beedb/include/buffer/lru_strategy.h

43 lines
2.1 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"
namespace beedb::buffer
{
/**
* Replaces the last recently used frame.
*/
class LRUStrategy final : public ReplacementStrategy
{
public:
LRUStrategy(std::size_t count_frames);
~LRUStrategy() 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:
std::vector<std::size_t> _last_pin_timestamps;
};
} // namespace beedb::buffer