feat: godot-engine-source-4.3-stable

engine/thirdparty/harfbuzz/src/hb-map.hh

@@ -0,0 +1,568 @@
+/*
+ * Copyright © 2018  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_MAP_HH
+#define HB_MAP_HH
+
+#include "hb.hh"
+
+#include "hb-set.hh"
+
+
+/*
+ * hb_hashmap_t
+ */
+
+extern HB_INTERNAL const hb_codepoint_t minus_1;
+
+template <typename K, typename V,
+	  bool minus_one = false>
+struct hb_hashmap_t
+{
+  static constexpr bool realloc_move = true;
+
+  hb_hashmap_t ()  { init (); }
+  ~hb_hashmap_t () { fini (); }
+
+  hb_hashmap_t (const hb_hashmap_t& o) : hb_hashmap_t ()
+  {
+    if (unlikely (!o.mask)) return;
+
+    if (item_t::is_trivial)
+    {
+      items = (item_t *) hb_malloc (sizeof (item_t) * (o.mask + 1));
+      if (unlikely (!items))
+      {
+	successful = false;
+	return;
+      }
+      population = o.population;
+      occupancy = o.occupancy;
+      mask = o.mask;
+      prime = o.prime;
+      max_chain_length = o.max_chain_length;
+      memcpy (items, o.items, sizeof (item_t) * (mask + 1));
+      return;
+    }
+
+    alloc (o.population); hb_copy (o, *this);
+  }
+  hb_hashmap_t (hb_hashmap_t&& o)  noexcept : hb_hashmap_t () { hb_swap (*this, o); }
+  hb_hashmap_t& operator= (const hb_hashmap_t& o)  { reset (); alloc (o.population); hb_copy (o, *this); return *this; }
+  hb_hashmap_t& operator= (hb_hashmap_t&& o)   noexcept { hb_swap (*this, o); return *this; }
+
+  hb_hashmap_t (std::initializer_list<hb_pair_t<K, V>> lst) : hb_hashmap_t ()
+  {
+    for (auto&& item : lst)
+      set (item.first, item.second);
+  }
+  template <typename Iterable,
+	    hb_requires (hb_is_iterable (Iterable))>
+  hb_hashmap_t (const Iterable &o) : hb_hashmap_t ()
+  {
+    auto iter = hb_iter (o);
+    if (iter.is_random_access_iterator || iter.has_fast_len)
+      alloc (hb_len (iter));
+    hb_copy (iter, *this);
+  }
+
+  struct item_t
+  {
+    K key;
+    uint32_t is_real_ : 1;
+    uint32_t is_used_ : 1;
+    uint32_t hash : 30;
+    V value;
+
+    item_t () : key (),
+		is_real_ (false), is_used_ (false),
+		hash (0),
+		value () {}
+
+    // Needed for https://github.com/harfbuzz/harfbuzz/issues/4138
+    K& get_key () { return key; }
+    V& get_value () { return value; }
+
+    bool is_used () const { return is_used_; }
+    void set_used (bool is_used) { is_used_ = is_used; }
+    void set_real (bool is_real) { is_real_ = is_real; }
+    bool is_real () const { return is_real_; }
+
+    template <bool v = minus_one,
+	      hb_enable_if (v == false)>
+    static inline const V& default_value () { return Null(V); };
+    template <bool v = minus_one,
+	      hb_enable_if (v == true)>
+    static inline const V& default_value ()
+    {
+      static_assert (hb_is_same (V, hb_codepoint_t), "");
+      return minus_1;
+    };
+
+    bool operator == (const K &o) const { return hb_deref (key) == hb_deref (o); }
+    bool operator == (const item_t &o) const { return *this == o.key; }
+    hb_pair_t<K, V> get_pair() const { return hb_pair_t<K, V> (key, value); }
+    hb_pair_t<const K &, V &> get_pair_ref() { return hb_pair_t<const K &, V &> (key, value); }
+
+    uint32_t total_hash () const
+    { return (hash * 31u) + hb_hash (value); }
+
+    static constexpr bool is_trivial = hb_is_trivially_constructible(K) &&
+				       hb_is_trivially_destructible(K) &&
+				       hb_is_trivially_constructible(V) &&
+				       hb_is_trivially_destructible(V);
+  };
+
+  hb_object_header_t header;
+  bool successful; /* Allocations successful */
+  unsigned short max_chain_length;
+  unsigned int population; /* Not including tombstones. */
+  unsigned int occupancy; /* Including tombstones. */
+  unsigned int mask;
+  unsigned int prime;
+  item_t *items;
+
+  friend void swap (hb_hashmap_t& a, hb_hashmap_t& b) noexcept
+  {
+    if (unlikely (!a.successful || !b.successful))
+      return;
+    hb_swap (a.max_chain_length, b.max_chain_length);
+    hb_swap (a.population, b.population);
+    hb_swap (a.occupancy, b.occupancy);
+    hb_swap (a.mask, b.mask);
+    hb_swap (a.prime, b.prime);
+    hb_swap (a.items, b.items);
+  }
+  void init ()
+  {
+    hb_object_init (this);
+
+    successful = true;
+    max_chain_length = 0;
+    population = occupancy = 0;
+    mask = 0;
+    prime = 0;
+    items = nullptr;
+  }
+  void fini ()
+  {
+    hb_object_fini (this);
+
+    if (likely (items))
+    {
+      unsigned size = mask + 1;
+      if (!item_t::is_trivial)
+	for (unsigned i = 0; i < size; i++)
+	  items[i].~item_t ();
+      hb_free (items);
+      items = nullptr;
+    }
+    population = occupancy = 0;
+  }
+
+  void reset ()
+  {
+    successful = true;
+    clear ();
+  }
+
+  bool in_error () const { return !successful; }
+
+  bool alloc (unsigned new_population = 0)
+  {
+    if (unlikely (!successful)) return false;
+
+    if (new_population != 0 && (new_population + new_population / 2) < mask) return true;
+
+    unsigned int power = hb_bit_storage (hb_max ((unsigned) population, new_population) * 2 + 8);
+    unsigned int new_size = 1u << power;
+    item_t *new_items = (item_t *) hb_malloc ((size_t) new_size * sizeof (item_t));
+    if (unlikely (!new_items))
+    {
+      successful = false;
+      return false;
+    }
+    if (!item_t::is_trivial)
+      for (auto &_ : hb_iter (new_items, new_size))
+	new (&_) item_t ();
+    else
+      hb_memset (new_items, 0, (size_t) new_size * sizeof (item_t));
+
+    unsigned int old_size = size ();
+    item_t *old_items = items;
+
+    /* Switch to new, empty, array. */
+    population = occupancy = 0;
+    mask = new_size - 1;
+    prime = prime_for (power);
+    max_chain_length = power * 2;
+    items = new_items;
+
+    /* Insert back old items. */
+    for (unsigned int i = 0; i < old_size; i++)
+    {
+      if (old_items[i].is_real ())
+      {
+	set_with_hash (std::move (old_items[i].key),
+		       old_items[i].hash,
+		       std::move (old_items[i].value));
+      }
+    }
+    if (!item_t::is_trivial)
+      for (unsigned int i = 0; i < old_size; i++)
+	old_items[i].~item_t ();
+
+    hb_free (old_items);
+
+    return true;
+  }
+
+  template <typename KK, typename VV>
+  bool set_with_hash (KK&& key, uint32_t hash, VV&& value, bool overwrite = true)
+  {
+    if (unlikely (!successful)) return false;
+    if (unlikely ((occupancy + occupancy / 2) >= mask && !alloc ())) return false;
+
+    hash &= 0x3FFFFFFF; // We only store lower 30bit of hash
+    unsigned int tombstone = (unsigned int) -1;
+    unsigned int i = hash % prime;
+    unsigned length = 0;
+    unsigned step = 0;
+    while (items[i].is_used ())
+    {
+      if ((std::is_integral<K>::value || items[i].hash == hash) &&
+	  items[i] == key)
+      {
+        if (!overwrite)
+	  return false;
+        else
+	  break;
+      }
+      if (!items[i].is_real () && tombstone == (unsigned) -1)
+        tombstone = i;
+      i = (i + ++step) & mask;
+      length++;
+    }
+
+    item_t &item = items[tombstone == (unsigned) -1 ? i : tombstone];
+
+    if (item.is_used ())
+    {
+      occupancy--;
+      population -= item.is_real ();
+    }
+
+    item.key = std::forward<KK> (key);
+    item.value = std::forward<VV> (value);
+    item.hash = hash;
+    item.set_used (true);
+    item.set_real (true);
+
+    occupancy++;
+    population++;
+
+    if (unlikely (length > max_chain_length) && occupancy * 8 > mask)
+      alloc (mask - 8); // This ensures we jump to next larger size
+
+    return true;
+  }
+
+  template <typename VV>
+  bool set (const K &key, VV&& value, bool overwrite = true) { return set_with_hash (key, hb_hash (key), std::forward<VV> (value), overwrite); }
+  template <typename VV>
+  bool set (K &&key, VV&& value, bool overwrite = true)
+  {
+    uint32_t hash = hb_hash (key);
+    return set_with_hash (std::move (key), hash, std::forward<VV> (value), overwrite);
+  }
+  bool add (const K &key)
+  {
+    uint32_t hash = hb_hash (key);
+    return set_with_hash (key, hash, item_t::default_value ());
+  }
+
+  const V& get_with_hash (const K &key, uint32_t hash) const
+  {
+    if (!items) return item_t::default_value ();
+    auto *item = fetch_item (key, hb_hash (key));
+    if (item)
+      return item->value;
+    return item_t::default_value ();
+  }
+  const V& get (const K &key) const
+  {
+    if (!items) return item_t::default_value ();
+    return get_with_hash (key, hb_hash (key));
+  }
+
+  void del (const K &key)
+  {
+    if (!items) return;
+    auto *item = fetch_item (key, hb_hash (key));
+    if (item)
+    {
+      item->set_real (false);
+      population--;
+    }
+  }
+
+  /* Has interface. */
+  const V& operator [] (K k) const { return get (k); }
+  template <typename VV=V>
+  bool has (const K &key, VV **vp = nullptr) const
+  {
+    if (!items) return false;
+    auto *item = fetch_item (key, hb_hash (key));
+    if (item)
+    {
+      if (vp) *vp = std::addressof (item->value);
+      return true;
+    }
+    return false;
+  }
+  item_t *fetch_item (const K &key, uint32_t hash) const
+  {
+    hash &= 0x3FFFFFFF; // We only store lower 30bit of hash
+    unsigned int i = hash % prime;
+    unsigned step = 0;
+    while (items[i].is_used ())
+    {
+      if ((std::is_integral<K>::value || items[i].hash == hash) &&
+	  items[i] == key)
+      {
+	if (items[i].is_real ())
+	  return &items[i];
+	else
+	  return nullptr;
+      }
+      i = (i + ++step) & mask;
+    }
+    return nullptr;
+  }
+  /* Projection. */
+  const V& operator () (K k) const { return get (k); }
+
+  unsigned size () const { return mask ? mask + 1 : 0; }
+
+  void clear ()
+  {
+    if (unlikely (!successful)) return;
+
+    for (auto &_ : hb_iter (items, size ()))
+    {
+      /* Reconstruct items. */
+      _.~item_t ();
+      new (&_) item_t ();
+    }
+
+    population = occupancy = 0;
+  }
+
+  bool is_empty () const { return population == 0; }
+  explicit operator bool () const { return !is_empty (); }
+
+  uint32_t hash () const
+  {
+    return
+    + iter_items ()
+    | hb_reduce ([] (uint32_t h, const item_t &_) { return h ^ _.total_hash (); }, (uint32_t) 0u)
+    ;
+  }
+
+  bool is_equal (const hb_hashmap_t &other) const
+  {
+    if (population != other.population) return false;
+
+    for (auto pair : iter ())
+      if (other.get (pair.first) != pair.second)
+        return false;
+
+    return true;
+  }
+  bool operator == (const hb_hashmap_t &other) const { return is_equal (other); }
+  bool operator != (const hb_hashmap_t &other) const { return !is_equal (other); }
+
+  unsigned int get_population () const { return population; }
+
+  void update (const hb_hashmap_t &other)
+  {
+    if (unlikely (!successful)) return;
+
+    hb_copy (other, *this);
+  }
+
+  /*
+   * Iterator
+   */
+
+  auto iter_items () const HB_AUTO_RETURN
+  (
+    + hb_iter (items, this->size ())
+    | hb_filter (&item_t::is_real)
+  )
+  auto iter_ref () const HB_AUTO_RETURN
+  (
+    + this->iter_items ()
+    | hb_map (&item_t::get_pair_ref)
+  )
+  auto iter () const HB_AUTO_RETURN
+  (
+    + this->iter_items ()
+    | hb_map (&item_t::get_pair)
+  )
+  auto keys_ref () const HB_AUTO_RETURN
+  (
+    + this->iter_items ()
+    | hb_map (&item_t::get_key)
+  )
+  auto keys () const HB_AUTO_RETURN
+  (
+    + this->keys_ref ()
+    | hb_map (hb_ridentity)
+  )
+  auto values_ref () const HB_AUTO_RETURN
+  (
+    + this->iter_items ()
+    | hb_map (&item_t::get_value)
+  )
+  auto values () const HB_AUTO_RETURN
+  (
+    + this->values_ref ()
+    | hb_map (hb_ridentity)
+  )
+
+  /* C iterator. */
+  bool next (int *idx,
+	     K *key,
+	     V *value) const
+  {
+    unsigned i = (unsigned) (*idx + 1);
+
+    unsigned count = size ();
+    while (i < count && !items[i].is_real ())
+      i++;
+
+    if (i >= count)
+    {
+      *idx = -1;
+      return false;
+    }
+
+    *key = items[i].key;
+    *value = items[i].value;
+
+    *idx = (signed) i;
+    return true;
+  }
+
+  /* Sink interface. */
+  hb_hashmap_t& operator << (const hb_pair_t<K, V>& v)
+  { set (v.first, v.second); return *this; }
+  hb_hashmap_t& operator << (const hb_pair_t<K, V&&>& v)
+  { set (v.first, std::move (v.second)); return *this; }
+  hb_hashmap_t& operator << (const hb_pair_t<K&&, V>& v)
+  { set (std::move (v.first), v.second); return *this; }
+  hb_hashmap_t& operator << (const hb_pair_t<K&&, V&&>& v)
+  { set (std::move (v.first), std::move (v.second)); return *this; }
+
+  static unsigned int prime_for (unsigned int shift)
+  {
+    /* Following comment and table copied from glib. */
+    /* Each table size has an associated prime modulo (the first prime
+     * lower than the table size) used to find the initial bucket. Probing
+     * then works modulo 2^n. The prime modulo is necessary to get a
+     * good distribution with poor hash functions.
+     */
+    /* Not declaring static to make all kinds of compilers happy... */
+    /*static*/ const unsigned int prime_mod [32] =
+    {
+      1,          /* For 1 << 0 */
+      2,
+      3,
+      7,
+      13,
+      31,
+      61,
+      127,
+      251,
+      509,
+      1021,
+      2039,
+      4093,
+      8191,
+      16381,
+      32749,
+      65521,      /* For 1 << 16 */
+      131071,
+      262139,
+      524287,
+      1048573,
+      2097143,
+      4194301,
+      8388593,
+      16777213,
+      33554393,
+      67108859,
+      134217689,
+      268435399,
+      536870909,
+      1073741789,
+      2147483647  /* For 1 << 31 */
+    };
+
+    if (unlikely (shift >= ARRAY_LENGTH (prime_mod)))
+      return prime_mod[ARRAY_LENGTH (prime_mod) - 1];
+
+    return prime_mod[shift];
+  }
+};
+
+/*
+ * hb_map_t
+ */
+
+struct hb_map_t : hb_hashmap_t<hb_codepoint_t,
+			       hb_codepoint_t,
+			       true>
+{
+  using hashmap = hb_hashmap_t<hb_codepoint_t,
+			       hb_codepoint_t,
+			       true>;
+
+  ~hb_map_t () = default;
+  hb_map_t () : hashmap () {}
+  hb_map_t (const hb_map_t &o) : hashmap ((hashmap &) o) {}
+  hb_map_t (hb_map_t &&o)  noexcept : hashmap (std::move ((hashmap &) o)) {}
+  hb_map_t& operator= (const hb_map_t&) = default;
+  hb_map_t& operator= (hb_map_t&&) = default;
+  hb_map_t (std::initializer_list<hb_codepoint_pair_t> lst) : hashmap (lst) {}
+  template <typename Iterable,
+	    hb_requires (hb_is_iterable (Iterable))>
+  hb_map_t (const Iterable &o) : hashmap (o) {}
+};
+
+
+#endif /* HB_MAP_HH */