text: // Copyright (c) 2018, The TurtleCoin Developers
  // Copyright (c) 2018, The Plenteum Developers
  // 
  // Please see the included LICENSE file for more information.
  
  #pragma once
  
  #include "CryptoTypes.h"
  
  #include <deque>
  
  #include "json.hpp"
  
  #include <vector>
  
  using nlohmann::json;
  
  class SynchronizationStatus
  {
      public:
  
          /////////////////////////////
          /* Public member functions */
          /////////////////////////////
  
          void storeBlockHash(
              const Crypto::Hash hash,
              const uint64_t blockHeight);
  
          std::vector<Crypto::Hash> getBlockHashCheckpoints() const;
  
          json toJson() const;
  
          void fromJson(const json &j);
  
          uint64_t getHeight() const;
  
      private:
  
          //////////////////////////////
          /* Private member variables */
          //////////////////////////////
  
          /* A store of block hashes (later blocks first, i.e. block 2 comes
             before block 1) These are stored every 5000 blocks or so, used
             for knowing where to resume sync from. We store these in addition
             to the most 100 recent blocks, in the case of deep forks. */
          std::deque<Crypto::Hash> m_blockHashCheckpoints;
  
          /* A double ended queue of the 100 most recently synced block hashes,
             used for knowing where to begin syncing from. Newer hashes come
             before older ones, so block 2 is in front of block 1 in the list. */
          std::deque<Crypto::Hash> m_lastKnownBlockHashes;
  
          /* The last block height we are aware of */
          uint64_t m_lastKnownBlockHeight = 0;
  };
  