return bnResult.GetCompact();
}
-unsigned int static GetNextWorkRequired(const CBlockIndex* pindexLast)
+// ppcoin: find last block index up to pindex
+const CBlockIndex* GetLastBlockIndex(const CBlockIndex* pindex, bool fProofOfStake)
+{
+ while (pindex && (pindex->IsProofOfStake() != fProofOfStake))
+ pindex = pindex->pprev;
+ return pindex;
+}
+
+unsigned int static GetNextTargetRequired(const CBlockIndex* pindexLast, bool fProofOfStake)
{
// Genesis block and first block
if (pindexLast == NULL || pindexLast->pprev == NULL)
return bnProofOfWorkLimit.GetCompact();
- int64 nActualSpacing = pindexLast->GetBlockTime() - pindexLast->pprev->GetBlockTime();
+ const CBlockIndex* pindexPrev = GetLastBlockIndex(pindexLast, fProofOfStake);
+ if (pindexPrev == NULL)
+ return bnProofOfWorkLimit.GetCompact();
+ const CBlockIndex* pindexPrevPrev = GetLastBlockIndex(pindexPrev->pprev, fProofOfStake);
+ if (pindexPrevPrev == NULL)
+ return bnProofOfWorkLimit.GetCompact();
+ int64 nActualSpacing = pindexPrev->GetBlockTime() - pindexPrevPrev->GetBlockTime();
// ppcoin: target change every block
// ppcoin: retarget with exponential moving toward target spacing
if (!CheckBlock())
return false;
+ // ppcoin: coin stake tx must meet target protocol
+ if (IsProofOfStake() && !vtx[1].CheckProofOfStake(txdb, nBits))
+ return error("ConnectBlock() : Block %s unable to meet hash target for coinstake", GetHash().ToString().c_str());
+
//// issue here: it doesn't know the version
- unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - 1 + GetSizeOfCompactSize(vtx.size());
+ unsigned int nTxPos = pindex->nBlockPos + ::GetSerializeSize(CBlock(), SER_DISK) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(vtx.size());
map<uint256, CTxIndex> mapQueuedChanges;
int64 nFees = 0;
}
+// ppcoin: coinstake must meet hash target according to the protocol:
+// at least one input must meet the formula
+// hash(nBits + txPrev.block.nTime + txPrev.nTime + nTime) < bnTarget * nCoinDay
+// this ensures that the chance of getting a coinstake is proportional to the
+// amount of coin age one owns.
+// The reason this hash is chosen is the following:
+// nBits: encodes all past block timestamps, prevents computing hash in advance
+// txPrev.block.nTime: prevent nodes from guessing a good timestamp to generate
+// transaction for future advantage
+// txPrev.nTime: prevent nodes from meeting target simultaneously
+// block/tx hash should not be used here as they can be generated in vast quatities
+// so as to generate blocks faster, degrading the system back into a proof-of-work
+// situation.
+//
+bool CTransaction::CheckProofOfStake(CTxDB& txdb, unsigned int nBits) const
+{
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+
+ if (!IsCoinStake())
+ return true;
+
+ BOOST_FOREACH(const CTxIn& txin, vin)
+ {
+ // First try finding the previous transaction in database
+ CTransaction txPrev;
+ CTxIndex txindex;
+ if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
+ continue; // previous transaction not in main chain
+ if (nTime < txPrev.nTime)
+ return false; // Transaction timestamp violation
+
+ // Read block header
+ CBlock block;
+ if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
+ return false; // unable to read block of previous transaction
+ if (block.GetBlockTime() + AUTO_CHECKPOINT_TRUST_SPAN > nTime)
+ continue; // only count coins from at least one week ago
+
+ int64 nValueIn = txPrev.vout[txin.prevout.n].nValue;
+ CBigNum bnCoinDay = CBigNum(nValueIn) * (nTime-txPrev.nTime) / COIN / (24 * 60 * 60);
+ // Calculate hash
+ CDataStream ss(SER_GETHASH, VERSION);
+ ss << nBits << block.nTime << txPrev.nTime << nTime;
+ if (CBigNum(Hash(ss.begin(), ss.end())) <= bnCoinDay * bnTargetPerCoinDay)
+ return true;
+ }
+
+ return false;
+}
+
// ppcoin: total coin age spent in transaction, in the unit of coin-days.
// Only those coins last spent at least a week ago count. As those
// transactions not in main chain are not currently indexed so we
return DoS(100, error("CheckBlock() : size limits failed"));
// Check proof of work matches claimed amount
- if (!CheckProofOfWork(GetHash(), nBits))
+ if (IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits))
return DoS(50, error("CheckBlock() : proof of work failed"));
// Check timestamp
if (hashMerkleRoot != BuildMerkleTree())
return DoS(100, error("CheckBlock() : hashMerkleRoot mismatch"));
+ // Coin base vout[0] scriptPubKey must be the same as coin stake vout[1]
+ // scriptPubKey
+ if (vtx.size() > 1 && vtx[1].IsCoinStake() &&
+ vtx[0].vout[0].scriptPubKey != vtx[1].vout[1].scriptPubKey)
+ return DoS(100, error("CheckBlock() : block key mismatch"));
+
+
// Check block signature
if (!CheckBlockSignature())
return DoS(100, error("CheckBlock() : bad block signature"));
CBlockIndex* pindexPrev = (*mi).second;
int nHeight = pindexPrev->nHeight+1;
- // Check proof of work
- if (nBits != GetNextWorkRequired(pindexPrev))
- return DoS(100, error("AcceptBlock() : incorrect proof of work"));
+ // ppcoin: check for coinstake duplicate
+ if (IsProofOfStake())
+ { // check if coinstake is already connected; that would imply the owner
+ // of the coinstake sent multiple blocks with the same coinstake
+ CTxIndex txindex;
+ if (CTxDB("r").ReadTxIndex(vtx[1].GetHash(), txindex))
+ return error("AcceptBlock() : block %s has duplicate coinstake %s", hash.ToString().c_str(), vtx[1].GetHash().ToString().c_str());
+ }
+
+ // Check proof-of-work or proof-of-stake
+ if (nBits != GetNextTargetRequired(pindexPrev, IsProofOfStake()))
+ return DoS(100, error("AcceptBlock() : incorrect proof-of-work/proof-of-stake"));
// Check timestamp against prev
if (GetBlockTime() <= pindexPrev->GetMedianTimePast() || GetBlockTime() + nMaxClockDrift < pindexPrev->GetBlockTime())
bnNewBlock.SetCompact(pblock->nBits);
CBigNum bnRequired;
bnRequired.SetCompact(ComputeMinWork(pcheckpoint->nBits, deltaTime));
- if (bnNewBlock > bnRequired)
+ if (pblock->IsProofOfWork() && bnNewBlock > bnRequired)
{
pfrom->Misbehaving(100);
return error("ProcessBlock() : block with too little proof-of-work");
assert(block.hashMerkleRoot == uint256("0xc7311b56de266580cca65be108ae53d7100b5c3b17da8b1106044103abd7a521"));
block.print();
assert(block.GetHash() == hashGenesisBlock);
+ assert(block.CheckBlock());
// Start new block file
unsigned int nFile;
pblock->vtx.push_back(txNew);
// ppcoin: if coinstake available add coinstake tx
- CTransaction txCoinStake;
- if (pwallet->CreateCoinStake(txNew.vout[0].scriptPubKey, txCoinStake))
- pblock->vtx.push_back(txCoinStake);
+ static unsigned int nLastCoinStakeCheckTime = GetAdjustedTime() - nMaxClockDrift; // only initialized at startup
+ pblock->nBits = GetNextTargetRequired(pindexPrev, true);
+ while (nLastCoinStakeCheckTime < GetAdjustedTime())
+ {
+ static CCriticalSection cs;
+ CTransaction txCoinStake;
+ CRITICAL_BLOCK(cs)
+ {
+ nLastCoinStakeCheckTime++;
+ txCoinStake.nTime = nLastCoinStakeCheckTime;
+ }
+ if (pwallet->CreateCoinStake(txNew.vout[0].scriptPubKey, pblock->nBits, txCoinStake))
+ {
+ pblock->vtx.push_back(txCoinStake);
+ break;
+ }
+ }
+ if (pblock->IsProofOfWork())
+ pblock->nBits = GetNextTargetRequired(pindexPrev, false);
// Collect memory pool transactions into the block
int64 nFees = 0;
}
}
}
- pblock->nBits = GetNextWorkRequired(pindexPrev);
pblock->vtx[0].vout[0].nValue = GetProofOfWorkReward(pblock->nBits);
// Fill in header
uint256 hash = pblock->GetHash();
uint256 hashTarget = CBigNum().SetCompact(pblock->nBits).getuint256();
- if (hash > hashTarget)
- return false;
+ if (hash > hashTarget && pblock->IsProofOfWork())
+ return error("BitcoinMiner : proof-of-work not meeting target");
//// debug print
printf("BitcoinMiner:\n");
- printf("proof-of-work found \n hash: %s \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
+ printf("new block found \n hash: %s \ntarget: %s\n", hash.GetHex().c_str(), hashTarget.GetHex().c_str());
pblock->print();
printf("%s ", DateTimeStrFormat("%x %H:%M", GetTime()).c_str());
printf("generated %s\n", FormatMoney(pblock->vtx[0].vout[0].nValue).c_str());
auto_ptr<CBlock> pblock(CreateNewBlock(pwallet));
if (!pblock.get())
return;
+
+ // ppcoin: if proof-of-stake block found then process block
+ if (pblock->IsProofOfStake())
+ {
+ // should be able to sign block - assert here for now
+ assert(pblock->SignBlock(*pwalletMain));
+ printf("BitcoinMiner : proof-of-stake block found %s\n", pblock->GetHash().ToString().c_str());
+ SetThreadPriority(THREAD_PRIORITY_NORMAL);
+ CheckWork(pblock.get(), *pwalletMain, reservekey);
+ SetThreadPriority(THREAD_PRIORITY_LOWEST);
+ continue;
+ }
+
IncrementExtraNonce(pblock.get(), pindexPrev, nExtraNonce);
printf("Running BitcoinMiner with %d transactions in block\n", pblock->vtx.size());
git://git.novaco.in / novacoin.git / blobdiff