int LitecoinChain::nextWorkRequired(BlockIterator blk) const { const int64_t nTargetTimespan = 3.5 * 24 * 60 * 60; // two weeks const int64_t nTargetSpacing = 2.5 * 60; const int64_t nInterval = nTargetTimespan / nTargetSpacing; // Genesis block int h = blk.height(); if (h == 0) // trick to test that it is asking for the genesis block return _genesisBlock.getBits(); // proofOfWorkLimit().GetCompact(); Actually not for the genesisblock - here it is 0x1e0ffff0, not 0x1e0fffff // Only change once per interval if ((h + 1) % nInterval != 0) return blk->bits; // Litecoin: This fixes an issue where a 51% attack can change difficulty at will. // Go back the full period unless it's the first retarget after genesis. Code courtesy of Art Forz int blockstogoback = nInterval-1; if ((h + 1) != nInterval) blockstogoback = nInterval; // Go back by what we want to be 3.5 days worth of blocks BlockIterator former = blk - blockstogoback; // Limit adjustment step int nActualTimespan = blk->time - former->time; log_debug(" nActualTimespan = %"PRI64d" before bounds", nActualTimespan); if (nActualTimespan < nTargetTimespan/4) nActualTimespan = nTargetTimespan/4; if (nActualTimespan > nTargetTimespan*4) nActualTimespan = nTargetTimespan*4; // Retarget CBigNum bnNew; bnNew.SetCompact(blk->bits); bnNew *= nActualTimespan; bnNew /= nTargetTimespan; if (bnNew > proofOfWorkLimit()) bnNew = proofOfWorkLimit(); /// debug print log_info("GetNextWorkRequired RETARGET"); log_info("\tnTargetTimespan = %"PRI64d" nActualTimespan = %"PRI64d"", nTargetTimespan, nActualTimespan); log_info("\tBefore: %08x %s", blk->bits, CBigNum().SetCompact(blk->bits).getuint256().toString().c_str()); log_info("\tAfter: %08x %s", bnNew.GetCompact(), bnNew.getuint256().toString().c_str()); return bnNew.GetCompact(); }
int TestNet3Chain::nextWorkRequired(BlockIterator blk) const { const int64_t nTargetTimespan = 14 * 24 * 60 * 60; // two weeks const int64_t nTargetSpacing = 10 * 60; const int64_t nInterval = nTargetTimespan / nTargetSpacing; // Genesis block int h = blk.height(); if (h == 0) // trick to test that it is asking for the genesis block return proofOfWorkLimit().GetCompact(); // Only change once per interval if ((h + 1) % nInterval != 0) { // Return the last non-special-min-difficulty-rules-block while (blk.height() % nInterval != 0 && blk->bits == proofOfWorkLimit().GetCompact()) blk--; return blk->bits; } // Go back by what we want to be 14 days worth of blocks BlockIterator former = blk - (nInterval-1); // Limit adjustment step int nActualTimespan = blk->time - former->time; log_debug(" nActualTimespan = %"PRI64d" before bounds", nActualTimespan); if (nActualTimespan < nTargetTimespan/4) nActualTimespan = nTargetTimespan/4; if (nActualTimespan > nTargetTimespan*4) nActualTimespan = nTargetTimespan*4; // Retarget CBigNum bnNew; bnNew.SetCompact(blk->bits); bnNew *= nActualTimespan; bnNew /= nTargetTimespan; if (bnNew > proofOfWorkLimit()) bnNew = proofOfWorkLimit(); /// debug print log_info("GetNextWorkRequired RETARGET"); log_info("\tnTargetTimespan = %"PRI64d" nActualTimespan = %"PRI64d"", nTargetTimespan, nActualTimespan); log_info("\tBefore: %08x %s", blk->bits, CBigNum().SetCompact(blk->bits).getuint256().toString().c_str()); log_info("\tAfter: %08x %s", bnNew.GetCompact(), bnNew.getuint256().toString().c_str()); return bnNew.GetCompact(); }
unsigned int BitcoinChain::nextWorkRequired(const CBlockIndex* pindexLast) const { const int64 nTargetTimespan = 14 * 24 * 60 * 60; // two weeks const int64 nTargetSpacing = 10 * 60; const int64 nInterval = nTargetTimespan / nTargetSpacing; // Genesis block if (pindexLast == NULL) return proofOfWorkLimit().GetCompact(); // Only change once per interval if ((pindexLast->nHeight+1) % nInterval != 0) return pindexLast->nBits; // Go back by what we want to be 14 days worth of blocks const CBlockIndex* pindexFirst = pindexLast; for (int i = 0; pindexFirst && i < nInterval-1; i++) pindexFirst = pindexFirst->pprev; assert(pindexFirst); // Limit adjustment step int64 nActualTimespan = pindexLast->GetBlockTime() - pindexFirst->GetBlockTime(); printf(" nActualTimespan = %"PRI64d" before bounds\n", nActualTimespan); if (nActualTimespan < nTargetTimespan/4) nActualTimespan = nTargetTimespan/4; if (nActualTimespan > nTargetTimespan*4) nActualTimespan = nTargetTimespan*4; // Retarget CBigNum bnNew; bnNew.SetCompact(pindexLast->nBits); bnNew *= nActualTimespan; bnNew /= nTargetTimespan; if (bnNew > proofOfWorkLimit()) bnNew = proofOfWorkLimit(); /// debug print printf("GetNextWorkRequired RETARGET\n"); printf("nTargetTimespan = %"PRI64d" nActualTimespan = %"PRI64d"\n", nTargetTimespan, nActualTimespan); printf("Before: %08x %s\n", pindexLast->nBits, CBigNum().SetCompact(pindexLast->nBits).getuint256().toString().c_str()); printf("After: %08x %s\n", bnNew.GetCompact(), bnNew.getuint256().toString().c_str()); return bnNew.GetCompact(); }
int TerracoinChain::nextWorkRequired(BlockIterator blk) const { const int64_t nTargetTimespan = 60 * 60; // one hour weeks const int64_t nTargetSpacing = 2 * 60; // new block every two minutes const int64_t nInterval = nTargetTimespan / nTargetSpacing; // Genesis block int h = blk.height(); if (h == 0) // trick to test that it is asking for the genesis block return proofOfWorkLimit().GetCompact(); // Only change once per interval if ((h + 1) % nInterval != 0) return blk->bits; // Go back by what we want to be 14 days worth of blocks BlockIterator former = blk - (nInterval-1); // Limit adjustment step int nActualTimespan = blk->time - former->time; log_debug(" nActualTimespan = %"PRI64d" before bounds", nActualTimespan); if (nActualTimespan < nTargetTimespan/4) nActualTimespan = nTargetTimespan/4; if (nActualTimespan > nTargetTimespan*4) nActualTimespan = nTargetTimespan*4; // Retarget CBigNum bnNew; bnNew.SetCompact(blk->bits); bnNew *= nActualTimespan; bnNew /= nTargetTimespan; if (bnNew > proofOfWorkLimit()) bnNew = proofOfWorkLimit(); /// debug print log_info("GetNextWorkRequired RETARGET"); log_info("nTargetTimespan = %"PRI64d" nActualTimespan = %"PRI64d"", nTargetTimespan, nActualTimespan); log_info("Before: %08x %s", blk->bits, CBigNum().SetCompact(blk->bits).getuint256().toString().c_str()); log_info("After: %08x %s", bnNew.GetCompact(), bnNew.getuint256().toString().c_str()); return bnNew.GetCompact(); }
bool CreateCoinStake( CBlock &blocknew, CKey &key, vector<const CWalletTx*> &StakeInputs, uint64_t &CoinAge, CWallet &wallet, CBlockIndex* pindexPrev ) { int64_t CoinWeight; CBigNum StakeKernelHash; CTxDB txdb("r"); int64_t StakeWeightSum = 0; double StakeValueSum = 0; int64_t StakeWeightMin=MAX_MONEY; int64_t StakeWeightMax=0; uint64_t StakeCoinAgeSum=0; double StakeDiffSum = 0; double StakeDiffMax = 0; CTransaction &txnew = blocknew.vtx[1]; // second tx is coinstake //initialize the transaction txnew.nTime = blocknew.nTime & (~STAKE_TIMESTAMP_MASK); txnew.vin.clear(); txnew.vout.clear(); // Choose coins to use set <pair <const CWalletTx*,unsigned int> > CoinsToStake; int64_t BalanceToStake = wallet.GetBalance(); int64_t nValueIn = 0; //Request all the coins here, check reserve later if ( BalanceToStake<=0 || !wallet.SelectCoinsForStaking(BalanceToStake*2, txnew.nTime, CoinsToStake, nValueIn) ) { LOCK(MinerStatus.lock); MinerStatus.ReasonNotStaking+=_("No coins; "); if (fDebug) LogPrintf("CreateCoinStake: %s",MinerStatus.ReasonNotStaking); return false; } BalanceToStake -= nReserveBalance; if(fDebug2) LogPrintf("\nCreateCoinStake: Staking nTime/16= %d Bits= %u", txnew.nTime/16,blocknew.nBits); for(const auto& pcoin : CoinsToStake) { const CTransaction &CoinTx =*pcoin.first; //transaction that produced this coin unsigned int CoinTxN =pcoin.second; //index of this coin inside it CTxIndex txindex; { LOCK2(cs_main, wallet.cs_wallet); if (!txdb.ReadTxIndex(pcoin.first->GetHash(), txindex)) continue; //error? } CBlock CoinBlock; //Block which contains CoinTx { LOCK2(cs_main, wallet.cs_wallet); if (!CoinBlock.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false)) continue; } // only count coins meeting min age requirement if (CoinBlock.GetBlockTime() + nStakeMinAge > txnew.nTime) continue; if (CoinTx.vout[CoinTxN].nValue > BalanceToStake) continue; { int64_t nStakeValue= CoinTx.vout[CoinTxN].nValue; StakeValueSum += nStakeValue /(double)COIN; //crazy formula... // todo: clean this // todo reuse calculated value for interst CBigNum bn = CBigNum(nStakeValue) * (blocknew.nTime-CoinTx.nTime) / CENT; bn = bn * CENT / COIN / (24 * 60 * 60); StakeCoinAgeSum += bn.getuint64(); } if(blocknew.nVersion==7) { NetworkTimer(); CoinWeight = CalculateStakeWeightV3(CoinTx,CoinTxN,GlobalCPUMiningCPID); StakeKernelHash= CalculateStakeHashV3(CoinBlock,CoinTx,CoinTxN,txnew.nTime,GlobalCPUMiningCPID,mdPORNonce); } else { uint64_t StakeModifier = 0; if(!FindStakeModifierRev(StakeModifier,pindexPrev)) continue; CoinWeight = CalculateStakeWeightV8(CoinTx,CoinTxN,GlobalCPUMiningCPID); StakeKernelHash= CalculateStakeHashV8(CoinBlock,CoinTx,CoinTxN,txnew.nTime,StakeModifier,GlobalCPUMiningCPID); } CBigNum StakeTarget; StakeTarget.SetCompact(blocknew.nBits); StakeTarget*=CoinWeight; StakeWeightSum += CoinWeight; StakeWeightMin=std::min(StakeWeightMin,CoinWeight); StakeWeightMax=std::max(StakeWeightMax,CoinWeight); double StakeKernelDiff = GetBlockDifficulty(StakeKernelHash.GetCompact())*CoinWeight; StakeDiffSum += StakeKernelDiff; StakeDiffMax = std::max(StakeDiffMax,StakeKernelDiff); if (fDebug2) { int64_t RSA_WEIGHT = GetRSAWeightByBlock(GlobalCPUMiningCPID); LogPrintf( "CreateCoinStake: V%d Time %.f, Por_Nonce %.f, Bits %jd, Weight %jd\n" " RSA_WEIGHT %.f\n" " Stk %72s\n" " Trg %72s\n" " Diff %0.7f of %0.7f\n", blocknew.nVersion, (double)txnew.nTime, mdPORNonce, (intmax_t)blocknew.nBits,(intmax_t)CoinWeight, (double)RSA_WEIGHT, StakeKernelHash.GetHex().c_str(), StakeTarget.GetHex().c_str(), StakeKernelDiff, GetBlockDifficulty(blocknew.nBits) ); } if( StakeKernelHash <= StakeTarget ) { // Found a kernel LogPrintf("\nCreateCoinStake: Found Kernel;\n"); blocknew.nNonce= mdPORNonce; vector<valtype> vSolutions; txnouttype whichType; CScript scriptPubKeyOut; CScript scriptPubKeyKernel; scriptPubKeyKernel = CoinTx.vout[CoinTxN].scriptPubKey; if (!Solver(scriptPubKeyKernel, whichType, vSolutions)) { LogPrintf("CreateCoinStake: failed to parse kernel\n"); break; } if (whichType == TX_PUBKEYHASH) // pay to address type { // convert to pay to public key type if (!wallet.GetKey(uint160(vSolutions[0]), key)) { LogPrintf("CreateCoinStake: failed to get key for kernel type=%d\n", whichType); break; // unable to find corresponding public key } scriptPubKeyOut << key.GetPubKey() << OP_CHECKSIG; } else if (whichType == TX_PUBKEY) // pay to public key type { valtype& vchPubKey = vSolutions[0]; if (!wallet.GetKey(Hash160(vchPubKey), key) || key.GetPubKey() != vchPubKey) { LogPrintf("CreateCoinStake: failed to get key for kernel type=%d\n", whichType); break; // unable to find corresponding public key } scriptPubKeyOut = scriptPubKeyKernel; } else { LogPrintf("CreateCoinStake: no support for kernel type=%d\n", whichType); break; // only support pay to public key and pay to address } txnew.vin.push_back(CTxIn(CoinTx.GetHash(), CoinTxN)); StakeInputs.push_back(pcoin.first); if (!txnew.GetCoinAge(txdb, CoinAge)) return error("CreateCoinStake: failed to calculate coin age"); int64_t nCredit = CoinTx.vout[CoinTxN].nValue; txnew.vout.push_back(CTxOut(0, CScript())); // First Must be empty txnew.vout.push_back(CTxOut(nCredit, scriptPubKeyOut)); //txnew.vout.push_back(CTxOut(0, scriptPubKeyOut)); LogPrintf("CreateCoinStake: added kernel type=%d credit=%f\n", whichType,CoinToDouble(nCredit)); LOCK(MinerStatus.lock); MinerStatus.KernelsFound++; MinerStatus.KernelDiffMax = 0; MinerStatus.KernelDiffSum = StakeDiffSum; return true; } } LOCK(MinerStatus.lock); MinerStatus.WeightSum = StakeWeightSum; MinerStatus.ValueSum = StakeValueSum; MinerStatus.WeightMin=StakeWeightMin; MinerStatus.WeightMax=StakeWeightMax; MinerStatus.CoinAgeSum=StakeCoinAgeSum; MinerStatus.KernelDiffMax = std::max(MinerStatus.KernelDiffMax,StakeDiffMax); MinerStatus.KernelDiffSum = StakeDiffSum; MinerStatus.nLastCoinStakeSearchInterval= txnew.nTime; return false; }
unsigned int RetargetGPU(const CBlockIndex* pindex, bool output) { /** Get the Last Block Index [1st block back in Channel]. **/ const CBlockIndex* pindexFirst = GetLastChannelIndex(pindex, 2); if (pindexFirst->pprev == NULL) return bnProofOfWorkStart[2].GetCompact(); /** Get Last Block Index [2nd block back in Channel]. **/ const CBlockIndex* pindexLast = GetLastChannelIndex(pindexFirst->pprev, 2); if (pindexLast->pprev == NULL) return bnProofOfWorkStart[2].GetCompact(); /** Get the Block Times with Minimum of 1 to Prevent Time Warps. **/ int64 nBlockTime = ((pindex->nVersion >= 4) ? GetWeightedTimes(pindexFirst, 5) : max(pindexFirst->GetBlockTime() - pindexLast->GetBlockTime(), (int64) 1)); int64 nBlockTarget = nTargetTimespan; /** Get the Chain Modular from Reserves. **/ double nChainMod = GetFractionalSubsidy(GetChainAge(pindexFirst->GetBlockTime()), 0, ((pindex->nVersion >= 3) ? 40.0 : 20.0)) / (pindexFirst->nReleasedReserve[0] + 1); nChainMod = min(nChainMod, 1.0); nChainMod = max(nChainMod, (pindex->nVersion == 1) ? 0.75 : 0.5); /** Enforce Block Version 2 Rule. Chain mod changes block time requirements, not actual mod after block times. **/ if(pindex->nVersion >= 2) nBlockTarget *= nChainMod; /** The Upper and Lower Bound Adjusters. **/ int64 nUpperBound = nBlockTarget; int64 nLowerBound = nBlockTarget; /** Handle for Version 3 Blocks. Mod determined by time multiplied by max / min. **/ if(pindex->nVersion >= 3) { /** If the time is above target, reduce difficulty by modular of one interval past timespan multiplied by maximum decrease. **/ if(nBlockTime >= nBlockTarget) { /** Take the Minimum overlap of Target Timespan to make that maximum interval. **/ uint64 nOverlap = (uint64)min((nBlockTime - nBlockTarget), (nBlockTarget * 2)); /** Get the Mod from the Proportion of Overlap in one Interval. **/ double nProportions = (double)nOverlap / (nBlockTarget * 2); /** Get Mod from Maximum Decrease Equation with Decimal portions multiplied by Propotions. **/ double nMod = 1.0 - (((pindex->nVersion >= 4) ? 0.15 : 0.75) * nProportions); nLowerBound = nBlockTarget * nMod; } /** If the time is below target, increase difficulty by modular of interval of 1 - Block Target with time of 1 being maximum increase **/ else { /** Get the overlap in reference from Target Timespan. **/ uint64 nOverlap = nBlockTarget - nBlockTime; /** Get the mod from overlap proportion. Time of 1 will be closest to mod of 1. **/ double nProportions = (double) nOverlap / nBlockTarget; /** Get the Mod from the Maximum Increase Equation with Decimal portion multiplied by Proportions. **/ double nMod = 1.0 + (nProportions * 0.075); nLowerBound = nBlockTarget * nMod; } } /** Handle for Version 2 Difficulty Adjustments. **/ else { double nBlockMod = (double) nBlockTarget / nBlockTime; nBlockMod = min(nBlockMod, 1.125); nBlockMod = max(nBlockMod, 0.75); /** Calculate the Lower Bounds. **/ nLowerBound = nBlockTarget * nBlockMod; /** Version 1 Blocks Change Lower Bound from Chain Modular. **/ if(pindex->nVersion == 1) nLowerBound *= nChainMod; /** Set Maximum [difficulty] up to 8%, and Minimum [difficulty] down to 50% **/ nLowerBound = min(nLowerBound, (int64)(nUpperBound + (nUpperBound / 8))); nLowerBound = max(nLowerBound, (3 * nUpperBound ) / 4); } /** Get the Difficulty Stored in Bignum Compact. **/ CBigNum bnNew; bnNew.SetCompact(pindexFirst->nBits); /** Change Number from Upper and Lower Bounds. **/ bnNew *= nUpperBound; bnNew /= nLowerBound; /** Don't allow Difficulty to decrease below minimum. **/ if (bnNew > bnProofOfWorkLimit[2]) bnNew = bnProofOfWorkLimit[2]; /** Console Output if Flagged. **/ if(output) { int64 nDays, nHours, nMinutes; GetChainTimes(GetChainAge(pindexFirst->GetBlockTime()), nDays, nHours, nMinutes); printf("RETARGET[GPU] weighted time=%"PRId64" actual time %"PRId64" [%f %%]\n\tchain time: [%"PRId64" / %"PRId64"]\n\treleased reward: %"PRId64" [%f %%]\n\tdifficulty: [%f to %f]\n\tGPU height: %"PRId64" [AGE %"PRId64" days, %"PRId64" hours, %"PRId64" minutes]\n\n", nBlockTime, max(pindexFirst->GetBlockTime() - pindexLast->GetBlockTime(), (int64) 1), (100.0 * nLowerBound) / nUpperBound, nBlockTarget, nBlockTime, pindexFirst->nReleasedReserve[0] / COIN, 100.0 * nChainMod, GetDifficulty(pindexFirst->nBits, 2), GetDifficulty(bnNew.GetCompact(), 2), pindexFirst->nChannelHeight, nDays, nHours, nMinutes); } return bnNew.GetCompact(); }
/** Proof of Stake Retargeting: Modulate Difficulty based on production rate. **/ unsigned int RetargetPOS(const CBlockIndex* pindex, bool output) { /** Get Last Block Index [1st block back in Channel]. **/ const CBlockIndex* pindexFirst = GetLastChannelIndex(pindex, 0); if (pindexFirst->pprev == NULL) return bnProofOfWorkStart[0].GetCompact(); /** Get Last Block Index [2nd block back in Channel]. **/ const CBlockIndex* pindexLast = GetLastChannelIndex(pindexFirst->pprev, 0); if (pindexLast->pprev == NULL) return bnProofOfWorkStart[0].GetCompact(); /** Get the Block Time and Target Spacing. **/ int64 nBlockTime = GetWeightedTimes(pindexFirst, 5); int64 nBlockTarget = STAKE_TARGET_SPACING; /** The Upper and Lower Bound Adjusters. **/ int64 nUpperBound = nBlockTarget; int64 nLowerBound = nBlockTarget; /** If the time is above target, reduce difficulty by modular of one interval past timespan multiplied by maximum decrease. **/ if(nBlockTime >= nBlockTarget) { /** Take the Minimum overlap of Target Timespan to make that maximum interval. **/ uint64 nOverlap = (uint64)min((nBlockTime - nBlockTarget), (nBlockTarget * 2)); /** Get the Mod from the Proportion of Overlap in one Interval. **/ double nProportions = (double)nOverlap / (nBlockTarget * 2); /** Get Mod from Maximum Decrease Equation with Decimal portions multiplied by Propotions. **/ double nMod = 1.0 - (0.15 * nProportions); nLowerBound = nBlockTarget * nMod; } /** If the time is below target, increase difficulty by modular of interval of 1 - Block Target with time of 1 being maximum increase **/ else { /** Get the overlap in reference from Target Timespan. **/ uint64 nOverlap = nBlockTarget - nBlockTime; /** Get the mod from overlap proportion. Time of 1 will be closest to mod of 1. **/ double nProportions = (double) nOverlap / nBlockTarget; /** Get the Mod from the Maximum Increase Equation with Decimal portion multiplied by Proportions. **/ double nMod = 1.0 + (nProportions * 0.075); nLowerBound = nBlockTarget * nMod; } /** Get the Difficulty Stored in Bignum Compact. **/ CBigNum bnNew; bnNew.SetCompact(pindexFirst->nBits); /** Change Number from Upper and Lower Bounds. **/ bnNew *= nUpperBound; bnNew /= nLowerBound; /** Don't allow Difficulty to decrease below minimum. **/ if (bnNew > bnProofOfWorkLimit[0]) bnNew = bnProofOfWorkLimit[0]; if(output) { int64 nDays, nHours, nMinutes; GetChainTimes(GetChainAge(pindexFirst->GetBlockTime()), nDays, nHours, nMinutes); printf("CHECK[POS] weighted time=%"PRId64" actual time =%"PRId64"[%f %%]\n\tchain time: [%"PRId64" / %"PRId64"]\n\tdifficulty: [%f to %f]\n\tPOS height: %"PRId64" [AGE %"PRId64" days, %"PRId64" hours, %"PRId64" minutes]\n\n", nBlockTime, max(pindexFirst->GetBlockTime() - pindexLast->GetBlockTime(), (int64) 1), ((100.0 * nLowerBound) / nUpperBound), nBlockTarget, nBlockTime, GetDifficulty(pindexFirst->nBits, 0), GetDifficulty(bnNew.GetCompact(), 0), pindexFirst->nChannelHeight, nDays, nHours, nMinutes); } return bnNew.GetCompact(); }