1 files changed, 53 insertions, 11 deletions

diff --git a/thirdparty/harfbuzz/src/hb-bit-set.hh b/thirdparty/harfbuzz/src/hb-bit-set.hh
index fcaff9f3be..11a4359dc9 100644
--- a/thirdparty/harfbuzz/src/hb-bit-set.hh
+++ b/thirdparty/harfbuzz/src/hb-bit-set.hh
@@ -97,6 +97,13 @@ struct hb_bit_set_t
     return true;
   }
 
+  void alloc (unsigned sz)
+  {
+    sz >>= (page_t::PAGE_BITS_LOG_2 - 1);
+    pages.alloc (sz);
+    page_map.alloc (sz);
+  }
+
   void reset ()
   {
     successful = true;
@@ -119,6 +126,14 @@ struct hb_bit_set_t
   }
   explicit operator bool () const { return !is_empty (); }
 
+  uint32_t hash () const
+  {
+    uint32_t h = 0;
+    for (auto &map : page_map)
+      h = h * 31 + hb_hash (map.major) + hb_hash (pages[map.index]);
+    return h;
+  }
+
   private:
   void dirty () { population = UINT_MAX; }
   public:
@@ -341,15 +356,14 @@ struct hb_bit_set_t
       return;
     population = other.population;
 
-    /* TODO switch to vector operator =. */
-    hb_memcpy ((void *) pages, (const void *) other.pages, count * pages.item_size);
-    hb_memcpy ((void *) page_map, (const void *) other.page_map, count * page_map.item_size);
+    page_map = other.page_map;
+    pages = other.pages;
   }
 
   bool is_equal (const hb_bit_set_t &other) const
   {
     if (has_population () && other.has_population () &&
-	get_population () != other.get_population ())
+	population != other.population)
       return false;
 
     unsigned int na = pages.length;
@@ -377,7 +391,7 @@ struct hb_bit_set_t
   bool is_subset (const hb_bit_set_t &larger_set) const
   {
     if (has_population () && larger_set.has_population () &&
-	get_population () != larger_set.get_population ())
+	population != larger_set.population)
       return false;
 
     uint32_t spi = 0;
@@ -874,7 +888,19 @@ struct hb_bit_set_t
 
   page_t *page_for (hb_codepoint_t g, bool insert = false)
   {
-    page_map_t map = {get_major (g), pages.length};
+    unsigned major = get_major (g);
+
+    /* The extra page_map length is necessary; can't just rely on vector here,
+     * since the next check would be tricked because a null page also has
+     * major==0, which we can't distinguish from an actualy major==0 page... */
+    if (likely (last_page_lookup < page_map.length))
+    {
+      auto &cached_page = page_map.arrayZ[last_page_lookup];
+      if (cached_page.major == major)
+	return &pages[cached_page.index];
+    }
+
+    page_map_t map = {major, pages.length};
     unsigned int i;
     if (!page_map.bfind (map, &i, HB_NOT_FOUND_STORE_CLOSEST))
     {
@@ -890,15 +916,31 @@ struct hb_bit_set_t
 	       (page_map.length - 1 - i) * page_map.item_size);
       page_map[i] = map;
     }
+
+    last_page_lookup = i;
     return &pages[page_map[i].index];
   }
   const page_t *page_for (hb_codepoint_t g) const
   {
-    page_map_t key = {get_major (g)};
-    const page_map_t *found = page_map.bsearch (key);
-    if (found)
-      return &pages[found->index];
-    return nullptr;
+    unsigned major = get_major (g);
+
+    /* The extra page_map length is necessary; can't just rely on vector here,
+     * since the next check would be tricked because a null page also has
+     * major==0, which we can't distinguish from an actualy major==0 page... */
+    if (likely (last_page_lookup < page_map.length))
+    {
+      auto &cached_page = page_map.arrayZ[last_page_lookup];
+      if (cached_page.major == major)
+	return &pages[cached_page.index];
+    }
+
+    page_map_t key = {major};
+    unsigned int i;
+    if (!page_map.bfind (key, &i))
+      return nullptr;
+
+    last_page_lookup = i;
+    return &pages[page_map[i].index];
   }
   page_t &page_at (unsigned int i) { return pages[page_map[i].index]; }
   const page_t &page_at (unsigned int i) const { return pages[page_map[i].index]; }