#include <boost/assign/list_of.hpp>
#include "kernel.h"
-#include "txdb.h"
+#include "db.h"
using namespace std;
static std::map<int, unsigned int> mapStakeModifierCheckpoints =
boost::assign::map_list_of
( 0, 0x0e00670bu )
- ( 9690, 0x97dcdafau )
- ( 12661, 0x5d84115du )
- ( 37092, 0xd230afccu )
+ ( 68600, 0x73a8cc4cu )
;
// Hard checkpoints of stake modifiers to ensure they are deterministic (testNet)
( 0, 0x0e00670bu )
;
+// 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;
// 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
ss << nTimeBlockFrom << nTxPrevOffset << txPrev.nTime << prevout.n << nTimeTx;
hashProofOfStake = Hash(ss.begin(), ss.end());
+
if (fPrintProofOfStake)
{
printf("CheckStakeKernelHash() : using modifier 0x%016"PRI64x" at height=%d timestamp=%s for block from height=%d timestamp=%s\n",
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());
// Kernel (input 0) must match the stake hash target per coin age (nBits)
const CTxIn& txin = tx.vin[0];
- // First try finding the previous transaction in database
- CTxDB txdb("r");
+ unsigned nTxPos;
+
CTransaction txPrev;
- CTxIndex txindex;
- 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
- txdb.Close();
+ CCoins coins;
+ CCoinsViewCache &view = *pcoinsTip;
- // Verify signature
- if (!VerifySignature(txPrev, tx, 0, true, 0))
- return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str()));
+ if (!view.GetCoins(txin.prevout.hash, coins))
+ return tx.DoS(1, error("CheckProofOfStake() : INFO: read coins for txPrev failed")); // previous transaction not in main chain, may occur during initial download
- // Read block header
+ CBlockIndex* pindex = FindBlockByHeight(coins.nHeight);
+
+ // Read block and scan it to find txPrev
CBlock block;
- if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
+ if (block.ReadFromDisk(pindex)) {
+ nTxPos = GetSerializeSize(CBlock(), SER_DISK, CLIENT_VERSION) - (2 * GetSizeOfCompactSize(0)) + GetSizeOfCompactSize(block.vtx.size());
+ BOOST_FOREACH(const CTransaction &tx, block.vtx) {
+ if (tx.GetHash() == txin.prevout.hash) {
+ txPrev = tx;
+ break;
+ }
+ nTxPos += tx.GetSerializeSize(SER_DISK, CLIENT_VERSION);
+ }
+ }
+ else
return fDebug? error("CheckProofOfStake() : read block failed") : false; // unable to read block of previous transaction
- if (!CheckStakeKernelHash(nBits, block, txindex.pos.nTxPos - txindex.pos.nBlockPos, txPrev, txin.prevout, tx.nTime, hashProofOfStake, targetProofOfStake, fDebug))
+ // Verify signature
+ if (!VerifySignature(coins, tx, 0, true, false, 0))
+ return tx.DoS(100, error("CheckProofOfStake() : VerifySignature failed on coinstake %s", tx.GetHash().ToString().c_str()));
+
+ if (!CheckStakeKernelHash(nBits, block, nTxPos, txPrev, txin.prevout, tx.nTime, hashProofOfStake, targetProofOfStake, fDebug))
return tx.DoS(1, error("CheckProofOfStake() : INFO: check kernel failed on coinstake %s, hashProof=%s", tx.GetHash().ToString().c_str(), hashProofOfStake.ToString().c_str())); // may occur during initial download or if behind on block chain sync
return true;
git://git.novaco.in / novacoin.git / blobdiff