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Diffstat (limited to 'src/miner.cpp')
| -rw-r--r-- | src/miner.cpp | 610 |
1 files changed, 610 insertions, 0 deletions
diff --git a/src/miner.cpp b/src/miner.cpp new file mode 100644 index 000000000..e80e8a265 --- /dev/null +++ b/src/miner.cpp @@ -0,0 +1,610 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2015 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "miner.h" + +#include "amount.h" +#include "chain.h" +#include "chainparams.h" +#include "coins.h" +#include "consensus/consensus.h" +#include "consensus/merkle.h" +#include "consensus/validation.h" +#include "hash.h" +#include "validation.h" +#include "net.h" +#include "policy/policy.h" +#include "pow.h" +#include "primitives/transaction.h" +#include "script/standard.h" +#include "timedata.h" +#include "txmempool.h" +#include "util.h" +#include "utilmoneystr.h" +#include "validationinterface.h" + +#include <algorithm> +#include <boost/thread.hpp> +#include <boost/tuple/tuple.hpp> +#include <queue> +#include <utility> + +using namespace std; + +////////////////////////////////////////////////////////////////////////////// +// +// BitcoinMiner +// + +// +// Unconfirmed transactions in the memory pool often depend on other +// transactions in the memory pool. When we select transactions from the +// pool, we select by highest priority or fee rate, so we might consider +// transactions that depend on transactions that aren't yet in the block. + +uint64_t nLastBlockTx = 0; +uint64_t nLastBlockSize = 0; +uint64_t nLastBlockWeight = 0; + +class ScoreCompare +{ +public: + ScoreCompare() {} + + bool operator()(const CTxMemPool::txiter a, const CTxMemPool::txiter b) + { + return CompareTxMemPoolEntryByScore()(*b,*a); // Convert to less than + } +}; + +int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev) +{ + int64_t nOldTime = pblock->nTime; + int64_t nNewTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime()); + + if (nOldTime < nNewTime) + pblock->nTime = nNewTime; + + // Updating time can change work required on testnet: + if (consensusParams.fPowAllowMinDifficultyBlocks) + pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, consensusParams); + + return nNewTime - nOldTime; +} + +BlockAssembler::BlockAssembler(const CChainParams& _chainparams) + : chainparams(_chainparams) +{ + // Block resource limits + // If neither -blockmaxsize or -blockmaxweight is given, limit to DEFAULT_BLOCK_MAX_* + // If only one is given, only restrict the specified resource. + // If both are given, restrict both. + nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT; + nBlockMaxSize = DEFAULT_BLOCK_MAX_SIZE; + bool fWeightSet = false; + if (mapArgs.count("-blockmaxweight")) { + nBlockMaxWeight = GetArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT); + nBlockMaxSize = MAX_BLOCK_SERIALIZED_SIZE; + fWeightSet = true; + } + if (mapArgs.count("-blockmaxsize")) { + nBlockMaxSize = GetArg("-blockmaxsize", DEFAULT_BLOCK_MAX_SIZE); + if (!fWeightSet) { + nBlockMaxWeight = nBlockMaxSize * WITNESS_SCALE_FACTOR; + } + } + + // Limit weight to between 4K and MAX_BLOCK_WEIGHT-4K for sanity: + nBlockMaxWeight = std::max((unsigned int)4000, std::min((unsigned int)(MAX_BLOCK_WEIGHT-4000), nBlockMaxWeight)); + // Limit size to between 1K and MAX_BLOCK_SERIALIZED_SIZE-1K for sanity: + nBlockMaxSize = std::max((unsigned int)1000, std::min((unsigned int)(MAX_BLOCK_SERIALIZED_SIZE-1000), nBlockMaxSize)); + + // Whether we need to account for byte usage (in addition to weight usage) + fNeedSizeAccounting = (nBlockMaxSize < MAX_BLOCK_SERIALIZED_SIZE-1000); +} + +void BlockAssembler::resetBlock() +{ + inBlock.clear(); + + // Reserve space for coinbase tx + nBlockSize = 1000; + nBlockWeight = 4000; + nBlockSigOpsCost = 400; + fIncludeWitness = false; + + // These counters do not include coinbase tx + nBlockTx = 0; + nFees = 0; + + lastFewTxs = 0; + blockFinished = false; +} + +std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& scriptPubKeyIn) +{ + resetBlock(); + + pblocktemplate.reset(new CBlockTemplate()); + + if(!pblocktemplate.get()) + return nullptr; + pblock = &pblocktemplate->block; // pointer for convenience + + // Add dummy coinbase tx as first transaction + pblock->vtx.emplace_back(); + pblocktemplate->vTxFees.push_back(-1); // updated at end + pblocktemplate->vTxSigOpsCost.push_back(-1); // updated at end + + LOCK2(cs_main, mempool.cs); + CBlockIndex* pindexPrev = chainActive.Tip(); + nHeight = pindexPrev->nHeight + 1; + + pblock->nVersion = ComputeBlockVersion(pindexPrev, chainparams.GetConsensus()); + // -regtest only: allow overriding block.nVersion with + // -blockversion=N to test forking scenarios + if (chainparams.MineBlocksOnDemand()) + pblock->nVersion = GetArg("-blockversion", pblock->nVersion); + + pblock->nTime = GetAdjustedTime(); + const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast(); + + nLockTimeCutoff = (STANDARD_LOCKTIME_VERIFY_FLAGS & LOCKTIME_MEDIAN_TIME_PAST) + ? nMedianTimePast + : pblock->GetBlockTime(); + + // Decide whether to include witness transactions + // This is only needed in case the witness softfork activation is reverted + // (which would require a very deep reorganization) or when + // -promiscuousmempoolflags is used. + // TODO: replace this with a call to main to assess validity of a mempool + // transaction (which in most cases can be a no-op). + fIncludeWitness = IsWitnessEnabled(pindexPrev, chainparams.GetConsensus()); + + addPriorityTxs(); + addPackageTxs(); + + nLastBlockTx = nBlockTx; + nLastBlockSize = nBlockSize; + nLastBlockWeight = nBlockWeight; + + // Create coinbase transaction. + CMutableTransaction coinbaseTx; + coinbaseTx.vin.resize(1); + coinbaseTx.vin[0].prevout.SetNull(); + coinbaseTx.vout.resize(1); + coinbaseTx.vout[0].scriptPubKey = scriptPubKeyIn; + coinbaseTx.vout[0].nValue = nFees + GetBlockSubsidy(nHeight, chainparams.GetConsensus()); + coinbaseTx.vin[0].scriptSig = CScript() << nHeight << OP_0; + pblock->vtx[0] = MakeTransactionRef(std::move(coinbaseTx)); + pblocktemplate->vchCoinbaseCommitment = GenerateCoinbaseCommitment(*pblock, pindexPrev, chainparams.GetConsensus()); + pblocktemplate->vTxFees[0] = -nFees; + + uint64_t nSerializeSize = GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION); + LogPrintf("CreateNewBlock(): total size: %u block weight: %u txs: %u fees: %ld sigops %d\n", nSerializeSize, GetBlockWeight(*pblock), nBlockTx, nFees, nBlockSigOpsCost); + + // Fill in header + pblock->hashPrevBlock = pindexPrev->GetBlockHash(); + UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev); + pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus()); + pblock->nNonce = 0; + pblocktemplate->vTxSigOpsCost[0] = WITNESS_SCALE_FACTOR * GetLegacySigOpCount(*pblock->vtx[0]); + + CValidationState state; + if (!TestBlockValidity(state, chainparams, *pblock, pindexPrev, false, false)) { + throw std::runtime_error(strprintf("%s: TestBlockValidity failed: %s", __func__, FormatStateMessage(state))); + } + + return std::move(pblocktemplate); +} + +bool BlockAssembler::isStillDependent(CTxMemPool::txiter iter) +{ + BOOST_FOREACH(CTxMemPool::txiter parent, mempool.GetMemPoolParents(iter)) + { + if (!inBlock.count(parent)) { + return true; + } + } + return false; +} + +void BlockAssembler::onlyUnconfirmed(CTxMemPool::setEntries& testSet) +{ + for (CTxMemPool::setEntries::iterator iit = testSet.begin(); iit != testSet.end(); ) { + // Only test txs not already in the block + if (inBlock.count(*iit)) { + testSet.erase(iit++); + } + else { + iit++; + } + } +} + +bool BlockAssembler::TestPackage(uint64_t packageSize, int64_t packageSigOpsCost) +{ + // TODO: switch to weight-based accounting for packages instead of vsize-based accounting. + if (nBlockWeight + WITNESS_SCALE_FACTOR * packageSize >= nBlockMaxWeight) + return false; + if (nBlockSigOpsCost + packageSigOpsCost >= MAX_BLOCK_SIGOPS_COST) + return false; + return true; +} + +// Perform transaction-level checks before adding to block: +// - transaction finality (locktime) +// - premature witness (in case segwit transactions are added to mempool before +// segwit activation) +// - serialized size (in case -blockmaxsize is in use) +bool BlockAssembler::TestPackageTransactions(const CTxMemPool::setEntries& package) +{ + uint64_t nPotentialBlockSize = nBlockSize; // only used with fNeedSizeAccounting + BOOST_FOREACH (const CTxMemPool::txiter it, package) { + if (!IsFinalTx(it->GetTx(), nHeight, nLockTimeCutoff)) + return false; + if (!fIncludeWitness && !it->GetTx().wit.IsNull()) + return false; + if (fNeedSizeAccounting) { + uint64_t nTxSize = ::GetSerializeSize(it->GetTx(), SER_NETWORK, PROTOCOL_VERSION); + if (nPotentialBlockSize + nTxSize >= nBlockMaxSize) { + return false; + } + nPotentialBlockSize += nTxSize; + } + } + return true; +} + +bool BlockAssembler::TestForBlock(CTxMemPool::txiter iter) +{ + if (nBlockWeight + iter->GetTxWeight() >= nBlockMaxWeight) { + // If the block is so close to full that no more txs will fit + // or if we've tried more than 50 times to fill remaining space + // then flag that the block is finished + if (nBlockWeight > nBlockMaxWeight - 400 || lastFewTxs > 50) { + blockFinished = true; + return false; + } + // Once we're within 4000 weight of a full block, only look at 50 more txs + // to try to fill the remaining space. + if (nBlockWeight > nBlockMaxWeight - 4000) { + lastFewTxs++; + } + return false; + } + + if (fNeedSizeAccounting) { + if (nBlockSize + ::GetSerializeSize(iter->GetTx(), SER_NETWORK, PROTOCOL_VERSION) >= nBlockMaxSize) { + if (nBlockSize > nBlockMaxSize - 100 || lastFewTxs > 50) { + blockFinished = true; + return false; + } + if (nBlockSize > nBlockMaxSize - 1000) { + lastFewTxs++; + } + return false; + } + } + + if (nBlockSigOpsCost + iter->GetSigOpCost() >= MAX_BLOCK_SIGOPS_COST) { + // If the block has room for no more sig ops then + // flag that the block is finished + if (nBlockSigOpsCost > MAX_BLOCK_SIGOPS_COST - 8) { + blockFinished = true; + return false; + } + // Otherwise attempt to find another tx with fewer sigops + // to put in the block. + return false; + } + + // Must check that lock times are still valid + // This can be removed once MTP is always enforced + // as long as reorgs keep the mempool consistent. + if (!IsFinalTx(iter->GetTx(), nHeight, nLockTimeCutoff)) + return false; + + return true; +} + +void BlockAssembler::AddToBlock(CTxMemPool::txiter iter) +{ + pblock->vtx.emplace_back(iter->GetSharedTx()); + pblocktemplate->vTxFees.push_back(iter->GetFee()); + pblocktemplate->vTxSigOpsCost.push_back(iter->GetSigOpCost()); + if (fNeedSizeAccounting) { + nBlockSize += ::GetSerializeSize(iter->GetTx(), SER_NETWORK, PROTOCOL_VERSION); + } + nBlockWeight += iter->GetTxWeight(); + ++nBlockTx; + nBlockSigOpsCost += iter->GetSigOpCost(); + nFees += iter->GetFee(); + inBlock.insert(iter); + + bool fPrintPriority = GetBoolArg("-printpriority", DEFAULT_PRINTPRIORITY); + if (fPrintPriority) { + double dPriority = iter->GetPriority(nHeight); + CAmount dummy; + mempool.ApplyDeltas(iter->GetTx().GetHash(), dPriority, dummy); + LogPrintf("priority %.1f fee %s txid %s\n", + dPriority, + CFeeRate(iter->GetModifiedFee(), iter->GetTxSize()).ToString(), + iter->GetTx().GetHash().ToString()); + } +} + +void BlockAssembler::UpdatePackagesForAdded(const CTxMemPool::setEntries& alreadyAdded, + indexed_modified_transaction_set &mapModifiedTx) +{ + BOOST_FOREACH(const CTxMemPool::txiter it, alreadyAdded) { + CTxMemPool::setEntries descendants; + mempool.CalculateDescendants(it, descendants); + // Insert all descendants (not yet in block) into the modified set + BOOST_FOREACH(CTxMemPool::txiter desc, descendants) { + if (alreadyAdded.count(desc)) + continue; + modtxiter mit = mapModifiedTx.find(desc); + if (mit == mapModifiedTx.end()) { + CTxMemPoolModifiedEntry modEntry(desc); + modEntry.nSizeWithAncestors -= it->GetTxSize(); + modEntry.nModFeesWithAncestors -= it->GetModifiedFee(); + modEntry.nSigOpCostWithAncestors -= it->GetSigOpCost(); + mapModifiedTx.insert(modEntry); + } else { + mapModifiedTx.modify(mit, update_for_parent_inclusion(it)); + } + } + } +} + +// Skip entries in mapTx that are already in a block or are present +// in mapModifiedTx (which implies that the mapTx ancestor state is +// stale due to ancestor inclusion in the block) +// Also skip transactions that we've already failed to add. This can happen if +// we consider a transaction in mapModifiedTx and it fails: we can then +// potentially consider it again while walking mapTx. It's currently +// guaranteed to fail again, but as a belt-and-suspenders check we put it in +// failedTx and avoid re-evaluation, since the re-evaluation would be using +// cached size/sigops/fee values that are not actually correct. +bool BlockAssembler::SkipMapTxEntry(CTxMemPool::txiter it, indexed_modified_transaction_set &mapModifiedTx, CTxMemPool::setEntries &failedTx) +{ + assert (it != mempool.mapTx.end()); + if (mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it)) + return true; + return false; +} + +void BlockAssembler::SortForBlock(const CTxMemPool::setEntries& package, CTxMemPool::txiter entry, std::vector<CTxMemPool::txiter>& sortedEntries) +{ + // Sort package by ancestor count + // If a transaction A depends on transaction B, then A's ancestor count + // must be greater than B's. So this is sufficient to validly order the + // transactions for block inclusion. + sortedEntries.clear(); + sortedEntries.insert(sortedEntries.begin(), package.begin(), package.end()); + std::sort(sortedEntries.begin(), sortedEntries.end(), CompareTxIterByAncestorCount()); +} + +// This transaction selection algorithm orders the mempool based +// on feerate of a transaction including all unconfirmed ancestors. +// Since we don't remove transactions from the mempool as we select them +// for block inclusion, we need an alternate method of updating the feerate +// of a transaction with its not-yet-selected ancestors as we go. +// This is accomplished by walking the in-mempool descendants of selected +// transactions and storing a temporary modified state in mapModifiedTxs. +// Each time through the loop, we compare the best transaction in +// mapModifiedTxs with the next transaction in the mempool to decide what +// transaction package to work on next. +void BlockAssembler::addPackageTxs() +{ + // mapModifiedTx will store sorted packages after they are modified + // because some of their txs are already in the block + indexed_modified_transaction_set mapModifiedTx; + // Keep track of entries that failed inclusion, to avoid duplicate work + CTxMemPool::setEntries failedTx; + + // Start by adding all descendants of previously added txs to mapModifiedTx + // and modifying them for their already included ancestors + UpdatePackagesForAdded(inBlock, mapModifiedTx); + + CTxMemPool::indexed_transaction_set::index<ancestor_score>::type::iterator mi = mempool.mapTx.get<ancestor_score>().begin(); + CTxMemPool::txiter iter; + while (mi != mempool.mapTx.get<ancestor_score>().end() || !mapModifiedTx.empty()) + { + // First try to find a new transaction in mapTx to evaluate. + if (mi != mempool.mapTx.get<ancestor_score>().end() && + SkipMapTxEntry(mempool.mapTx.project<0>(mi), mapModifiedTx, failedTx)) { + ++mi; + continue; + } + + // Now that mi is not stale, determine which transaction to evaluate: + // the next entry from mapTx, or the best from mapModifiedTx? + bool fUsingModified = false; + + modtxscoreiter modit = mapModifiedTx.get<ancestor_score>().begin(); + if (mi == mempool.mapTx.get<ancestor_score>().end()) { + // We're out of entries in mapTx; use the entry from mapModifiedTx + iter = modit->iter; + fUsingModified = true; + } else { + // Try to compare the mapTx entry to the mapModifiedTx entry + iter = mempool.mapTx.project<0>(mi); + if (modit != mapModifiedTx.get<ancestor_score>().end() && + CompareModifiedEntry()(*modit, CTxMemPoolModifiedEntry(iter))) { + // The best entry in mapModifiedTx has higher score + // than the one from mapTx. + // Switch which transaction (package) to consider + iter = modit->iter; + fUsingModified = true; + } else { + // Either no entry in mapModifiedTx, or it's worse than mapTx. + // Increment mi for the next loop iteration. + ++mi; + } + } + + // We skip mapTx entries that are inBlock, and mapModifiedTx shouldn't + // contain anything that is inBlock. + assert(!inBlock.count(iter)); + + uint64_t packageSize = iter->GetSizeWithAncestors(); + CAmount packageFees = iter->GetModFeesWithAncestors(); + int64_t packageSigOpsCost = iter->GetSigOpCostWithAncestors(); + if (fUsingModified) { + packageSize = modit->nSizeWithAncestors; + packageFees = modit->nModFeesWithAncestors; + packageSigOpsCost = modit->nSigOpCostWithAncestors; + } + + if (packageFees < ::minRelayTxFee.GetFee(packageSize)) { + // Everything else we might consider has a lower fee rate + return; + } + + if (!TestPackage(packageSize, packageSigOpsCost)) { + if (fUsingModified) { + // Since we always look at the best entry in mapModifiedTx, + // we must erase failed entries so that we can consider the + // next best entry on the next loop iteration + mapModifiedTx.get<ancestor_score>().erase(modit); + failedTx.insert(iter); + } + continue; + } + + CTxMemPool::setEntries ancestors; + uint64_t nNoLimit = std::numeric_limits<uint64_t>::max(); + std::string dummy; + mempool.CalculateMemPoolAncestors(*iter, ancestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false); + + onlyUnconfirmed(ancestors); + ancestors.insert(iter); + + // Test if all tx's are Final + if (!TestPackageTransactions(ancestors)) { + if (fUsingModified) { + mapModifiedTx.get<ancestor_score>().erase(modit); + failedTx.insert(iter); + } + continue; + } + + // Package can be added. Sort the entries in a valid order. + vector<CTxMemPool::txiter> sortedEntries; + SortForBlock(ancestors, iter, sortedEntries); + + for (size_t i=0; i<sortedEntries.size(); ++i) { + AddToBlock(sortedEntries[i]); + // Erase from the modified set, if present + mapModifiedTx.erase(sortedEntries[i]); + } + + // Update transactions that depend on each of these + UpdatePackagesForAdded(ancestors, mapModifiedTx); + } +} + +void BlockAssembler::addPriorityTxs() +{ + // How much of the block should be dedicated to high-priority transactions, + // included regardless of the fees they pay + unsigned int nBlockPrioritySize = GetArg("-blockprioritysize", DEFAULT_BLOCK_PRIORITY_SIZE); + nBlockPrioritySize = std::min(nBlockMaxSize, nBlockPrioritySize); + + if (nBlockPrioritySize == 0) { + return; + } + + bool fSizeAccounting = fNeedSizeAccounting; + fNeedSizeAccounting = true; + + // This vector will be sorted into a priority queue: + vector<TxCoinAgePriority> vecPriority; + TxCoinAgePriorityCompare pricomparer; + std::map<CTxMemPool::txiter, double, CTxMemPool::CompareIteratorByHash> waitPriMap; + typedef std::map<CTxMemPool::txiter, double, CTxMemPool::CompareIteratorByHash>::iterator waitPriIter; + double actualPriority = -1; + + vecPriority.reserve(mempool.mapTx.size()); + for (CTxMemPool::indexed_transaction_set::iterator mi = mempool.mapTx.begin(); + mi != mempool.mapTx.end(); ++mi) + { + double dPriority = mi->GetPriority(nHeight); + CAmount dummy; + mempool.ApplyDeltas(mi->GetTx().GetHash(), dPriority, dummy); + vecPriority.push_back(TxCoinAgePriority(dPriority, mi)); + } + std::make_heap(vecPriority.begin(), vecPriority.end(), pricomparer); + + CTxMemPool::txiter iter; + while (!vecPriority.empty() && !blockFinished) { // add a tx from priority queue to fill the blockprioritysize + iter = vecPriority.front().second; + actualPriority = vecPriority.front().first; + std::pop_heap(vecPriority.begin(), vecPriority.end(), pricomparer); + vecPriority.pop_back(); + + // If tx already in block, skip + if (inBlock.count(iter)) { + assert(false); // shouldn't happen for priority txs + continue; + } + + // cannot accept witness transactions into a non-witness block + if (!fIncludeWitness && !iter->GetTx().wit.IsNull()) + continue; + + // If tx is dependent on other mempool txs which haven't yet been included + // then put it in the waitSet + if (isStillDependent(iter)) { + waitPriMap.insert(std::make_pair(iter, actualPriority)); + continue; + } + + // If this tx fits in the block add it, otherwise keep looping + if (TestForBlock(iter)) { + AddToBlock(iter); + + // If now that this txs is added we've surpassed our desired priority size + // or have dropped below the AllowFreeThreshold, then we're done adding priority txs + if (nBlockSize >= nBlockPrioritySize || !AllowFree(actualPriority)) { + break; + } + + // This tx was successfully added, so + // add transactions that depend on this one to the priority queue to try again + BOOST_FOREACH(CTxMemPool::txiter child, mempool.GetMemPoolChildren(iter)) + { + waitPriIter wpiter = waitPriMap.find(child); + if (wpiter != waitPriMap.end()) { + vecPriority.push_back(TxCoinAgePriority(wpiter->second,child)); + std::push_heap(vecPriority.begin(), vecPriority.end(), pricomparer); + waitPriMap.erase(wpiter); + } + } + } + } + fNeedSizeAccounting = fSizeAccounting; +} + +void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce) +{ + // Update nExtraNonce + static uint256 hashPrevBlock; + if (hashPrevBlock != pblock->hashPrevBlock) + { + nExtraNonce = 0; + hashPrevBlock = pblock->hashPrevBlock; + } + ++nExtraNonce; + unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2 + CMutableTransaction txCoinbase(*pblock->vtx[0]); + txCoinbase.vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce)) + COINBASE_FLAGS; + assert(txCoinbase.vin[0].scriptSig.size() <= 100); + + pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase)); + pblock->hashMerkleRoot = BlockMerkleRoot(*pblock); +} |