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Adjust from average difficulty instead of previous difficulty

This commit is contained in:
Jack Grigg 2016-09-05 22:25:11 +12:00
parent b181f7032b
commit 29842505cc
2 changed files with 21 additions and 9 deletions
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26
src/pow.cpp
View File

@ -43,7 +43,15 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
// Find the first block in the averaging interval
const CBlockIndex* pindexFirst = pindexLast;
arith_uint256 bnAvg;
arith_uint256 bnTmp;
for (int i = 0; pindexFirst && i < params.nPowAveragingWindow; i++) {
if (i == 0) {
bnAvg.SetCompact(pindexFirst->nBits);
} else {
bnTmp.SetCompact(pindexFirst->nBits);
bnAvg = ((bnAvg * i) + bnTmp) / (i + 1);
}
pindexFirst = pindexFirst->pprev;
}
@ -51,15 +59,20 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
if (pindexFirst == NULL)
return nProofOfWorkLimit;
return CalculateNextWorkRequired(pindexBits->nBits, pindexLast->GetMedianTimePast(), pindexFirst->GetMedianTimePast(), params);
return CalculateNextWorkRequired(bnAvg, pindexLast->GetMedianTimePast(), pindexFirst->GetMedianTimePast(), params);
}
// Left for testing purposes
unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)
{
return CalculateNextWorkRequired(pindexLast->nBits, pindexLast->GetMedianTimePast(), nFirstBlockTime, params);
arith_uint256 bnAvg;
bnAvg.SetCompact(pindexLast->nBits);
return CalculateNextWorkRequired(bnAvg, pindexLast->GetMedianTimePast(), nFirstBlockTime, params);
}
unsigned int CalculateNextWorkRequired(uint32_t nBits, int64_t nLastBlockTime, int64_t nFirstBlockTime, const Consensus::Params& params)
unsigned int CalculateNextWorkRequired(arith_uint256 bnAvg,
int64_t nLastBlockTime, int64_t nFirstBlockTime,
const Consensus::Params& params)
{
// Limit adjustment step
// Use medians to prevent time-warp attacks
@ -75,10 +88,7 @@ unsigned int CalculateNextWorkRequired(uint32_t nBits, int64_t nLastBlockTime, i
// Retarget
const arith_uint256 bnPowLimit = UintToArith256(params.powLimit);
arith_uint256 bnNew;
arith_uint256 bnOld;
bnNew.SetCompact(nBits);
bnOld = bnNew;
arith_uint256 bnNew {bnAvg};
bnNew /= params.AveragingWindowTimespan();
bnNew *= nActualTimespan;
@ -88,7 +98,7 @@ unsigned int CalculateNextWorkRequired(uint32_t nBits, int64_t nLastBlockTime, i
/// debug print
LogPrint("pow", "GetNextWorkRequired RETARGET\n");
LogPrint("pow", "params.AveragingWindowTimespan() = %d nActualTimespan = %d\n", params.AveragingWindowTimespan(), nActualTimespan);
LogPrint("pow", "Before: %08x %s\n", nBits, bnOld.ToString());
LogPrint("pow", "Current average: %08x %s\n", bnAvg.GetCompact(), bnAvg.ToString());
LogPrint("pow", "After: %08x %s\n", bnNew.GetCompact(), bnNew.ToString());
return bnNew.GetCompact();

4
src/pow.h
View File

@ -18,7 +18,9 @@ class arith_uint256;
unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params&);
unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params&);
unsigned int CalculateNextWorkRequired(uint32_t nBits, int64_t nLastBlockTime, int64_t nFirstBlockTime, const Consensus::Params&);
unsigned int CalculateNextWorkRequired(arith_uint256 bnAvg,
int64_t nLastBlockTime, int64_t nFirstBlockTime,
const Consensus::Params&);
/** Check whether the Equihash solution in a block header is valid */
bool CheckEquihashSolution(const CBlockHeader *pblock, const CChainParams&);