unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
assert(pindexLast != nullptr);
int nHeight = pindexLast->nHeight + 1;
bool postfork = nHeight >= params.BTGHeight;
unsigned int nProofOfWorkLimit = UintToArith256(params.PowLimit(postfork)).GetCompact();
if (postfork == false) {
return BitcoinGetNextWorkRequired(pindexLast, pblock, params);
}
else if (nHeight < params.BTGHeight + params.BTGPremineWindow) {
return nProofOfWorkLimit;
}
else if (nHeight < params.BTGHeight + params.BTGPremineWindow + params.nPowAveragingWindow){
return UintToArith256(params.powLimitStart).GetCompact();
}
const CBlockIndex* pindexFirst = pindexLast;
arith_uint256 bnTot {0};
for (int i = 0; pindexFirst && i < params.nPowAveragingWindow; i++) {
arith_uint256 bnTmp;
bnTmp.SetCompact(pindexFirst->nBits);
bnTot += bnTmp;
pindexFirst = pindexFirst->pprev;
}
if (pindexFirst == NULL)
return nProofOfWorkLimit;
arith_uint256 bnAvg {bnTot / params.nPowAveragingWindow};
return CalculateNextWorkRequired(bnAvg, pindexLast->GetMedianTimePast(), pindexFirst->GetMedianTimePast(), params);
}
unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;
// Find the first block in the averaging interval
const CBlockIndex* pindexFirst = pindexLast;
arith_uint256 bnTot {0};
for (int i = 0; pindexFirst && i < params.nPowAveragingWindow; i++) {
arith_uint256 bnTmp;
bnTmp.SetCompact(pindexFirst->nBits);
bnTot += bnTmp;
pindexFirst = pindexFirst->pprev;
}
// Check we have enough blocks
if (pindexFirst == NULL)
return nProofOfWorkLimit;
arith_uint256 bnAvg {bnTot / params.nPowAveragingWindow};
return CalculateNextWorkRequired(bnAvg, pindexLast->GetMedianTimePast(), pindexFirst->GetMedianTimePast(), params);
}
unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;
// Only change once per difficulty adjustment interval
if ((pindexLast->nHeight+1) % params.DifficultyAdjustmentInterval() != 0)
{
if (params.AllowMinDifficultyBlocks(pblock->GetBlockTime()))
{
/* khal's port of this code from Bitcoin to the old namecoind
has a bug: Comparison of block times is done by an unsigned
difference. Consequently, the minimum difficulty is also
applied if the block's timestamp is earlier than the preceding
block's. Reproduce this. */
if (pblock->GetBlockTime() < pindexLast->GetBlockTime())
return nProofOfWorkLimit;
// Special difficulty rule for testnet:
// If the new block's timestamp is more than 2* 10 minutes
// then allow mining of a min-difficulty block.
if (pblock->GetBlockTime() > pindexLast->GetBlockTime() + params.nPowTargetSpacing*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % params.DifficultyAdjustmentInterval() != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}
return pindexLast->nBits;
}
/* Adapt the retargeting interval after merge-mining start
according to the changed Namecoin rules. */
int nBlocksBack = params.DifficultyAdjustmentInterval() - 1;
if (pindexLast->nHeight >= params.nAuxpowStartHeight
&& (pindexLast->nHeight + 1 > params.DifficultyAdjustmentInterval()))
nBlocksBack = params.DifficultyAdjustmentInterval();
// Go back by what we want to be 14 days worth of blocks
int nHeightFirst = pindexLast->nHeight - nBlocksBack;
assert(nHeightFirst >= 0);
const CBlockIndex* pindexFirst = pindexLast->GetAncestor(nHeightFirst);
assert(pindexFirst);
return CalculateNextWorkRequired(pindexLast, pindexFirst->GetBlockTime(), params);
}
// DigiShield retargeting
unsigned int GetNextWorkRequired_V2(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;
// Only change once per interval
if ((pindexLast->nHeight+1) % params.DifficultyAdjustmentIntervalV2() != 0)
{
if (params.fPowAllowMinDifficultyBlocks)
{
// Special difficulty rule for testnet:
// If the new block's timestamp is more than 2* nTargetSpacing minutes
// then allow mining of a min-difficulty block.
if (pblock->GetBlockTime() > pindexLast->GetBlockTime() + params.nPowTargetSpacingV2*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % params.DifficultyAdjustmentIntervalV2() != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}
return pindexLast->nBits;
}
// Machinecoin: 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 = params.DifficultyAdjustmentIntervalV2()-1;
if ((pindexLast->nHeight+1) != params.DifficultyAdjustmentIntervalV2())
blockstogoback = params.DifficultyAdjustmentIntervalV2();
// Go back by what we want to be 14 days worth of blocks
const CBlockIndex* pindexFirst = pindexLast;
for (int i = 0; pindexFirst && i < blockstogoback; i++)
pindexFirst = pindexFirst->pprev;
assert(pindexFirst);
return CalculateNextWorkRequired(pindexLast, pindexFirst->GetBlockTime(), params);
}
unsigned int GetNextWorkRequiredBTC(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;
// Only change once per interval
if ((pindexLast->nHeight+1) % params.DifficultyAdjustmentInterval() != 0)
{
if (params.fPowAllowMinDifficultyBlocks)
{
// Special difficulty rule for testnet:
// If the new block's timestamp is more than 2* 2.5 minutes
// then allow mining of a min-difficulty block.
if (pblock->GetBlockTime() > pindexLast->GetBlockTime() + params.nPowTargetSpacing*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % params.DifficultyAdjustmentInterval() != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}
return pindexLast->nBits;
}
// Go back by what we want to be 1 day worth of blocks
int nHeightFirst = pindexLast->nHeight - (params.DifficultyAdjustmentInterval()-1);
assert(nHeightFirst >= 0);
const CBlockIndex* pindexFirst = pindexLast->GetAncestor(nHeightFirst);
assert(pindexFirst);
return CalculateNextWorkRequired(pindexLast, pindexFirst->GetBlockTime(), params);
}
unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
{
return CalculateNextWorkRequired(pindexLast, 0, params);
}
