128 lines
4.0 KiB
C++
128 lines
4.0 KiB
C++
/*************************************************************************/
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/* lru.h */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* https://godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
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/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#ifndef LRU_H
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#define LRU_H
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#include "core/math/math_funcs.h"
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#include "hash_map.h"
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#include "list.h"
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template <class TKey, class TData, class Hasher = HashMapHasherDefault, class Comparator = HashMapComparatorDefault<TKey>>
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class LRUCache {
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private:
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struct Pair {
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TKey key;
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TData data;
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Pair() {}
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Pair(const TKey &p_key, const TData &p_data) :
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key(p_key),
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data(p_data) {
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}
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};
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typedef typename List<Pair>::Element *Element;
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List<Pair> _list;
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HashMap<TKey, Element, Hasher, Comparator> _map;
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size_t capacity;
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public:
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const TData *insert(const TKey &p_key, const TData &p_value) {
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Element *e = _map.getptr(p_key);
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Element n = _list.push_front(Pair(p_key, p_value));
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if (e) {
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_list.erase(*e);
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_map.erase(p_key);
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}
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_map[p_key] = _list.front();
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while (_map.size() > capacity) {
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Element d = _list.back();
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_map.erase(d->get().key);
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_list.pop_back();
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}
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return &n->get().data;
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}
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void clear() {
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_map.clear();
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_list.clear();
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}
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bool has(const TKey &p_key) const {
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return _map.getptr(p_key);
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}
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const TData &get(const TKey &p_key) {
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Element *e = _map.getptr(p_key);
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CRASH_COND(!e);
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_list.move_to_front(*e);
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return (*e)->get().data;
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};
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const TData *getptr(const TKey &p_key) {
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Element *e = _map.getptr(p_key);
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if (!e) {
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return nullptr;
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} else {
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_list.move_to_front(*e);
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return &(*e)->get().data;
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}
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}
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_FORCE_INLINE_ size_t get_capacity() const { return capacity; }
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_FORCE_INLINE_ size_t get_size() const { return _map.size(); }
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void set_capacity(size_t p_capacity) {
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if (capacity > 0) {
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capacity = p_capacity;
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while (_map.size() > capacity) {
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Element d = _list.back();
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_map.erase(d->get().key);
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_list.pop_back();
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}
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}
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}
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LRUCache() {
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capacity = 64;
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}
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LRUCache(int p_capacity) {
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capacity = p_capacity;
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}
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};
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#endif
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