[glyf] Reduce malloc pressure
Benchmark 15% faster for draw.
diff --git a/src/OT/glyf/glyf.hh b/src/OT/glyf/glyf.hh
index 395484c..1b85203 100644
--- a/src/OT/glyf/glyf.hh
+++ b/src/OT/glyf/glyf.hh
@@ -198,6 +198,13 @@
}
~glyf_accelerator_t ()
{
+ auto *scratch = cached_scratch.get_relaxed ();
+ if (scratch)
+ {
+ scratch->~hb_glyf_scratch_t ();
+ hb_free (scratch);
+ }
+
glyf_table.destroy ();
}
@@ -463,10 +470,34 @@
bool
get_path (hb_font_t *font, hb_codepoint_t gid, hb_draw_session_t &draw_session) const
{
- hb_glyf_scratch_t scratch;
- return get_points (font, gid, glyf_impl::path_builder_t (font, draw_session),
- hb_array (font->coords, font->num_coords),
- scratch); }
+ if (!has_data ()) return false;
+
+ hb_glyf_scratch_t *scratch;
+
+ // Borrow the cached strach buffer.
+ {
+ scratch = cached_scratch.get_acquire ();
+ if (!scratch || unlikely (!cached_scratch.cmpexch (scratch, nullptr)))
+ {
+ scratch = (hb_glyf_scratch_t *) hb_calloc (1, sizeof (hb_glyf_scratch_t));
+ if (unlikely (!scratch))
+ return true;
+ }
+ }
+
+ bool ret = get_points (font, gid, glyf_impl::path_builder_t (font, draw_session),
+ hb_array (font->coords, font->num_coords),
+ *scratch);
+
+ // Put it back.
+ if (!cached_scratch.cmpexch (nullptr, scratch))
+ {
+ scratch->~hb_glyf_scratch_t ();
+ hb_free (scratch);
+ }
+
+ return ret;
+ }
bool
get_path_at (hb_font_t *font, hb_codepoint_t gid, hb_draw_session_t &draw_session,
@@ -489,6 +520,7 @@
unsigned int num_glyphs;
hb_blob_ptr_t<loca> loca_table;
hb_blob_ptr_t<glyf> glyf_table;
+ hb_atomic_ptr_t<hb_glyf_scratch_t> cached_scratch;
};
