Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Testnet difficulty calculation changes, to take effect Feb 15 2012 #686

Merged
merged 1 commit into from Jan 31, 2012
+29 −4
Merged

Testnet difficulty calculation changes, to take effect Feb 15 2012 #686

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
33 changes: 29 additions & 4 deletions src/main.cpp
View file
Open in desktop
Expand Up @@ -768,6 +768,11 @@ static const int64 nInterval = nTargetTimespan / nTargetSpacing;
//
unsigned int ComputeMinWork(unsigned int nBase, int64 nTime)
{
// Testnet has min-difficulty blocks
// after nTargetSpacing*2 time between blocks:
if (fTestNet && nTime > nTargetSpacing*2)
return bnProofOfWorkLimit.GetCompact();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm not sure whether this affects anything, but this does not check pblock->nTime > 1326585600 like the other one.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It is OK-- the code that calls ComputeMinWork call pblock->GetBlockTime() which just return pblock->nTime.


CBigNum bnResult;
bnResult.SetCompact(nBase);
while (nTime > 0 && bnResult < bnProofOfWorkLimit)
Expand All @@ -782,16 +787,36 @@ unsigned int ComputeMinWork(unsigned int nBase, int64 nTime)
return bnResult.GetCompact();
}

unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast)
unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlock *pblock)
{
unsigned int nProofOfWorkLimit = bnProofOfWorkLimit.GetCompact();

// Genesis block
if (pindexLast == NULL)
return bnProofOfWorkLimit.GetCompact();
return nProofOfWorkLimit;

// Only change once per interval
if ((pindexLast->nHeight+1) % nInterval != 0)
{
// Special rules for testnet after 15 Feb 2012:
if (fTestNet && pblock->nTime > 1329264000)
{
// If the new block's timestamp is more than 2* 10 minutes
// then allow mining of a min-difficulty block.
if (pblock->nTime - pindexLast->nTime > nTargetSpacing*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % nInterval != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}

return pindexLast->nBits;
}

// Go back by what we want to be 14 days worth of blocks
const CBlockIndex* pindexFirst = pindexLast;
Expand Down Expand Up @@ -1540,7 +1565,7 @@ bool CBlock::AcceptBlock()
int nHeight = pindexPrev->nHeight+1;

// Check proof of work
if (nBits != GetNextWorkRequired(pindexPrev))
if (nBits != GetNextWorkRequired(pindexPrev, this))
return DoS(100, error("AcceptBlock() : incorrect proof of work"));

// Check timestamp against prev
Expand Down Expand Up @@ -3120,7 +3145,7 @@ CBlock* CreateNewBlock(CReserveKey& reservekey)
pblock->hashPrevBlock = pindexPrev->GetBlockHash();
pblock->hashMerkleRoot = pblock->BuildMerkleTree();
pblock->nTime = max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
pblock->nBits = GetNextWorkRequired(pindexPrev);
pblock->nBits = GetNextWorkRequired(pindexPrev, pblock.get());
pblock->nNonce = 0;

return pblock.release();
Expand Down