LCOV - code coverage report
Current view: top level - src/node - mini_miner.cpp (source / functions) Coverage Total Hit
Test: total_coverage.info Lines: 93.8 % 211 198
Test Date: 2025-11-28 05:09:59 Functions: 100.0 % 11 11
Branches: 67.2 % 250 168

             Branch data     Line data    Source code
       1                 :             : // Copyright (c) 2023 The Bitcoin Core developers
       2                 :             : // Distributed under the MIT software license, see the accompanying
       3                 :             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       4                 :             : 
       5                 :             : #include <node/mini_miner.h>
       6                 :             : 
       7                 :             : #include <boost/multi_index/detail/hash_index_iterator.hpp>
       8                 :             : #include <boost/operators.hpp>
       9                 :             : #include <consensus/amount.h>
      10                 :             : #include <policy/feerate.h>
      11                 :             : #include <primitives/transaction.h>
      12                 :             : #include <sync.h>
      13                 :             : #include <txmempool.h>
      14                 :             : #include <uint256.h>
      15                 :             : #include <util/check.h>
      16                 :             : 
      17                 :             : #include <algorithm>
      18                 :             : #include <numeric>
      19                 :             : #include <ranges>
      20                 :             : #include <utility>
      21                 :             : 
      22                 :             : namespace node {
      23                 :             : 
      24         [ +  - ]:       13257 : MiniMiner::MiniMiner(const CTxMemPool& mempool, const std::vector<COutPoint>& outpoints)
      25                 :             : {
      26         [ +  - ]:       13257 :     LOCK(mempool.cs);
      27                 :             :     // Find which outpoints to calculate bump fees for.
      28                 :             :     // Anything that's spent by the mempool is to-be-replaced
      29                 :             :     // Anything otherwise unavailable just has a bump fee of 0
      30         [ +  + ]:      166497 :     for (const auto& outpoint : outpoints) {
      31   [ +  -  +  + ]:      153240 :         if (!mempool.exists(outpoint.hash)) {
      32                 :             :             // This UTXO is either confirmed or not yet submitted to mempool.
      33                 :             :             // If it's confirmed, no bump fee is required.
      34                 :             :             // If it's not yet submitted, we have no information, so return 0.
      35         [ +  - ]:      103355 :             m_bump_fees.emplace(outpoint, 0);
      36                 :      103355 :             continue;
      37                 :             :         }
      38                 :             : 
      39                 :             :         // UXTO is created by transaction in mempool, add to map.
      40                 :             :         // Note: This will either create a missing entry or add the outpoint to an existing entry
      41   [ +  -  +  - ]:       49885 :         m_requested_outpoints_by_txid[outpoint.hash].push_back(outpoint);
      42                 :             : 
      43   [ +  -  +  + ]:       49885 :         if (const auto ptx{mempool.GetConflictTx(outpoint)}) {
      44                 :             :             // This outpoint is already being spent by another transaction in the mempool. We
      45                 :             :             // assume that the caller wants to replace this transaction and its descendants. It
      46                 :             :             // would be unusual for the transaction to have descendants as the wallet won’t normally
      47                 :             :             // attempt to replace transactions with descendants. If the outpoint is from a mempool
      48                 :             :             // transaction, we still need to calculate its ancestors bump fees (added to
      49                 :             :             // m_requested_outpoints_by_txid below), but after removing the to-be-replaced entries.
      50                 :             :             //
      51                 :             :             // Note that the descendants of a transaction include the transaction itself. Also note,
      52                 :             :             // that this is only calculating bump fees. RBF fee rules should be handled separately.
      53         [ +  - ]:         112 :             CTxMemPool::setEntries descendants;
      54   [ +  -  +  - ]:         224 :             mempool.CalculateDescendants(mempool.GetIter(ptx->GetHash()).value(), descendants);
      55         [ +  + ]:         224 :             for (const auto& desc_txiter : descendants) {
      56         [ +  - ]:         112 :                 m_to_be_replaced.insert(desc_txiter->GetTx().GetHash());
      57                 :             :             }
      58                 :         112 :         }
      59                 :             :     }
      60                 :             : 
      61                 :             :     // No unconfirmed UTXOs, so nothing mempool-related needs to be calculated.
      62         [ +  + ]:       13257 :     if (m_requested_outpoints_by_txid.empty()) return;
      63                 :             : 
      64                 :             :     // Calculate the cluster and construct the entry map.
      65         [ +  - ]:        3041 :     auto txids_needed{m_requested_outpoints_by_txid | std::views::keys};
      66   [ +  -  +  -  :        6082 :     const auto cluster = mempool.GatherClusters({txids_needed.begin(), txids_needed.end()});
                   -  + ]
      67         [ -  + ]:        3041 :     if (cluster.empty()) {
      68                 :             :         // An empty cluster means that at least one of the transactions is missing from the mempool
      69                 :             :         // (should not be possible given processing above) or DoS limit was hit.
      70                 :           0 :         m_ready_to_calculate = false;
      71                 :           0 :         return;
      72                 :             :     }
      73                 :             : 
      74                 :             :     // Add every entry to m_entries_by_txid and m_entries, except the ones that will be replaced.
      75         [ +  + ]:       71250 :     for (const auto& txiter : cluster) {
      76         [ +  + ]:       68209 :         if (!m_to_be_replaced.count(txiter->GetTx().GetHash())) {
      77   [ +  -  +  - ]:       68097 :             auto [ancestor_count, ancestor_size, ancestor_fee] = mempool.CalculateAncestorData(*txiter);
      78   [ +  -  +  -  :      136194 :             auto [mapiter, success] = m_entries_by_txid.emplace(txiter->GetTx().GetHash(),
                   +  - ]
      79   [ +  -  +  -  :      204291 :                 MiniMinerMempoolEntry{/*tx_in=*/txiter->GetSharedTx(),
                   +  - ]
      80         [ +  - ]:       68097 :                                       /*vsize_self=*/txiter->GetTxSize(),
      81                 :             :                                       /*vsize_ancestor=*/int64_t(ancestor_size),
      82                 :             :                                       /*fee_self=*/txiter->GetModifiedFee(),
      83   [ +  -  +  -  :      136194 :                                       /*fee_ancestor=*/ancestor_fee});
                   +  - ]
      84         [ +  - ]:       68097 :             m_entries.push_back(mapiter);
      85                 :             :         } else {
      86                 :         112 :             auto outpoints_it = m_requested_outpoints_by_txid.find(txiter->GetTx().GetHash());
      87         [ -  + ]:         112 :             if (outpoints_it != m_requested_outpoints_by_txid.end()) {
      88                 :             :                 // This UTXO is the output of a to-be-replaced transaction. Bump fee is 0; spending
      89                 :             :                 // this UTXO is impossible as it will no longer exist after the replacement.
      90         [ #  # ]:           0 :                 for (const auto& outpoint : outpoints_it->second) {
      91         [ #  # ]:           0 :                     m_bump_fees.emplace(outpoint, 0);
      92                 :             :                 }
      93                 :           0 :                 m_requested_outpoints_by_txid.erase(outpoints_it);
      94                 :             :             }
      95                 :             :         }
      96                 :             :     }
      97                 :             : 
      98                 :             :     // Build the m_descendant_set_by_txid cache.
      99         [ +  + ]:       71250 :     for (const auto& txiter : cluster) {
     100                 :       68209 :         const auto& txid = txiter->GetTx().GetHash();
     101                 :             :         // Cache descendants for future use. Unlike the real mempool, a descendant MiniMinerMempoolEntry
     102                 :             :         // will not exist without its ancestor MiniMinerMempoolEntry, so these sets won't be invalidated.
     103                 :       68209 :         std::vector<MockEntryMap::iterator> cached_descendants;
     104                 :       68209 :         const bool remove{m_to_be_replaced.count(txid) > 0};
     105         [ +  - ]:       68209 :         CTxMemPool::setEntries descendants;
     106         [ +  - ]:       68209 :         mempool.CalculateDescendants(txiter, descendants);
     107                 :       68209 :         Assume(descendants.count(txiter) > 0);
     108         [ +  + ]:      168597 :         for (const auto& desc_txiter : descendants) {
     109                 :      100388 :             const auto txid_desc = desc_txiter->GetTx().GetHash();
     110                 :      100388 :             const bool remove_desc{m_to_be_replaced.count(txid_desc) > 0};
     111                 :      100388 :             auto desc_it{m_entries_by_txid.find(txid_desc)};
     112         [ +  + ]:      100388 :             Assume((desc_it == m_entries_by_txid.end()) == remove_desc);
     113         [ +  + ]:      100388 :             if (remove) Assume(remove_desc);
     114                 :             :             // It's possible that remove=false but remove_desc=true.
     115         [ +  + ]:      100388 :             if (!remove && !remove_desc) {
     116         [ +  - ]:      100164 :                 cached_descendants.push_back(desc_it);
     117                 :             :             }
     118                 :             :         }
     119         [ +  + ]:       68209 :         if (remove) {
     120                 :         112 :             Assume(cached_descendants.empty());
     121                 :             :         } else {
     122         [ +  - ]:       68097 :             m_descendant_set_by_txid.emplace(txid, cached_descendants);
     123                 :             :         }
     124                 :       68209 :     }
     125                 :             : 
     126                 :             :     // Release the mempool lock; we now have all the information we need for a subset of the entries
     127                 :             :     // we care about. We will solely operate on the MiniMinerMempoolEntry map from now on.
     128         [ -  + ]:        3041 :     Assume(m_in_block.empty());
     129   [ -  +  +  - ]:        3041 :     Assume(m_requested_outpoints_by_txid.size() <= outpoints.size());
     130         [ +  - ]:        3041 :     SanityCheck();
     131         [ +  - ]:       16298 : }
     132                 :             : 
     133                 :           3 : MiniMiner::MiniMiner(const std::vector<MiniMinerMempoolEntry>& manual_entries,
     134                 :           3 :                      const std::map<Txid, std::set<Txid>>& descendant_caches)
     135                 :             : {
     136         [ +  + ]:          26 :     for (const auto& entry : manual_entries) {
     137                 :          23 :         const auto& txid = entry.GetTx().GetHash();
     138                 :             :         // We need to know the descendant set of every transaction.
     139         [ -  + ]:          23 :         if (!Assume(descendant_caches.count(txid) > 0)) {
     140                 :           0 :             m_ready_to_calculate = false;
     141                 :           0 :             return;
     142                 :             :         }
     143                 :             :         // Just forward these args onto MiniMinerMempoolEntry
     144   [ +  -  +  - ]:          23 :         auto [mapiter, success] = m_entries_by_txid.emplace(txid, entry);
     145                 :             :         // Txids must be unique; this txid shouldn't already be an entry in m_entries_by_txid
     146   [ +  -  +  - ]:          23 :         if (Assume(success)) m_entries.push_back(mapiter);
     147                 :             :     }
     148                 :             :     // Descendant cache is already built, but we need to translate them to m_entries_by_txid iters.
     149   [ -  +  +  + ]:          26 :     for (const auto& [txid, desc_txids] : descendant_caches) {
     150                 :             :         // Descendant cache should include at least the tx itself.
     151         [ -  + ]:          23 :         if (!Assume(!desc_txids.empty())) {
     152                 :           0 :             m_ready_to_calculate = false;
     153                 :           0 :             return;
     154                 :             :         }
     155                 :          23 :         std::vector<MockEntryMap::iterator> descendants;
     156         [ +  + ]:          67 :         for (const auto& desc_txid : desc_txids) {
     157                 :          44 :             auto desc_it{m_entries_by_txid.find(desc_txid)};
     158                 :             :             // Descendants should only include transactions with corresponding entries.
     159         [ -  + ]:          44 :             if (!Assume(desc_it != m_entries_by_txid.end())) {
     160                 :           0 :                 m_ready_to_calculate = false;
     161                 :           0 :                 return;
     162                 :             :             } else {
     163         [ +  - ]:          44 :                 descendants.emplace_back(desc_it);
     164                 :             :             }
     165                 :             :         }
     166         [ +  - ]:          23 :         m_descendant_set_by_txid.emplace(txid, descendants);
     167                 :          23 :     }
     168         [ +  - ]:           3 :     Assume(m_to_be_replaced.empty());
     169         [ +  - ]:           3 :     Assume(m_requested_outpoints_by_txid.empty());
     170                 :           3 :     Assume(m_bump_fees.empty());
     171                 :           3 :     Assume(m_inclusion_order.empty());
     172         [ +  - ]:           3 :     SanityCheck();
     173                 :           0 : }
     174                 :             : 
     175                 :             : // Compare by min(ancestor feerate, individual feerate), then txid
     176                 :             : //
     177                 :             : // Under the ancestor-based mining approach, high-feerate children can pay for parents, but high-feerate
     178                 :             : // parents do not incentive inclusion of their children. Therefore the mining algorithm only considers
     179                 :             : // transactions for inclusion on basis of the minimum of their own feerate or their ancestor feerate.
     180                 :             : struct AncestorFeerateComparator
     181                 :             : {
     182                 :             :     template<typename I>
     183         [ +  + ]:    19846174 :     bool operator()(const I& a, const I& b) const {
     184                 :    39692348 :         auto min_feerate = [](const MiniMinerMempoolEntry& e) -> FeeFrac {
     185                 :    39692348 :             FeeFrac self_feerate(e.GetModifiedFee(), e.GetTxSize());
     186                 :    39692348 :             FeeFrac ancestor_feerate(e.GetModFeesWithAncestors(), e.GetSizeWithAncestors());
     187                 :    39692348 :             return std::min(ancestor_feerate, self_feerate);
     188                 :             :         };
     189                 :    19846174 :         FeeFrac a_feerate{min_feerate(a->second)};
     190         [ +  + ]:    19846174 :         FeeFrac b_feerate{min_feerate(b->second)};
     191                 :    16359647 :         if (a_feerate != b_feerate) {
     192                 :     3486527 :             return a_feerate > b_feerate;
     193                 :             :         }
     194                 :             :         // Use txid as tiebreaker for stable sorting
     195                 :    16359647 :         return a->first < b->first;
     196                 :             :     }
     197                 :             : };
     198                 :             : 
     199                 :       67765 : void MiniMiner::DeleteAncestorPackage(const std::set<MockEntryMap::iterator, IteratorComparator>& ancestors)
     200                 :             : {
     201                 :       67765 :     Assume(ancestors.size() >= 1);
     202                 :             :     // "Mine" all transactions in this ancestor set.
     203         [ +  + ]:      135660 :     for (auto& anc : ancestors) {
     204                 :       67895 :         Assume(m_in_block.count(anc->first) == 0);
     205                 :       67895 :         m_in_block.insert(anc->first);
     206                 :       67895 :         m_total_fees += anc->second.GetModifiedFee();
     207                 :       67895 :         m_total_vsize += anc->second.GetTxSize();
     208                 :       67895 :         auto it = m_descendant_set_by_txid.find(anc->first);
     209                 :             :         // Each entry’s descendant set includes itself
     210                 :       67895 :         Assume(it != m_descendant_set_by_txid.end());
     211         [ +  + ]:      167828 :         for (auto& descendant : it->second) {
     212                 :             :             // If these fail, we must be double-deducting.
     213                 :       99933 :             Assume(descendant->second.GetModFeesWithAncestors() >= anc->second.GetModifiedFee());
     214                 :       99933 :             Assume(descendant->second.GetSizeWithAncestors() >= anc->second.GetTxSize());
     215                 :       99933 :             descendant->second.UpdateAncestorState(-anc->second.GetTxSize(), -anc->second.GetModifiedFee());
     216                 :             :         }
     217                 :             :     }
     218                 :             :     // Delete these entries.
     219         [ +  + ]:      135660 :     for (const auto& anc : ancestors) {
     220                 :       67895 :         m_descendant_set_by_txid.erase(anc->first);
     221                 :             :         // The above loop should have deducted each ancestor's size and fees from each of their
     222                 :             :         // respective descendants exactly once.
     223                 :       67895 :         Assume(anc->second.GetModFeesWithAncestors() == 0);
     224                 :       67895 :         Assume(anc->second.GetSizeWithAncestors() == 0);
     225                 :       67895 :         auto vec_it = std::find(m_entries.begin(), m_entries.end(), anc);
     226                 :       67895 :         Assume(vec_it != m_entries.end());
     227                 :       67895 :         m_entries.erase(vec_it);
     228                 :       67895 :         m_entries_by_txid.erase(anc);
     229                 :             :     }
     230                 :       67765 : }
     231                 :             : 
     232                 :       70809 : void MiniMiner::SanityCheck() const
     233                 :             : {
     234                 :             :     // m_entries, m_entries_by_txid, and m_descendant_set_by_txid all same size
     235         [ -  + ]:       70809 :     Assume(m_entries.size() == m_entries_by_txid.size());
     236                 :       70809 :     Assume(m_entries.size() == m_descendant_set_by_txid.size());
     237                 :             :     // Cached ancestor values should be at least as large as the transaction's own fee and size
     238   [ +  -  +  - ]:     3537401 :     Assume(std::all_of(m_entries.begin(), m_entries.end(), [](const auto& entry) {
     239                 :             :         return entry->second.GetSizeWithAncestors() >= entry->second.GetTxSize() &&
     240                 :             :                entry->second.GetModFeesWithAncestors() >= entry->second.GetModifiedFee();}));
     241                 :             :     // None of the entries should be to-be-replaced transactions
     242                 :       71215 :     Assume(std::all_of(m_to_be_replaced.begin(), m_to_be_replaced.end(),
     243                 :             :         [&](const auto& txid){return m_entries_by_txid.find(txid) == m_entries_by_txid.end();}));
     244                 :       70809 : }
     245                 :             : 
     246                 :       13260 : void MiniMiner::BuildMockTemplate(std::optional<CFeeRate> target_feerate)
     247                 :             : {
     248                 :       13260 :     const auto num_txns{m_entries_by_txid.size()};
     249                 :       13260 :     uint32_t sequence_num{0};
     250         [ +  + ]:       81025 :     while (!m_entries_by_txid.empty()) {
     251                 :             :         // Sort again, since transaction removal may change some m_entries' ancestor feerates.
     252                 :       67919 :         std::sort(m_entries.begin(), m_entries.end(), AncestorFeerateComparator());
     253                 :             : 
     254                 :             :         // Pick highest ancestor feerate entry.
     255         [ +  + ]:       67919 :         auto best_iter = m_entries.begin();
     256         [ +  + ]:       67919 :         Assume(best_iter != m_entries.end());
     257         [ +  + ]:       67919 :         const auto ancestor_package_size = (*best_iter)->second.GetSizeWithAncestors();
     258         [ +  + ]:       67919 :         const auto ancestor_package_fee = (*best_iter)->second.GetModFeesWithAncestors();
     259                 :             :         // Stop here. Everything that didn't "make it into the block" has bumpfee.
     260   [ +  +  +  + ]:      135813 :         if (target_feerate.has_value() &&
     261                 :       67894 :             ancestor_package_fee < target_feerate->GetFee(ancestor_package_size)) {
     262                 :             :             break;
     263                 :             :         }
     264                 :             : 
     265                 :             :         // Calculate ancestors on the fly. This lookup should be fairly cheap, and ancestor sets
     266                 :             :         // change at every iteration, so this is more efficient than maintaining a cache.
     267         [ +  - ]:       67765 :         std::set<MockEntryMap::iterator, IteratorComparator> ancestors;
     268                 :       67765 :         {
     269                 :       67765 :             std::set<MockEntryMap::iterator, IteratorComparator> to_process;
     270         [ +  - ]:       67765 :             to_process.insert(*best_iter);
     271         [ +  + ]:      135660 :             while (!to_process.empty()) {
     272         [ +  - ]:       67895 :                 auto iter = to_process.begin();
     273         [ +  - ]:       67895 :                 Assume(iter != to_process.end());
     274         [ +  - ]:       67895 :                 ancestors.insert(*iter);
     275         [ +  + ]:      140879 :                 for (const auto& input : (*iter)->second.GetTx().vin) {
     276         [ +  + ]:       72984 :                     if (auto parent_it{m_entries_by_txid.find(input.prevout.hash)}; parent_it != m_entries_by_txid.end()) {
     277         [ +  - ]:         130 :                         if (ancestors.count(parent_it) == 0) {
     278         [ +  - ]:         130 :                             to_process.insert(parent_it);
     279                 :             :                         }
     280                 :             :                     }
     281                 :             :                 }
     282                 :       67895 :                 to_process.erase(iter);
     283                 :             :             }
     284                 :           0 :         }
     285                 :             :         // Track the order in which transactions were selected.
     286         [ +  + ]:      135660 :         for (const auto& ancestor : ancestors) {
     287         [ +  - ]:       67895 :             m_inclusion_order.emplace(ancestor->first, sequence_num);
     288                 :             :         }
     289         [ +  - ]:       67765 :         DeleteAncestorPackage(ancestors);
     290         [ +  - ]:       67765 :         SanityCheck();
     291                 :       67765 :         ++sequence_num;
     292                 :       67765 :     }
     293         [ +  + ]:       13260 :     if (!target_feerate.has_value()) {
     294                 :           6 :         Assume(m_in_block.size() == num_txns);
     295                 :             :     } else {
     296         [ +  + ]:       13254 :         Assume(m_in_block.empty() || m_total_fees >= target_feerate->GetFee(m_total_vsize));
     297                 :             :     }
     298                 :       13260 :     Assume(m_in_block.empty() || sequence_num > 0);
     299                 :       13260 :     Assume(m_in_block.size() == m_inclusion_order.size());
     300                 :             :     // Do not try to continue building the block template with a different feerate.
     301                 :       13260 :     m_ready_to_calculate = false;
     302                 :       13260 : }
     303                 :             : 
     304                 :             : 
     305                 :           5 : std::map<Txid, uint32_t> MiniMiner::Linearize()
     306                 :             : {
     307                 :           5 :     BuildMockTemplate(std::nullopt);
     308                 :           5 :     return m_inclusion_order;
     309                 :             : }
     310                 :             : 
     311                 :        4088 : std::map<COutPoint, CAmount> MiniMiner::CalculateBumpFees(const CFeeRate& target_feerate)
     312                 :             : {
     313         [ -  + ]:        4088 :     if (!m_ready_to_calculate) return {};
     314                 :             :     // Build a block template until the target feerate is hit.
     315                 :        4088 :     BuildMockTemplate(target_feerate);
     316                 :             : 
     317                 :             :     // Each transaction that "made it into the block" has a bumpfee of 0, i.e. they are part of an
     318                 :             :     // ancestor package with at least the target feerate and don't need to be bumped.
     319         [ +  + ]:       69180 :     for (const auto& txid : m_in_block) {
     320                 :             :         // Not all of the block transactions were necessarily requested.
     321                 :       65092 :         auto it = m_requested_outpoints_by_txid.find(txid);
     322         [ +  + ]:       65092 :         if (it != m_requested_outpoints_by_txid.end()) {
     323         [ +  + ]:       95688 :             for (const auto& outpoint : it->second) {
     324                 :       47931 :                 m_bump_fees.emplace(outpoint, 0);
     325                 :             :             }
     326                 :       47757 :             m_requested_outpoints_by_txid.erase(it);
     327                 :             :         }
     328                 :             :     }
     329                 :             : 
     330                 :             :     // A transactions and its ancestors will only be picked into a block when
     331                 :             :     // both the ancestor set feerate and the individual feerate meet the target
     332                 :             :     // feerate.
     333                 :             :     //
     334                 :             :     // We had to convince ourselves that after running the mini miner and
     335                 :             :     // picking all eligible transactions into our MockBlockTemplate, there
     336                 :             :     // could still be transactions remaining that have a lower individual
     337                 :             :     // feerate than their ancestor feerate. So here is an example:
     338                 :             :     //
     339                 :             :     //               ┌─────────────────┐
     340                 :             :     //               │                 │
     341                 :             :     //               │   Grandparent   │
     342                 :             :     //               │    1700 vB      │
     343                 :             :     //               │    1700 sats    │                    Target feerate: 10    s/vB
     344                 :             :     //               │       1 s/vB    │    GP Ancestor Set Feerate (ASFR):  1    s/vB
     345                 :             :     //               │                 │                           P1_ASFR:  9.84 s/vB
     346                 :             :     //               └──────▲───▲──────┘                           P2_ASFR:  2.47 s/vB
     347                 :             :     //                      │   │                                   C_ASFR: 10.27 s/vB
     348                 :             :     // ┌───────────────┐    │   │    ┌──────────────┐
     349                 :             :     // │               ├────┘   └────┤              │             ⇒ C_FR < TFR < C_ASFR
     350                 :             :     // │   Parent 1    │             │   Parent 2   │
     351                 :             :     // │    200 vB     │             │    200 vB    │
     352                 :             :     // │  17000 sats   │             │   3000 sats  │
     353                 :             :     // │     85 s/vB   │             │     15 s/vB  │
     354                 :             :     // │               │             │              │
     355                 :             :     // └───────────▲───┘             └───▲──────────┘
     356                 :             :     //             │                     │
     357                 :             :     //             │    ┌───────────┐    │
     358                 :             :     //             └────┤           ├────┘
     359                 :             :     //                  │   Child   │
     360                 :             :     //                  │  100 vB   │
     361                 :             :     //                  │  900 sats │
     362                 :             :     //                  │    9 s/vB │
     363                 :             :     //                  │           │
     364                 :             :     //                  └───────────┘
     365                 :             :     //
     366                 :             :     // We therefore calculate both the bump fee that is necessary to elevate
     367                 :             :     // the individual transaction to the target feerate:
     368                 :             :     //         target_feerate × tx_size - tx_fees
     369                 :             :     // and the bump fee that is necessary to bump the entire ancestor set to
     370                 :             :     // the target feerate:
     371                 :             :     //         target_feerate × ancestor_set_size - ancestor_set_fees
     372                 :             :     // By picking the maximum from the two, we ensure that a transaction meets
     373                 :             :     // both criteria.
     374         [ +  + ]:        4211 :     for (const auto& [txid, outpoints] : m_requested_outpoints_by_txid) {
     375                 :         123 :         auto it = m_entries_by_txid.find(txid);
     376         [ +  - ]:         123 :         Assume(it != m_entries_by_txid.end());
     377         [ +  - ]:         123 :         if (it != m_entries_by_txid.end()) {
     378                 :         123 :             Assume(target_feerate.GetFee(it->second.GetSizeWithAncestors()) > std::min(it->second.GetModifiedFee(), it->second.GetModFeesWithAncestors()));
     379                 :         123 :             CAmount bump_fee_with_ancestors = target_feerate.GetFee(it->second.GetSizeWithAncestors()) - it->second.GetModFeesWithAncestors();
     380         [ +  - ]:         123 :             CAmount bump_fee_individual = target_feerate.GetFee(it->second.GetTxSize()) - it->second.GetModifiedFee();
     381         [ +  - ]:         123 :             const CAmount bump_fee{std::max(bump_fee_with_ancestors, bump_fee_individual)};
     382                 :         123 :             Assume(bump_fee >= 0);
     383         [ +  + ]:         302 :             for (const auto& outpoint : outpoints) {
     384                 :         179 :                 m_bump_fees.emplace(outpoint, bump_fee);
     385                 :             :             }
     386                 :             :         }
     387                 :             :     }
     388                 :        4088 :     return m_bump_fees;
     389                 :             : }
     390                 :             : 
     391                 :        9165 : std::optional<CAmount> MiniMiner::CalculateTotalBumpFees(const CFeeRate& target_feerate)
     392                 :             : {
     393         [ -  + ]:        9165 :     if (!m_ready_to_calculate) return std::nullopt;
     394                 :             :     // Build a block template until the target feerate is hit.
     395                 :        9165 :     BuildMockTemplate(target_feerate);
     396                 :             : 
     397                 :             :     // All remaining ancestors that are not part of m_in_block must be bumped, but no other relatives
     398                 :        9165 :     std::set<MockEntryMap::iterator, IteratorComparator> ancestors;
     399                 :        9165 :     std::set<MockEntryMap::iterator, IteratorComparator> to_process;
     400         [ +  + ]:       10883 :     for (const auto& [txid, outpoints] : m_requested_outpoints_by_txid) {
     401                 :             :         // Skip any ancestors that already have a miner score higher than the target feerate
     402                 :             :         // (already "made it" into the block)
     403         [ +  + ]:        1718 :         if (m_in_block.count(txid)) continue;
     404                 :          80 :         auto iter = m_entries_by_txid.find(txid);
     405         [ -  + ]:          80 :         if (iter == m_entries_by_txid.end()) continue;
     406         [ +  - ]:          80 :         to_process.insert(iter);
     407         [ +  - ]:          80 :         ancestors.insert(iter);
     408                 :             :     }
     409                 :             : 
     410                 :        9165 :     std::set<Txid> has_been_processed;
     411         [ +  + ]:        9259 :     while (!to_process.empty()) {
     412                 :          94 :         auto iter = to_process.begin();
     413                 :          94 :         const CTransaction& tx = (*iter)->second.GetTx();
     414         [ +  + ]:         204 :         for (const auto& input : tx.vin) {
     415         [ +  + ]:         110 :             if (auto parent_it{m_entries_by_txid.find(input.prevout.hash)}; parent_it != m_entries_by_txid.end()) {
     416         [ +  + ]:          29 :                 if (!has_been_processed.count(input.prevout.hash)) {
     417         [ +  - ]:          26 :                     to_process.insert(parent_it);
     418                 :             :                 }
     419         [ +  - ]:          29 :                 ancestors.insert(parent_it);
     420                 :             :             }
     421                 :             :         }
     422         [ +  - ]:          94 :         has_been_processed.insert(tx.GetHash());
     423                 :          94 :         to_process.erase(iter);
     424                 :             :     }
     425                 :        9165 :     const auto ancestor_package_size = std::accumulate(ancestors.cbegin(), ancestors.cend(), int64_t{0},
     426                 :          94 :         [](int64_t sum, const auto it) {return sum + it->second.GetTxSize();});
     427                 :        9165 :     const auto ancestor_package_fee = std::accumulate(ancestors.cbegin(), ancestors.cend(), CAmount{0},
     428                 :          94 :         [](CAmount sum, const auto it) {return sum + it->second.GetModifiedFee();});
     429         [ +  - ]:        9165 :     return target_feerate.GetFee(ancestor_package_size) - ancestor_package_fee;
     430                 :        9165 : }
     431                 :             : } // namespace node
        

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