1 // Copyright (c) 2012-2013 The PPCoin developers
2 // Distributed under the MIT/X11 software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 #ifndef PPCOIN_KERNEL_H
5 #define PPCOIN_KERNEL_H
9 extern unsigned int nStakeMaxAge;
11 // ChainDB upgrade time
12 extern unsigned int nModifierUpgradeTime;
14 // MODIFIER_INTERVAL: time to elapse before new modifier is computed
15 extern unsigned int nModifierInterval;
17 // MODIFIER_INTERVAL_RATIO:
18 // ratio of group interval length between the last group and the first group
19 static const int MODIFIER_INTERVAL_RATIO = 3;
21 // Whether the given block is subject to new modifier protocol
22 bool IsFixedModifierInterval(unsigned int nTimeBlock);
24 // Compute the hash modifier for proof-of-stake
25 bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64_t& nStakeModifier, bool& fGeneratedStakeModifier);
27 // The stake modifier used to hash for a stake kernel is chosen as the stake
28 // modifier about a selection interval later than the coin generating the kernel
29 bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64_t& nStakeModifier);
31 // Check whether stake kernel meets hash target
32 // Sets hashProofOfStake on success return
33 bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, uint32_t nTxPrevOffset, const CTransaction& txPrev, const COutPoint& prevout, uint32_t nTimeTx, uint256& hashProofOfStake, uint256& targetProofOfStake, bool fPrintProofOfStake=false);
35 // Scan given kernel for solutions
36 bool ScanKernelForward(unsigned char *kernel, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair<uint32_t, uint32_t> &SearchInterval, std::vector<std::pair<uint256, uint32_t> > &solutions);
38 // Check kernel hash target and coinstake signature
39 // Sets hashProofOfStake on success return
40 bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hashProofOfStake, uint256& targetProofOfStake);
42 // Get stake modifier checksum
43 uint32_t GetStakeModifierChecksum(const CBlockIndex* pindex);
45 // Check stake modifier hard checkpoints
46 bool CheckStakeModifierCheckpoints(int nHeight, uint32_t nStakeModifierChecksum);
48 // Get time weight using supplied timestamps
49 inline int64_t GetWeight(int64_t nIntervalBeginning, int64_t nIntervalEnd)
51 // Kernel hash weight starts from 0 at the 30-day min age
52 // this change increases active coins participating the hash and helps
53 // to secure the network when proof-of-stake difficulty is low
55 // Maximum TimeWeight is 90 days.
57 return std::min(nIntervalEnd - nIntervalBeginning - nStakeMinAge, (int64_t)nStakeMaxAge);
60 #endif // PPCOIN_KERNEL_H