X-Git-Url: https://git.novaco.in/?a=blobdiff_plain;f=src%2Fkernel.cpp;h=9c63eaf1ee1b6fcaeaaa0c5a48f50af4f0529305;hb=054d268dbcd71a393c77ee01b40063b968313578;hp=4055314749a6bf60d9d75ab872a31c7d688d2241;hpb=1e7993f68d8ada2bf6a523ac3b4afec64157f8ed;p=novacoin.git diff --git a/src/kernel.cpp b/src/kernel.cpp index 4055314..9c63eaf 100644 --- a/src/kernel.cpp +++ b/src/kernel.cpp @@ -32,6 +32,7 @@ static std::map mapStakeModifierCheckpoints = (143990, 0x9c592c78u ) (149000, 0x48f2bdc4u ) (160000, 0x789df0f0u ) + (200000, 0x01ec1503u ) ; // Hard checkpoints of stake modifiers to ensure they are deterministic (testNet) @@ -94,18 +95,6 @@ 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 +399,10 @@ 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 @@ -426,136 +415,111 @@ 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) +// 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) { - uint256 hashProofOfStake = 0; + // Build static part of kernel + CDataStream ssKernel(SER_GETHASH, 0); + ssKernel << nStakeModifier; + ssKernel << nBlockTime << nTxOffset << nInputTxTime << nOut; + CDataStream::const_iterator it = ssKernel.begin(); + + // Init sha256 context and update it + // with first 24 bytes of kernel + SHA256_Init(&ctx); + SHA256_Update(&ctx, (unsigned char*)&it[0], 8 + 16); +} - // (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; +// Scan given midstate for solution +bool ScanMidstateForward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair &SearchInterval, std::pair &solution) +{ + CBigNum bnTargetPerCoinDay; + bnTargetPerCoinDay.SetCompact(nBits); - CTxIndex txindex = (*meta_item).second.first.first; - CBlock block = (*meta_item).second.second.first; - uint64_t nStakeModifier = (*meta_item).second.second.second; + // 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(); - // Get coin - CoinsSet::value_type pcoin = meta_item->second.first.second; + SHA256_CTX ctxCopy = ctx; - static unsigned int nMaxStakeSearchInterval = 60; + // Search forward in time from the given timestamp + // Stopping search in case of shutting down + for (uint32_t nTimeTx=SearchInterval.first; nTimeTx nTime - nMaxStakeSearchInterval) - continue; + // Restore context + ctxCopy = ctx; - // Transaction offset inside block - uint32_t nTxOffset = txindex.pos.nTxPos - txindex.pos.nBlockPos; + // Finally, calculate kernel hash + uint256 hashProofOfStake; + SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake); - // Current timestamp scanning interval - unsigned int nCurrentSearchInterval = min(nSearchInterval, nMaxStakeSearchInterval); + // Skip if hash doesn't satisfy the maximum target + if (hashProofOfStake > maxTarget) + continue; - nBlockTime = block.nTime; - CBigNum bnTargetPerCoinDay; - bnTargetPerCoinDay.SetCompact(nBits); - int64_t nValueIn = pcoin.first->vout[pcoin.second].nValue; + CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60); + CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay; - // 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; n= CBigNum(hashProofOfStake)) { - nTimeTx = nTime - n; - CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)pcoin.first->nTime, (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; - } + solution.first = hashProofOfStake; + solution.second = nTimeTx; - 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 true; } } return false; } -// Scan given input for kernel solution -bool ScanInputForStakeKernelHash(CTransaction &tx, uint32_t nOut, uint32_t nBits, uint32_t nSearchInterval, std::pair &solution) +// 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) { - CBlock block; - CTxIndex txindex; - uint256 hashProofOfStake; + CBigNum bnTargetPerCoinDay; + bnTargetPerCoinDay.SetCompact(nBits); - int nTime = GetTime(); + // 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(); - CTxDB txdb("r"); + SHA256_CTX ctxCopy = ctx; - // Load transaction index item - if (!txdb.ReadTxIndex(tx.GetHash(), txindex)) - return false; - - // Read block header - if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false)) - return false; + // 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); - uint64_t nStakeModifier = 0; - if (!GetKernelStakeModifier(block.GetHash(), nStakeModifier)) - return false; + // Restore context + ctxCopy = ctx; - // Transaction offset inside block - uint32_t nTxOffset = txindex.pos.nTxPos - txindex.pos.nBlockPos; + // Finally, calculate kernel hash + uint256 hashProofOfStake; + SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake); - uint32_t nBlockTime = block.nTime; - CBigNum bnTargetPerCoinDay; - bnTargetPerCoinDay.SetCompact(nBits); - int64_t nValueIn = tx.vout[nOut].nValue; + // Skip if hash doesn't satisfy the maximum target + if (hashProofOfStake > maxTarget) + continue; - // Search forward in time from the given timestamp - // Stopping search in case of shutting down - for (unsigned int n=0; n= CBigNum(hashProofOfStake)) { solution.first = hashProofOfStake; @@ -614,7 +578,7 @@ uint32_t GetStakeModifierChecksum(const CBlockIndex* pindex) ss << pindex->nFlags << pindex->hashProofOfStake << pindex->nStakeModifier; uint256 hashChecksum = Hash(ss.begin(), ss.end()); hashChecksum >>= (256 - 32); - return hashChecksum.Get64(); + return static_cast(hashChecksum.Get64()); } // Check stake modifier hard checkpoints