X-Git-Url: https://git.novaco.in/?p=novacoin.git;a=blobdiff_plain;f=src%2Fkernel.cpp;h=a7df10e58d989373fbceef86c0e04f7ff88e43e3;hp=58a4b88538bf9ae0b965e96ae59bf27219ffd26c;hb=9417ff30cae6ffffd1c4fc4f4b1a81551f04dbc5;hpb=68938e65fd9e607b8822db4edb76731c1edfe85c diff --git a/src/kernel.cpp b/src/kernel.cpp index 58a4b88..a7df10e 100644 --- a/src/kernel.cpp +++ b/src/kernel.cpp @@ -94,18 +94,6 @@ bool IsFixedModifierInterval(unsigned int nTimeBlock) return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime)); } -// Get time weight -int64_t GetWeight(int64_t nIntervalBeginning, int64_t 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_t)nStakeMaxAge); -} - // Get the last stake modifier and its generation time from a given block static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64_t& nStakeModifier, int64_t& nModifierTime) { @@ -410,10 +398,10 @@ bool CheckStakeKernelHash(uint32_t nBits, const CBlock& blockFrom, uint32_t nTxP DateTimeStrFormat(nStakeModifierTime).c_str(), mapBlockIndex[hashBlockFrom]->nHeight, DateTimeStrFormat(blockFrom.GetBlockTime()).c_str()); - printf("CheckStakeKernelHash() : check modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", + printf("CheckStakeKernelHash() : check modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n", nStakeModifier, nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx, - hashProofOfStake.ToString().c_str()); + targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str()); } // Now check if proof-of-stake hash meets target protocol @@ -426,89 +414,14 @@ bool CheckStakeKernelHash(uint32_t nBits, const CBlock& blockFrom, uint32_t nTxP DateTimeStrFormat(nStakeModifierTime).c_str(), mapBlockIndex[hashBlockFrom]->nHeight, DateTimeStrFormat(blockFrom.GetBlockTime()).c_str()); - printf("CheckStakeKernelHash() : pass modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n", + printf("CheckStakeKernelHash() : pass modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n", nStakeModifier, nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx, - hashProofOfStake.ToString().c_str()); + targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str()); } return true; } -// Scan given coins set for kernel solution -bool ScanForStakeKernelHash(MetaMap &mapMeta, uint32_t nBits, uint32_t nTime, uint32_t nSearchInterval, CoinsSet::value_type &kernelcoin, uint32_t &nTimeTx, uint32_t &nBlockTime, uint64_t &nKernelsTried, uint64_t &nCoinDaysTried) -{ - uint256 hashProofOfStake = 0; - - // (txid, vout.n) => ((txindex, (tx, vout.n)), (block, modifier)) - for(MetaMap::const_iterator meta_item = mapMeta.begin(); meta_item != mapMeta.end(); meta_item++) - { - if (!fCoinsDataActual) - break; - - CTxIndex txindex = (*meta_item).second.first.first; - CBlock block = (*meta_item).second.second.first; - uint64_t nStakeModifier = (*meta_item).second.second.second; - - // Get coin - CoinsSet::value_type pcoin = meta_item->second.first.second; - - static unsigned int nMaxStakeSearchInterval = 60; - - // only count coins meeting min age requirement - if (nStakeMinAge + block.nTime > nTime - nMaxStakeSearchInterval) - continue; - - // Transaction offset inside block - uint32_t nTxOffset = txindex.pos.nTxPos - txindex.pos.nBlockPos; - - // Current timestamp scanning interval - unsigned int nCurrentSearchInterval = min(nSearchInterval, nMaxStakeSearchInterval); - - nBlockTime = block.nTime; - CBigNum bnTargetPerCoinDay; - bnTargetPerCoinDay.SetCompact(nBits); - int64_t nValueIn = pcoin.first->vout[pcoin.second].nValue; - - // Search backward in time from the given timestamp - // Search nSearchInterval seconds back up to nMaxStakeSearchInterval - // Stopping search in case of shutting down or cache invalidation - for (unsigned int n=0; nnTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60); - CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay; - - // Build kernel - CDataStream ss(SER_GETHASH, 0); - ss << nStakeModifier; - ss << nBlockTime << nTxOffset << pcoin.first->nTime << pcoin.second << nTimeTx; - - // Calculate kernel hash - hashProofOfStake = Hash(ss.begin(), ss.end()); - - // Update statistics - nKernelsTried += 1; - nCoinDaysTried += bnCoinDayWeight.getuint64(); - - if (bnTargetProofOfStake >= CBigNum(hashProofOfStake)) - { - if (fDebug) - printf("nStakeModifier=0x%016" PRIx64 ", nBlockTime=%u nTxOffset=%u nTxPrevTime=%u nVout=%u nTimeTx=%u hashProofOfStake=%s Success=true\n", - nStakeModifier, nBlockTime, nTxOffset, pcoin.first->nTime, pcoin.second, nTimeTx, hashProofOfStake.GetHex().c_str()); - - kernelcoin = pcoin; - return true; - } - - if (fDebug) - printf("nStakeModifier=0x%016" PRIx64 ", nBlockTime=%u nTxOffset=%u nTxPrevTime=%u nTxNumber=%u nTimeTx=%u hashProofOfStake=%s Success=false\n", - nStakeModifier, nBlockTime, nTxOffset, pcoin.first->nTime, pcoin.second, nTimeTx, hashProofOfStake.GetHex().c_str()); - } - } - - return false; -} - // Precompute hashing state for static part of kernel void GetKernelMidstate(uint64_t nStakeModifier, uint32_t nBlockTime, uint32_t nTxOffset, uint32_t nInputTxTime, uint32_t nOut, SHA256_CTX &ctx) { @@ -571,6 +484,53 @@ bool ScanMidstateForward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, return false; } +// Scan given midstate for solution +bool ScanMidstateBackward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair &SearchInterval, std::pair &solution) +{ + CBigNum bnTargetPerCoinDay; + bnTargetPerCoinDay.SetCompact(nBits); + + // Get maximum possible target to filter out the majority of obviously insufficient hashes + CBigNum bnMaxTargetPerCoinDay = bnTargetPerCoinDay * CBigNum(nValueIn) * nStakeMaxAge / COIN / (24 * 60 * 60); + uint256 maxTarget = bnMaxTargetPerCoinDay.getuint256(); + + SHA256_CTX ctxCopy = ctx; + + // Search backward in time from the given timestamp + // Stopping search in case of shutting down + for (uint32_t nTimeTx=SearchInterval.first; nTimeTx>SearchInterval.second && !fShutdown; nTimeTx--) + { + // Complete first hashing iteration + uint256 hash1; + SHA256_Update(&ctxCopy, (unsigned char*)&nTimeTx, 4); + SHA256_Final((unsigned char*)&hash1, &ctxCopy); + + // Restore context + ctxCopy = ctx; + + // Finally, calculate kernel hash + uint256 hashProofOfStake; + SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake); + + // Skip if hash doesn't satisfy the maximum target + if (hashProofOfStake > maxTarget) + continue; + + CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60); + CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay; + + if (bnTargetProofOfStake >= CBigNum(hashProofOfStake)) + { + solution.first = hashProofOfStake; + solution.second = nTimeTx; + + return true; + } + } + + return false; +} + // Check kernel hash target and coinstake signature bool CheckProofOfStake(const CTransaction& tx, unsigned int nBits, uint256& hashProofOfStake, uint256& targetProofOfStake) {