heappage.h

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/*
 * SwatDB
 *
 * @authors: See Contributors.doc for code contributors
 *
 * Copyright (c) 2020 Swarthmore College Computer Science Department
 * Swarthmore PA, Professors Tia Newhall, Ameet Soni
 */
 
// @@@@ SWATDB_ASSIGNMENT: ADDTODODATE
 
#ifndef  _SWATDB_HEAPPAGE_H_
#define  _SWATDB_HEAPPAGE_H_
 
 
#include <cstddef>
#include <mutex>
#include "swatdb_types.h"
#include "page.h"
 
class Data;
 
class HeapPage;
 
struct HeapPageHeader{
 
  PageNum prev_page;
 
  PageNum next_page;
 
  std::uint32_t free_space_begin;
 
  std::uint32_t free_space_end;
 
  std::uint32_t size;
 
  std::uint32_t capacity;
};
 
struct SlotInfo{
 
  uint32_t offset;
 
  uint32_t length;
};
 
class HeapPage : public Page {
 
  friend class HeapPageScanner;
 
  public:
 
    HeapPage() = delete;
 
    ~HeapPage() {}
 
    void initializeHeader();
 
    void setNext(PageNum page_num);
 
    void setPrev(PageNum page_num);
 
    PageNum getNext();
 
    PageNum getPrev();
 
 
    std::uint32_t getFreeSpace();
 
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
    void zeroFreeSpace();
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
 
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
     // @post true is returned if used space/PAGE_SIZE exceeds 
     // MAX_HEAP_PAGE_LOAD and false is returned otherwise.
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
    bool isFull();
 
    bool isEmpty();
 
    SlotId insertRecord(Data *record_data);
 
    void getRecord(SlotId slot_id, Data *data);
 
    void deleteRecord(SlotId slot_id);
 
    void updateRecord(SlotId slot_id, Data  *record_data);
 
    HeapPageHeader getHeader();
 
    SlotInfo getSlotInfo(SlotId slot_id);
 
    std::uint32_t getInvalidNum();
 
    void printHeapPageState();
 
    // @@@@ SWATDB_ASSIGNMENT: CUT_START 
    void removeAll();
    // @@@@ SWATDB_ASSIGNMENT: CUT_END 
 
    std::uint32_t getNumRecs();
 
  private:
 
    HeapPageHeader* _getPageHeader();
 
    SlotInfo* _getSlotDirectory();
 
    // @@@@ SWATDB_ASSIGNMENT: CUT_START 
    SlotId _getFreeSlot();
    // @@@@ SWATDB_ASSIGNMENT: CUT_END 
 
    SlotInfo* _getSlotInfo(SlotId slot_id);
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
    // @@@@ SWATDB_ASSIGNMENT: CUT_END 
    void _insertRecord(SlotId slot_id, Data* record_data);
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
 
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
     //If free_space_end is less than the slot offset of the corresponding
     //    slot info, the records to the left of the record to be deleted are
     //    shifted to right by the size of the deleted record, effectively
     //    compactifying space occupied by the records. The slot offset of all
     //    shifted records are updated accordingly. free_space_end is
     //    incremented by the size of the deleted record. Page header size is
     //    decremented.
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
    void _deleteRecord(SlotId slot_id);
     // @@@@ SWATDB_ASSIGNMENT: CUT_START 
     // @@@@ SWATDB_ASSIGNMENT: CUT_END 
 
};
 
#endif