static void
byte_char_debug_check (struct buffer *b, EMACS_INT charpos, EMACS_INT bytepos)
{
EMACS_INT nchars = 0;
if (bytepos > BUF_GPT_BYTE (b))
{
nchars = multibyte_chars_in_text (BUF_BEG_ADDR (b),
BUF_GPT_BYTE (b) - BUF_BEG_BYTE (b));
nchars += multibyte_chars_in_text (BUF_GAP_END_ADDR (b),
bytepos - BUF_GPT_BYTE (b));
}
else
nchars = multibyte_chars_in_text (BUF_BEG_ADDR (b),
bytepos - BUF_BEG_BYTE (b));
if (charpos - 1 != nchars)
abort ();
}
static void
byte_char_debug_check (struct buffer *b, ptrdiff_t charpos, ptrdiff_t bytepos)
{
ptrdiff_t nchars;
if (NILP (BVAR (b, enable_multibyte_characters)))
return;
if (bytepos > BUF_GPT_BYTE (b))
nchars
= multibyte_chars_in_text (BUF_BEG_ADDR (b),
BUF_GPT_BYTE (b) - BUF_BEG_BYTE (b))
+ multibyte_chars_in_text (BUF_GAP_END_ADDR (b),
bytepos - BUF_GPT_BYTE (b));
else
nchars = multibyte_chars_in_text (BUF_BEG_ADDR (b),
bytepos - BUF_BEG_BYTE (b));
if (charpos - 1 != nchars)
emacs_abort ();
}
EMACS_INT
buf_bytepos_to_charpos (struct buffer *b, EMACS_INT bytepos)
{
struct Lisp_Marker *tail;
EMACS_INT best_above, best_above_byte;
EMACS_INT best_below, best_below_byte;
if (bytepos < BUF_BEG_BYTE (b) || bytepos > BUF_Z_BYTE (b))
abort ();
best_above = BUF_Z (b);
best_above_byte = BUF_Z_BYTE (b);
/* If this buffer has as many characters as bytes,
each character must be one byte.
This takes care of the case where enable-multibyte-characters is nil. */
if (best_above == best_above_byte)
return bytepos;
best_below = BEG;
best_below_byte = BEG_BYTE;
CONSIDER (BUF_PT_BYTE (b), BUF_PT (b));
CONSIDER (BUF_GPT_BYTE (b), BUF_GPT (b));
CONSIDER (BUF_BEGV_BYTE (b), BUF_BEGV (b));
CONSIDER (BUF_ZV_BYTE (b), BUF_ZV (b));
if (b == cached_buffer && BUF_MODIFF (b) == cached_modiff)
CONSIDER (cached_bytepos, cached_charpos);
for (tail = BUF_MARKERS (b); tail; tail = tail->next)
{
CONSIDER (tail->bytepos, tail->charpos);
/* If we are down to a range of 50 chars,
don't bother checking any other markers;
scan the intervening chars directly now. */
if (best_above - best_below < 50)
break;
}
/* We get here if we did not exactly hit one of the known places.
We have one known above and one known below.
Scan, counting characters, from whichever one is closer. */
if (bytepos - best_below_byte < best_above_byte - bytepos)
{
int record = bytepos - best_below_byte > 5000;
while (best_below_byte < bytepos)
{
best_below++;
BUF_INC_POS (b, best_below_byte);
}
/* If this position is quite far from the nearest known position,
cache the correspondence by creating a marker here.
It will last until the next GC.
But don't do it if BUF_MARKERS is nil;
that is a signal from Fset_buffer_multibyte. */
if (record && BUF_MARKERS (b))
{
Lisp_Object marker, buffer;
marker = Fmake_marker ();
XSETBUFFER (buffer, b);
set_marker_both (marker, buffer, best_below, best_below_byte);
}
if (byte_debug_flag)
byte_char_debug_check (b, best_below, bytepos);
cached_buffer = b;
cached_modiff = BUF_MODIFF (b);
cached_charpos = best_below;
cached_bytepos = best_below_byte;
return best_below;
}
else
{
int record = best_above_byte - bytepos > 5000;
while (best_above_byte > bytepos)
{
best_above--;
BUF_DEC_POS (b, best_above_byte);
}
/* If this position is quite far from the nearest known position,
cache the correspondence by creating a marker here.
It will last until the next GC.
But don't do it if BUF_MARKERS is nil;
that is a signal from Fset_buffer_multibyte. */
if (record && BUF_MARKERS (b))
{
Lisp_Object marker, buffer;
marker = Fmake_marker ();
XSETBUFFER (buffer, b);
set_marker_both (marker, buffer, best_above, best_above_byte);
}
if (byte_debug_flag)
byte_char_debug_check (b, best_above, bytepos);
cached_buffer = b;
cached_modiff = BUF_MODIFF (b);
cached_charpos = best_above;
cached_bytepos = best_above_byte;
return best_above;
}
}
