Merge bitcoin/bitcoin#23517: scripted-diff: Move miner to src/node

fa4e09924b11b0dc94e377005f86a83c09761265 refactor: Replace validation.h include with forward-decl in miner.h (MarcoFalke)
fa0739a7d398aea952a07b73ef565e7c2da75898 style: Sort file list after rename (MarcoFalke)
fa53e3a58c94731a90514fe92fad365a49adb10c scripted-diff: Move miner to src/node (MarcoFalke)

Pull request description:

  It is impossible to run the miner without a node (validation, chainstate, mempool, rpc, ...). Also, the module is in the node library. Thus, it should be moved to `src/node`.

  Also, replace the `validation.h` include in the header with a forward-declaration.

ACKs for top commit:
  theStack:
    Code-review ACK fa4e09924b11b0dc94e377005f86a83c09761265

Tree-SHA512: 791e6caa5839d8dc83b0f58f3f49bc0a7e3c1710822e8a44dede254c87b6f7531a0586fb95e8a067c181457a3895ad6041718aa2a2fac64cfc136bf04bb851d5

2 files changed, 664 insertions, 0 deletions

diff --git a/src/node/miner.cpp b/src/node/miner.cpp
new file mode 100644
index 0000000000..8778a79f8b
--- /dev/null
+++ b/src/node/miner.cpp
@@ -0,0 +1,456 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2020 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 <node/miner.h>
+
+#include <chain.h>
+#include <chainparams.h>
+#include <coins.h>
+#include <consensus/amount.h>
+#include <consensus/consensus.h>
+#include <consensus/merkle.h>
+#include <consensus/tx_verify.h>
+#include <consensus/validation.h>
+#include <deploymentstatus.h>
+#include <policy/feerate.h>
+#include <policy/policy.h>
+#include <pow.h>
+#include <primitives/transaction.h>
+#include <timedata.h>
+#include <util/moneystr.h>
+#include <util/system.h>
+#include <validation.h>
+
+#include <algorithm>
+#include <utility>
+
+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;
+}
+
+void RegenerateCommitments(CBlock& block, ChainstateManager& chainman)
+{
+    CMutableTransaction tx{*block.vtx.at(0)};
+    tx.vout.erase(tx.vout.begin() + GetWitnessCommitmentIndex(block));
+    block.vtx.at(0) = MakeTransactionRef(tx);
+
+    CBlockIndex* prev_block = WITH_LOCK(::cs_main, return chainman.m_blockman.LookupBlockIndex(block.hashPrevBlock));
+    GenerateCoinbaseCommitment(block, prev_block, Params().GetConsensus());
+
+    block.hashMerkleRoot = BlockMerkleRoot(block);
+}
+
+BlockAssembler::Options::Options() {
+    blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
+    nBlockMaxWeight = DEFAULT_BLOCK_MAX_WEIGHT;
+}
+
+BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params, const Options& options)
+    : chainparams(params),
+      m_mempool(mempool),
+      m_chainstate(chainstate)
+{
+    blockMinFeeRate = options.blockMinFeeRate;
+    // Limit weight to between 4K and MAX_BLOCK_WEIGHT-4K for sanity:
+    nBlockMaxWeight = std::max<size_t>(4000, std::min<size_t>(MAX_BLOCK_WEIGHT - 4000, options.nBlockMaxWeight));
+}
+
+static BlockAssembler::Options DefaultOptions()
+{
+    // Block resource limits
+    // If -blockmaxweight is not given, limit to DEFAULT_BLOCK_MAX_WEIGHT
+    BlockAssembler::Options options;
+    options.nBlockMaxWeight = gArgs.GetIntArg("-blockmaxweight", DEFAULT_BLOCK_MAX_WEIGHT);
+    if (gArgs.IsArgSet("-blockmintxfee")) {
+        std::optional<CAmount> parsed = ParseMoney(gArgs.GetArg("-blockmintxfee", ""));
+        options.blockMinFeeRate = CFeeRate{parsed.value_or(DEFAULT_BLOCK_MIN_TX_FEE)};
+    } else {
+        options.blockMinFeeRate = CFeeRate{DEFAULT_BLOCK_MIN_TX_FEE};
+    }
+    return options;
+}
+
+BlockAssembler::BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params)
+    : BlockAssembler(chainstate, mempool, params, DefaultOptions()) {}
+
+void BlockAssembler::resetBlock()
+{
+    inBlock.clear();
+
+    // Reserve space for coinbase tx
+    nBlockWeight = 4000;
+    nBlockSigOpsCost = 400;
+    fIncludeWitness = false;
+
+    // These counters do not include coinbase tx
+    nBlockTx = 0;
+    nFees = 0;
+}
+
+std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& scriptPubKeyIn)
+{
+    int64_t nTimeStart = GetTimeMicros();
+
+    resetBlock();
+
+    pblocktemplate.reset(new CBlockTemplate());
+
+    if(!pblocktemplate.get())
+        return nullptr;
+    CBlock* const 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, m_mempool.cs);
+    CBlockIndex* pindexPrev = m_chainstate.m_chain.Tip();
+    assert(pindexPrev != nullptr);
+    nHeight = pindexPrev->nHeight + 1;
+
+    pblock->nVersion = g_versionbitscache.ComputeBlockVersion(pindexPrev, chainparams.GetConsensus());
+    // -regtest only: allow overriding block.nVersion with
+    // -blockversion=N to test forking scenarios
+    if (chainparams.MineBlocksOnDemand())
+        pblock->nVersion = gArgs.GetIntArg("-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).
+    // Note that the mempool would accept transactions with witness data before
+    // the deployment is active, but we would only ever mine blocks after activation
+    // unless there is a massive block reorganization with the witness softfork
+    // not activated.
+    // 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 = DeploymentActiveAfter(pindexPrev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT);
+
+    int nPackagesSelected = 0;
+    int nDescendantsUpdated = 0;
+    addPackageTxs(nPackagesSelected, nDescendantsUpdated);
+
+    int64_t nTime1 = GetTimeMicros();
+
+    m_last_block_num_txs = nBlockTx;
+    m_last_block_weight = 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;
+
+    LogPrintf("CreateNewBlock(): block weight: %u txs: %u fees: %ld sigops %d\n", 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]);
+
+    BlockValidationState state;
+    if (!TestBlockValidity(state, chainparams, m_chainstate, *pblock, pindexPrev, false, false)) {
+        throw std::runtime_error(strprintf("%s: TestBlockValidity failed: %s", __func__, state.ToString()));
+    }
+    int64_t nTime2 = GetTimeMicros();
+
+    LogPrint(BCLog::BENCH, "CreateNewBlock() packages: %.2fms (%d packages, %d updated descendants), validity: %.2fms (total %.2fms)\n", 0.001 * (nTime1 - nTimeStart), nPackagesSelected, nDescendantsUpdated, 0.001 * (nTime2 - nTime1), 0.001 * (nTime2 - nTimeStart));
+
+    return std::move(pblocktemplate);
+}
+
+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) const
+{
+    // 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)
+bool BlockAssembler::TestPackageTransactions(const CTxMemPool::setEntries& package) const
+{
+    for (CTxMemPool::txiter it : package) {
+        if (!IsFinalTx(it->GetTx(), nHeight, nLockTimeCutoff))
+            return false;
+        if (!fIncludeWitness && it->GetTx().HasWitness())
+            return false;
+    }
+    return true;
+}
+
+void BlockAssembler::AddToBlock(CTxMemPool::txiter iter)
+{
+    pblocktemplate->block.vtx.emplace_back(iter->GetSharedTx());
+    pblocktemplate->vTxFees.push_back(iter->GetFee());
+    pblocktemplate->vTxSigOpsCost.push_back(iter->GetSigOpCost());
+    nBlockWeight += iter->GetTxWeight();
+    ++nBlockTx;
+    nBlockSigOpsCost += iter->GetSigOpCost();
+    nFees += iter->GetFee();
+    inBlock.insert(iter);
+
+    bool fPrintPriority = gArgs.GetBoolArg("-printpriority", DEFAULT_PRINTPRIORITY);
+    if (fPrintPriority) {
+        LogPrintf("fee rate %s txid %s\n",
+                  CFeeRate(iter->GetModifiedFee(), iter->GetTxSize()).ToString(),
+                  iter->GetTx().GetHash().ToString());
+    }
+}
+
+int BlockAssembler::UpdatePackagesForAdded(const CTxMemPool::setEntries& alreadyAdded,
+        indexed_modified_transaction_set &mapModifiedTx)
+{
+    int nDescendantsUpdated = 0;
+    for (CTxMemPool::txiter it : alreadyAdded) {
+        CTxMemPool::setEntries descendants;
+        m_mempool.CalculateDescendants(it, descendants);
+        // Insert all descendants (not yet in block) into the modified set
+        for (CTxMemPool::txiter desc : descendants) {
+            if (alreadyAdded.count(desc))
+                continue;
+            ++nDescendantsUpdated;
+            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));
+            }
+        }
+    }
+    return nDescendantsUpdated;
+}
+
+// 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 != m_mempool.mapTx.end());
+    return mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it);
+}
+
+void BlockAssembler::SortForBlock(const CTxMemPool::setEntries& package, 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(int &nPackagesSelected, int &nDescendantsUpdated)
+{
+    // 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 = m_mempool.mapTx.get<ancestor_score>().begin();
+    CTxMemPool::txiter iter;
+
+    // Limit the number of attempts to add transactions to the block when it is
+    // close to full; this is just a simple heuristic to finish quickly if the
+    // mempool has a lot of entries.
+    const int64_t MAX_CONSECUTIVE_FAILURES = 1000;
+    int64_t nConsecutiveFailed = 0;
+
+    while (mi != m_mempool.mapTx.get<ancestor_score>().end() || !mapModifiedTx.empty()) {
+        // First try to find a new transaction in mapTx to evaluate.
+        if (mi != m_mempool.mapTx.get<ancestor_score>().end() &&
+            SkipMapTxEntry(m_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 == m_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 = m_mempool.mapTx.project<0>(mi);
+            if (modit != mapModifiedTx.get<ancestor_score>().end() &&
+                    CompareTxMemPoolEntryByAncestorFee()(*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 < blockMinFeeRate.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);
+            }
+
+            ++nConsecutiveFailed;
+
+            if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockWeight >
+                    nBlockMaxWeight - 4000) {
+                // Give up if we're close to full and haven't succeeded in a while
+                break;
+            }
+            continue;
+        }
+
+        CTxMemPool::setEntries ancestors;
+        uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
+        std::string dummy;
+        m_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;
+        }
+
+        // This transaction will make it in; reset the failed counter.
+        nConsecutiveFailed = 0;
+
+        // Package can be added. Sort the entries in a valid order.
+        std::vector<CTxMemPool::txiter> sortedEntries;
+        SortForBlock(ancestors, sortedEntries);
+
+        for (size_t i=0; i<sortedEntries.size(); ++i) {
+            AddToBlock(sortedEntries[i]);
+            // Erase from the modified set, if present
+            mapModifiedTx.erase(sortedEntries[i]);
+        }
+
+        ++nPackagesSelected;
+
+        // Update transactions that depend on each of these
+        nDescendantsUpdated += UpdatePackagesForAdded(ancestors, mapModifiedTx);
+    }
+}
+
+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));
+    assert(txCoinbase.vin[0].scriptSig.size() <= 100);
+
+    pblock->vtx[0] = MakeTransactionRef(std::move(txCoinbase));
+    pblock->hashMerkleRoot = BlockMerkleRoot(*pblock);
+}
diff --git a/src/node/miner.h b/src/node/miner.h
new file mode 100644
index 0000000000..0e8c02793a
--- /dev/null
+++ b/src/node/miner.h
@@ -0,0 +1,208 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_NODE_MINER_H
+#define BITCOIN_NODE_MINER_H
+
+#include <primitives/block.h>
+#include <txmempool.h>
+
+#include <memory>
+#include <optional>
+#include <stdint.h>
+
+#include <boost/multi_index/ordered_index.hpp>
+#include <boost/multi_index_container.hpp>
+
+class ChainstateManager;
+class CBlockIndex;
+class CChainParams;
+class CScript;
+
+namespace Consensus { struct Params; };
+
+static const bool DEFAULT_PRINTPRIORITY = false;
+
+struct CBlockTemplate
+{
+    CBlock block;
+    std::vector<CAmount> vTxFees;
+    std::vector<int64_t> vTxSigOpsCost;
+    std::vector<unsigned char> vchCoinbaseCommitment;
+};
+
+// Container for tracking updates to ancestor feerate as we include (parent)
+// transactions in a block
+struct CTxMemPoolModifiedEntry {
+    explicit CTxMemPoolModifiedEntry(CTxMemPool::txiter entry)
+    {
+        iter = entry;
+        nSizeWithAncestors = entry->GetSizeWithAncestors();
+        nModFeesWithAncestors = entry->GetModFeesWithAncestors();
+        nSigOpCostWithAncestors = entry->GetSigOpCostWithAncestors();
+    }
+
+    int64_t GetModifiedFee() const { return iter->GetModifiedFee(); }
+    uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
+    CAmount GetModFeesWithAncestors() const { return nModFeesWithAncestors; }
+    size_t GetTxSize() const { return iter->GetTxSize(); }
+    const CTransaction& GetTx() const { return iter->GetTx(); }
+
+    CTxMemPool::txiter iter;
+    uint64_t nSizeWithAncestors;
+    CAmount nModFeesWithAncestors;
+    int64_t nSigOpCostWithAncestors;
+};
+
+/** Comparator for CTxMemPool::txiter objects.
+ *  It simply compares the internal memory address of the CTxMemPoolEntry object
+ *  pointed to. This means it has no meaning, and is only useful for using them
+ *  as key in other indexes.
+ */
+struct CompareCTxMemPoolIter {
+    bool operator()(const CTxMemPool::txiter& a, const CTxMemPool::txiter& b) const
+    {
+        return &(*a) < &(*b);
+    }
+};
+
+struct modifiedentry_iter {
+    typedef CTxMemPool::txiter result_type;
+    result_type operator() (const CTxMemPoolModifiedEntry &entry) const
+    {
+        return entry.iter;
+    }
+};
+
+// A comparator that sorts transactions based on number of ancestors.
+// This is sufficient to sort an ancestor package in an order that is valid
+// to appear in a block.
+struct CompareTxIterByAncestorCount {
+    bool operator()(const CTxMemPool::txiter &a, const CTxMemPool::txiter &b) const
+    {
+        if (a->GetCountWithAncestors() != b->GetCountWithAncestors())
+            return a->GetCountWithAncestors() < b->GetCountWithAncestors();
+        return CompareIteratorByHash()(a, b);
+    }
+};
+
+typedef boost::multi_index_container<
+    CTxMemPoolModifiedEntry,
+    boost::multi_index::indexed_by<
+        boost::multi_index::ordered_unique<
+            modifiedentry_iter,
+            CompareCTxMemPoolIter
+        >,
+        // sorted by modified ancestor fee rate
+        boost::multi_index::ordered_non_unique<
+            // Reuse same tag from CTxMemPool's similar index
+            boost::multi_index::tag<ancestor_score>,
+            boost::multi_index::identity<CTxMemPoolModifiedEntry>,
+            CompareTxMemPoolEntryByAncestorFee
+        >
+    >
+> indexed_modified_transaction_set;
+
+typedef indexed_modified_transaction_set::nth_index<0>::type::iterator modtxiter;
+typedef indexed_modified_transaction_set::index<ancestor_score>::type::iterator modtxscoreiter;
+
+struct update_for_parent_inclusion
+{
+    explicit update_for_parent_inclusion(CTxMemPool::txiter it) : iter(it) {}
+
+    void operator() (CTxMemPoolModifiedEntry &e)
+    {
+        e.nModFeesWithAncestors -= iter->GetFee();
+        e.nSizeWithAncestors -= iter->GetTxSize();
+        e.nSigOpCostWithAncestors -= iter->GetSigOpCost();
+    }
+
+    CTxMemPool::txiter iter;
+};
+
+/** Generate a new block, without valid proof-of-work */
+class BlockAssembler
+{
+private:
+    // The constructed block template
+    std::unique_ptr<CBlockTemplate> pblocktemplate;
+
+    // Configuration parameters for the block size
+    bool fIncludeWitness;
+    unsigned int nBlockMaxWeight;
+    CFeeRate blockMinFeeRate;
+
+    // Information on the current status of the block
+    uint64_t nBlockWeight;
+    uint64_t nBlockTx;
+    uint64_t nBlockSigOpsCost;
+    CAmount nFees;
+    CTxMemPool::setEntries inBlock;
+
+    // Chain context for the block
+    int nHeight;
+    int64_t nLockTimeCutoff;
+    const CChainParams& chainparams;
+    const CTxMemPool& m_mempool;
+    CChainState& m_chainstate;
+
+public:
+    struct Options {
+        Options();
+        size_t nBlockMaxWeight;
+        CFeeRate blockMinFeeRate;
+    };
+
+    explicit BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params);
+    explicit BlockAssembler(CChainState& chainstate, const CTxMemPool& mempool, const CChainParams& params, const Options& options);
+
+    /** Construct a new block template with coinbase to scriptPubKeyIn */
+    std::unique_ptr<CBlockTemplate> CreateNewBlock(const CScript& scriptPubKeyIn);
+
+    inline static std::optional<int64_t> m_last_block_num_txs{};
+    inline static std::optional<int64_t> m_last_block_weight{};
+
+private:
+    // utility functions
+    /** Clear the block's state and prepare for assembling a new block */
+    void resetBlock();
+    /** Add a tx to the block */
+    void AddToBlock(CTxMemPool::txiter iter);
+
+    // Methods for how to add transactions to a block.
+    /** Add transactions based on feerate including unconfirmed ancestors
+      * Increments nPackagesSelected / nDescendantsUpdated with corresponding
+      * statistics from the package selection (for logging statistics). */
+    void addPackageTxs(int& nPackagesSelected, int& nDescendantsUpdated) EXCLUSIVE_LOCKS_REQUIRED(m_mempool.cs);
+
+    // helper functions for addPackageTxs()
+    /** Remove confirmed (inBlock) entries from given set */
+    void onlyUnconfirmed(CTxMemPool::setEntries& testSet);
+    /** Test if a new package would "fit" in the block */
+    bool TestPackage(uint64_t packageSize, int64_t packageSigOpsCost) const;
+    /** Perform checks on each transaction in a package:
+      * locktime, premature-witness, serialized size (if necessary)
+      * These checks should always succeed, and they're here
+      * only as an extra check in case of suboptimal node configuration */
+    bool TestPackageTransactions(const CTxMemPool::setEntries& package) const;
+    /** Return true if given transaction from mapTx has already been evaluated,
+      * or if the transaction's cached data in mapTx is incorrect. */
+    bool SkipMapTxEntry(CTxMemPool::txiter it, indexed_modified_transaction_set& mapModifiedTx, CTxMemPool::setEntries& failedTx) EXCLUSIVE_LOCKS_REQUIRED(m_mempool.cs);
+    /** Sort the package in an order that is valid to appear in a block */
+    void SortForBlock(const CTxMemPool::setEntries& package, std::vector<CTxMemPool::txiter>& sortedEntries);
+    /** Add descendants of given transactions to mapModifiedTx with ancestor
+      * state updated assuming given transactions are inBlock. Returns number
+      * of updated descendants. */
+    int UpdatePackagesForAdded(const CTxMemPool::setEntries& alreadyAdded, indexed_modified_transaction_set& mapModifiedTx) EXCLUSIVE_LOCKS_REQUIRED(m_mempool.cs);
+};
+
+/** Modify the extranonce in a block */
+void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce);
+int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
+
+/** Update an old GenerateCoinbaseCommitment from CreateNewBlock after the block txs have changed */
+void RegenerateCommitments(CBlock& block, ChainstateManager& chainman);
+
+#endif // BITCOIN_NODE_MINER_H