| /* |
| * 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" |
| |
| |
| /* |
| * hb_hashmap_t |
| */ |
| |
| template <typename K, typename V, |
| K kINVALID = hb_is_pointer (K) ? 0 : std::is_signed<K>::value ? hb_int_min (K) : (K) -1, |
| V vINVALID = hb_is_pointer (V) ? 0 : std::is_signed<V>::value ? hb_int_min (V) : (V) -1> |
| struct hb_hashmap_t |
| { |
| hb_hashmap_t () { init (); } |
| ~hb_hashmap_t () { fini (); } |
| |
| hb_hashmap_t (const hb_hashmap_t& o) : hb_hashmap_t () { hb_copy (o, *this); } |
| hb_hashmap_t (hb_hashmap_t&& o) : hb_hashmap_t () { hb_swap (*this, o); } |
| hb_hashmap_t& operator= (const hb_hashmap_t&& o) { hb_copy (o, *this); return *this; } |
| hb_hashmap_t& operator= (hb_hashmap_t&& o) { 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 () |
| { |
| hb_copy (o, *this); |
| } |
| |
| static_assert (std::is_integral<K>::value || hb_is_pointer (K), ""); |
| static_assert (std::is_integral<V>::value || hb_is_pointer (V), ""); |
| |
| struct item_t |
| { |
| K key; |
| V value; |
| uint32_t hash; |
| |
| void clear () { key = kINVALID; value = vINVALID; hash = 0; } |
| |
| bool operator == (const K &o) { return hb_deref (key) == hb_deref (o); } |
| bool operator == (const item_t &o) { return *this == o.key; } |
| bool is_unused () const { return key == kINVALID; } |
| bool is_tombstone () const { return key != kINVALID && value == vINVALID; } |
| bool is_real () const { return key != kINVALID && value != vINVALID; } |
| hb_pair_t<K, V> get_pair() const { return hb_pair_t<K, V> (key, value); } |
| }; |
| |
| hb_object_header_t header; |
| bool successful; /* Allocations successful */ |
| 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) |
| { |
| if (unlikely (!a.successful || !b.successful)) |
| return; |
| 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_shallow () |
| { |
| successful = true; |
| population = occupancy = 0; |
| mask = 0; |
| prime = 0; |
| items = nullptr; |
| } |
| void init () |
| { |
| hb_object_init (this); |
| init_shallow (); |
| } |
| void fini_shallow () |
| { |
| hb_free (items); |
| items = nullptr; |
| population = occupancy = 0; |
| } |
| void fini () |
| { |
| hb_object_fini (this); |
| fini_shallow (); |
| } |
| |
| void reset () |
| { |
| successful = true; |
| clear (); |
| } |
| |
| bool in_error () const { return !successful; } |
| |
| bool resize () |
| { |
| if (unlikely (!successful)) return false; |
| |
| unsigned int power = hb_bit_storage (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; |
| } |
| for (auto &_ : hb_iter (new_items, new_size)) |
| _.clear (); |
| |
| unsigned int old_size = mask + 1; |
| item_t *old_items = items; |
| |
| /* Switch to new, empty, array. */ |
| population = occupancy = 0; |
| mask = new_size - 1; |
| prime = prime_for (power); |
| items = new_items; |
| |
| /* Insert back old items. */ |
| if (old_items) |
| for (unsigned int i = 0; i < old_size; i++) |
| if (old_items[i].is_real ()) |
| set_with_hash (old_items[i].key, |
| old_items[i].hash, |
| std::move (old_items[i].value)); |
| |
| hb_free (old_items); |
| |
| return true; |
| } |
| |
| bool set (K key, const V& value) { return set_with_hash (key, hb_hash (key), value); } |
| bool set (K key, V&& value) { return set_with_hash (key, hb_hash (key), std::move (value)); } |
| |
| V get (K key) const |
| { |
| if (unlikely (!items)) return vINVALID; |
| unsigned int i = bucket_for (key); |
| return items[i].is_real () && items[i] == key ? items[i].value : vINVALID; |
| } |
| |
| void del (K key) { set (key, vINVALID); } |
| |
| /* Has interface. */ |
| static constexpr V SENTINEL = vINVALID; |
| typedef V value_t; |
| value_t operator [] (K k) const { return get (k); } |
| bool has (K k, V *vp = nullptr) const |
| { |
| V v = (*this)[k]; |
| if (vp) *vp = v; |
| return v != SENTINEL; |
| } |
| /* Projection. */ |
| V operator () (K k) const { return get (k); } |
| |
| void clear () |
| { |
| if (unlikely (!successful)) return; |
| |
| if (items) |
| for (auto &_ : hb_iter (items, mask + 1)) |
| _.clear (); |
| |
| population = occupancy = 0; |
| } |
| |
| bool is_empty () const { return population == 0; } |
| explicit operator bool () const { return !is_empty (); } |
| |
| unsigned int get_population () const { return population; } |
| |
| /* |
| * Iterator |
| */ |
| auto iter () const HB_AUTO_RETURN |
| ( |
| + hb_array (items, mask ? mask + 1 : 0) |
| | hb_filter (&item_t::is_real) |
| | hb_map (&item_t::get_pair) |
| ) |
| auto keys () const HB_AUTO_RETURN |
| ( |
| + hb_array (items, mask ? mask + 1 : 0) |
| | hb_filter (&item_t::is_real) |
| | hb_map (&item_t::key) |
| | hb_map (hb_ridentity) |
| ) |
| auto values () const HB_AUTO_RETURN |
| ( |
| + hb_array (items, mask ? mask + 1 : 0) |
| | hb_filter (&item_t::is_real) |
| | hb_map (&item_t::value) |
| | hb_map (hb_ridentity) |
| ) |
| |
| /* Sink interface. */ |
| hb_hashmap_t& operator << (const hb_pair_t<K, V>& v) |
| { set (v.first, v.second); return *this; } |
| |
| protected: |
| |
| template <typename VV> |
| bool set_with_hash (K key, uint32_t hash, VV&& value) |
| { |
| if (unlikely (!successful)) return false; |
| if (unlikely (key == kINVALID)) return true; |
| if (unlikely ((occupancy + occupancy / 2) >= mask && !resize ())) return false; |
| unsigned int i = bucket_for_hash (key, hash); |
| |
| if (value == vINVALID && items[i].key != key) |
| return true; /* Trying to delete non-existent key. */ |
| |
| if (!items[i].is_unused ()) |
| { |
| occupancy--; |
| if (!items[i].is_tombstone ()) |
| population--; |
| } |
| |
| items[i].key = key; |
| items[i].value = value; |
| items[i].hash = hash; |
| |
| occupancy++; |
| if (!items[i].is_tombstone ()) |
| population++; |
| |
| return true; |
| } |
| |
| unsigned int bucket_for (K key) const |
| { |
| return bucket_for_hash (key, hb_hash (key)); |
| } |
| |
| unsigned int bucket_for_hash (K key, uint32_t hash) const |
| { |
| unsigned int i = hash % prime; |
| unsigned int step = 0; |
| unsigned int tombstone = (unsigned) -1; |
| while (!items[i].is_unused ()) |
| { |
| if (items[i].hash == hash && items[i] == key) |
| return i; |
| if (tombstone == (unsigned) -1 && items[i].is_tombstone ()) |
| tombstone = i; |
| i = (i + ++step) & mask; |
| } |
| return tombstone == (unsigned) -1 ? i : tombstone; |
| } |
| |
| 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, |
| HB_MAP_VALUE_INVALID, |
| HB_MAP_VALUE_INVALID> |
| { |
| using hashmap = hb_hashmap_t<hb_codepoint_t, |
| hb_codepoint_t, |
| HB_MAP_VALUE_INVALID, |
| HB_MAP_VALUE_INVALID>; |
| |
| hb_map_t () = default; |
| ~hb_map_t () = default; |
| hb_map_t (hb_map_t& o) = default; |
| hb_map_t& operator= (const hb_map_t& other) = default; |
| hb_map_t& operator= (hb_map_t&& other) = default; |
| hb_map_t (std::initializer_list<hb_pair_t<hb_codepoint_t, hb_codepoint_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 */ |