Atmosphere/libraries/libvapours/include/vapours/util/util_bounded_map.hpp
2021-07-08 02:37:26 -07:00

130 lines
4.2 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vapours/common.hpp>
#include <vapours/assert.hpp>
#include <vapours/util/util_typed_storage.hpp>
namespace ams::util {
template<class Key, class Value, size_t N>
class BoundedMap {
private:
std::array<util::optional<Key>, N> keys;
std::array<TypedStorage<Value>, N> values;
private:
ALWAYS_INLINE void FreeEntry(size_t i) {
this->keys[i].reset();
DestroyAt(this->values[i]);
}
public:
constexpr BoundedMap() : keys(), values() { /* ... */ }
Value *Find(const Key &key) {
for (size_t i = 0; i < N; i++) {
if (this->keys[i] && this->keys[i].value() == key) {
return GetPointer(this->values[i]);
}
}
return nullptr;
}
void Remove(const Key &key) {
for (size_t i = 0; i < N; i++) {
if (this->keys[i] && this->keys[i].value() == key) {
this->FreeEntry(i);
break;
}
}
}
void RemoveAll() {
for (size_t i = 0; i < N; i++) {
this->FreeEntry(i);
}
}
bool IsFull() {
for (size_t i = 0; i < N; i++) {
if (!this->keys[i]) {
return false;
}
}
return true;
}
bool Insert(const Key &key, Value &&value) {
/* We can't insert if the key is used. */
if (this->Find(key) != nullptr) {
return false;
}
/* Find a free value. */
for (size_t i = 0; i < N; i++) {
if (!this->keys[i]) {
this->keys[i] = key;
ConstructAt(this->values[i], std::forward<Value>(value));
return true;
}
}
return false;
}
bool InsertOrAssign(const Key &key, Value &&value) {
/* Try to find and assign an existing value. */
for (size_t i = 0; i < N; i++) {
if (this->keys[i] && this->keys[i].value() == key) {
GetReference(this->values[i]) = std::forward<Value>(value);
return true;
}
}
/* Find a free value. */
for (size_t i = 0; i < N; i++) {
if (!this->keys[i]) {
this->keys[i] = key;
ConstructAt(this->values[i], std::move(value));
return true;
}
}
return false;
}
template<class... Args>
bool Emplace(const Key &key, Args&&... args) {
/* We can't emplace if the key is used. */
if (this->Find(key) != nullptr) {
return false;
}
/* Find a free value. */
for (size_t i = 0; i < N; i++) {
if (!this->keys[i]) {
this->keys[i] = key;
ConstructAt(this->values[i], std::forward<Args>(args)...);
return true;
}
}
return false;
}
};
}