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[HB] Improve buffer. Don't dup out buffer unless out is longer than in 

That is, we work in-place even for ligatures now.
This commit is contained in:
Behdad Esfahbod 2009-05-30 12:02:46 -04:00
parent 6734ed4b6b
commit e35bbd570a
2 changed files with 71 additions and 92 deletions
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156
src/hb-buffer.c
View File

@ -36,24 +36,16 @@
*
* As an optimization, both in_string and out_string may point to the
* same piece of memory, which is owned by in_string. This remains the
* case as long as:
* case as long as out_length doesn't exceed in_length at any time.
* In that case, swap() is no-op and the glyph operations operate mostly
* in-place.
*
* - copy_glyph() is called
* - replace_glyph() is called with inplace=TRUE
* - add_output_glyph() and add_output_glyphs() are not called
*
* In that case swap(), and copy_glyph(), and replace_glyph() are all
* mostly no-op.
*
* As soon an add_output_glyph[s]() or replace_glyph() with inplace=FALSE is
* called, out_string is moved over to an alternate buffer (alt_string), and
* its current contents (out_length entries) are copied to the alt buffer.
* This should all remain transparent to the user. swap() then switches
* in_string and alt_string. alt_string is not allocated until its needed,
* but after that it's grown with in_string unconditionally.
*
* The buffer->separate_out boolean keeps status of whether out_string points
* to in_string (FALSE) or alt_string (TRUE).
* As soon as out_string gets longer than in_string, out_string is moved over
* to an alternate buffer (alt_string), and its current contents (out_length
* entries) are copied to the alt buffer. This should all remain transparent
* to the user. swap() then switches in_string and alt_string. alt_string is
* not allocated until its needed, but after that it's grown with in_string
* unconditionally.
*/
/* XXX err handling */
@ -66,52 +58,47 @@ hb_buffer_ensure (hb_buffer_t *buffer, unsigned int size)
unsigned int new_allocated = buffer->allocated;
if (size > new_allocated)
{
while (size > new_allocated)
new_allocated += (new_allocated >> 1) + 8;
if (buffer->positions)
buffer->positions = realloc (buffer->positions, new_allocated * sizeof (buffer->positions[0]));
buffer->in_string = realloc (buffer->in_string, new_allocated * sizeof (buffer->in_string[0]));
if (buffer->out_string != buffer->in_string)
{
while (size > new_allocated)
new_allocated += (new_allocated >> 1) + 8;
if (buffer->positions)
buffer->positions = realloc (buffer->positions, new_allocated * sizeof (buffer->positions[0]));
buffer->in_string = realloc (buffer->in_string, new_allocated * sizeof (buffer->in_string[0]));
if (buffer->separate_out)
{
buffer->alt_string = realloc (buffer->alt_string, new_allocated * sizeof (buffer->alt_string[0]));
buffer->out_string = buffer->alt_string;
}
else
{
buffer->out_string = buffer->in_string;
if (buffer->alt_string)
{
free (buffer->alt_string);
buffer->alt_string = NULL;
}
}
buffer->allocated = new_allocated;
buffer->alt_string = realloc (buffer->alt_string, new_allocated * sizeof (buffer->alt_string[0]));
buffer->out_string = buffer->alt_string;
}
}
else
{
buffer->out_string = buffer->in_string;
static void
hb_buffer_duplicate_out_buffer (hb_buffer_t *buffer)
{
if (!buffer->alt_string)
buffer->alt_string = malloc (buffer->allocated * sizeof (buffer->alt_string[0]));
if (buffer->alt_string)
{
free (buffer->alt_string);
buffer->alt_string = NULL;
}
}
buffer->out_string = buffer->alt_string;
memcpy (buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]));
buffer->separate_out = TRUE;
buffer->allocated = new_allocated;
}
}
static void
hb_buffer_ensure_separate (hb_buffer_t *buffer, unsigned int size)
{
hb_buffer_ensure (buffer, size);
if ( !buffer->separate_out )
hb_buffer_duplicate_out_buffer (buffer);
if (buffer->out_string == buffer->in_string)
{
if (!buffer->alt_string)
buffer->alt_string = malloc (buffer->allocated * sizeof (buffer->alt_string[0]));
buffer->out_string = buffer->alt_string;
memcpy (buffer->out_string, buffer->in_string, buffer->out_length * sizeof (buffer->out_string[0]));
}
}
/* Public API */
@ -152,7 +139,6 @@ hb_buffer_clear (hb_buffer_t *buffer)
buffer->in_pos = 0;
buffer->out_pos = 0;
buffer->out_string = buffer->in_string;
buffer->separate_out = FALSE;
buffer->max_lig_id = 0;
}
@ -185,7 +171,6 @@ _hb_buffer_clear_output (hb_buffer_t *buffer)
buffer->out_length = 0;
buffer->out_pos = 0;
buffer->out_string = buffer->in_string;
buffer->separate_out = FALSE;
}
HB_INTERNAL void
@ -207,14 +192,14 @@ _hb_buffer_swap (hb_buffer_t *buffer)
{
unsigned int tmp;
if (buffer->separate_out)
{
hb_glyph_info_t *tmp_string;
tmp_string = buffer->in_string;
buffer->in_string = buffer->out_string;
buffer->out_string = tmp_string;
buffer->alt_string = buffer->out_string;
}
if (buffer->out_string != buffer->in_string)
{
hb_glyph_info_t *tmp_string;
tmp_string = buffer->in_string;
buffer->in_string = buffer->out_string;
buffer->out_string = tmp_string;
buffer->alt_string = buffer->out_string;
}
tmp = buffer->in_length;
buffer->in_length = buffer->out_length;
@ -256,7 +241,11 @@ _hb_buffer_add_output_glyphs (hb_buffer_t *buffer,
unsigned int properties;
unsigned int cluster;
hb_buffer_ensure_separate (buffer, buffer->out_pos + num_out);
if (buffer->out_string == buffer->in_string &&
buffer->out_pos + num_out > buffer->in_pos + num_in)
{
hb_buffer_ensure_separate (buffer, buffer->out_pos + num_out);
}
properties = buffer->in_string[buffer->in_pos].properties;
cluster = buffer->in_string[buffer->in_pos].cluster;
@ -268,7 +257,6 @@ _hb_buffer_add_output_glyphs (hb_buffer_t *buffer,
for (i = 0; i < num_out; i++)
{
hb_glyph_info_t *info = &buffer->out_string[buffer->out_pos + i];
info->gindex = hb_be_uint16_t (glyph_data_be[i]);
info->properties = properties;
info->cluster = cluster;
@ -279,7 +267,6 @@ _hb_buffer_add_output_glyphs (hb_buffer_t *buffer,
buffer->in_pos += num_in;
buffer->out_pos += num_out;
buffer->out_length = buffer->out_pos;
}
@ -292,11 +279,15 @@ _hb_buffer_add_output_glyph (hb_buffer_t *buffer,
{
hb_glyph_info_t *info;
hb_buffer_ensure_separate (buffer, buffer->out_pos + 1);
if (buffer->out_string != buffer->in_string)
{
hb_buffer_ensure (buffer, buffer->out_pos + 1);
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
}
else if (buffer->out_pos != buffer->in_pos)
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
info = &buffer->out_string[buffer->out_pos];
*info = buffer->in_string[buffer->in_pos];
info->gindex = glyph_index;
if (component != 0xFFFF)
info->component = component;
@ -306,19 +297,19 @@ _hb_buffer_add_output_glyph (hb_buffer_t *buffer,
buffer->in_pos++;
buffer->out_pos++;
buffer->out_length = buffer->out_pos;
}
HB_INTERNAL void
_hb_buffer_next_glyph (hb_buffer_t *buffer)
{
if (buffer->separate_out)
{
hb_buffer_ensure (buffer, buffer->out_pos + 1);
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
}
if (buffer->out_string != buffer->in_string)
{
hb_buffer_ensure (buffer, buffer->out_pos + 1);
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
}
else if (buffer->out_pos != buffer->in_pos)
buffer->out_string[buffer->out_pos] = buffer->in_string[buffer->in_pos];
buffer->in_pos++;
buffer->out_pos++;
@ -329,18 +320,7 @@ HB_INTERNAL void
_hb_buffer_replace_glyph (hb_buffer_t *buffer,
hb_codepoint_t glyph_index)
{
if (!buffer->separate_out)
{
buffer->out_string[buffer->out_pos].gindex = glyph_index;
buffer->in_pos++;
buffer->out_pos++;
buffer->out_length = buffer->out_pos;
}
else
{
return _hb_buffer_add_output_glyph (buffer, glyph_index, 0xFFFF, 0xFFFF);
}
_hb_buffer_add_output_glyph (buffer, glyph_index, 0xFFFF, 0xFFFF);
}
HB_INTERNAL unsigned short

7
src/hb-buffer.h
View File

@ -49,14 +49,14 @@ typedef struct _hb_glyph_position_t {
hb_position_t x_advance;
hb_position_t y_advance;
unsigned short back; /* number of glyphs to go back
for drawing current glyph */
for drawing current glyph */
hb_bool_t new_advance; /* if set, the advance width values are
absolute, i.e., they won't be
added to the original glyph's value
but rather replace them. */
but rather replace them */
short cursive_chain; /* character to which this connects,
may be positive or negative; used
only internally */
only internally */
} hb_glyph_position_t;
@ -68,7 +68,6 @@ typedef struct _hb_buffer_t {
unsigned int in_pos;
unsigned int out_pos;
hb_bool_t separate_out;
hb_glyph_info_t *in_string;
hb_glyph_info_t *out_string;
hb_glyph_info_t *alt_string;