55 lines
2.4 KiB
C++
55 lines
2.4 KiB
C++
/*------------------------------------------------------------------------------*
|
|
* Architecture & Implementation of DBMS *
|
|
*------------------------------------------------------------------------------*
|
|
* Copyright 2022 Databases and Information Systems Group TU Dortmund *
|
|
* Visit us at *
|
|
* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
|
|
* *
|
|
* 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. *
|
|
* *
|
|
* Authors: *
|
|
* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
|
|
* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
|
|
* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
|
|
*------------------------------------------------------------------------------*
|
|
*/
|
|
|
|
#pragma once
|
|
#include "replacement_strategy.h"
|
|
#include <list>
|
|
|
|
namespace beedb::buffer
|
|
{
|
|
class LRUKStrategy final : public ReplacementStrategy
|
|
{
|
|
public:
|
|
LRUKStrategy(std::size_t count_frames, std::size_t k);
|
|
~LRUKStrategy() override = default;
|
|
std::size_t find_victim(std::vector<storage::Page> &pages) override;
|
|
void on_pin(std::size_t frame_index, std::size_t timestamp) override;
|
|
|
|
private:
|
|
// Configured K-parameter.
|
|
const std::size_t _k = 0;
|
|
|
|
// List of timestamps for every page.
|
|
std::vector<std::vector<std::size_t>> _history;
|
|
|
|
[[nodiscard]] std::size_t last_timestamp(std::size_t frame_index) const
|
|
{
|
|
if (_history[frame_index].empty())
|
|
{
|
|
return std::numeric_limits<std::size_t>::max();
|
|
}
|
|
|
|
return _history[frame_index].back();
|
|
}
|
|
};
|
|
} // namespace beedb::buffer
|