DBMS/Buffer.hpp at main · bodyhedia44/DBMS · GitHub

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#ifndef BUFFER_PAGE_HPP
#define BUFFER_PAGE_HPP

#include <iomanip>
#include <vector>
#include <unordered_map>
#include <iostream>
#include <fstream>
#include <cstring>

#define PAGE_SIZE 4096


enum PageType {
    INDEX_PAGE,
    DATA_PAGE
};


class Buffer_Page {
public:
    int pageId;
    PageType type;
    bool referenceBit;
    bool dirtyBit;
    int pinCount;
    char data[PAGE_SIZE];


    Buffer_Page(int id, PageType t);


    void writeToDisk();


    static Buffer_Page* readFromDisk(int pageId, PageType type);
};


class BufferPool {
private:
    int bufferSize;
    std::vector<Buffer_Page*> bufferPool;
    std::unordered_map<int, Buffer_Page*> pageTable;
    int clockHand;

public:

    BufferPool(int size);


    ~BufferPool();


    Buffer_Page* requestPage(int pageId, PageType type, bool isWrite = false);


    void releasePage(int pageId);


    void displayBufferPool() const;


    int getNewPageId();

private:

    Buffer_Page* replacePage(int pageId, PageType type, bool isWrite);
};

#endif