Reinstate previous testnet adjustment behaviour
When the difficulty adjustment algorithm was altered, the special testnet min-difficulty case was maintained, but the difficulty adjustment for the following block then adjusted from min-difficulty instead of from the last non-min-difficulty block. This caused the difficulty on the testnet to sawtooth instead of stabilising. The intended behaviour is restored here.
This commit is contained in:
parent
cebeabb2f4
commit
e99731b4a4
21
src/pow.cpp
21
src/pow.cpp
|
@ -24,14 +24,20 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
|
|||
if (pindexLast == NULL)
|
||||
return nProofOfWorkLimit;
|
||||
|
||||
const CBlockIndex* pindexBits = pindexLast;
|
||||
{
|
||||
if (params.fPowAllowMinDifficultyBlocks)
|
||||
{
|
||||
// Special difficulty rule for testnet:
|
||||
// If the new block's timestamp is more than 2* 10 minutes
|
||||
// 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 {
|
||||
// Get the last non-min-difficulty (or at worst the genesis difficulty)
|
||||
while (pindexBits->pprev && pindexBits->nBits == nProofOfWorkLimit)
|
||||
pindexBits = pindexBits->pprev;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -45,14 +51,19 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
|
|||
if (pindexFirst == NULL)
|
||||
return nProofOfWorkLimit;
|
||||
|
||||
return CalculateNextWorkRequired(pindexLast, pindexFirst->GetMedianTimePast(), params);
|
||||
return CalculateNextWorkRequired(pindexBits->nBits, pindexLast->GetMedianTimePast(), pindexFirst->GetMedianTimePast(), params);
|
||||
}
|
||||
|
||||
unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)
|
||||
{
|
||||
return CalculateNextWorkRequired(pindexLast->nBits, pindexLast->GetMedianTimePast(), nFirstBlockTime, params);
|
||||
}
|
||||
|
||||
unsigned int CalculateNextWorkRequired(uint32_t nBits, int64_t nLastBlockTime, int64_t nFirstBlockTime, const Consensus::Params& params)
|
||||
{
|
||||
// Limit adjustment step
|
||||
// Use medians to prevent time-warp attacks
|
||||
int64_t nActualTimespan = pindexLast->GetMedianTimePast() - nFirstBlockTime;
|
||||
int64_t nActualTimespan = nLastBlockTime - nFirstBlockTime;
|
||||
LogPrint("pow", " nActualTimespan = %d before dampening\n", nActualTimespan);
|
||||
nActualTimespan = params.AveragingWindowTimespan() + (nActualTimespan - params.AveragingWindowTimespan())/4;
|
||||
LogPrint("pow", " nActualTimespan = %d before bounds\n", nActualTimespan);
|
||||
|
@ -66,7 +77,7 @@ unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nF
|
|||
const arith_uint256 bnPowLimit = UintToArith256(params.powLimit);
|
||||
arith_uint256 bnNew;
|
||||
arith_uint256 bnOld;
|
||||
bnNew.SetCompact(pindexLast->nBits);
|
||||
bnNew.SetCompact(nBits);
|
||||
bnOld = bnNew;
|
||||
bnNew /= params.AveragingWindowTimespan();
|
||||
bnNew *= nActualTimespan;
|
||||
|
@ -77,7 +88,7 @@ unsigned int CalculateNextWorkRequired(const CBlockIndex* pindexLast, int64_t nF
|
|||
/// debug print
|
||||
LogPrint("pow", "GetNextWorkRequired RETARGET\n");
|
||||
LogPrint("pow", "params.AveragingWindowTimespan() = %d nActualTimespan = %d\n", params.AveragingWindowTimespan(), nActualTimespan);
|
||||
LogPrint("pow", "Before: %08x %s\n", pindexLast->nBits, bnOld.ToString());
|
||||
LogPrint("pow", "Before: %08x %s\n", nBits, bnOld.ToString());
|
||||
LogPrint("pow", "After: %08x %s\n", bnNew.GetCompact(), bnNew.ToString());
|
||||
|
||||
return bnNew.GetCompact();
|
||||
|
|
|
@ -18,6 +18,7 @@ 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&);
|
||||
|
||||
/** Check whether the Equihash solution in a block header is valid */
|
||||
bool CheckEquihashSolution(const CBlockHeader *pblock, const CChainParams&);
|
||||
|
|
Loading…
Reference in New Issue