extern int nStakeMaxAge;
extern int nStakeTargetSpacing;
+// Protocol switch time for fixed kernel modifier interval
+unsigned int nModifierSwitchTime = 1413763200; // Mon, 20 Oct 2014 00:00:00 GMT
+unsigned int nModifierTestSwitchTime = 1397520000; // Tue, 15 Apr 2014 00:00:00 GMT
+
+// Note: user must upgrade before the protocol switch deadline, otherwise it's required to
+// re-download the blockchain. The timestamp of upgrade is recorded in the blockchain
+// database.
+unsigned int nModifierUpgradeTime = 0;
+
typedef std::map<int, unsigned int> MapModifierCheckpoints;
// Hard checkpoints of stake modifiers to ensure they are deterministic
( 9690, 0x97dcdafau )
( 12661, 0x5d84115du )
( 37092, 0xd230afccu )
+ ( 44200, 0x05370164u )
+ ( 65000, 0xc8e7be6au )
+ ( 68600, 0x73a8cc4cu )
+ ( 92161, 0xe21a911au )
+ ( 98661, 0xd20c44d4u )
;
// Hard checkpoints of stake modifiers to ensure they are deterministic (testNet)
( 0, 0x0e00670bu )
;
+// Whether the given block is subject to new modifier protocol
+bool IsFixedModifierInterval(unsigned int nTimeBlock)
+{
+ return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime));
+}
+
+// Get time weight
+int64 GetWeight(int64 nIntervalBeginning, int64 nIntervalEnd)
+{
+ // Kernel hash weight starts from 0 at the 30-day min age
+ // this change increases active coins participating the hash and helps
+ // to secure the network when proof-of-stake difficulty is low
+ //
+ // Maximum TimeWeight is 90 days.
+
+ return min(nIntervalEnd - nIntervalBeginning - nStakeMinAge, (int64)nStakeMaxAge);
+}
+
// Get the last stake modifier and its generation time from a given block
static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64& nStakeModifier, int64& nModifierTime)
{
// select a block from the candidate blocks in vSortedByTimestamp, excluding
// already selected blocks in vSelectedBlocks, and with timestamp up to
// nSelectionIntervalStop.
-static bool SelectBlockFromCandidates(
- vector<pair<int64, uint256> >& vSortedByTimestamp,
- map<uint256, const CBlockIndex*>& mapSelectedBlocks,
- int64 nSelectionIntervalStop, uint64 nStakeModifierPrev,
- const CBlockIndex** pindexSelected)
+static bool SelectBlockFromCandidates(vector<pair<int64, uint256> >& vSortedByTimestamp, map<uint256, const CBlockIndex*>& mapSelectedBlocks,
+ int64 nSelectionIntervalStop, uint64 nStakeModifierPrev, const CBlockIndex** pindexSelected)
{
bool fSelected = false;
uint256 hashBest = 0;
// block. This is to make it difficult for an attacker to gain control of
// additional bits in the stake modifier, even after generating a chain of
// blocks.
-bool ComputeNextStakeModifier(const CBlockIndex* pindexPrev, uint64& nStakeModifier, bool& fGeneratedStakeModifier)
+bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64& nStakeModifier, bool& fGeneratedStakeModifier)
{
nStakeModifier = 0;
fGeneratedStakeModifier = false;
+ const CBlockIndex* pindexPrev = pindexCurrent->pprev;
if (!pindexPrev)
{
fGeneratedStakeModifier = true;
return true; // genesis block's modifier is 0
}
+
// First find current stake modifier and its generation block time
// if it's not old enough, return the same stake modifier
int64 nModifierTime = 0;
return error("ComputeNextStakeModifier: unable to get last modifier");
if (fDebug)
{
- printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str());
+ printf("ComputeNextStakeModifier: prev modifier=0x%016"PRI64x" time=%s epoch=%u\n", nStakeModifier, DateTimeStrFormat(nModifierTime).c_str(), (unsigned int)nModifierTime);
}
if (nModifierTime / nModifierInterval >= pindexPrev->GetBlockTime() / nModifierInterval)
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexPrev nHeight=%d nTime=%u\n", pindexPrev->nHeight, (unsigned int)pindexPrev->GetBlockTime());
+ }
return true;
+ }
+ if (nModifierTime / nModifierInterval >= pindexCurrent->GetBlockTime() / nModifierInterval)
+ {
+ // fixed interval protocol requires current block timestamp also be in a different modifier interval
+ if (IsFixedModifierInterval(pindexCurrent->nTime))
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: no new interval keep current modifier: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+ }
+ return true;
+ }
+ else
+ {
+ if (fDebug)
+ {
+ printf("ComputeNextStakeModifier: old modifier at block %s not meeting fixed modifier interval: pindexCurrent nHeight=%d nTime=%u\n", pindexCurrent->GetBlockHash().ToString().c_str(), pindexCurrent->nHeight, (unsigned int)pindexCurrent->GetBlockTime());
+ }
+ }
+ }
// Sort candidate blocks by timestamp
vector<pair<int64, uint256> > vSortedByTimestamp;
// add the selected block from candidates to selected list
mapSelectedBlocks.insert(make_pair(pindex->GetBlockHash(), pindex));
if (fDebug && GetBoolArg("-printstakemodifier"))
- printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n",
- nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit());
+ printf("ComputeNextStakeModifier: selected round %d stop=%s height=%d bit=%d\n", nRound, DateTimeStrFormat(nSelectionIntervalStop).c_str(), pindex->nHeight, pindex->GetStakeEntropyBit());
}
// Print selection map for visualization of the selected blocks
// 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:
-// nStakeModifier:
-// (v0.3) scrambles computation to make it very difficult to precompute
-// future proof-of-stake at the time of the coin's confirmation
-// (v0.2) nBits (deprecated): encodes all past block timestamps
+// nStakeModifier: scrambles computation to make it very difficult to precompute
+// future proof-of-stake at the time of the coin's confirmation
// txPrev.block.nTime: prevent nodes from guessing a good timestamp to
// generate transaction for future advantage
// txPrev.offset: offset of txPrev inside block, to reduce the chance of
bnTargetPerCoinDay.SetCompact(nBits);
int64 nValueIn = txPrev.vout[prevout.n].nValue;
- int64 nTimeWeight;
uint256 hashBlockFrom = blockFrom.GetHash();
- // Kernel hash weight starts from 0 at the 30-day min age
- // this change increases active coins participating the hash and helps
- // to secure the network when proof-of-stake difficulty is low
- //
- if(fTestNet || (STAKEWEIGHT_SWITCH_TIME < nTimeTx))
- {
- // New rule since 01 Jan 2014: Maximum TimeWeight is 90 days.
- nTimeWeight = min((int64)nTimeTx - txPrev.nTime - nStakeMinAge, (int64)nStakeMaxAge);
- }
- else
- {
- // Current rule: Maximum TimeWeight is 60 days.
- nTimeWeight = min((int64)nTimeTx - txPrev.nTime, (int64)nStakeMaxAge) - nStakeMinAge;
- }
-
- CBigNum bnCoinDayWeight = CBigNum(nValueIn) * nTimeWeight / COIN / (24 * 60 * 60);
+ CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64)txPrev.nTime, (int64)nTimeTx) / COIN / (24 * 60 * 60);
targetProofOfStake = (bnCoinDayWeight * bnTargetPerCoinDay).getuint256();
// Calculate hash
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : check protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
- "0.3",
+ printf("CheckStakeKernelHash() : check modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
hashProofOfStake.ToString().c_str());
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : pass protocol=%s modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
- "0.3",
+ printf("CheckStakeKernelHash() : pass modifier=0x%016"PRI64x" nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
hashProofOfStake.ToString().c_str());
if (!txPrev.ReadFromDisk(txdb, txin.prevout, txindex))
return tx.DoS(1, error("CheckProofOfStake() : INFO: read txPrev failed")); // previous transaction not in main chain, may occur during initial download
-#ifndef USE_LEVELDB
- txdb.Close();
-#endif
-
// Verify signature
- if (!VerifySignature(txPrev, tx, 0, true, 0))
+ if (!VerifySignature(txPrev, tx, 0, STANDARD_SCRIPT_VERIFY_FLAGS, 0))
return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str()));
// Read block header
return true;
}
-// Check whether the coinstake timestamp meets protocol
-bool CheckCoinStakeTimestamp(int64 nTimeBlock, int64 nTimeTx)
-{
- // v0.3 protocol
- return (nTimeBlock == nTimeTx);
-}
-
// Get stake modifier checksum
unsigned int GetStakeModifierChecksum(const CBlockIndex* pindex)
{
git://git.novaco.in / novacoin.git / blobdiff