text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2016-2018 The PIVX developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_TXDB_H
  #define BITCOIN_TXDB_H
  
  #include "leveldbwrapper.h"
  #include "main.h"
  #include "primitives/zerocoin.h"
  
  #include <map>
  #include <string>
  #include <utility>
  #include <vector>
  
  class CCoins;
  class uint256;
  
  //! -dbcache default (MiB)
  static const int64_t nDefaultDbCache = 100;
  //! max. -dbcache in (MiB)
  static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 4096 : 1024;
  //! min. -dbcache in (MiB)
  static const int64_t nMinDbCache = 4;
  
  /** CCoinsView backed by the LevelDB coin database (chainstate/) */
  class CCoinsViewDB : public CCoinsView
  {
  protected:
      CLevelDBWrapper db;
  
  public:
      CCoinsViewDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
  
      bool GetCoins(const uint256& txid, CCoins& coins) const;
      bool HaveCoins(const uint256& txid) const;
      uint256 GetBestBlock() const;
      bool BatchWrite(CCoinsMap& mapCoins, const uint256& hashBlock);
      bool GetStats(CCoinsStats& stats) const;
  };
  
  /** Access to the block database (blocks/index/) */
  class CBlockTreeDB : public CLevelDBWrapper
  {
  public:
      CBlockTreeDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
  
  private:
      CBlockTreeDB(const CBlockTreeDB&);
      void operator=(const CBlockTreeDB&);
  
  public:
      bool WriteBlockIndex(const CDiskBlockIndex& blockindex);
      bool ReadBlockFileInfo(int nFile, CBlockFileInfo& fileinfo);
      bool WriteBlockFileInfo(int nFile, const CBlockFileInfo& fileinfo);
      bool ReadLastBlockFile(int& nFile);
      bool WriteLastBlockFile(int nFile);
      bool WriteReindexing(bool fReindex);
      bool ReadReindexing(bool& fReindex);
      bool ReadTxIndex(const uint256& txid, CDiskTxPos& pos);
      bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> >& list);
      bool WriteFlag(const std::string& name, bool fValue);
      bool ReadFlag(const std::string& name, bool& fValue);
      bool WriteInt(const std::string& name, int nValue);
      bool ReadInt(const std::string& name, int& nValue);
      bool LoadBlockIndexGuts();
  };
  
  /** Zerocoin database (zerocoin/) */
  class CZerocoinDB : public CLevelDBWrapper
  {
  public:
      CZerocoinDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
  
  private:
      CZerocoinDB(const CZerocoinDB&);
      void operator=(const CZerocoinDB&);
  
  public:
      /** Write zCOVID19mints to the zerocoinDB in a batch */
      bool WriteCoinMintBatch(const std::vector<std::pair<libzerocoin::PublicCoin, uint256> >& mintInfo);
      bool ReadCoinMint(const CBigNum& bnPubcoin, uint256& txHash);
      bool ReadCoinMint(const uint256& hashPubcoin, uint256& hashTx);
      /** Write zCOVID19spends to the zerocoinDB in a batch */
      bool WriteCoinSpendBatch(const std::vector<std::pair<libzerocoin::CoinSpend, uint256> >& spendInfo);
      bool ReadCoinSpend(const CBigNum& bnSerial, uint256& txHash);
      bool ReadCoinSpend(const uint256& hashSerial, uint256 &txHash);
      bool EraseCoinMint(const CBigNum& bnPubcoin);
      bool EraseCoinSpend(const CBigNum& bnSerial);
      bool WipeCoins(std::string strType);
      bool WriteAccumulatorValue(const uint32_t& nChecksum, const CBigNum& bnValue);
      bool ReadAccumulatorValue(const uint32_t& nChecksum, CBigNum& bnValue);
      bool EraseAccumulatorValue(const uint32_t& nChecksum);
  };
  
  #endif // BITCOIN_TXDB_H
  