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Spruce up ftfont.c memory allocation

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* src/ftfont.c (setup_otf_gstring):
Avoid O(N**2) behavior when reallocating.
(ftfont_shape_by_flt): Prefer xpalloc to xrealloc when
reallocating buffers; this simplifies the code.  Do not trust
mflt_run to leave the output areas unchanged on failure, as
this isn’t part of its interface spec.
This commit is contained in:
Paul Eggert 2015-11-13 12:02:21 -08:00
parent 4c4b520520
commit 04ac097f34
1 changed files with 49 additions and 55 deletions
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104
src/ftfont.c
View file

@ -1776,9 +1776,11 @@ setup_otf_gstring (int size)
{
if (otf_gstring.size < size)
{
otf_gstring.glyphs = xnrealloc (otf_gstring.glyphs,
size, sizeof (OTF_Glyph));
otf_gstring.size = size;
ptrdiff_t new_size = otf_gstring.size;
xfree (otf_gstring.glyphs);
otf_gstring.glyphs = xpalloc (NULL, &new_size, size - otf_gstring.size,
INT_MAX, sizeof *otf_gstring.glyphs);
otf_gstring.size = new_size;
}
otf_gstring.used = size;
memset (otf_gstring.glyphs, 0, sizeof (OTF_Glyph) * size);
@ -2505,8 +2507,7 @@ ftfont_shape_by_flt (Lisp_Object lgstring, struct font *font,
ptrdiff_t i;
struct MFLTFontFT flt_font_ft;
MFLT *flt = NULL;
bool with_variation_selector = 0;
MFLTGlyphFT *glyphs;
bool with_variation_selector = false;
if (! m17n_flt_initialized)
{
@ -2527,7 +2528,7 @@ ftfont_shape_by_flt (Lisp_Object lgstring, struct font *font,
break;
c = LGLYPH_CHAR (g);
if (CHAR_VARIATION_SELECTOR_P (c))
with_variation_selector = 1;
with_variation_selector = true;
}
len = i;
@ -2561,39 +2562,6 @@ ftfont_shape_by_flt (Lisp_Object lgstring, struct font *font,
}
}
int len2;
if (INT_MULTIPLY_WRAPV (len, 2, &len2))
memory_full (SIZE_MAX);
if (gstring.allocated == 0)
{
gstring.glyph_size = sizeof (MFLTGlyphFT);
gstring.glyphs = xnmalloc (len2, sizeof (MFLTGlyphFT));
gstring.allocated = len2;
}
else if (gstring.allocated < len2)
{
gstring.glyphs = xnrealloc (gstring.glyphs, len2,
sizeof (MFLTGlyphFT));
gstring.allocated = len2;
}
glyphs = (MFLTGlyphFT *) (gstring.glyphs);
memset (glyphs, 0, len * sizeof (MFLTGlyphFT));
for (i = 0; i < len; i++)
{
Lisp_Object g = LGSTRING_GLYPH (lgstring, i);
glyphs[i].g.c = LGLYPH_CHAR (g);
if (with_variation_selector)
{
glyphs[i].g.code = LGLYPH_CODE (g);
glyphs[i].g.encoded = 1;
}
}
gstring.used = len;
gstring.r2l = 0;
{
Lisp_Object family = Ffont_get (LGSTRING_FONT (lgstring), QCfamily);
@ -2614,24 +2582,50 @@ ftfont_shape_by_flt (Lisp_Object lgstring, struct font *font,
flt_font_ft.ft_face = ft_face;
flt_font_ft.otf = otf;
flt_font_ft.matrix = matrix->xx != 0 ? matrix : 0;
if (len > 1
&& gstring.glyphs[1].c >= 0x300 && gstring.glyphs[1].c <= 0x36F)
/* A little bit ad hoc. Perhaps, shaper must get script and
language information, and select a proper flt for them
here. */
flt = mflt_get (msymbol ("combining"));
for (i = 0; i < 3; i++)
if (1 < len)
{
int result = mflt_run (&gstring, 0, len, &flt_font_ft.flt_font, flt);
if (result != -2)
break;
int len2;
if (INT_MULTIPLY_WRAPV (gstring.allocated, 2, &len2))
memory_full (SIZE_MAX);
gstring.glyphs = xnrealloc (gstring.glyphs,
gstring.allocated, 2 * sizeof (MFLTGlyphFT));
gstring.allocated = len2;
/* A little bit ad hoc. Perhaps, shaper must get script and
language information, and select a proper flt for them
here. */
int c1 = LGLYPH_CHAR (LGSTRING_GLYPH (lgstring, 1));
if (0x300 <= c1 && c1 <= 0x36F)
flt = mflt_get (msymbol ("combining"));
}
MFLTGlyphFT *glyphs = (MFLTGlyphFT *) gstring.glyphs;
ptrdiff_t allocated = gstring.allocated;
ptrdiff_t incr_min = len - allocated;
do
{
if (0 < incr_min)
{
xfree (glyphs);
glyphs = xpalloc (NULL, &allocated, incr_min, INT_MAX, sizeof *glyphs);
}
incr_min = 1;
for (i = 0; i < len; i++)
{
Lisp_Object g = LGSTRING_GLYPH (lgstring, i);
memset (&glyphs[i], 0, sizeof glyphs[i]);
glyphs[i].g.c = LGLYPH_CHAR (g);
if (with_variation_selector)
{
glyphs[i].g.code = LGLYPH_CODE (g);
glyphs[i].g.encoded = 1;
}
}
gstring.glyph_size = sizeof *glyphs;
gstring.glyphs = (MFLTGlyph *) glyphs;
gstring.allocated = allocated;
gstring.used = len;
gstring.r2l = 0;
}
while (mflt_run (&gstring, 0, len, &flt_font_ft.flt_font, flt) == -2);
if (gstring.used > LGSTRING_GLYPH_LEN (lgstring))
return Qnil;
for (i = 0; i < gstring.used; i++)