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/**************************************************************************/
/* lru.h */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* 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 */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#ifndef LRU_H
#define LRU_H
#include "core/math/math_funcs.h"
#include "hash_map.h"
#include "list.h"
template <class TKey, class TData, class Hasher = HashMapHasherDefault, class Comparator = HashMapComparatorDefault<TKey>>
class LRUCache {
private:
struct Pair {
TKey key;
TData data;
Pair() {}
Pair(const TKey &p_key, const TData &p_data) :
key(p_key),
data(p_data) {
}
};
typedef typename List<Pair>::Element *Element;
List<Pair> _list;
HashMap<TKey, Element, Hasher, Comparator> _map;
size_t capacity;
public:
const TData *insert(const TKey &p_key, const TData &p_value) {
Element *e = _map.getptr(p_key);
Element n = _list.push_front(Pair(p_key, p_value));
if (e) {
_list.erase(*e);
_map.erase(p_key);
}
_map[p_key] = _list.front();
while (_map.size() > capacity) {
Element d = _list.back();
_map.erase(d->get().key);
_list.pop_back();
}
return &n->get().data;
}
void clear() {
_map.clear();
_list.clear();
}
bool has(const TKey &p_key) const {
return _map.getptr(p_key);
}
const TData &get(const TKey &p_key) {
Element *e = _map.getptr(p_key);
CRASH_COND(!e);
_list.move_to_front(*e);
return (*e)->get().data;
};
const TData *getptr(const TKey &p_key) {
Element *e = _map.getptr(p_key);
if (!e) {
return nullptr;
} else {
_list.move_to_front(*e);
return &(*e)->get().data;
}
}
_FORCE_INLINE_ size_t get_capacity() const { return capacity; }
_FORCE_INLINE_ size_t get_size() const { return _map.size(); }
void set_capacity(size_t p_capacity) {
if (capacity > 0) {
capacity = p_capacity;
while (_map.size() > capacity) {
Element d = _list.back();
_map.erase(d->get().key);
_list.pop_back();
}
}
}
LRUCache() {
capacity = 64;
}
LRUCache(int p_capacity) {
capacity = p_capacity;
}
};
#endif // LRU_H
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