// Copyright (c) 2012-2013 The PPCoin developers
+// Copyright (c) 2013-2015 The Novacoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
(143990, 0x9c592c78u )
(149000, 0x48f2bdc4u )
(160000, 0x789df0f0u )
+ (200000, 0x01ec1503u )
;
// Hard checkpoints of stake modifiers to ensure they are deterministic (testNet)
return (nTimeBlock >= (fTestNet? nModifierTestSwitchTime : nModifierSwitchTime));
}
-// Get time weight
-int64_t GetWeight(int64_t nIntervalBeginning, int64_t 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_t)nStakeMaxAge);
-}
-
// Get the last stake modifier and its generation time from a given block
static bool GetLastStakeModifier(const CBlockIndex* pindex, uint64_t& nStakeModifier, int64_t& nModifierTime)
{
uint256 hashBlockFrom = blockFrom.GetHash();
- CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)txPrev.nTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
+ CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)txPrev.nTime, (int64_t)nTimeTx) / COIN / nOneDay;
targetProofOfStake = (bnCoinDayWeight * bnTargetPerCoinDay).getuint256();
// Calculate hash
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : check modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
+ printf("CheckStakeKernelHash() : check modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
- hashProofOfStake.ToString().c_str());
+ targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str());
}
// Now check if proof-of-stake hash meets target protocol
DateTimeStrFormat(nStakeModifierTime).c_str(),
mapBlockIndex[hashBlockFrom]->nHeight,
DateTimeStrFormat(blockFrom.GetBlockTime()).c_str());
- printf("CheckStakeKernelHash() : pass modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashProof=%s\n",
+ printf("CheckStakeKernelHash() : pass modifier=0x%016" PRIx64 " nTimeBlockFrom=%u nTxPrevOffset=%u nTimeTxPrev=%u nPrevout=%u nTimeTx=%u hashTarget=%s hashProof=%s\n",
nStakeModifier,
nTimeBlockFrom, nTxPrevOffset, txPrev.nTime, prevout.n, nTimeTx,
- hashProofOfStake.ToString().c_str());
+ targetProofOfStake.ToString().c_str(), hashProofOfStake.ToString().c_str());
}
return true;
}
-// Scan given coins set for kernel solution
-bool ScanForStakeKernelHash(MetaMap &mapMeta, uint32_t nBits, uint32_t nTime, uint32_t nSearchInterval, CoinsSet::value_type &kernelcoin, uint32_t &nTimeTx, uint32_t &nBlockTime, uint64_t &nKernelsTried, uint64_t &nCoinDaysTried)
+
+#ifdef USE_ASM
+
+// kernel padding
+static const uint32_t block1_suffix[9] = { 0x80000000, 0, 0, 0, 0, 0, 0, 0, 0x000000e0 };
+static const uint32_t block1_suffix_4way[4 * 9] = {
+ 0x80000000, 0x80000000, 0x80000000, 0x80000000,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0x000000e0, 0x000000e0, 0x000000e0, 0x000000e0
+};
+
+// hash padding
+static const uint32_t block2_suffix[8] = { 0x80000000, 0, 0, 0, 0, 0, 0, 0x00000100 };
+static const uint32_t block2_suffix_4way[4 * 8] = {
+ 0x80000000, 0x80000000, 0x80000000, 0x80000000,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0,
+ 0x00000100, 0x00000100, 0x00000100, 0x00000100
+};
+
+// Sha256 initial state
+static const uint32_t sha256_initial[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
+
+extern "C" int sha256_use_4way();
+#ifndef __i386__
+extern "C" void sha256_transform(uint32_t *state, const uint32_t *block, int swap);
+#endif
+
+extern "C" void sha256_init_4way(uint32_t *state);
+extern "C" void sha256_transform_4way(uint32_t *state, const uint32_t *block, int swap);
+
+#ifdef USE_SSSE3
+#include <immintrin.h>
+
+extern "C" int sha256_use_ssse3();
+bool fUseSSSE3 = sha256_use_ssse3() != 0;
+
+inline void copyrow_swap32(uint32_t *to, uint32_t *from)
+{
+ if (!fUseSSSE3)
+ {
+ for (int i = 0; i < 4; i++)
+ to[i] = __builtin_bswap32(from[i]);
+ }
+ else
+ {
+ __m128i mask = _mm_set_epi8(12, 13, 14, 15, 8, 9, 10, 11, 4, 5, 6, 7, 0, 1, 2, 3);
+ _mm_storeu_si128((__m128i *)&to[0], _mm_shuffle_epi8(_mm_loadu_si128((__m128i *)&from[0]), mask));
+ }
+}
+#else
+inline void copyrow_swap32(uint32_t *to, uint32_t *from)
+{
+ for (int i = 0; i < 4; i++)
+ to[i] = __builtin_bswap32(from[i]);
+}
+#endif
+
+bool fUse4Way = sha256_use_4way() != 0;
+
+class ScanMidstateWorker
{
- uint256 hashProofOfStake = 0;
+public:
+ ScanMidstateWorker()
+ { }
+ ScanMidstateWorker(unsigned char *kernel, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, uint32_t nIntervalBegin, uint32_t nIntervalEnd)
+ : kernel(kernel), nBits(nBits), nInputTxTime(nInputTxTime), bnValueIn(nValueIn), nIntervalBegin(nIntervalBegin), nIntervalEnd(nIntervalEnd)
+ {
+ solutions = vector<std::pair<uint256,uint32_t> >();
+ }
- // (txid, vout.n) => ((txindex, (tx, vout.n)), (block, modifier))
- for(MetaMap::const_iterator meta_item = mapMeta.begin(); meta_item != mapMeta.end(); meta_item++)
+ void Do_4way()
{
- if (!fCoinsDataActual)
- break;
+ SetThreadPriority(THREAD_PRIORITY_LOWEST);
+
+ // Compute maximum possible target to filter out majority of obviously insufficient hashes
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+ uint256 nMaxTarget = (bnTargetPerCoinDay * bnValueIn * nStakeMaxAge / COIN / nOneDay).getuint256();
+
+ uint32_t blocks1[4 * 16] __attribute__((aligned(16)));
+ uint32_t blocks2[4 * 16] __attribute__((aligned(16)));
+ uint32_t candidates[4 * 8] __attribute__((aligned(16)));
+
+ vector<uint32_t> vRow = vector<uint32_t>(4);
+ uint32_t *pnKernel = (uint32_t *) kernel;
- CTxIndex txindex = (*meta_item).second.first.first;
- CBlock block = (*meta_item).second.second.first;
- uint64_t nStakeModifier = (*meta_item).second.second.second;
+ for(int i = 0; i < 7; i++)
+ {
+ fill(vRow.begin(), vRow.end(), pnKernel[i]);
+ copyrow_swap32(&blocks1[i*4], &vRow[0]);
+ }
- // Get coin
- CoinsSet::value_type pcoin = meta_item->second.first.second;
+ memcpy(&blocks1[28], &block1_suffix_4way[0], 36*4); // sha256 padding
+ memcpy(&blocks2[32], &block2_suffix_4way[0], 32*4);
- static unsigned int nMaxStakeSearchInterval = 60;
+ uint32_t nTimeStamps[4] = {0, 0, 0, 0};
+ uint32_t nHashes[4] = {0, 0, 0, 0};
- // only count coins meeting min age requirement
- if (nStakeMinAge + block.nTime > nTime - nMaxStakeSearchInterval)
- continue;
+ // Search forward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=nIntervalBegin, nMaxTarget32 = nMaxTarget.Get32(7); nTimeTx<nIntervalEnd && !fShutdown; nTimeTx +=4)
+ {
+ sha256_init_4way(blocks2);
+ sha256_init_4way(candidates);
- // Transaction offset inside block
- uint32_t nTxOffset = txindex.pos.nTxPos - txindex.pos.nBlockPos;
+ nTimeStamps[0] = nTimeTx;
+ nTimeStamps[1] = nTimeTx+1;
+ nTimeStamps[2] = nTimeTx+2;
+ nTimeStamps[3] = nTimeTx+3;
+
+ copyrow_swap32(&blocks1[24], &nTimeStamps[0]); // Kernel timestamps
+
+ sha256_transform_4way(&blocks2[0], &blocks1[0], 0); // first hashing
+ sha256_transform_4way(&candidates[0], &blocks2[0], 0); // second hashing
+ copyrow_swap32(&nHashes[0], &candidates[28]);
+
+ for(int nResult = 0; nResult < 4; nResult++)
+ {
+ if (nHashes[nResult] <= nMaxTarget32) // Possible hit
+ {
+ uint256 nHashProofOfStake = 0;
+ uint32_t *pnHashProofOfStake = (uint32_t *) &nHashProofOfStake;
+
+ for (int i = 0; i < 7; i++)
+ pnHashProofOfStake[i] = __builtin_bswap32(candidates[(i*4) + nResult]);
+ pnHashProofOfStake[7] = nHashes[nResult];
+
+ CBigNum bnCoinDayWeight = bnValueIn * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeStamps[nResult]) / COIN / nOneDay;
+ CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
+
+ if (bnTargetProofOfStake >= CBigNum(nHashProofOfStake))
+ solutions.push_back(std::pair<uint256,uint32_t>(nHashProofOfStake, nTimeStamps[nResult]));
+ }
+ }
+ }
+ }
- // Current timestamp scanning interval
- unsigned int nCurrentSearchInterval = min(nSearchInterval, nMaxStakeSearchInterval);
+ void Do_oneway()
+ {
+ SetThreadPriority(THREAD_PRIORITY_LOWEST);
- nBlockTime = block.nTime;
+ // Compute maximum possible target to filter out majority of obviously insufficient hashes
CBigNum bnTargetPerCoinDay;
bnTargetPerCoinDay.SetCompact(nBits);
- int64_t nValueIn = pcoin.first->vout[pcoin.second].nValue;
+ uint256 nMaxTarget = (bnTargetPerCoinDay * bnValueIn * nStakeMaxAge / COIN / nOneDay).getuint256();
+
+#ifdef __i386__
+ SHA256_CTX ctx, workerCtx;
+ // Init new sha256 context and update it
+ // with first 24 bytes of kernel
+ SHA256_Init(&ctx);
+ SHA256_Update(&ctx, kernel, 8 + 16);
+ workerCtx = ctx; // save context
+
+ // Sha256 result buffer
+ uint32_t hashProofOfStake[8];
+ uint256 *pnHashProofOfStake = (uint256 *)&hashProofOfStake;
+
+ // Search forward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=nIntervalBegin, nMaxTarget32 = nMaxTarget.Get32(7); nTimeTx<nIntervalEnd && !fShutdown; nTimeTx++)
+ {
+ // Complete first hashing iteration
+ uint256 hash1;
+ SHA256_Update(&ctx, (unsigned char*)&nTimeTx, 4);
+ SHA256_Final((unsigned char*)&hash1, &ctx);
+
+ // Restore context
+ ctx = workerCtx;
+
+ // Finally, calculate kernel hash
+ SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake);
+
+ // Skip if hash doesn't satisfy the maximum target
+ if (hashProofOfStake[7] > nMaxTarget32)
+ continue;
+
+ CBigNum bnCoinDayWeight = bnValueIn * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / nOneDay;
+ CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
- // Search backward in time from the given timestamp
- // Search nSearchInterval seconds back up to nMaxStakeSearchInterval
- // Stopping search in case of shutting down or cache invalidation
- for (unsigned int n=0; n<nCurrentSearchInterval && fCoinsDataActual && !fShutdown; n++)
+ if (bnTargetProofOfStake >= CBigNum(*pnHashProofOfStake))
+ solutions.push_back(std::pair<uint256,uint32_t>(*pnHashProofOfStake, nTimeTx));
+ }
+#else
+ uint32_t block1[16] __attribute__((aligned(16)));
+ uint32_t block2[16] __attribute__((aligned(16)));
+ uint32_t candidate[8] __attribute__((aligned(16)));
+
+ memcpy(&block1[7], &block1_suffix[0], 36); // sha256 padding
+ memcpy(&block2[8], &block2_suffix[0], 32);
+
+ uint32_t *pnKernel = (uint32_t *) kernel;
+ copyrow_swap32(&block1[0], pnKernel);
+ block1[4] = __builtin_bswap32(pnKernel[4]);
+ block1[5] = __builtin_bswap32(pnKernel[5]);
+
+ // Search forward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=nIntervalBegin, nMaxTarget32 = nMaxTarget.Get32(7); nTimeTx<nIntervalEnd && !fShutdown; nTimeTx++)
{
- nTimeTx = nTime - n;
- CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)pcoin.first->nTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
+ memcpy(&block2[0], &sha256_initial[0], 32);
+ memcpy(&candidate[0], &sha256_initial[0], 32);
+
+ block1[6] = __builtin_bswap32(nTimeTx);
+
+ sha256_transform(&block2[0], &block1[0], 0); // first hashing
+ sha256_transform(&candidate[0], &block2[0], 0); // second hashing
+
+ uint32_t nHash7 = __builtin_bswap32(candidate[7]);
+
+ // Skip if hash doesn't satisfy the maximum target
+ if (nHash7 > nMaxTarget32)
+ continue;
+
+ uint256 nHashProofOfStake;
+ uint32_t *pnHashProofOfStake = (uint32_t *) &nHashProofOfStake;
+
+ for (int i = 0; i < 7; i++)
+ pnHashProofOfStake[i] = __builtin_bswap32(candidate[i]);
+ pnHashProofOfStake[7] = nHash7;
+
+ CBigNum bnCoinDayWeight = bnValueIn * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / nOneDay;
CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
- // Build kernel
- CDataStream ss(SER_GETHASH, 0);
- ss << nStakeModifier;
- ss << nBlockTime << nTxOffset << pcoin.first->nTime << pcoin.second << nTimeTx;
+ if (bnTargetProofOfStake >= CBigNum(nHashProofOfStake))
+ solutions.push_back(std::pair<uint256,uint32_t>(nHashProofOfStake, nTimeTx));
+ }
+#endif
+ }
- // Calculate kernel hash
- hashProofOfStake = Hash(ss.begin(), ss.end());
+ void Do()
+ {
+ if (fUse4Way)
+ Do_4way();
+ else
+ Do_oneway();
+ }
- // Update statistics
- nKernelsTried += 1;
- nCoinDaysTried += bnCoinDayWeight.getuint64();
+ vector<std::pair<uint256,uint32_t> >& GetSolutions()
+ {
+ return solutions;
+ }
- if (bnTargetProofOfStake >= CBigNum(hashProofOfStake))
- {
- if (fDebug)
- printf("nStakeModifier=0x%016" PRIx64 ", nBlockTime=%u nTxOffset=%u nTxPrevTime=%u nVout=%u nTimeTx=%u hashProofOfStake=%s Success=true\n",
- nStakeModifier, nBlockTime, nTxOffset, pcoin.first->nTime, pcoin.second, nTimeTx, hashProofOfStake.GetHex().c_str());
+private:
+ std::vector<std::pair<uint256,uint32_t> > solutions;
- kernelcoin = pcoin;
- return true;
- }
+ uint8_t *kernel;
+ uint32_t nBits;
+ uint32_t nInputTxTime;
+ CBigNum bnValueIn;
+ uint32_t nIntervalBegin;
+ uint32_t nIntervalEnd;
+};
- if (fDebug)
- printf("nStakeModifier=0x%016" PRIx64 ", nBlockTime=%u nTxOffset=%u nTxPrevTime=%u nTxNumber=%u nTimeTx=%u hashProofOfStake=%s Success=false\n",
- nStakeModifier, nBlockTime, nTxOffset, pcoin.first->nTime, pcoin.second, nTimeTx, hashProofOfStake.GetHex().c_str());
+#else
+class ScanMidstateWorker
+{
+public:
+ ScanMidstateWorker()
+ { }
+ ScanMidstateWorker(unsigned char *kernel, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, uint32_t nIntervalBegin, uint32_t nIntervalEnd)
+ : nBits(nBits), nInputTxTime(nInputTxTime), bnValueIn(nValueIn), nIntervalBegin(nIntervalBegin), nIntervalEnd(nIntervalEnd)
+ {
+ // Init new sha256 context and update it
+ // with first 24 bytes of kernel
+ SHA256_Init(&workerCtx);
+ SHA256_Update(&workerCtx, kernel, 8 + 16);
+ solutions = vector<std::pair<uint256,uint32_t> >();
+ }
+
+ void Do()
+ {
+ SetThreadPriority(THREAD_PRIORITY_LOWEST);
+ SHA256_CTX ctx = workerCtx;
+
+ // Sha256 result buffer
+ uint32_t hashProofOfStake[8];
+
+ // Compute maximum possible target to filter out majority of obviously insufficient hashes
+ CBigNum bnTargetPerCoinDay;
+ bnTargetPerCoinDay.SetCompact(nBits);
+
+ uint256 nMaxTarget = (bnTargetPerCoinDay * bnValueIn * nStakeMaxAge / COIN / nOneDay).getuint256(),
+ *pnHashProofOfStake = (uint256 *)&hashProofOfStake;
+
+ // Search forward in time from the given timestamp
+ // Stopping search in case of shutting down
+ for (uint32_t nTimeTx=nIntervalBegin, nMaxTarget32 = nMaxTarget.Get32(7); nTimeTx<nIntervalEnd && !fShutdown; nTimeTx++)
+ {
+ // Complete first hashing iteration
+ uint256 hash1;
+ SHA256_Update(&ctx, (unsigned char*)&nTimeTx, 4);
+ SHA256_Final((unsigned char*)&hash1, &ctx);
+
+ // Restore context
+ ctx = workerCtx;
+
+ // Finally, calculate kernel hash
+ SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake);
+
+ // Skip if hash doesn't satisfy the maximum target
+ if (hashProofOfStake[7] > nMaxTarget32)
+ continue;
+
+ CBigNum bnCoinDayWeight = bnValueIn * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / nOneDay;
+ CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
+
+ if (bnTargetProofOfStake >= CBigNum(*pnHashProofOfStake))
+ solutions.push_back(std::pair<uint256,uint32_t>(*pnHashProofOfStake, nTimeTx));
}
}
- return false;
-}
+ vector<std::pair<uint256,uint32_t> >& GetSolutions()
+ {
+ return solutions;
+ }
+
+private:
+ SHA256_CTX workerCtx;
+ std::vector<std::pair<uint256,uint32_t> > solutions;
-// Scan given input for kernel solution
-bool ScanInputForStakeKernelHash(CTransaction &tx, uint32_t nOut, uint32_t nBits, uint32_t nSearchInterval, std::pair<uint256, uint32_t> &solution)
+ uint32_t nBits;
+ uint32_t nInputTxTime;
+ CBigNum bnValueIn;
+ uint32_t nIntervalBegin;
+ uint32_t nIntervalEnd;
+};
+
+#endif
+// Scan given kernel for solution
+bool ScanKernelForward(unsigned char *kernel, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair<uint32_t, uint32_t> &SearchInterval, std::vector<std::pair<uint256, uint32_t> > &solutions)
{
- CTxDB txdb("r");
+ // TODO: custom threads amount
- CBlock block;
- CTxIndex txindex;
+ uint32_t nThreads = boost::thread::hardware_concurrency();
+ uint32_t nPart = (SearchInterval.second - SearchInterval.first) / nThreads;
- // Load transaction index item
- if (!txdb.ReadTxIndex(tx.GetHash(), txindex))
- return false;
- // Read block header
- if (!block.ReadFromDisk(txindex.pos.nFile, txindex.pos.nBlockPos, false))
- return false;
+ ScanMidstateWorker *workers = new ScanMidstateWorker[nThreads];
- uint64_t nStakeModifier = 0;
- if (!GetKernelStakeModifier(block.GetHash(), nStakeModifier))
- return false;
+ boost::thread_group group;
+ for(size_t i = 0; i < nThreads; i++)
+ {
+ uint32_t nBegin = SearchInterval.first + nPart * i;
+ uint32_t nEnd = SearchInterval.first + nPart * (i + 1);
+ workers[i] = ScanMidstateWorker(kernel, nBits, nInputTxTime, nValueIn, nBegin, nEnd);
+ boost::function<void()> workerFnc = boost::bind(&ScanMidstateWorker::Do, &workers[i]);
+ group.create_thread(workerFnc);
+ }
- uint32_t nTime = GetTime();
- // Only count coins meeting min age requirement
- if (nStakeMinAge + block.nTime > nTime)
- nTime += (nStakeMinAge + block.nTime - nTime);
+ group.join_all();
+ solutions.clear();
+
+ for(size_t i = 0; i < nThreads; i++)
+ {
+ std::vector<std::pair<uint256, uint32_t> > ws = workers[i].GetSolutions();
+ solutions.insert(solutions.end(), ws.begin(), ws.end());
+ }
- // Transaction offset inside block
- uint32_t nTxOffset = txindex.pos.nTxPos - txindex.pos.nBlockPos;
- int64_t nValueIn = tx.vout[nOut].nValue;
+ delete [] workers;
+ if (solutions.size() == 0)
+ {
+ // no solutions
+ return false;
+ }
+
+ return true;
+}
+
+// Scan given midstate for solution
+bool ScanContextBackward(SHA256_CTX &ctx, uint32_t nBits, uint32_t nInputTxTime, int64_t nValueIn, std::pair<uint32_t, uint32_t> &SearchInterval, std::pair<uint256, uint32_t> &solution)
+{
CBigNum bnTargetPerCoinDay;
bnTargetPerCoinDay.SetCompact(nBits);
// Get maximum possible target to filter out the majority of obviously insufficient hashes
- CBigNum bnMaxTargetPerCoinDay = bnTargetPerCoinDay * CBigNum(nValueIn) * nStakeMaxAge / COIN / (24 * 60 * 60);
+ CBigNum bnMaxTargetPerCoinDay = bnTargetPerCoinDay * CBigNum(nValueIn) * nStakeMaxAge / COIN / nOneDay;
uint256 maxTarget = bnMaxTargetPerCoinDay.getuint256();
- // Search forward in time from the given timestamp
+ SHA256_CTX ctxCopy = ctx;
+
+ // Search backward in time from the given timestamp
// Stopping search in case of shutting down
- for (unsigned int n=0; n<nSearchInterval && !fShutdown; n++)
+ for (uint32_t nTimeTx=SearchInterval.first; nTimeTx>SearchInterval.second && !fShutdown; nTimeTx--)
{
- uint32_t nTimeTx = nTime + n;
+ // Complete first hashing iteration
+ uint256 hash1;
+ SHA256_Update(&ctxCopy, (unsigned char*)&nTimeTx, 4);
+ SHA256_Final((unsigned char*)&hash1, &ctxCopy);
- // Build kernel
- CDataStream ss(SER_GETHASH, 0);
- ss << nStakeModifier;
- ss << block.nTime << nTxOffset << tx.nTime << nOut << nTimeTx;
+ // Restore context
+ ctxCopy = ctx;
- // Calculate kernel hash
- uint256 hashProofOfStake = Hash(ss.begin(), ss.end());
+ // Finally, calculate kernel hash
+ uint256 hashProofOfStake;
+ SHA256((unsigned char*)&hash1, sizeof(hashProofOfStake), (unsigned char*)&hashProofOfStake);
// Skip if hash doesn't satisfy the maximum target
if (hashProofOfStake > maxTarget)
continue;
- CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)tx.nTime, (int64_t)nTimeTx) / COIN / (24 * 60 * 60);
+ CBigNum bnCoinDayWeight = CBigNum(nValueIn) * GetWeight((int64_t)nInputTxTime, (int64_t)nTimeTx) / COIN / nOneDay;
CBigNum bnTargetProofOfStake = bnCoinDayWeight * bnTargetPerCoinDay;
if (bnTargetProofOfStake >= CBigNum(hashProofOfStake))
ss << pindex->nFlags << pindex->hashProofOfStake << pindex->nStakeModifier;
uint256 hashChecksum = Hash(ss.begin(), ss.end());
hashChecksum >>= (256 - 32);
- return hashChecksum.Get64();
+ return static_cast<uint32_t>(hashChecksum.Get64());
}
// Check stake modifier hard checkpoints