text: // Copyright (c) 2012-2013 The PPCoin developers
  // Copyright (c) 2015 The HoldCoin developers
  // Copyright (c) 2016 The AlohaCoin developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  #ifndef ALOHACOIN_KERNEL_H
  #define ALOHACOIN_KERNEL_H
  
  #include "main.h"
  
  // MODIFIER_INTERVAL: time to elapse before new modifier is computed
  static const unsigned int MODIFIER_INTERVAL = 6 * 60 * 60;
  extern unsigned int nModifierInterval;
  
  // MODIFIER_INTERVAL_RATIO:
  // ratio of group interval length between the last group and the first group
  static const int MODIFIER_INTERVAL_RATIO = 3;
  
  // Protocol switch time of v0.3 kernel protocol
  extern unsigned int nProtocolV03SwitchTime;
  extern unsigned int nProtocolV03TestSwitchTime;
  // TxDB upgrade time for v0.4 protocol
  extern unsigned int nProtocolV04UpgradeTime;
  
  // Whether a given coinstake is subject to new v0.3 protocol
  bool IsProtocolV03(unsigned int nTimeCoinStake);
  // Whether a given block is subject to new v0.4 protocol
  bool IsProtocolV04(unsigned int nTimeBlock);
  
  // Compute the hash modifier for proof-of-stake
  bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64& nStakeModifier, bool& fGeneratedStakeModifier);
  
  // Check whether stake kernel meets hash target
  // Sets hashProofOfStake on success return
  bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, unsigned int nTxPrevOffset, const CTransaction& txPrev, const COutPoint& prevout, unsigned int nTimeTx, uint256& hashProofOfStake, bool fPrintProofOfStake=false);
  
  // Check kernel hash target and coinstake signature
  // Sets hashProofOfStake on success return
  bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hashProofOfStake);
  
  // Check whether the coinstake timestamp meets protocol
  bool CheckCoinStakeTimestamp(int64 nTimeBlock, int64 nTimeTx);
  
  // Get stake modifier checksum
  unsigned int GetStakeModifierChecksum(const CBlockIndex* pindex);
  
  // Check stake modifier hard checkpoints
  bool CheckStakeModifierCheckpoints(int nHeight, unsigned int nStakeModifierChecksum);
  
  #endif // ALOHACOIN_KERNEL_H
  