From: CryptoManiac Date: Mon, 7 Sep 2015 21:05:50 +0000 (+0300) Subject: GetProofOfStakeReward X-Git-Url: https://git.novaco.in/?p=NovacoinLibrary.git;a=commitdiff_plain;h=bc970ef64962497a7e29d49c9d8b1f7945eb77c0 GetProofOfStakeReward --- diff --git a/Novacoin/CBlock.cs b/Novacoin/CBlock.cs index bf487cf..6c10d6e 100644 --- a/Novacoin/CBlock.cs +++ b/Novacoin/CBlock.cs @@ -517,9 +517,84 @@ namespace Novacoin return Math.Min(nSubsidy, NetInfo.nMaxMintProofOfWork) + nFees; } - internal static ulong GetProofOfStakeReward(ulong nCoinAge, uint nBits, uint nTime) + public static ulong GetProofOfStakeReward(ulong nCoinAge, uint nBits, uint nTime) { - throw new NotImplementedException(); + ulong nRewardCoinYear, nSubsidy, nSubsidyLimit = 10 * CTransaction.nCoin; + + if (nTime > NetInfo.nDynamicStakeRewardTime) + { + // Stage 2 of emission process is PoS-based. It will be active on mainNet since 20 Jun 2013. + + BigInteger bnRewardCoinYearLimit = NetInfo.nMaxMintProofOfStake; // Base stake mint rate, 100% year interest + + uint256 nTarget = 0; + nTarget.Compact = nBits; + + BigInteger bnTarget = new BigInteger(nTarget); + BigInteger bnTargetLimit = new BigInteger(NetInfo.GetProofOfStakeLimit(0, nTime)); + + // NovaCoin: A reasonably continuous curve is used to avoid shock to market + + BigInteger bnLowerBound = CTransaction.nCent, // Lower interest bound is 1% per year + bnUpperBound = bnRewardCoinYearLimit, // Upper interest bound is 100% per year + bnMidPart, bnRewardPart; + + while (bnLowerBound + CTransaction.nCent <= bnUpperBound) + { + BigInteger bnMidValue = (bnLowerBound + bnUpperBound) / 2; + if (nTime < NetInfo.nStakeCurveSwitchTime) + { + // + // Until 20 Oct 2013: reward for coin-year is cut in half every 64x multiply of PoS difficulty + // + // (nRewardCoinYearLimit / nRewardCoinYear) ** 6 == bnProofOfStakeLimit / bnTarget + // + // Human readable form: nRewardCoinYear = 1 / (posdiff ^ 1/6) + // + + bnMidPart = bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue * bnMidValue; + bnRewardPart = bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit; + } + else + { + // + // Since 20 Oct 2013: reward for coin-year is cut in half every 8x multiply of PoS difficulty + // + // (nRewardCoinYearLimit / nRewardCoinYear) ** 3 == bnProofOfStakeLimit / bnTarget + // + // Human readable form: nRewardCoinYear = 1 / (posdiff ^ 1/3) + // + + bnMidPart = bnMidValue * bnMidValue * bnMidValue; + bnRewardPart = bnRewardCoinYearLimit * bnRewardCoinYearLimit * bnRewardCoinYearLimit; + } + + if (bnMidPart * bnTargetLimit > bnRewardPart * bnTarget) + bnUpperBound = bnMidValue; + else + bnLowerBound = bnMidValue; + } + + nRewardCoinYear = (ulong)bnUpperBound; + nRewardCoinYear = Math.Min((nRewardCoinYear / CTransaction.nCent) * CTransaction.nCent, NetInfo.nMaxMintProofOfStake); + } + else + { + // Old creation amount per coin-year, 5% fixed stake mint rate + nRewardCoinYear = 5 * CTransaction.nCent; + } + + nSubsidy = nCoinAge * nRewardCoinYear * 33 / (365 * 33 + 8); + + // Set reasonable reward limit for large inputs since 20 Oct 2013 + // + // This will stimulate large holders to use smaller inputs, that's good for the network protection + if (NetInfo.nStakeCurveSwitchTime < nTime) + { + nSubsidy = Math.Min(nSubsidy, nSubsidyLimit); + } + + return nSubsidy; } } } diff --git a/Novacoin/NetInfo.cs b/Novacoin/NetInfo.cs index 345d7ae..6db6c22 100644 --- a/Novacoin/NetInfo.cs +++ b/Novacoin/NetInfo.cs @@ -1,6 +1,4 @@ -using System; - -namespace Novacoin +namespace Novacoin { /// /// Basic network params. @@ -43,11 +41,26 @@ namespace Novacoin public const uint nChainChecksSwitchTime = 1379635200; /// + /// Sat, 20 Jul 2013 00:00:00 GMT + /// + public const uint nTargetsSwitchTime = 1374278400; + + /// /// Wed, 20 Aug 2014 00:00:00 GMT /// public const uint nStakeValidationSwitchTime = 1408492800; /// + /// Thu, 20 Jun 2013 00:00:00 GMT + /// + public const uint nDynamicStakeRewardTime = 1371686400; + + /// + /// Sun, 20 Oct 2013 00:00:00 GMT + /// + public const uint nStakeCurveSwitchTime = 1382227200; + + /// /// Hash of block #0 /// public static uint256 nHashGenesisBlock = new uint256("00000a060336cbb72fe969666d337b87198b1add2abaa59cca226820b32933a4"); @@ -64,6 +77,11 @@ namespace Novacoin /// public const ulong nMaxMintProofOfWork = CTransaction.nCoin * 100; + /// + /// Maximum possible proof-of-stake reward per coin*year. + /// + public const ulong nMaxMintProofOfStake = CTransaction.nCoin * 100; + public static uint GetAdjustedTime() { return Interop.GetTime(); @@ -78,5 +96,17 @@ namespace Novacoin { return nTime - nDrift; // up to 2 hours from the past } + + internal static uint256 GetProofOfStakeLimit(uint nHeight, uint nTime) + { + if (nTime > nTargetsSwitchTime) // 27 bits since 20 July 2013 + return nProofOfStakeLimit; + if (nHeight + 1 > 15000) // 24 bits since block 15000 + return nProofOfStakeLegacyLimit; + if (nHeight + 1 > 14060) // 31 bits since block 14060 until 15000 + return nProofOfStakeHardLimit; + + return nProofOfWorkLimit; // return bnProofOfWorkLimit of none matched + } } } \ No newline at end of file