X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fkernel.cpp;h=ec0803cdbdaa96c56f4af3e9573a9fa5d5fbf72b;hb=a5240a08a7d624d20344344b79441c67311f7fd9;hp=4b03c7fab3b6a4097fbeab875e2f761afaa44aea;hpb=7e9ceb798f2685429f3387625beb872bbda1567c;p=novacoin.git diff --git a/src/kernel.cpp b/src/kernel.cpp index 4b03c7f..ec0803c 100644 --- a/src/kernel.cpp +++ b/src/kernel.cpp @@ -12,6 +12,15 @@ using namespace std; extern int nStakeMaxAge; extern int nStakeTargetSpacing; +// Protocol switch time for fixed kernel modifier interval +unsigned int nModifierSwitchTime = 1413763200; // Mon, 20 Oct 2014 00:00:00 GMT +unsigned int nModifierTestSwitchTime = 1397520000; // Tue, 15 Apr 2014 00:00:00 GMT + +// Note: user must upgrade before the protocol switch deadline, otherwise it's required to +// re-download the blockchain. The timestamp of upgrade is recorded in the blockchain +// database. +unsigned int nModifierUpgradeTime = 0; + typedef std::map MapModifierCheckpoints; // Hard checkpoints of stake modifiers to ensure they are deterministic @@ -22,6 +31,10 @@ static std::map mapStakeModifierCheckpoints = ( 12661, 0x5d84115du ) ( 37092, 0xd230afccu ) ( 44200, 0x05370164u ) + ( 65000, 0xc8e7be6au ) + ( 68600, 0x73a8cc4cu ) + ( 92161, 0xe21a911au ) + ( 98661, 0xd20c44d4u ) ; // Hard checkpoints of stake modifiers to ensure they are deterministic (testNet) @@ -30,6 +43,24 @@ static std::map mapStakeModifierCheckpointsTestNet = ( 0, 0x0e00670bu ) ; +// Whether the given block is subject to new modifier protocol +bool IsFixedModifierInterval(unsigned int nTimeBlock) +{ + return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime)); +} + +// Get time weight +int64 GetWeight(int64 nIntervalBeginning, int64 nIntervalEnd) +{ + // Kernel hash weight starts from 0 at the 30-day min age + // this change increases active coins participating the hash and helps + // to secure the network when proof-of-stake difficulty is low + // + // Maximum TimeWeight is 90 days. + + return min(nIntervalEnd - nIntervalBeginning - nStakeMinAge, (int64)nStakeMaxAge); +} + // Get the last stake modifier and its generation time from a given block static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64& nStakeModifier, int64& nModifierTime) { @@ -63,11 +94,8 @@ static int64 GetStakeModifierSelectionInterval() // select a block from the candidate blocks in vSortedByTimestamp, excluding // already selected blocks in vSelectedBlocks, and with timestamp up to // nSelectionIntervalStop. -static bool SelectBlockFromCandidates( - vector >& vSortedByTimestamp, - map& mapSelectedBlocks, - int64 nSelectionIntervalStop, uint64 nStakeModifierPrev, - const CBlockIndex** pindexSelected) +static bool SelectBlockFromCandidates(vector >& vSortedByTimestamp, map& mapSelectedBlocks, + int64 nSelectionIntervalStop, uint64 nStakeModifierPrev, const CBlockIndex** pindexSelected) { bool fSelected = false; uint256 hashBest = 0; @@ -122,15 +150,17 @@ static bool SelectBlockFromCandidates( // block. This is to make it difficult for an attacker to gain control of // additional bits in the stake modifier, even after generating a chain of // blocks. -bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier) +bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64& nStakeModifier, bool& fGeneratedStakeModifier) { nStakeModifier = 0; fGeneratedStakeModifier = false; + const CBlockIndex* pindexPrev = pindexCurrent->pprev; if (!pindexPrev) { fGeneratedStakeModifier = true; return true; // genesis block's modifier is 0 } + // First find current stake modifier and its generation block time // if it's not old enough, return the same stake modifier int64 nModifierTime = 0; @@ -138,10 +168,35 @@ bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModif return error("ComputeNextStakeModifier: unable to get last modifier"); if (fDebug) { - printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str()); + printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s epoch=%u\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str(), (unsigned int)nModifierTime); } if (nModifierTime / nModifierInterval >= pindexPrev->GetBlockTime() / nModifierInterval) + { + if (fDebug) + { + printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexPrev nHeight=%d nTime=%u\n", pindexPrev->nHeight, (unsigned int)pindexPrev->GetBlockTime()); + } return true; + } + if (nModifierTime / nModifierInterval >= pindexCurrent->GetBlockTime() / nModifierInterval) + { + // fixed interval protocol requires current block timestamp also be in a different modifier interval + if (IsFixedModifierInterval(pindexCurrent->nTime)) + { + if (fDebug) + { + printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime()); + } + return true; + } + else + { + if (fDebug) + { + printf("ComputeNextStakeModifier: old modifier at block %s not meeting fixed modifier interval: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->GetBlockHash().ToString().c_str(), pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime()); + } + } + } // Sort candidate blocks by timestamp vector > vSortedByTimestamp; @@ -174,8 +229,7 @@ bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModif // add the selected block from candidates to selected list mapSelectedBlocks.insert(make_pair(pindex->GetBlockHash(), pindex)); if (fDebug && GetBoolArg("-printstakemodifier")) - printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n", - nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit()); + printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n", nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit()); } // Print selection map for visualization of the selected blocks @@ -251,10 +305,8 @@ static bool GetKernelStakeModifier(uint256 hashBlockFrom, uint64& nStakeModifier // this ensures that the chance of getting a coinstake is proportional to the // amount of coin age one owns. // The reason this hash is chosen is the following: -// nStakeModifier: -// (v0.3) scrambles computation to make it very difficult to precompute -// future proof-of-stake at the time of the coin's confirmation -// (v0.2) nBits (deprecated): encodes all past block timestamps +// nStakeModifier: scrambles computation to make it very difficult to precompute +// future proof-of-stake at the time of the coin's confirmation // txPrev.block.nTime: prevent nodes from guessing a good timestamp to // generate transaction for future advantage // txPrev.offset: offset of txPrev inside block, to reduce the chance of @@ -280,25 +332,9 @@ bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, unsigned bnTargetPerCoinDay.SetCompact(nBits); int64 nValueIn = txPrev.vout[prevout.n].nValue; - int64 nTimeWeight; uint256 hashBlockFrom = blockFrom.GetHash(); - // Kernel hash weight starts from 0 at the 30-day min age - // this change increases active coins participating the hash and helps - // to secure the network when proof-of-stake difficulty is low - // - if(fTestNet || (STAKEWEIGHT_SWITCH_TIME < nTimeTx)) - { - // New rule since 01 Jan 2014: Maximum TimeWeight is 90 days. - nTimeWeight = min((int64)nTimeTx - txPrev.nTime - nStakeMinAge, (int64)nStakeMaxAge); - } - else - { - // Current rule: Maximum TimeWeight is 60 days. - nTimeWeight = min((int64)nTimeTx - txPrev.nTime, (int64)nStakeMaxAge) - nStakeMinAge; - } - - CBigNum bnCoinDayWeight = CBigNum(nValueIn) * nTimeWeight / COIN / (24 * 60 * 60); + CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64)txPrev.nTime, (int64)nTimeTx) / COIN / (24 * 60 * 60); targetProofOfStake = (bnCoinDayWeight * bnTargetPerCoinDay).getuint256(); // Calculate hash @@ -320,8 +356,7 @@ bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, unsigned DateTimeStrFormat(nStakeModifierTime).c_str(), mapBlockIndex[hashBlockFrom]->nHeight, DateTimeStrFormat(blockFrom.GetBlockTime()).c_str()); - printf("CheckStakeKernelHash() : check protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", - "0.3", + printf("CheckStakeKernelHash() : check modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", nStakeModifier, nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx, hashProofOfStake.ToString().c_str()); @@ -337,8 +372,7 @@ bool CheckStakeKernelHash(unsigned int nBits, const CBlock& blockFrom, unsigned DateTimeStrFormat(nStakeModifierTime).c_str(), mapBlockIndex[hashBlockFrom]->nHeight, DateTimeStrFormat(blockFrom.GetBlockTime()).c_str()); - printf("CheckStakeKernelHash() : pass protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", - "0.3", + printf("CheckStakeKernelHash() : pass modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", nStakeModifier, nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx, hashProofOfStake.ToString().c_str()); @@ -362,12 +396,8 @@ bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hash if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex)) return tx.DoS(1, error("CheckProofOfStake() : INFO: read txPrev failed")); // previous transaction not in main chain, may occur during initial download -#ifndef USE_LEVELDB - txdb.Close(); -#endif - // Verify signature - if (!VerifySignature(txPrev, tx, 0, true, 0)) + if (!VerifySignature(txPrev, tx, 0, MANDATORY_SCRIPT_VERIFY_FLAGS, 0)) return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str())); // Read block header @@ -381,13 +411,6 @@ bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hash return true; } -// Check whether the coinstake timestamp meets protocol -bool CheckCoinStakeTimestamp(int64 nTimeBlock, int64 nTimeTx) -{ - // v0.3 protocol - return (nTimeBlock == nTimeTx); -} - // Get stake modifier checksum unsigned int GetStakeModifierChecksum(const CBlockIndex* pindex) {