[layout] Build lookup accelerators lazily on-demand
Reduces memory consumption for large multi-script fonts
drastically.
diff --git a/src/hb-ot-font.cc b/src/hb-ot-font.cc
index 42f3143..92f9e39 100644
--- a/src/hb-ot-font.cc
+++ b/src/hb-ot-font.cc
@@ -121,8 +121,7 @@
hb_ot_font_t *ot_font = (hb_ot_font_t *) font_data;
auto *cache = ot_font->advance_cache.get_relaxed ();
- if (cache)
- hb_free (cache);
+ hb_free (cache);
hb_free (ot_font);
}
diff --git a/src/hb-ot-layout-gpos-table.hh b/src/hb-ot-layout-gpos-table.hh
index afc02f5..0cfa139 100644
--- a/src/hb-ot-layout-gpos-table.hh
+++ b/src/hb-ot-layout-gpos-table.hh
@@ -64,11 +64,8 @@
c->set_lookup_props (l.get_props ());
bool ret = false;
- if (lookup_index < gpos->lookup_count)
- {
- auto &accel = gpos->accels[lookup_index];
- ret = accel.apply (c, l.get_subtable_count (), false);
- }
+ auto *accel = gpos->get_accel (lookup_index);
+ ret = accel && accel->apply (c, l.get_subtable_count (), false);
c->set_lookup_index (saved_lookup_index);
c->set_lookup_props (saved_lookup_props);
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index 6a3d12c..fd8a68b 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -77,11 +77,8 @@
c->set_lookup_props (l.get_props ());
bool ret = false;
- if (lookup_index < gsub->lookup_count)
- {
- auto &accel = gsub->accels[lookup_index];
- ret = accel.apply (c, l.get_subtable_count (), false);
- }
+ auto *accel = gsub->get_accel (lookup_index);
+ ret = accel && accel->apply (c, l.get_subtable_count (), false);
c->set_lookup_index (saved_lookup_index);
c->set_lookup_props (saved_lookup_props);
diff --git a/src/hb-ot-layout-gsubgpos.hh b/src/hb-ot-layout-gsubgpos.hh
index 1b9be91..8d0f400 100644
--- a/src/hb-ot-layout-gsubgpos.hh
+++ b/src/hb-ot-layout-gsubgpos.hh
@@ -4013,37 +4013,40 @@
struct hb_ot_layout_lookup_accelerator_t
{
template <typename TLookup>
- void init (const TLookup &lookup)
+ static hb_ot_layout_lookup_accelerator_t *create (const TLookup &lookup)
{
unsigned count = lookup.get_subtable_count ();
- subtables = (hb_accelerate_subtables_context_t::hb_applicable_t *)
- hb_calloc (count, sizeof (hb_accelerate_subtables_context_t::hb_applicable_t));
- if (unlikely (!subtables))
- return;
- hb_accelerate_subtables_context_t c_accelerate_subtables (subtables);
+ unsigned size = sizeof (hb_ot_layout_lookup_accelerator_t) -
+ HB_VAR_ARRAY * sizeof (hb_accelerate_subtables_context_t::hb_applicable_t) +
+ count * sizeof (hb_accelerate_subtables_context_t::hb_applicable_t);
+
+ auto *thiz = (hb_ot_layout_lookup_accelerator_t *) hb_calloc (1, size);
+ if (unlikely (!thiz))
+ return nullptr;
+
+ hb_accelerate_subtables_context_t c_accelerate_subtables (thiz->subtables);
lookup.dispatch (&c_accelerate_subtables);
- digest.init ();
- for (auto& subtable : hb_iter (subtables, count))
- digest.add (subtable.digest);
+ thiz->digest.init ();
+ for (auto& subtable : hb_iter (thiz->subtables, count))
+ thiz->digest.add (subtable.digest);
#ifndef HB_NO_OT_LAYOUT_LOOKUP_CACHE
- cache_user_idx = c_accelerate_subtables.cache_user_idx;
+ thiz->cache_user_idx = c_accelerate_subtables.cache_user_idx;
for (unsigned i = 0; i < count; i++)
- if (i != cache_user_idx)
- subtables[i].apply_cached_func = subtables[i].apply_func;
+ if (i != thiz->cache_user_idx)
+ thiz->subtables[i].apply_cached_func = thiz->subtables[i].apply_func;
#endif
+
+ return thiz;
}
- void fini () { hb_free (subtables); }
bool may_have (hb_codepoint_t g) const
{ return digest.may_have (g); }
bool apply (hb_ot_apply_context_t *c, unsigned subtables_count, bool use_cache) const
{
- if (unlikely (!subtables)) return false;
-
#ifndef HB_NO_OT_LAYOUT_LOOKUP_CACHE
if (use_cache)
{
@@ -4084,10 +4087,10 @@
hb_set_digest_t digest;
private:
- hb_accelerate_subtables_context_t::hb_applicable_t *subtables;
#ifndef HB_NO_OT_LAYOUT_LOOKUP_CACHE
unsigned cache_user_idx = (unsigned) -1;
#endif
+ hb_accelerate_subtables_context_t::hb_applicable_t subtables[HB_VAR_ARRAY];
};
template <typename Types>
@@ -4450,28 +4453,47 @@
this->lookup_count = table->get_lookup_count ();
- this->accels = (hb_ot_layout_lookup_accelerator_t *) hb_calloc (this->lookup_count, sizeof (hb_ot_layout_lookup_accelerator_t));
+ this->accels = (hb_atomic_ptr_t<hb_ot_layout_lookup_accelerator_t> *) hb_calloc (this->lookup_count, sizeof (*accels));
if (unlikely (!this->accels))
{
this->lookup_count = 0;
this->table.destroy ();
this->table = hb_blob_get_empty ();
}
-
- for (unsigned int i = 0; i < this->lookup_count; i++)
- this->accels[i].init (table->get_lookup (i));
}
~accelerator_t ()
{
for (unsigned int i = 0; i < this->lookup_count; i++)
- this->accels[i].fini ();
+ hb_free (this->accels[i]);
hb_free (this->accels);
this->table.destroy ();
}
+ hb_ot_layout_lookup_accelerator_t *get_accel (unsigned lookup_index) const
+ {
+ if (unlikely (lookup_index >= lookup_count)) return nullptr;
+
+ retry:
+ auto *accel = accels[lookup_index].get_acquire ();
+ if (unlikely (!accel))
+ {
+ accel = hb_ot_layout_lookup_accelerator_t::create (table->get_lookup (lookup_index));
+ if (unlikely (!accel))
+ return nullptr;
+
+ if (unlikely (!accels[lookup_index].cmpexch (nullptr, accel)))
+ {
+ hb_free (accel);
+ goto retry;
+ }
+ }
+
+ return accel;
+ }
+
hb_blob_ptr_t<T> table;
unsigned int lookup_count;
- hb_ot_layout_lookup_accelerator_t *accels;
+ hb_atomic_ptr_t<hb_ot_layout_lookup_accelerator_t> *accels;
};
protected:
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index dcaf62d..44c1ea6 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -1487,11 +1487,13 @@
unsigned int glyphs_length,
hb_bool_t zero_context)
{
- if (unlikely (lookup_index >= face->table.GSUB->lookup_count)) return false;
+ auto &gsub = face->table.GSUB;
+ if (unlikely (lookup_index >= gsub->lookup_count)) return false;
OT::hb_would_apply_context_t c (face, glyphs, glyphs_length, (bool) zero_context);
- const OT::SubstLookup& l = face->table.GSUB->table->get_lookup (lookup_index);
- return l.would_apply (&c, &face->table.GSUB->accels[lookup_index]);
+ const OT::SubstLookup& l = gsub->table->get_lookup (lookup_index);
+ auto *accel = gsub->get_accel (lookup_index);
+ return accel && l.would_apply (&c, accel);
}
@@ -1830,11 +1832,9 @@
typedef OT::SubstLookup Lookup;
GSUBProxy (hb_face_t *face) :
- table (*face->table.GSUB->table),
- accels (face->table.GSUB->accels) {}
+ accel (*face->table.GSUB) {}
- const GSUB &table;
- const OT::hb_ot_layout_lookup_accelerator_t *accels;
+ const GSUB::accelerator_t &accel;
};
struct GPOSProxy
@@ -1844,11 +1844,9 @@
typedef OT::PosLookup Lookup;
GPOSProxy (hb_face_t *face) :
- table (*face->table.GPOS->table),
- accels (face->table.GPOS->accels) {}
+ accel (*face->table.GPOS) {}
- const GPOS &table;
- const OT::hb_ot_layout_lookup_accelerator_t *accels;
+ const GPOS::accelerator_t &accel;
};
@@ -1911,12 +1909,13 @@
const typename Proxy::Lookup &lookup,
const OT::hb_ot_layout_lookup_accelerator_t &accel)
{
- bool ret = false;
hb_buffer_t *buffer = c->buffer;
unsigned subtable_count = lookup.get_subtable_count ();
if (unlikely (!buffer->len || !c->lookup_mask))
- return ret;
+ return false;
+
+ bool ret = false;
c->set_lookup_props (lookup.get_props ());
@@ -1962,6 +1961,10 @@
auto &lookup = lookups[table_index][i];
unsigned int lookup_index = lookup.index;
+
+ auto *accel = proxy.accel.get_accel (lookup_index);
+ if (unlikely (!accel)) continue;
+
if (buffer->messaging () &&
!buffer->message (font, "start lookup %u feature '%c%c%c%c'", lookup_index, HB_UNTAG (lookup.feature_tag))) continue;
@@ -1969,7 +1972,7 @@
* (plus some past glyphs).
*
* Only try applying the lookup if there is any overlap. */
- if (proxy.accels[lookup_index].digest.may_have (c.digest))
+ if (accel->digest.may_have (c.digest))
{
c.set_lookup_index (lookup_index);
c.set_lookup_mask (lookup.mask);
@@ -1979,8 +1982,8 @@
c.set_per_syllable (lookup.per_syllable);
apply_string<Proxy> (&c,
- proxy.table.get_lookup (lookup_index),
- proxy.accels[lookup_index]);
+ proxy.accel.table->get_lookup (lookup_index),
+ *accel);
}
else if (buffer->messaging ())
(void) buffer->message (font, "skipped lookup %u feature '%c%c%c%c' because no glyph matches", lookup_index, HB_UNTAG (lookup.feature_tag));
diff --git a/src/hb-ot-shaper-arabic-fallback.hh b/src/hb-ot-shaper-arabic-fallback.hh
index 6ba1ec7..e7a6900 100644
--- a/src/hb-ot-shaper-arabic-fallback.hh
+++ b/src/hb-ot-shaper-arabic-fallback.hh
@@ -228,7 +228,7 @@
hb_mask_t mask_array[ARABIC_FALLBACK_MAX_LOOKUPS];
OT::SubstLookup *lookup_array[ARABIC_FALLBACK_MAX_LOOKUPS];
- OT::hb_ot_layout_lookup_accelerator_t accel_array[ARABIC_FALLBACK_MAX_LOOKUPS];
+ OT::hb_ot_layout_lookup_accelerator_t *accel_array[ARABIC_FALLBACK_MAX_LOOKUPS];
};
#if defined(_WIN32) && !defined(HB_NO_WIN1256)
@@ -278,7 +278,7 @@
fallback_plan->lookup_array[j] = const_cast<OT::SubstLookup*> (&(&manifest+manifest[i].lookupOffset));
if (fallback_plan->lookup_array[j])
{
- fallback_plan->accel_array[j].init (*fallback_plan->lookup_array[j]);
+ fallback_plan->accel_array[j] = OT::hb_ot_layout_lookup_accelerator_t::create (*fallback_plan->lookup_array[j]);
j++;
}
}
@@ -308,7 +308,7 @@
fallback_plan->lookup_array[j] = arabic_fallback_synthesize_lookup (plan, font, i);
if (fallback_plan->lookup_array[j])
{
- fallback_plan->accel_array[j].init (*fallback_plan->lookup_array[j]);
+ fallback_plan->accel_array[j] = OT::hb_ot_layout_lookup_accelerator_t::create (*fallback_plan->lookup_array[j]);
j++;
}
}
@@ -355,7 +355,7 @@
for (unsigned int i = 0; i < fallback_plan->num_lookups; i++)
if (fallback_plan->lookup_array[i])
{
- fallback_plan->accel_array[i].fini ();
+ hb_free (fallback_plan->accel_array[i]);
if (fallback_plan->free_lookups)
hb_free (fallback_plan->lookup_array[i]);
}
@@ -372,9 +372,10 @@
for (unsigned int i = 0; i < fallback_plan->num_lookups; i++)
if (fallback_plan->lookup_array[i]) {
c.set_lookup_mask (fallback_plan->mask_array[i]);
- hb_ot_layout_substitute_lookup (&c,
- *fallback_plan->lookup_array[i],
- fallback_plan->accel_array[i]);
+ if (fallback_plan->accel_array[i])
+ hb_ot_layout_substitute_lookup (&c,
+ *fallback_plan->lookup_array[i],
+ *fallback_plan->accel_array[i]);
}
}
