Hash.h

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 /** \file     Hash.h
     \brief    Hash class (header)
 */


#ifndef __HASH__
#define __HASH__

 // Include files

#include "CommonLib/Buffer.h"
#include "CommonLib/CommonDef.h"
#include "CommonLib/TrQuant.h"
#include "CommonLib/Unit.h"
#include "CommonLib/UnitPartitioner.h"
#include <vector>


struct BlockHash
{
  short x;
  short y;
  uint32_t hashValue2;
};

typedef std::vector<BlockHash>::iterator MapIterator;

// ====================================================================================================================
// Class definitions
// ====================================================================================================================

struct CrcCalculatorLight
{
public:
  CrcCalculatorLight(uint32_t bits, uint32_t truncPoly);
  ~CrcCalculatorLight();

public:
  void     processData(const uint8_t *curData, size_t dataLength);
  void     reset() { m_remainder = 0; }
  uint32_t getCRC() { return m_remainder & m_finalResultMask; }

private:
  void xInitTable();

private:
  uint32_t m_remainder;
  uint32_t m_truncPoly;
  uint32_t m_bits;
  uint32_t m_table[256];
  uint32_t m_finalResultMask;
};

struct Hash
{
  static constexpr int MIN_LOG_BLK_SIZE  = 2;
  static constexpr int MAX_LOG_BLK_SIZE  = 6;
  static constexpr int NUM_LOG_BLK_SIZES = MAX_LOG_BLK_SIZE - MIN_LOG_BLK_SIZE + 1;
  static constexpr int LOG_SIZE_BITS     = 3;
  static_assert(NUM_LOG_BLK_SIZES <= (1 << LOG_SIZE_BITS), "Hash::LOG_SIZE_BITS is too small");

public:
  Hash();
  ~Hash();
  void create(int picWidth, int picHeight);
  void clearAll();
  void addToTable(uint32_t hashValue, const BlockHash& blockHash);
  int count(uint32_t hashValue);
  int count(uint32_t hashValue) const;
  MapIterator getFirstIterator(uint32_t hashValue);
  const MapIterator getFirstIterator(uint32_t hashValue) const;
  bool hasExactMatch(uint32_t hashValue1, uint32_t hashValue2);

  void generateBlock2x2HashValue(const PelUnitBuf &curPicBuf, int picWidth, int picHeight, const BitDepths bitDepths, uint32_t* picBlockHash[2], bool* picBlockSameInfo[3]);
  void generateBlockHashValue(int picWidth, int picHeight, int width, int height, uint32_t* srcPicBlockHash[2], uint32_t* dstPicBlockHash[2], bool* srcPicBlockSameInfo[3], bool* dstPicBlockSameInfo[3]);
  void addToHashMapByRowWithPrecalData(uint32_t* srcHash[2], bool* srcIsSame, int picWidth, int picHeight, int width, int height);
  bool isInitial() { return tableHasContent; }
  void setInitial() { tableHasContent = true; }
  uint16_t *getHashPic(int baseSize) const { return hashPic[floorLog2(baseSize) - MIN_LOG_BLK_SIZE]; }

public:
  static uint32_t getCRCValue1(const uint8_t *p, size_t length);
  static uint32_t getCRCValue2(const uint8_t *p, size_t length);
  static void getPixelsIn1DCharArrayByBlock2x2(const PelUnitBuf &curPicBuf, unsigned char* pixelsIn1D, int xStart, int yStart, const BitDepths& bitDepths, bool includeAllComponent = true);
  static bool isBlock2x2RowSameValue(unsigned char* p, bool includeAllComponent = true);
  static bool isBlock2x2ColSameValue(unsigned char* p, bool includeAllComponent = true);
  static bool getBlockHashValue(const PelUnitBuf &curPicBuf, int width, int height, int xStart, int yStart, const BitDepths bitDepths, uint32_t& hashValue1, uint32_t& hashValue2);
  static void initBlockSizeToIndex();
  static bool     isHorizontalPerfectLuma(const Pel *srcPel, ptrdiff_t stride, int width, int height);
  static bool     isVerticalPerfectLuma(const Pel *srcPel, ptrdiff_t stride, int width, int height);

private:
  std::vector<BlockHash>** m_lookupTable;
  bool tableHasContent;
  std::array<uint16_t *, NUM_LOG_BLK_SIZES> hashPic;   // 4x4 ~ 64x64

private:
  static constexpr int CRC_BITS = 16;

  static int getIndexFromBlockSize(int w, int h)
  {
    if (w != h)
    {
      return -1;
    }
    return w == 4 ? 4 : floorLog2(w) - 3;
  }

  static CrcCalculatorLight m_crcCalculator1;
  static CrcCalculatorLight m_crcCalculator2;
};

#endif // __HASH__