/// <inheritdoc/>
public ChainedHeader GetLastPowPosChainedBlock(IStakeChain stakeChain, ChainedHeader startChainedHeader, bool proofOfStake)
{
Guard.Assert(startChainedHeader != null);
BlockStake blockStake = stakeChain.Get(startChainedHeader.HashBlock);
while ((startChainedHeader.Previous != null) && (blockStake.IsProofOfStake() != proofOfStake))
{
startChainedHeader = startChainedHeader.Previous;
blockStake = stakeChain.Get(startChainedHeader.HashBlock);
}
return(startChainedHeader);
}
/// <inheritdoc />
public ChainedHeader GetLastPowPosChainedBlock(IStakeChain stakeChain, ChainedHeader startChainedHeader,
bool proofOfStake)
{
Guard.NotNull(stakeChain, nameof(stakeChain));
Guard.Assert(startChainedHeader != null);
var blockStake = stakeChain.Get(startChainedHeader.HashBlock);
while (startChainedHeader.Previous != null && blockStake.IsProofOfStake() != proofOfStake)
{
startChainedHeader = startChainedHeader.Previous;
blockStake = stakeChain.Get(startChainedHeader.HashBlock);
}
return(startChainedHeader);
}
/// <inheritdoc/>
public ChainedHeader GetLastPowPosChainedBlock(IStakeChain stakeChain, ChainedHeader startChainedHeader, bool proofOfStake)
{
Guard.Assert(startChainedHeader != null);
this.logger.LogTrace("({0}:'{1}',{2}:{3})", nameof(startChainedHeader), startChainedHeader, nameof(proofOfStake), proofOfStake);
BlockStake blockStake = stakeChain.Get(startChainedHeader.HashBlock);
while ((startChainedHeader.Previous != null) && (blockStake.IsProofOfStake() != proofOfStake))
{
startChainedHeader = startChainedHeader.Previous;
blockStake = stakeChain.Get(startChainedHeader.HashBlock);
}
this.logger.LogTrace("(-)':{0}'", startChainedHeader);
return(startChainedHeader);
}
/// <inheritdoc/>
public Target GetNextTargetRequired(IStakeChain stakeChain, ChainedHeader chainTip, IConsensus consensus, bool proofOfStake)
{
Guard.NotNull(stakeChain, nameof(stakeChain));
// If the chain uses a PosPowRatchet, we branch away here, 4 blocks after it has activated. A safe delta of 4
// is used, so that when we iterate over blocks backwards, we'll never hit non-Ratchet blocks.
if (consensus.Options is X1ConsensusOptions options &&
options.IsPosPowRatchetActiveAtHeight(chainTip.Height - 4))
{
bool isChainTipProofOfStake = stakeChain.Get(chainTip.HashBlock).IsProofOfStake();
if (isChainTipProofOfStake && chainTip.Height % 2 != 0 || !isChainTipProofOfStake && chainTip.Height % 2 == 0)
{
throw new InvalidOperationException("Misconfiguration: When the ratchet is active for a height, the convention that PoS block heights are even numbers, must be met.");
}
return(options.GetNextTargetRequired(chainTip, isChainTipProofOfStake, consensus, proofOfStake));
}
// Genesis block.
if (chainTip == null)
{
this.logger.LogTrace("(-)[GENESIS]:'{0}'", consensus.PowLimit);
return(consensus.PowLimit);
}
// Find the last two blocks that correspond to the mining algo
// (i.e if this is a POS block we need to find the last two POS blocks).
BigInteger targetLimit = proofOfStake
? consensus.ProofOfStakeLimitV2
: consensus.PowLimit.ToBigInteger();
// First block.
ChainedHeader lastPowPosBlock = this.GetLastPowPosChainedBlock(stakeChain, chainTip, proofOfStake);
if (lastPowPosBlock.Previous == null)
{
var res = new Target(targetLimit);
this.logger.LogTrace("(-)[FIRST_BLOCK]:'{0}'", res);
return(res);
}
// Second block.
ChainedHeader prevLastPowPosBlock = this.GetLastPowPosChainedBlock(stakeChain, lastPowPosBlock.Previous, proofOfStake);
if (prevLastPowPosBlock.Previous == null)
{
var res = new Target(targetLimit);
this.logger.LogTrace("(-)[SECOND_BLOCK]:'{0}'", res);
return(res);
}
// This is used in tests to allow quickly mining blocks.
if (!proofOfStake && consensus.PowNoRetargeting)
{
this.logger.LogTrace("(-)[NO_POW_RETARGET]:'{0}'", lastPowPosBlock.Header.Bits);
return(lastPowPosBlock.Header.Bits);
}
if (proofOfStake && consensus.PosNoRetargeting)
{
this.logger.LogTrace("(-)[NO_POS_RETARGET]:'{0}'", lastPowPosBlock.Header.Bits);
return(lastPowPosBlock.Header.Bits);
}
Target finalTarget = this.CalculateRetarget(lastPowPosBlock.Header.Time, lastPowPosBlock.Header.Bits, prevLastPowPosBlock.Header.Time, targetLimit);
return(finalTarget);
}