85 lines
3.0 KiB
C
85 lines
3.0 KiB
C
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/*------------------------------------------------------------------------------*
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* Architecture & Implementation of DBMS *
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*------------------------------------------------------------------------------*
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* Copyright 2022 Databases and Information Systems Group TU Dortmund *
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* Visit us at *
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* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
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* *
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
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* OTHER DEALINGS IN THE SOFTWARE. *
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* *
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* Authors: *
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* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
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* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
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* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
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*------------------------------------------------------------------------------*
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*/
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#pragma once
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#include "page.h"
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#include <atomic>
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#include <cstddef>
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#include <cstdint>
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#include <fstream>
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#include <string>
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namespace beedb::storage
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{
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/**
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* The StorageManager grants access to the data written to the disk.
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*/
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class Manager
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{
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public:
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explicit Manager(const std::string &file_name);
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~Manager();
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/**
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* Copy a page from disk to memory.
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*
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* @param page_id Id of the page.
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* @param buffer Location where to store the data in memory.
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*/
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void read(Page::id_t page_id, std::byte *buffer);
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/**
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* Write the page from memory to disk.
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*
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* @param page_id Page to be written.
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* @param data Location in memory of the data to write to disk.
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*/
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void write(Page::id_t page_id, const std::byte *data);
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/**
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* Allocates a new page in the disk file and extends the
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* file by the new allocated page.
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*
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* @return Id of the new allocated page.
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*/
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template <typename P> Page::id_t allocate()
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{
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const auto page_id = this->_count_pages.fetch_add(1);
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P page;
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this->write(page_id, page.data());
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return page_id;
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}
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/**
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* @return Number of pages stored in the disk file.
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*/
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[[nodiscard]] std::size_t count_pages() const
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{
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return _count_pages;
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}
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private:
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std::atomic_size_t _count_pages = 0u;
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std::fstream _storage_file;
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};
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} // namespace beedb::storage
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