) + 1;
+ ptrdiff_t lim_byte = ceiling_byte + 1;
- while (cursor < ceiling_addr)
- {
+ /* Nonpositive offsets (relative to LIM_ADDR and LIM_BYTE)
+ of the base, the cursor, and the next line. */
+ ptrdiff_t base = start_byte - lim_byte;
+ ptrdiff_t cursor, next;
+
+ for (cursor = base; cursor < 0; cursor = next)
+ {
/* The dumb loop. */
- unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor);
+ unsigned char *nl = memchr (lim_addr + cursor, '\n', - cursor);
+ next = nl ? nl - lim_addr : 0;
/* If we're looking for newlines, cache the fact that
- the region from start to cursor is free of them. */
+ this line's region is free of them. */
if (newline_cache)
{
- unsigned char *low = cursor;
- unsigned char *lim = nl ? nl : ceiling_addr;
know_region_cache (current_buffer, newline_cache,
- BYTE_TO_CHAR (low - base + start_byte),
- BYTE_TO_CHAR (lim - base + start_byte));
+ BYTE_TO_CHAR (lim_byte + cursor),
+ BYTE_TO_CHAR (lim_byte + next));
+ /* know_region_cache can relocate buffer text. */
+ lim_addr = BYTE_POS_ADDR (ceiling_byte) + 1;
}
if (! nl)
break;
+ next++;
if (--count == 0)
{
immediate_quit = 0;
if (bytepos)
- *bytepos = nl + 1 - base + start_byte;
- return BYTE_TO_CHAR (nl + 1 - base + start_byte);
+ *bytepos = lim_byte + next;
+ return BYTE_TO_CHAR (lim_byte + next);
}
- cursor = nl + 1;
}
- start_byte += ceiling_addr - base;
+ start_byte = lim_byte;
start = BYTE_TO_CHAR (start_byte);
}
}
{
/* The termination address of the dumb loop. */
- register unsigned char *ceiling_addr = BYTE_POS_ADDR (ceiling_byte);
- register unsigned char *cursor = BYTE_POS_ADDR (start_byte - 1);
- unsigned char *base = cursor;
+ unsigned char *ceiling_addr = BYTE_POS_ADDR (ceiling_byte);
- while (cursor >= ceiling_addr)
+ /* Offsets (relative to CEILING_ADDR and CEILING_BYTE) of
+ the base, the cursor, and the previous line. These
+ offsets are at least -1. */
+ ptrdiff_t base = start_byte - ceiling_byte;
+ ptrdiff_t cursor, prev;
+
+ for (cursor = base; 0 < cursor; cursor = prev)
{
- unsigned char *nl = memrchr (ceiling_addr, '\n',
- cursor + 1 - ceiling_addr);
+ unsigned char *nl = memrchr (ceiling_addr, '\n', cursor);
+ prev = nl ? nl - ceiling_addr : -1;
/* If we're looking for newlines, cache the fact that
- the region from after the cursor to start is free of them. */
+ this line's region is free of them. */
if (newline_cache)
{
- unsigned char *low = nl ? nl : ceiling_addr - 1;
- unsigned char *lim = cursor;
know_region_cache (current_buffer, newline_cache,
- BYTE_TO_CHAR (low - base + start_byte),
- BYTE_TO_CHAR (lim - base + start_byte));
+ BYTE_TO_CHAR (ceiling_byte + prev + 1),
+ BYTE_TO_CHAR (ceiling_byte + cursor));
+ /* know_region_cache can relocate buffer text. */
+ ceiling_addr = BYTE_POS_ADDR (ceiling_byte);
}
if (! nl)
{
immediate_quit = 0;
if (bytepos)
- *bytepos = nl - base + start_byte;
- return BYTE_TO_CHAR (nl - base + start_byte);
+ *bytepos = ceiling_byte + prev + 1;
+ return BYTE_TO_CHAR (ceiling_byte + prev + 1);
}
- cursor = nl - 1;
}
- start_byte += ceiling_addr - 1 - base;
+ start_byte = ceiling_byte;
start = BYTE_TO_CHAR (start_byte);
}
}
If ALLOW_QUIT, set immediate_quit. That's good to do
except in special cases. */
-EMACS_INT
+ptrdiff_t
scan_newline (ptrdiff_t start, ptrdiff_t start_byte,
ptrdiff_t limit, ptrdiff_t limit_byte,
- EMACS_INT count, bool allow_quit)
+ ptrdiff_t count, bool allow_quit)
{
- int direction = ((count > 0) ? 1 : -1);
+ ptrdiff_t charpos, bytepos, shortage;
- unsigned char *cursor;
- unsigned char *base;
-
- ptrdiff_t ceiling;
- unsigned char *ceiling_addr;
-
- bool old_immediate_quit = immediate_quit;
-
- if (allow_quit)
- immediate_quit++;
-
- if (count > 0)
- {
- while (start_byte < limit_byte)
- {
- ceiling = BUFFER_CEILING_OF (start_byte);
- ceiling = min (limit_byte - 1, ceiling);
- ceiling_addr = BYTE_POS_ADDR (ceiling) + 1;
- base = (cursor = BYTE_POS_ADDR (start_byte));
-
- do
- {
- unsigned char *nl = memchr (cursor, '\n', ceiling_addr - cursor);
- if (! nl)
- break;
- if (--count == 0)
- {
- immediate_quit = old_immediate_quit;
- start_byte += nl - base + 1;
- start = BYTE_TO_CHAR (start_byte);
- TEMP_SET_PT_BOTH (start, start_byte);
- return 0;
- }
- cursor = nl + 1;
- }
- while (cursor < ceiling_addr);
-
- start_byte += ceiling_addr - base;
- }
- }
+ charpos = find_newline (start, start_byte, limit, limit_byte,
+ count, &shortage, &bytepos, allow_quit);
+ if (shortage)
+ TEMP_SET_PT_BOTH (limit, limit_byte);
else
- {
- while (start_byte > limit_byte)
- {
- ceiling = BUFFER_FLOOR_OF (start_byte - 1);
- ceiling = max (limit_byte, ceiling);
- ceiling_addr = BYTE_POS_ADDR (ceiling);
- base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1);
- while (1)
- {
- unsigned char *nl = memrchr (ceiling_addr, '\n',
- cursor - ceiling_addr);
- if (! nl)
- break;
-
- if (++count == 0)
- {
- immediate_quit = old_immediate_quit;
- /* Return the position AFTER the match we found. */
- start_byte += nl - base + 1;
- start = BYTE_TO_CHAR (start_byte);
- TEMP_SET_PT_BOTH (start, start_byte);
- return 0;
- }
-
- cursor = nl;
- }
- start_byte += ceiling_addr - base;
- }
- }
-
- TEMP_SET_PT_BOTH (limit, limit_byte);
- immediate_quit = old_immediate_quit;
-
- return count * direction;
+ TEMP_SET_PT_BOTH (charpos, bytepos);
+ return shortage;
}
/* Like find_newline, but doesn't allow QUITting and doesn't return