[ot-font] Add a cmap cache
Speeds up Roboto shaping by 7%, for 1kb per face.
diff --git a/src/hb-ot-cmap-table.hh b/src/hb-ot-cmap-table.hh
index 3c7d2f0..c4a0987 100644
--- a/src/hb-ot-cmap-table.hh
+++ b/src/hb-ot-cmap-table.hh
@@ -1901,20 +1901,37 @@
if (unlikely (!this->get_glyph_funcZ)) return false;
return this->get_glyph_funcZ (this->get_glyph_data, unicode, glyph);
}
+
+ template <typename cache_t = void>
+ inline bool _cached_get (hb_codepoint_t unicode,
+ hb_codepoint_t *glyph,
+ cache_t *cache) const
+ {
+ unsigned v;
+ if (cache && cache->get (unicode, &v))
+ {
+ *glyph = v;
+ return true;
+ }
+ bool ret = this->get_glyph_funcZ (this->get_glyph_data, unicode, glyph);
+ if (cache && ret)
+ cache->set (unicode, *glyph);
+ return ret;
+ }
+
+ template <typename cache_t = void>
unsigned int get_nominal_glyphs (unsigned int count,
const hb_codepoint_t *first_unicode,
unsigned int unicode_stride,
hb_codepoint_t *first_glyph,
- unsigned int glyph_stride) const
+ unsigned int glyph_stride,
+ cache_t *cache = nullptr) const
{
if (unlikely (!this->get_glyph_funcZ)) return 0;
- hb_cmap_get_glyph_func_t get_glyph_funcZ = this->get_glyph_funcZ;
- const void *get_glyph_data = this->get_glyph_data;
-
unsigned int done;
for (done = 0;
- done < count && get_glyph_funcZ (get_glyph_data, *first_unicode, first_glyph);
+ done < count && _cached_get (*first_unicode, first_glyph, cache);
done++)
{
first_unicode = &StructAtOffsetUnaligned<hb_codepoint_t> (first_unicode, unicode_stride);
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 0fc6a10..df5ee6c 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -60,12 +60,17 @@
* never need to call these functions directly.
**/
+using hb_ot_font_cmap_cache_t = hb_cache_t<21, 16, 8, true>;
using hb_ot_font_advance_cache_t = hb_cache_t<24, 16, 8, true>;
+static hb_user_data_key_t hb_ot_font_cmap_cache_user_data_key;
+
struct hb_ot_font_t
{
const hb_ot_face_t *ot_face;
+ hb_ot_font_cmap_cache_t *cmap_cache;
+
/* h_advance caching */
mutable hb_atomic_int_t cached_coords_serial;
mutable hb_atomic_ptr_t<hb_ot_font_advance_cache_t> advance_cache;
@@ -80,6 +85,31 @@
ot_font->ot_face = &font->face->table;
+ auto *cmap_cache = (hb_ot_font_cmap_cache_t *) hb_face_get_user_data (font->face,
+ &hb_ot_font_cmap_cache_user_data_key);
+ if (!cmap_cache)
+ {
+ cmap_cache = (hb_ot_font_cmap_cache_t *) hb_malloc (sizeof (hb_ot_font_cmap_cache_t));
+ if (unlikely (!cmap_cache)) goto out;
+ cmap_cache->init ();
+ if (!hb_face_set_user_data (font->face,
+ &hb_ot_font_cmap_cache_user_data_key,
+ cmap_cache,
+ hb_free,
+ false))
+ {
+ /* Normally we would retry after this, but that would
+ * infinite-loop if the face is the empty-face.
+ * Just let it go and this font will be uncached if it
+ * happened to collide with anothe thread creating the
+ * cache at the same time. */
+ hb_free (cmap_cache);
+ cmap_cache = nullptr;
+ }
+ }
+ out:
+ ot_font->cmap_cache = cmap_cache;
+
return ot_font;
}
@@ -121,7 +151,8 @@
const hb_ot_face_t *ot_face = ot_font->ot_face;
return ot_face->cmap->get_nominal_glyphs (count,
first_unicode, unicode_stride,
- first_glyph, glyph_stride);
+ first_glyph, glyph_stride,
+ ot_font->cmap_cache);
}
static hb_bool_t
