godot/core/templates/ordered_hash_map.h

302 lines
8.7 KiB
C++

/*************************************************************************/
/* ordered_hash_map.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef ORDERED_HASH_MAP_H
#define ORDERED_HASH_MAP_H
#include "core/templates/hash_map.h"
#include "core/templates/list.h"
#include "core/templates/pair.h"
/**
* A hash map which allows to iterate elements in insertion order.
* Insertion, lookup, deletion have O(1) complexity.
* The API aims to be consistent with Map rather than HashMap, because the
* former is more frequently used and is more coherent with the rest of the
* codebase.
* Deletion during iteration is safe and will preserve the order.
*/
template <class K, class V, class Hasher = HashMapHasherDefault, class Comparator = HashMapComparatorDefault<K>, uint8_t MIN_HASH_TABLE_POWER = 3, uint8_t RELATIONSHIP = 8>
class OrderedHashMap {
typedef List<Pair<const K *, V>> InternalList;
typedef HashMap<K, typename InternalList::Element *, Hasher, Comparator, MIN_HASH_TABLE_POWER, RELATIONSHIP> InternalMap;
InternalList list;
InternalMap map;
public:
class Element {
friend class OrderedHashMap<K, V, Hasher, Comparator, MIN_HASH_TABLE_POWER, RELATIONSHIP>;
typename InternalList::Element *list_element = nullptr;
typename InternalList::Element *prev_element = nullptr;
typename InternalList::Element *next_element = nullptr;
Element(typename InternalList::Element *p_element) {
list_element = p_element;
if (list_element) {
next_element = list_element->next();
prev_element = list_element->prev();
}
}
public:
_FORCE_INLINE_ Element() {}
Element next() const {
return Element(next_element);
}
Element prev() const {
return Element(prev_element);
}
Element(const Element &other) :
list_element(other.list_element),
prev_element(other.prev_element),
next_element(other.next_element) {
}
void operator=(const Element &other) {
list_element = other.list_element;
next_element = other.next_element;
prev_element = other.prev_element;
}
_FORCE_INLINE_ bool operator==(const Element &p_other) const {
return this->list_element == p_other.list_element;
}
_FORCE_INLINE_ bool operator!=(const Element &p_other) const {
return this->list_element != p_other.list_element;
}
operator bool() const {
return (list_element != nullptr);
}
const K &key() const {
CRASH_COND(!list_element);
return *(list_element->get().first);
}
V &value() {
CRASH_COND(!list_element);
return list_element->get().second;
}
const V &value() const {
CRASH_COND(!list_element);
return list_element->get().second;
}
V &get() {
CRASH_COND(!list_element);
return list_element->get().second;
}
const V &get() const {
CRASH_COND(!list_element);
return list_element->get().second;
}
};
class ConstElement {
friend class OrderedHashMap<K, V, Hasher, Comparator, MIN_HASH_TABLE_POWER, RELATIONSHIP>;
const typename InternalList::Element *list_element = nullptr;
ConstElement(const typename InternalList::Element *p_element) :
list_element(p_element) {
}
public:
_FORCE_INLINE_ ConstElement() {}
ConstElement(const ConstElement &other) :
list_element(other.list_element) {
}
void operator=(const ConstElement &other) {
list_element = other.list_element;
}
ConstElement next() const {
return ConstElement(list_element ? list_element->next() : nullptr);
}
ConstElement prev() const {
return ConstElement(list_element ? list_element->prev() : nullptr);
}
_FORCE_INLINE_ bool operator==(const ConstElement &p_other) const {
return this->list_element == p_other.list_element;
}
_FORCE_INLINE_ bool operator!=(const ConstElement &p_other) const {
return this->list_element != p_other.list_element;
}
operator bool() const {
return (list_element != nullptr);
}
const K &key() const {
CRASH_COND(!list_element);
return *(list_element->get().first);
}
const V &value() const {
CRASH_COND(!list_element);
return list_element->get().second;
}
const V &get() const {
CRASH_COND(!list_element);
return list_element->get().second;
}
};
ConstElement find(const K &p_key) const {
typename InternalList::Element *const *list_element = map.getptr(p_key);
if (list_element) {
return ConstElement(*list_element);
}
return ConstElement(nullptr);
}
Element find(const K &p_key) {
typename InternalList::Element **list_element = map.getptr(p_key);
if (list_element) {
return Element(*list_element);
}
return Element(nullptr);
}
Element insert(const K &p_key, const V &p_value) {
typename InternalList::Element **list_element = map.getptr(p_key);
if (list_element) {
(*list_element)->get().second = p_value;
return Element(*list_element);
}
// Incorrectly set the first value of the pair with a value that will
// be invalid as soon as we leave this function...
typename InternalList::Element *new_element = list.push_back(Pair<const K *, V>(&p_key, p_value));
// ...this is needed here in case the hashmap recursively reference itself...
typename InternalMap::Element *e = map.set(p_key, new_element);
// ...now we can set the right value !
new_element->get().first = &e->key();
return Element(new_element);
}
void erase(Element &p_element) {
map.erase(p_element.key());
list.erase(p_element.list_element);
p_element.list_element = nullptr;
}
bool erase(const K &p_key) {
typename InternalList::Element **list_element = map.getptr(p_key);
if (list_element) {
list.erase(*list_element);
map.erase(p_key);
return true;
}
return false;
}
inline bool has(const K &p_key) const {
return map.has(p_key);
}
const V &operator[](const K &p_key) const {
ConstElement e = find(p_key);
CRASH_COND(!e);
return e.value();
}
V &operator[](const K &p_key) {
Element e = find(p_key);
if (!e) {
// consistent with Map behaviour
e = insert(p_key, V());
}
return e.value();
}
inline Element front() {
return Element(list.front());
}
inline Element back() {
return Element(list.back());
}
inline ConstElement front() const {
return ConstElement(list.front());
}
inline ConstElement back() const {
return ConstElement(list.back());
}
inline bool is_empty() const { return list.is_empty(); }
inline int size() const { return list.size(); }
const void *id() const {
return list.id();
}
void clear() {
map.clear();
list.clear();
}
private:
void _copy_from(const OrderedHashMap &p_map) {
for (ConstElement E = p_map.front(); E; E = E.next()) {
insert(E.key(), E.value());
}
}
public:
void operator=(const OrderedHashMap &p_map) {
_copy_from(p_map);
}
OrderedHashMap(const OrderedHashMap &p_map) {
_copy_from(p_map);
}
_FORCE_INLINE_ OrderedHashMap() {}
};
#endif // ORDERED_HASH_MAP_H