public bool CreateCoinStake(ChainedBlock pindexBest, uint bits, long nSearchInterval, long fees, ref Transaction txNew,
ref Key key)
{
var pindexPrev = pindexBest;
var bnTargetPerCoinDay = new Target(bits).ToCompact();
txNew.Inputs.Clear();
txNew.Outputs.Clear();
// Mark coin stake transaction
txNew.Outputs.Add(new TxOut(Money.Zero, new Script()));
// Choose coins to use
var nBalance = this.GetBalance().Satoshi;
if (nBalance <= this.reserveBalance)
{
return(false);
}
List <WalletTx> vwtxPrev = new List <WalletTx>();
List <WalletTx> setCoins;
long nValueIn = 0;
// Select coins with suitable depth
if (!SelectCoinsForStaking(nBalance - this.reserveBalance, txNew.Time, out setCoins, out nValueIn))
{
return(false);
}
// check if coins are already staking
// this is different from the c++ implementation
// which pushes the new block to the main chain
// and removes it when a longer chain is found
foreach (var walletTx in setCoins.ToList())
{
if (this.minerService.IsStaking(walletTx.Transactionid, walletTx.OutputIndex))
{
setCoins.Remove(walletTx);
}
}
if (setCoins.Empty())
{
return(false);
}
long nCredit = 0;
Script scriptPubKeyKernel = null;
foreach (var coin in setCoins)
{
int maxStakeSearchInterval = 60;
bool fKernelFound = false;
for (uint n = 0;
n < Math.Min(nSearchInterval, maxStakeSearchInterval) && !fKernelFound && pindexPrev == this.chainIndex.Tip;
n++)
{
var prevoutStake = new OutPoint(coin.Transactionid, coin.OutputIndex);
long nBlockTime = 0;
if (BlockValidator.CheckKernel(this.chainIndex, this.chainIndex, this.chainIndex, pindexPrev, bits,
txNew.Time - n, prevoutStake, ref nBlockTime))
{
scriptPubKeyKernel = coin.TxOut.ScriptPubKey;
key = null;
// calculate the key type
if (PayToPubkeyTemplate.Instance.CheckScriptPubKey(scriptPubKeyKernel))
{
var outPubKey = scriptPubKeyKernel.GetDestinationAddress(this.Context.Network);
key = this.walletStore.GetKey(outPubKey);
}
else if (PayToPubkeyHashTemplate.Instance.CheckScriptPubKey(scriptPubKeyKernel))
{
var outPubKey = scriptPubKeyKernel.GetDestinationAddress(this.Context.Network);
key = this.walletStore.GetKey(outPubKey);
}
else
{
//LogPrint("coinstake", "CreateCoinStake : no support for kernel type=%d\n", whichType);
break; // only support pay to public key and pay to address
}
// create a pubkey script form the current script
var scriptPubKeyOut = PayToPubkeyTemplate.Instance.GenerateScriptPubKey(key.PubKey); //scriptPubKeyKernel;
txNew.Time -= n;
txNew.AddInput(new TxIn(prevoutStake));
nCredit += coin.TxOut.Value;
vwtxPrev.Add(coin);
txNew.Outputs.Add(new TxOut(0, scriptPubKeyOut));
//LogPrint("coinstake", "CreateCoinStake : added kernel type=%d\n", whichType);
fKernelFound = true;
break;
}
}
if (fKernelFound)
{
break; // if kernel is found stop searching
}
}
if (nCredit == 0 || nCredit > nBalance - this.reserveBalance)
{
return(false);
}
foreach (var coin in setCoins)
{
var cointrx = coin;
//var coinIndex = coin.Value;
// Attempt to add more inputs
// Only add coins of the same key/address as kernel
if (txNew.Outputs.Count == 2 &&
(
cointrx.TxOut.ScriptPubKey == scriptPubKeyKernel ||
cointrx.TxOut.ScriptPubKey == txNew.Outputs[1].ScriptPubKey
) &&
cointrx.Transactionid != txNew.Inputs[0].PrevOut.Hash)
{
long nTimeWeight = BlockValidator.GetWeight((long)cointrx.Transaction.Time, (long)txNew.Time);
// Stop adding more inputs if already too many inputs
if (txNew.Inputs.Count >= 100)
{
break;
}
// Stop adding inputs if reached reserve limit
if (nCredit + cointrx.TxOut.Value > nBalance - this.reserveBalance)
{
break;
}
// Do not add additional significant input
if (cointrx.TxOut.Value >= GetStakeCombineThreshold())
{
continue;
}
// Do not add input that is still too young
if (BlockValidator.IsProtocolV3((int)txNew.Time))
{
// properly handled by selection function
}
else
{
if (nTimeWeight < BlockValidator.StakeMinAge)
{
continue;
}
}
txNew.Inputs.Add(new TxIn(new OutPoint(cointrx.Transactionid, cointrx.OutputIndex)));
nCredit += cointrx.TxOut.Value;
vwtxPrev.Add(coin);
}
}
// Calculate coin age reward
ulong nCoinAge;
if (!BlockValidator.GetCoinAge(this.chainIndex, this.chainIndex, this.chainIndex, txNew, pindexPrev, out nCoinAge))
{
return(false); //error("CreateCoinStake : failed to calculate coin age");
}
long nReward = BlockValidator.GetProofOfStakeReward(pindexPrev, nCoinAge, fees);
if (nReward <= 0)
{
return(false);
}
nCredit += nReward;
if (nCredit >= GetStakeSplitThreshold())
{
txNew.Outputs.Add(new TxOut(0, txNew.Outputs[1].ScriptPubKey)); //split stake
}
// Set output amount
if (txNew.Outputs.Count == 3)
{
txNew.Outputs[1].Value = (nCredit / 2 / BlockValidator.CENT) * BlockValidator.CENT;
txNew.Outputs[2].Value = nCredit - txNew.Outputs[1].Value;
}
else
{
txNew.Outputs[1].Value = nCredit;
}
// Sign
int nIn = 0;
foreach (var walletTx in vwtxPrev)
{
if (!SignSignature(new[] { key }, walletTx.Transaction, txNew, nIn++))
{
return(false); // error("CreateCoinStake : failed to sign coinstake");
}
}
// Limit size
int nBytes = txNew.GetSerializedSize(ProtocolVersion.PROTOCOL_VERSION, SerializationType.Network);
if (nBytes >= MAX_BLOCK_SIZE_GEN / 5)
{
return(false); // error("CreateCoinStake : exceeded coinstake size limit");
}
// Successfully generated coinstake
return(true);
}