1  // Copyright (c) 2009-2010 Satoshi Nakamoto
   2  // Copyright (c) 2009-2022 The Bitcoin Core developers
   3  // Distributed under the MIT software license, see the accompanying
   4  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5  
   6  #include <txmempool.h>
   7  
   8  #include <chain.h>
   9  #include <coins.h>
  10  #include <common/system.h>
  11  #include <consensus/consensus.h>
  12  #include <consensus/tx_verify.h>
  13  #include <consensus/validation.h>
  14  #include <logging.h>
  15  #include <policy/policy.h>
  16  #include <policy/settings.h>
  17  #include <random.h>
  18  #include <tinyformat.h>
  19  #include <util/check.h>
  20  #include <util/feefrac.h>
  21  #include <util/moneystr.h>
  22  #include <util/overflow.h>
  23  #include <util/result.h>
  24  #include <util/time.h>
  25  #include <util/trace.h>
  26  #include <util/translation.h>
  27  #include <validationinterface.h>
  28  
  29  #include <algorithm>
  30  #include <cmath>
  31  #include <numeric>
  32  #include <optional>
  33  #include <ranges>
  34  #include <string_view>
  35  #include <utility>
  36  
  37  TRACEPOINT_SEMAPHORE(mempool, added);
  38  TRACEPOINT_SEMAPHORE(mempool, removed);
  39  
  40  bool TestLockPointValidity(CChain& active_chain, const LockPoints& lp)
  41  {
  42      AssertLockHeld(cs_main);
  43      // If there are relative lock times then the maxInputBlock will be set
  44      // If there are no relative lock times, the LockPoints don't depend on the chain
  45      if (lp.maxInputBlock) {
  46          // Check whether active_chain is an extension of the block at which the LockPoints
  47          // calculation was valid.  If not LockPoints are no longer valid
  48          if (!active_chain.Contains(lp.maxInputBlock)) {
  49              return false;
  50          }
  51      }
  52  
  53      // LockPoints still valid
  54      return true;
  55  }
  56  
  57  std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> CTxMemPool::GetChildren(const CTxMemPoolEntry& entry) const
  58  {
  59      LOCK(cs);
  60      std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> ret;
  61      WITH_FRESH_EPOCH(m_epoch);
  62      auto iter = mapNextTx.lower_bound(COutPoint(entry.GetTx().GetHash(), 0));
  63      for (; iter != mapNextTx.end() && iter->first->hash == entry.GetTx().GetHash(); ++iter) {
  64          if (!visited(iter->second)) {
  65              ret.emplace_back(*(iter->second));
  66          }
  67      }
  68      return ret;
  69  }
  70  
  71  std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> CTxMemPool::GetParents(const CTxMemPoolEntry& entry) const
  72  {
  73      LOCK(cs);
  74      std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> ret;
  75      std::set<Txid> inputs;
  76      for (const auto& txin : entry.GetTx().vin) {
  77          inputs.insert(txin.prevout.hash);
  78      }
  79      for (const auto& hash : inputs) {
  80          std::optional<txiter> piter = GetIter(hash);
  81          if (piter) {
  82              ret.emplace_back(**piter);
  83          }
  84      }
  85      return ret;
  86  }
  87  
  88  void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<Txid>& vHashesToUpdate)
  89  {
  90      AssertLockHeld(cs);
  91  
  92      // Iterate in reverse, so that whenever we are looking at a transaction
  93      // we are sure that all in-mempool descendants have already been processed.
  94      for (const Txid& hash : vHashesToUpdate | std::views::reverse) {
  95          // calculate children from mapNextTx
  96          txiter it = mapTx.find(hash);
  97          if (it == mapTx.end()) {
  98              continue;
  99          }
 100          auto iter = mapNextTx.lower_bound(COutPoint(hash, 0));
 101          {
 102              for (; iter != mapNextTx.end() && iter->first->hash == hash; ++iter) {
 103                  txiter childIter = iter->second;
 104                  assert(childIter != mapTx.end());
 105                  // Add dependencies that are discovered between transactions in the
 106                  // block and transactions that were in the mempool to txgraph.
 107                  m_txgraph->AddDependency(/*parent=*/*it, /*child=*/*childIter);
 108              }
 109          }
 110      }
 111  
 112      auto txs_to_remove = m_txgraph->Trim(); // Enforce cluster size limits.
 113      for (auto txptr : txs_to_remove) {
 114          const CTxMemPoolEntry& entry = *(static_cast<const CTxMemPoolEntry*>(txptr));
 115          removeUnchecked(mapTx.iterator_to(entry), MemPoolRemovalReason::SIZELIMIT);
 116      }
 117  }
 118  
 119  bool CTxMemPool::HasDescendants(const Txid& txid) const
 120  {
 121      LOCK(cs);
 122      auto entry = GetEntry(txid);
 123      if (!entry) return false;
 124      return m_txgraph->GetDescendants(*entry, TxGraph::Level::MAIN).size() > 1;
 125  }
 126  
 127  CTxMemPool::setEntries CTxMemPool::CalculateMemPoolAncestors(const CTxMemPoolEntry &entry) const
 128  {
 129      auto ancestors = m_txgraph->GetAncestors(entry, TxGraph::Level::MAIN);
 130      setEntries ret;
 131      if (ancestors.size() > 0) {
 132          for (auto ancestor : ancestors) {
 133              if (ancestor != &entry) {
 134                  ret.insert(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*ancestor)));
 135              }
 136          }
 137          return ret;
 138      }
 139  
 140      // If we didn't get anything back, the transaction is not in the graph.
 141      // Find each parent and call GetAncestors on each.
 142      setEntries staged_parents;
 143      const CTransaction &tx = entry.GetTx();
 144  
 145      // Get parents of this transaction that are in the mempool
 146      for (unsigned int i = 0; i < tx.vin.size(); i++) {
 147          std::optional<txiter> piter = GetIter(tx.vin[i].prevout.hash);
 148          if (piter) {
 149              staged_parents.insert(*piter);
 150          }
 151      }
 152  
 153      for (const auto& parent : staged_parents) {
 154          auto parent_ancestors = m_txgraph->GetAncestors(*parent, TxGraph::Level::MAIN);
 155          for (auto ancestor : parent_ancestors) {
 156              ret.insert(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*ancestor)));
 157          }
 158      }
 159  
 160      return ret;
 161  }
 162  
 163  static CTxMemPool::Options&& Flatten(CTxMemPool::Options&& opts, bilingual_str& error)
 164  {
 165      opts.check_ratio = std::clamp<int>(opts.check_ratio, 0, 1'000'000);
 166      int64_t cluster_limit_bytes = opts.limits.cluster_size_vbytes * 40;
 167      if (opts.max_size_bytes < 0 || (opts.max_size_bytes > 0 && opts.max_size_bytes < cluster_limit_bytes)) {
 168          error = strprintf(_("-maxmempool must be at least %d MB"), std::ceil(cluster_limit_bytes / 1'000'000.0));
 169      }
 170      return std::move(opts);
 171  }
 172  
 173  CTxMemPool::CTxMemPool(Options opts, bilingual_str& error)
 174      : m_opts{Flatten(std::move(opts), error)}
 175  {
 176      m_txgraph = MakeTxGraph(m_opts.limits.cluster_count, m_opts.limits.cluster_size_vbytes * WITNESS_SCALE_FACTOR, ACCEPTABLE_ITERS);
 177  }
 178  
 179  bool CTxMemPool::isSpent(const COutPoint& outpoint) const
 180  {
 181      LOCK(cs);
 182      return mapNextTx.count(outpoint);
 183  }
 184  
 185  unsigned int CTxMemPool::GetTransactionsUpdated() const
 186  {
 187      return nTransactionsUpdated;
 188  }
 189  
 190  void CTxMemPool::AddTransactionsUpdated(unsigned int n)
 191  {
 192      nTransactionsUpdated += n;
 193  }
 194  
 195  void CTxMemPool::Apply(ChangeSet* changeset)
 196  {
 197      AssertLockHeld(cs);
 198      m_txgraph->CommitStaging();
 199  
 200      RemoveStaged(changeset->m_to_remove, MemPoolRemovalReason::REPLACED);
 201  
 202      for (size_t i=0; i<changeset->m_entry_vec.size(); ++i) {
 203          auto tx_entry = changeset->m_entry_vec[i];
 204          // First splice this entry into mapTx.
 205          auto node_handle = changeset->m_to_add.extract(tx_entry);
 206          auto result = mapTx.insert(std::move(node_handle));
 207  
 208          Assume(result.inserted);
 209          txiter it = result.position;
 210  
 211          addNewTransaction(it);
 212      }
 213      m_txgraph->DoWork(POST_CHANGE_WORK);
 214  }
 215  
 216  void CTxMemPool::addNewTransaction(CTxMemPool::txiter newit)
 217  {
 218      const CTxMemPoolEntry& entry = *newit;
 219  
 220      // Update cachedInnerUsage to include contained transaction's usage.
 221      // (When we update the entry for in-mempool parents, memory usage will be
 222      // further updated.)
 223      cachedInnerUsage += entry.DynamicMemoryUsage();
 224  
 225      const CTransaction& tx = newit->GetTx();
 226      for (unsigned int i = 0; i < tx.vin.size(); i++) {
 227          mapNextTx.insert(std::make_pair(&tx.vin[i].prevout, newit));
 228      }
 229      // Don't bother worrying about child transactions of this one.
 230      // Normal case of a new transaction arriving is that there can't be any
 231      // children, because such children would be orphans.
 232      // An exception to that is if a transaction enters that used to be in a block.
 233      // In that case, our disconnect block logic will call UpdateTransactionsFromBlock
 234      // to clean up the mess we're leaving here.
 235  
 236      nTransactionsUpdated++;
 237      totalTxSize += entry.GetTxSize();
 238      m_total_fee += entry.GetFee();
 239  
 240      txns_randomized.emplace_back(tx.GetWitnessHash(), newit);
 241      newit->idx_randomized = txns_randomized.size() - 1;
 242  
 243      TRACEPOINT(mempool, added,
 244          entry.GetTx().GetHash().data(),
 245          entry.GetTxSize(),
 246          entry.GetFee()
 247      );
 248  }
 249  
 250  void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason)
 251  {
 252      // We increment mempool sequence value no matter removal reason
 253      // even if not directly reported below.
 254      uint64_t mempool_sequence = GetAndIncrementSequence();
 255  
 256      if (reason != MemPoolRemovalReason::BLOCK && m_opts.signals) {
 257          // Notify clients that a transaction has been removed from the mempool
 258          // for any reason except being included in a block. Clients interested
 259          // in transactions included in blocks can subscribe to the BlockConnected
 260          // notification.
 261          m_opts.signals->TransactionRemovedFromMempool(it->GetSharedTx(), reason, mempool_sequence);
 262      }
 263      TRACEPOINT(mempool, removed,
 264          it->GetTx().GetHash().data(),
 265          RemovalReasonToString(reason).c_str(),
 266          it->GetTxSize(),
 267          it->GetFee(),
 268          std::chrono::duration_cast<std::chrono::duration<std::uint64_t>>(it->GetTime()).count()
 269      );
 270  
 271      for (const CTxIn& txin : it->GetTx().vin)
 272          mapNextTx.erase(txin.prevout);
 273  
 274      RemoveUnbroadcastTx(it->GetTx().GetHash(), true /* add logging because unchecked */);
 275  
 276      if (txns_randomized.size() > 1) {
 277          // Remove entry from txns_randomized by replacing it with the back and deleting the back.
 278          txns_randomized[it->idx_randomized] = std::move(txns_randomized.back());
 279          txns_randomized[it->idx_randomized].second->idx_randomized = it->idx_randomized;
 280          txns_randomized.pop_back();
 281          if (txns_randomized.size() * 2 < txns_randomized.capacity()) {
 282              txns_randomized.shrink_to_fit();
 283          }
 284      } else {
 285          txns_randomized.clear();
 286      }
 287  
 288      totalTxSize -= it->GetTxSize();
 289      m_total_fee -= it->GetFee();
 290      cachedInnerUsage -= it->DynamicMemoryUsage();
 291      mapTx.erase(it);
 292      nTransactionsUpdated++;
 293  }
 294  
 295  // Calculates descendants of given entry and adds to setDescendants.
 296  void CTxMemPool::CalculateDescendants(txiter entryit, setEntries& setDescendants) const
 297  {
 298      (void)CalculateDescendants(*entryit, setDescendants);
 299      return;
 300  }
 301  
 302  CTxMemPool::txiter CTxMemPool::CalculateDescendants(const CTxMemPoolEntry& entry, setEntries& setDescendants) const
 303  {
 304      for (auto tx : m_txgraph->GetDescendants(entry, TxGraph::Level::MAIN)) {
 305          setDescendants.insert(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*tx)));
 306      }
 307      return mapTx.iterator_to(entry);
 308  }
 309  
 310  void CTxMemPool::removeRecursive(CTxMemPool::txiter to_remove, MemPoolRemovalReason reason)
 311  {
 312      AssertLockHeld(cs);
 313      Assume(!m_have_changeset);
 314      auto descendants = m_txgraph->GetDescendants(*to_remove, TxGraph::Level::MAIN);
 315      for (auto tx: descendants) {
 316          removeUnchecked(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*tx)), reason);
 317      }
 318  }
 319  
 320  void CTxMemPool::removeRecursive(const CTransaction &origTx, MemPoolRemovalReason reason)
 321  {
 322      // Remove transaction from memory pool
 323      AssertLockHeld(cs);
 324      Assume(!m_have_changeset);
 325      txiter origit = mapTx.find(origTx.GetHash());
 326      if (origit != mapTx.end()) {
 327          removeRecursive(origit, reason);
 328      } else {
 329          // When recursively removing but origTx isn't in the mempool
 330          // be sure to remove any descendants that are in the pool. This can
 331          // happen during chain re-orgs if origTx isn't re-accepted into
 332          // the mempool for any reason.
 333          auto iter = mapNextTx.lower_bound(COutPoint(origTx.GetHash(), 0));
 334          std::vector<const TxGraph::Ref*> to_remove;
 335          while (iter != mapNextTx.end() && iter->first->hash == origTx.GetHash()) {
 336              to_remove.emplace_back(&*(iter->second));
 337              ++iter;
 338          }
 339          auto all_removes = m_txgraph->GetDescendantsUnion(to_remove, TxGraph::Level::MAIN);
 340          for (auto ref : all_removes) {
 341              auto tx = mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*ref));
 342              removeUnchecked(tx, reason);
 343          }
 344      }
 345  }
 346  
 347  void CTxMemPool::removeForReorg(CChain& chain, std::function<bool(txiter)> check_final_and_mature)
 348  {
 349      // Remove transactions spending a coinbase which are now immature and no-longer-final transactions
 350      AssertLockHeld(cs);
 351      AssertLockHeld(::cs_main);
 352      Assume(!m_have_changeset);
 353  
 354      std::vector<const TxGraph::Ref*> to_remove;
 355      for (txiter it = mapTx.begin(); it != mapTx.end(); it++) {
 356          if (check_final_and_mature(it)) {
 357              to_remove.emplace_back(&*it);
 358          }
 359      }
 360  
 361      auto all_to_remove = m_txgraph->GetDescendantsUnion(to_remove, TxGraph::Level::MAIN);
 362  
 363      for (auto ref : all_to_remove) {
 364          auto it = mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*ref));
 365          removeUnchecked(it, MemPoolRemovalReason::REORG);
 366      }
 367      for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) {
 368          assert(TestLockPointValidity(chain, it->GetLockPoints()));
 369      }
 370      m_txgraph->DoWork(POST_CHANGE_WORK);
 371  }
 372  
 373  void CTxMemPool::removeConflicts(const CTransaction &tx)
 374  {
 375      // Remove transactions which depend on inputs of tx, recursively
 376      AssertLockHeld(cs);
 377      for (const CTxIn &txin : tx.vin) {
 378          auto it = mapNextTx.find(txin.prevout);
 379          if (it != mapNextTx.end()) {
 380              const CTransaction &txConflict = it->second->GetTx();
 381              if (Assume(txConflict.GetHash() != tx.GetHash()))
 382              {
 383                  ClearPrioritisation(txConflict.GetHash());
 384                  removeRecursive(it->second, MemPoolRemovalReason::CONFLICT);
 385              }
 386          }
 387      }
 388  }
 389  
 390  void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight)
 391  {
 392      // Remove confirmed txs and conflicts when a new block is connected, updating the fee logic
 393      AssertLockHeld(cs);
 394      Assume(!m_have_changeset);
 395      std::vector<RemovedMempoolTransactionInfo> txs_removed_for_block;
 396      if (mapTx.size() || mapNextTx.size() || mapDeltas.size()) {
 397          txs_removed_for_block.reserve(vtx.size());
 398          for (const auto& tx : vtx) {
 399              txiter it = mapTx.find(tx->GetHash());
 400              if (it != mapTx.end()) {
 401                  txs_removed_for_block.emplace_back(*it);
 402                  removeUnchecked(it, MemPoolRemovalReason::BLOCK);
 403              }
 404              removeConflicts(*tx);
 405              ClearPrioritisation(tx->GetHash());
 406          }
 407      }
 408      if (m_opts.signals) {
 409          m_opts.signals->MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight);
 410      }
 411      lastRollingFeeUpdate = GetTime();
 412      blockSinceLastRollingFeeBump = true;
 413      m_txgraph->DoWork(POST_CHANGE_WORK);
 414  }
 415  
 416  void CTxMemPool::check(const CCoinsViewCache& active_coins_tip, int64_t spendheight) const
 417  {
 418      if (m_opts.check_ratio == 0) return;
 419  
 420      if (FastRandomContext().randrange(m_opts.check_ratio) >= 1) return;
 421  
 422      AssertLockHeld(::cs_main);
 423      LOCK(cs);
 424      LogDebug(BCLog::MEMPOOL, "Checking mempool with %u transactions and %u inputs\n", (unsigned int)mapTx.size(), (unsigned int)mapNextTx.size());
 425  
 426      uint64_t checkTotal = 0;
 427      CAmount check_total_fee{0};
 428      CAmount check_total_modified_fee{0};
 429      int64_t check_total_adjusted_weight{0};
 430      uint64_t innerUsage = 0;
 431  
 432      assert(!m_txgraph->IsOversized(TxGraph::Level::MAIN));
 433      m_txgraph->SanityCheck();
 434  
 435      CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache*>(&active_coins_tip));
 436  
 437      const auto score_with_topo{GetSortedScoreWithTopology()};
 438  
 439      // Number of chunks is bounded by number of transactions.
 440      const auto diagram{GetFeerateDiagram()};
 441      assert(diagram.size() <= score_with_topo.size() + 1);
 442      assert(diagram.size() >= 1);
 443  
 444      std::optional<Wtxid> last_wtxid = std::nullopt;
 445      auto diagram_iter = diagram.cbegin();
 446  
 447      for (const auto& it : score_with_topo) {
 448          // GetSortedScoreWithTopology() contains the same chunks as the feerate
 449          // diagram. We do not know where the chunk boundaries are, but we can
 450          // check that there are points at which they match the cumulative fee
 451          // and weight.
 452          // The feerate diagram should never get behind the current transaction
 453          // size totals.
 454          assert(diagram_iter->size >= check_total_adjusted_weight);
 455          if (diagram_iter->fee == check_total_modified_fee &&
 456                  diagram_iter->size == check_total_adjusted_weight) {
 457              ++diagram_iter;
 458          }
 459          checkTotal += it->GetTxSize();
 460          check_total_adjusted_weight += it->GetAdjustedWeight();
 461          check_total_fee += it->GetFee();
 462          check_total_modified_fee += it->GetModifiedFee();
 463          innerUsage += it->DynamicMemoryUsage();
 464          const CTransaction& tx = it->GetTx();
 465  
 466          // CompareMiningScoreWithTopology should agree with GetSortedScoreWithTopology()
 467          if (last_wtxid) {
 468              assert(CompareMiningScoreWithTopology(*last_wtxid, tx.GetWitnessHash()));
 469          }
 470          last_wtxid = tx.GetWitnessHash();
 471  
 472          std::set<CTxMemPoolEntry::CTxMemPoolEntryRef, CompareIteratorByHash> setParentCheck;
 473          std::set<CTxMemPoolEntry::CTxMemPoolEntryRef, CompareIteratorByHash> setParentsStored;
 474          for (const CTxIn &txin : tx.vin) {
 475              // Check that every mempool transaction's inputs refer to available coins, or other mempool tx's.
 476              indexed_transaction_set::const_iterator it2 = mapTx.find(txin.prevout.hash);
 477              if (it2 != mapTx.end()) {
 478                  const CTransaction& tx2 = it2->GetTx();
 479                  assert(tx2.vout.size() > txin.prevout.n && !tx2.vout[txin.prevout.n].IsNull());
 480                  setParentCheck.insert(*it2);
 481              }
 482              // We are iterating through the mempool entries sorted
 483              // topologically and by mining score. All parents must have been
 484              // checked before their children and their coins added to the
 485              // mempoolDuplicate coins cache.
 486              assert(mempoolDuplicate.HaveCoin(txin.prevout));
 487              // Check whether its inputs are marked in mapNextTx.
 488              auto it3 = mapNextTx.find(txin.prevout);
 489              assert(it3 != mapNextTx.end());
 490              assert(it3->first == &txin.prevout);
 491              assert(&it3->second->GetTx() == &tx);
 492          }
 493          auto comp = [](const CTxMemPoolEntry& a, const CTxMemPoolEntry& b) -> bool {
 494              return a.GetTx().GetHash() == b.GetTx().GetHash();
 495          };
 496          for (auto &txentry : GetParents(*it)) {
 497              setParentsStored.insert(dynamic_cast<const CTxMemPoolEntry&>(txentry.get()));
 498          }
 499          assert(setParentCheck.size() == setParentsStored.size());
 500          assert(std::equal(setParentCheck.begin(), setParentCheck.end(), setParentsStored.begin(), comp));
 501  
 502          // Check children against mapNextTx
 503          std::set<CTxMemPoolEntry::CTxMemPoolEntryRef, CompareIteratorByHash> setChildrenCheck;
 504          std::set<CTxMemPoolEntry::CTxMemPoolEntryRef, CompareIteratorByHash> setChildrenStored;
 505          auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetHash(), 0));
 506          for (; iter != mapNextTx.end() && iter->first->hash == it->GetTx().GetHash(); ++iter) {
 507              txiter childit = iter->second;
 508              assert(childit != mapTx.end()); // mapNextTx points to in-mempool transactions
 509              setChildrenCheck.insert(*childit);
 510          }
 511          for (auto &txentry : GetChildren(*it)) {
 512              setChildrenStored.insert(dynamic_cast<const CTxMemPoolEntry&>(txentry.get()));
 513          }
 514          assert(setChildrenCheck.size() == setChildrenStored.size());
 515          assert(std::equal(setChildrenCheck.begin(), setChildrenCheck.end(), setChildrenStored.begin(), comp));
 516  
 517          TxValidationState dummy_state; // Not used. CheckTxInputs() should always pass
 518          CAmount txfee = 0;
 519          assert(!tx.IsCoinBase());
 520          assert(Consensus::CheckTxInputs(tx, dummy_state, mempoolDuplicate, spendheight, txfee));
 521          for (const auto& input: tx.vin) mempoolDuplicate.SpendCoin(input.prevout);
 522          AddCoins(mempoolDuplicate, tx, std::numeric_limits<int>::max());
 523      }
 524      for (auto it = mapNextTx.cbegin(); it != mapNextTx.cend(); it++) {
 525          indexed_transaction_set::const_iterator it2 = it->second;
 526          assert(it2 != mapTx.end());
 527      }
 528  
 529      ++diagram_iter;
 530      assert(diagram_iter == diagram.cend());
 531  
 532      assert(totalTxSize == checkTotal);
 533      assert(m_total_fee == check_total_fee);
 534      assert(diagram.back().fee == check_total_modified_fee);
 535      assert(diagram.back().size == check_total_adjusted_weight);
 536      assert(innerUsage == cachedInnerUsage);
 537  }
 538  
 539  bool CTxMemPool::CompareMiningScoreWithTopology(const Wtxid& hasha, const Wtxid& hashb) const
 540  {
 541      /* Return `true` if hasha should be considered sooner than hashb, namely when:
 542       *     a is not in the mempool but b is, or
 543       *     both are in the mempool but a is sorted before b in the total mempool ordering
 544       *     (which takes dependencies and (chunk) feerates into account).
 545       */
 546      LOCK(cs);
 547      auto j{GetIter(hashb)};
 548      if (!j.has_value()) return false;
 549      auto i{GetIter(hasha)};
 550      if (!i.has_value()) return true;
 551  
 552      return m_txgraph->CompareMainOrder(*i.value(), *j.value()) < 0;
 553  }
 554  
 555  std::vector<CTxMemPool::indexed_transaction_set::const_iterator> CTxMemPool::GetSortedScoreWithTopology() const
 556  {
 557      std::vector<indexed_transaction_set::const_iterator> iters;
 558      AssertLockHeld(cs);
 559  
 560      iters.reserve(mapTx.size());
 561  
 562      for (indexed_transaction_set::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi) {
 563          iters.push_back(mi);
 564      }
 565      std::sort(iters.begin(), iters.end(), [this](const auto& a, const auto& b) EXCLUSIVE_LOCKS_REQUIRED(cs) noexcept {
 566          return m_txgraph->CompareMainOrder(*a, *b) < 0;
 567      });
 568      return iters;
 569  }
 570  
 571  std::vector<CTxMemPoolEntryRef> CTxMemPool::entryAll() const
 572  {
 573      AssertLockHeld(cs);
 574  
 575      std::vector<CTxMemPoolEntryRef> ret;
 576      ret.reserve(mapTx.size());
 577      for (const auto& it : GetSortedScoreWithTopology()) {
 578          ret.emplace_back(*it);
 579      }
 580      return ret;
 581  }
 582  
 583  std::vector<TxMempoolInfo> CTxMemPool::infoAll() const
 584  {
 585      LOCK(cs);
 586      auto iters = GetSortedScoreWithTopology();
 587  
 588      std::vector<TxMempoolInfo> ret;
 589      ret.reserve(mapTx.size());
 590      for (auto it : iters) {
 591          ret.push_back(GetInfo(it));
 592      }
 593  
 594      return ret;
 595  }
 596  
 597  const CTxMemPoolEntry* CTxMemPool::GetEntry(const Txid& txid) const
 598  {
 599      AssertLockHeld(cs);
 600      const auto i = mapTx.find(txid);
 601      return i == mapTx.end() ? nullptr : &(*i);
 602  }
 603  
 604  CTransactionRef CTxMemPool::get(const Txid& hash) const
 605  {
 606      LOCK(cs);
 607      indexed_transaction_set::const_iterator i = mapTx.find(hash);
 608      if (i == mapTx.end())
 609          return nullptr;
 610      return i->GetSharedTx();
 611  }
 612  
 613  void CTxMemPool::PrioritiseTransaction(const Txid& hash, const CAmount& nFeeDelta)
 614  {
 615      {
 616          LOCK(cs);
 617          CAmount &delta = mapDeltas[hash];
 618          delta = SaturatingAdd(delta, nFeeDelta);
 619          txiter it = mapTx.find(hash);
 620          if (it != mapTx.end()) {
 621              // PrioritiseTransaction calls stack on previous ones. Set the new
 622              // transaction fee to be current modified fee + feedelta.
 623              it->UpdateModifiedFee(nFeeDelta);
 624              m_txgraph->SetTransactionFee(*it, it->GetModifiedFee());
 625              ++nTransactionsUpdated;
 626          }
 627          if (delta == 0) {
 628              mapDeltas.erase(hash);
 629              LogPrintf("PrioritiseTransaction: %s (%sin mempool) delta cleared\n", hash.ToString(), it == mapTx.end() ? "not " : "");
 630          } else {
 631              LogPrintf("PrioritiseTransaction: %s (%sin mempool) fee += %s, new delta=%s\n",
 632                        hash.ToString(),
 633                        it == mapTx.end() ? "not " : "",
 634                        FormatMoney(nFeeDelta),
 635                        FormatMoney(delta));
 636          }
 637      }
 638  }
 639  
 640  void CTxMemPool::ApplyDelta(const Txid& hash, CAmount &nFeeDelta) const
 641  {
 642      AssertLockHeld(cs);
 643      std::map<Txid, CAmount>::const_iterator pos = mapDeltas.find(hash);
 644      if (pos == mapDeltas.end())
 645          return;
 646      const CAmount &delta = pos->second;
 647      nFeeDelta += delta;
 648  }
 649  
 650  void CTxMemPool::ClearPrioritisation(const Txid& hash)
 651  {
 652      AssertLockHeld(cs);
 653      mapDeltas.erase(hash);
 654  }
 655  
 656  std::vector<CTxMemPool::delta_info> CTxMemPool::GetPrioritisedTransactions() const
 657  {
 658      AssertLockNotHeld(cs);
 659      LOCK(cs);
 660      std::vector<delta_info> result;
 661      result.reserve(mapDeltas.size());
 662      for (const auto& [txid, delta] : mapDeltas) {
 663          const auto iter{mapTx.find(txid)};
 664          const bool in_mempool{iter != mapTx.end()};
 665          std::optional<CAmount> modified_fee;
 666          if (in_mempool) modified_fee = iter->GetModifiedFee();
 667          result.emplace_back(delta_info{in_mempool, delta, modified_fee, txid});
 668      }
 669      return result;
 670  }
 671  
 672  const CTransaction* CTxMemPool::GetConflictTx(const COutPoint& prevout) const
 673  {
 674      const auto it = mapNextTx.find(prevout);
 675      return it == mapNextTx.end() ? nullptr : &(it->second->GetTx());
 676  }
 677  
 678  std::optional<CTxMemPool::txiter> CTxMemPool::GetIter(const Txid& txid) const
 679  {
 680      AssertLockHeld(cs);
 681      auto it = mapTx.find(txid);
 682      return it != mapTx.end() ? std::make_optional(it) : std::nullopt;
 683  }
 684  
 685  std::optional<CTxMemPool::txiter> CTxMemPool::GetIter(const Wtxid& wtxid) const
 686  {
 687      AssertLockHeld(cs);
 688      auto it{mapTx.project<0>(mapTx.get<index_by_wtxid>().find(wtxid))};
 689      return it != mapTx.end() ? std::make_optional(it) : std::nullopt;
 690  }
 691  
 692  CTxMemPool::setEntries CTxMemPool::GetIterSet(const std::set<Txid>& hashes) const
 693  {
 694      CTxMemPool::setEntries ret;
 695      for (const auto& h : hashes) {
 696          const auto mi = GetIter(h);
 697          if (mi) ret.insert(*mi);
 698      }
 699      return ret;
 700  }
 701  
 702  std::vector<CTxMemPool::txiter> CTxMemPool::GetIterVec(const std::vector<Txid>& txids) const
 703  {
 704      AssertLockHeld(cs);
 705      std::vector<txiter> ret;
 706      ret.reserve(txids.size());
 707      for (const auto& txid : txids) {
 708          const auto it{GetIter(txid)};
 709          if (!it) return {};
 710          ret.push_back(*it);
 711      }
 712      return ret;
 713  }
 714  
 715  bool CTxMemPool::HasNoInputsOf(const CTransaction &tx) const
 716  {
 717      for (unsigned int i = 0; i < tx.vin.size(); i++)
 718          if (exists(tx.vin[i].prevout.hash))
 719              return false;
 720      return true;
 721  }
 722  
 723  CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView* baseIn, const CTxMemPool& mempoolIn) : CCoinsViewBacked(baseIn), mempool(mempoolIn) { }
 724  
 725  std::optional<Coin> CCoinsViewMemPool::GetCoin(const COutPoint& outpoint) const
 726  {
 727      // Check to see if the inputs are made available by another tx in the package.
 728      // These Coins would not be available in the underlying CoinsView.
 729      if (auto it = m_temp_added.find(outpoint); it != m_temp_added.end()) {
 730          return it->second;
 731      }
 732  
 733      // If an entry in the mempool exists, always return that one, as it's guaranteed to never
 734      // conflict with the underlying cache, and it cannot have pruned entries (as it contains full)
 735      // transactions. First checking the underlying cache risks returning a pruned entry instead.
 736      CTransactionRef ptx = mempool.get(outpoint.hash);
 737      if (ptx) {
 738          if (outpoint.n < ptx->vout.size()) {
 739              Coin coin(ptx->vout[outpoint.n], MEMPOOL_HEIGHT, false);
 740              m_non_base_coins.emplace(outpoint);
 741              return coin;
 742          }
 743          return std::nullopt;
 744      }
 745      return base->GetCoin(outpoint);
 746  }
 747  
 748  void CCoinsViewMemPool::PackageAddTransaction(const CTransactionRef& tx)
 749  {
 750      for (unsigned int n = 0; n < tx->vout.size(); ++n) {
 751          m_temp_added.emplace(COutPoint(tx->GetHash(), n), Coin(tx->vout[n], MEMPOOL_HEIGHT, false));
 752          m_non_base_coins.emplace(tx->GetHash(), n);
 753      }
 754  }
 755  void CCoinsViewMemPool::Reset()
 756  {
 757      m_temp_added.clear();
 758      m_non_base_coins.clear();
 759  }
 760  
 761  size_t CTxMemPool::DynamicMemoryUsage() const {
 762      LOCK(cs);
 763      // Estimate the overhead of mapTx to be 9 pointers (3 pointers per index) + an allocation, as no exact formula for boost::multi_index_contained is implemented.
 764      return memusage::MallocUsage(sizeof(CTxMemPoolEntry) + 9 * sizeof(void*)) * mapTx.size() + memusage::DynamicUsage(mapNextTx) + memusage::DynamicUsage(mapDeltas) + memusage::DynamicUsage(txns_randomized) + m_txgraph->GetMainMemoryUsage() + cachedInnerUsage;
 765  }
 766  
 767  void CTxMemPool::RemoveUnbroadcastTx(const Txid& txid, const bool unchecked) {
 768      LOCK(cs);
 769  
 770      if (m_unbroadcast_txids.erase(txid))
 771      {
 772          LogDebug(BCLog::MEMPOOL, "Removed %i from set of unbroadcast txns%s\n", txid.GetHex(), (unchecked ? " before confirmation that txn was sent out" : ""));
 773      }
 774  }
 775  
 776  void CTxMemPool::RemoveStaged(setEntries &stage, MemPoolRemovalReason reason) {
 777      AssertLockHeld(cs);
 778      for (txiter it : stage) {
 779          removeUnchecked(it, reason);
 780      }
 781  }
 782  
 783  bool CTxMemPool::CheckPolicyLimits(const CTransactionRef& tx)
 784  {
 785      LOCK(cs);
 786      // Use ChangeSet interface to check whether the cluster count
 787      // limits would be violated. Note that the changeset will be destroyed
 788      // when it goes out of scope.
 789      auto changeset = GetChangeSet();
 790      (void) changeset->StageAddition(tx, /*fee=*/0, /*time=*/0, /*entry_height=*/0, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/0, LockPoints{});
 791      return changeset->CheckMemPoolPolicyLimits();
 792  }
 793  
 794  int CTxMemPool::Expire(std::chrono::seconds time)
 795  {
 796      AssertLockHeld(cs);
 797      Assume(!m_have_changeset);
 798      indexed_transaction_set::index<entry_time>::type::iterator it = mapTx.get<entry_time>().begin();
 799      setEntries toremove;
 800      while (it != mapTx.get<entry_time>().end() && it->GetTime() < time) {
 801          toremove.insert(mapTx.project<0>(it));
 802          it++;
 803      }
 804      setEntries stage;
 805      for (txiter removeit : toremove) {
 806          CalculateDescendants(removeit, stage);
 807      }
 808      RemoveStaged(stage, MemPoolRemovalReason::EXPIRY);
 809      return stage.size();
 810  }
 811  
 812  CFeeRate CTxMemPool::GetMinFee(size_t sizelimit) const {
 813      LOCK(cs);
 814      if (!blockSinceLastRollingFeeBump || rollingMinimumFeeRate == 0)
 815          return CFeeRate(llround(rollingMinimumFeeRate));
 816  
 817      int64_t time = GetTime();
 818      if (time > lastRollingFeeUpdate + 10) {
 819          double halflife = ROLLING_FEE_HALFLIFE;
 820          if (DynamicMemoryUsage() < sizelimit / 4)
 821              halflife /= 4;
 822          else if (DynamicMemoryUsage() < sizelimit / 2)
 823              halflife /= 2;
 824  
 825          rollingMinimumFeeRate = rollingMinimumFeeRate / pow(2.0, (time - lastRollingFeeUpdate) / halflife);
 826          lastRollingFeeUpdate = time;
 827  
 828          if (rollingMinimumFeeRate < (double)m_opts.incremental_relay_feerate.GetFeePerK() / 2) {
 829              rollingMinimumFeeRate = 0;
 830              return CFeeRate(0);
 831          }
 832      }
 833      return std::max(CFeeRate(llround(rollingMinimumFeeRate)), m_opts.incremental_relay_feerate);
 834  }
 835  
 836  void CTxMemPool::trackPackageRemoved(const CFeeRate& rate) {
 837      AssertLockHeld(cs);
 838      if (rate.GetFeePerK() > rollingMinimumFeeRate) {
 839          rollingMinimumFeeRate = rate.GetFeePerK();
 840          blockSinceLastRollingFeeBump = false;
 841      }
 842  }
 843  
 844  void CTxMemPool::TrimToSize(size_t sizelimit, std::vector<COutPoint>* pvNoSpendsRemaining) {
 845      AssertLockHeld(cs);
 846      Assume(!m_have_changeset);
 847  
 848      unsigned nTxnRemoved = 0;
 849      CFeeRate maxFeeRateRemoved(0);
 850  
 851      while (!mapTx.empty() && DynamicMemoryUsage() > sizelimit) {
 852          const auto &[worst_chunk, feeperweight] = m_txgraph->GetWorstMainChunk();
 853          FeePerVSize feerate = ToFeePerVSize(feeperweight);
 854          CFeeRate removed{feerate.fee, feerate.size};
 855  
 856          // We set the new mempool min fee to the feerate of the removed set, plus the
 857          // "minimum reasonable fee rate" (ie some value under which we consider txn
 858          // to have 0 fee). This way, we don't allow txn to enter mempool with feerate
 859          // equal to txn which were removed with no block in between.
 860          removed += m_opts.incremental_relay_feerate;
 861          trackPackageRemoved(removed);
 862          maxFeeRateRemoved = std::max(maxFeeRateRemoved, removed);
 863  
 864          nTxnRemoved += worst_chunk.size();
 865  
 866          std::vector<CTransaction> txn;
 867          if (pvNoSpendsRemaining) {
 868              txn.reserve(worst_chunk.size());
 869              for (auto ref : worst_chunk) {
 870                  txn.emplace_back(static_cast<const CTxMemPoolEntry&>(*ref).GetTx());
 871              }
 872          }
 873  
 874          setEntries stage;
 875          for (auto ref : worst_chunk) {
 876              stage.insert(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*ref)));
 877          }
 878          for (auto e : stage) {
 879              removeUnchecked(e, MemPoolRemovalReason::SIZELIMIT);
 880          }
 881          if (pvNoSpendsRemaining) {
 882              for (const CTransaction& tx : txn) {
 883                  for (const CTxIn& txin : tx.vin) {
 884                      if (exists(txin.prevout.hash)) continue;
 885                      pvNoSpendsRemaining->push_back(txin.prevout);
 886                  }
 887              }
 888          }
 889      }
 890  
 891      if (maxFeeRateRemoved > CFeeRate(0)) {
 892          LogDebug(BCLog::MEMPOOL, "Removed %u txn, rolling minimum fee bumped to %s\n", nTxnRemoved, maxFeeRateRemoved.ToString());
 893      }
 894  }
 895  
 896  std::tuple<size_t, size_t, CAmount> CTxMemPool::CalculateAncestorData(const CTxMemPoolEntry& entry) const
 897  {
 898      auto ancestors = m_txgraph->GetAncestors(entry, TxGraph::Level::MAIN);
 899  
 900      size_t ancestor_count = ancestors.size();
 901      size_t ancestor_size = 0;
 902      CAmount ancestor_fees = 0;
 903      for (auto tx: ancestors) {
 904          const CTxMemPoolEntry& anc = static_cast<const CTxMemPoolEntry&>(*tx);
 905          ancestor_size += anc.GetTxSize();
 906          ancestor_fees += anc.GetModifiedFee();
 907      }
 908      return {ancestor_count, ancestor_size, ancestor_fees};
 909  }
 910  
 911  std::tuple<size_t, size_t, CAmount> CTxMemPool::CalculateDescendantData(const CTxMemPoolEntry& entry) const
 912  {
 913      auto descendants = m_txgraph->GetDescendants(entry, TxGraph::Level::MAIN);
 914      size_t descendant_count = descendants.size();
 915      size_t descendant_size = 0;
 916      CAmount descendant_fees = 0;
 917  
 918      for (auto tx: descendants) {
 919          const CTxMemPoolEntry &desc = static_cast<const CTxMemPoolEntry&>(*tx);
 920          descendant_size += desc.GetTxSize();
 921          descendant_fees += desc.GetModifiedFee();
 922      }
 923      return {descendant_count, descendant_size, descendant_fees};
 924  }
 925  
 926  void CTxMemPool::GetTransactionAncestry(const Txid& txid, size_t& ancestors, size_t& cluster_count, size_t* const ancestorsize, CAmount* const ancestorfees) const {
 927      LOCK(cs);
 928      auto it = mapTx.find(txid);
 929      ancestors = cluster_count = 0;
 930      if (it != mapTx.end()) {
 931          auto [ancestor_count, ancestor_size, ancestor_fees] = CalculateAncestorData(*it);
 932          ancestors = ancestor_count;
 933          if (ancestorsize) *ancestorsize = ancestor_size;
 934          if (ancestorfees) *ancestorfees = ancestor_fees;
 935          cluster_count = m_txgraph->GetCluster(*it, TxGraph::Level::MAIN).size();
 936      }
 937  }
 938  
 939  bool CTxMemPool::GetLoadTried() const
 940  {
 941      LOCK(cs);
 942      return m_load_tried;
 943  }
 944  
 945  void CTxMemPool::SetLoadTried(bool load_tried)
 946  {
 947      LOCK(cs);
 948      m_load_tried = load_tried;
 949  }
 950  
 951  std::vector<CTxMemPool::txiter> CTxMemPool::GatherClusters(const std::vector<Txid>& txids) const
 952  {
 953      AssertLockHeld(cs);
 954  
 955      std::vector<CTxMemPool::txiter> ret;
 956      std::set<const CTxMemPoolEntry*> unique_cluster_representatives;
 957      for (auto txid : txids) {
 958          auto it = mapTx.find(txid);
 959          if (it != mapTx.end()) {
 960              // Note that TxGraph::GetCluster will return results in graph
 961              // order, which is deterministic (as long as we are not modifying
 962              // the graph).
 963              auto cluster = m_txgraph->GetCluster(*it, TxGraph::Level::MAIN);
 964              if (unique_cluster_representatives.insert(static_cast<const CTxMemPoolEntry*>(&(**cluster.begin()))).second) {
 965                  for (auto tx : cluster) {
 966                      ret.emplace_back(mapTx.iterator_to(static_cast<const CTxMemPoolEntry&>(*tx)));
 967                  }
 968              }
 969          }
 970      }
 971      if (ret.size() > 500) {
 972          return {};
 973      }
 974      return ret;
 975  }
 976  
 977  util::Result<std::pair<std::vector<FeeFrac>, std::vector<FeeFrac>>> CTxMemPool::ChangeSet::CalculateChunksForRBF()
 978  {
 979      LOCK(m_pool->cs);
 980  
 981      if (!CheckMemPoolPolicyLimits()) {
 982          return util::Error{Untranslated("cluster size limit exceeded")};
 983      }
 984  
 985      return m_pool->m_txgraph->GetMainStagingDiagrams();
 986  }
 987  
 988  CTxMemPool::ChangeSet::TxHandle CTxMemPool::ChangeSet::StageAddition(const CTransactionRef& tx, const CAmount fee, int64_t time, unsigned int entry_height, uint64_t entry_sequence, bool spends_coinbase, int64_t sigops_cost, LockPoints lp)
 989  {
 990      LOCK(m_pool->cs);
 991      Assume(m_to_add.find(tx->GetHash()) == m_to_add.end());
 992      Assume(!m_dependencies_processed);
 993  
 994      // We need to process dependencies after adding a new transaction.
 995      m_dependencies_processed = false;
 996  
 997      CAmount delta{0};
 998      m_pool->ApplyDelta(tx->GetHash(), delta);
 999  
1000      TxGraph::Ref ref(m_pool->m_txgraph->AddTransaction(FeePerWeight(fee, GetSigOpsAdjustedWeight(GetTransactionWeight(*tx), sigops_cost, ::nBytesPerSigOp))));
1001      auto newit = m_to_add.emplace(std::move(ref), tx, fee, time, entry_height, entry_sequence, spends_coinbase, sigops_cost, lp).first;
1002      if (delta) {
1003          newit->UpdateModifiedFee(delta);
1004          m_pool->m_txgraph->SetTransactionFee(*newit, newit->GetModifiedFee());
1005      }
1006  
1007      m_entry_vec.push_back(newit);
1008  
1009      return newit;
1010  }
1011  
1012  void CTxMemPool::ChangeSet::StageRemoval(CTxMemPool::txiter it)
1013  {
1014      LOCK(m_pool->cs);
1015      m_pool->m_txgraph->RemoveTransaction(*it);
1016      m_to_remove.insert(it);
1017  }
1018  
1019  void CTxMemPool::ChangeSet::Apply()
1020  {
1021      LOCK(m_pool->cs);
1022      if (!m_dependencies_processed) {
1023          ProcessDependencies();
1024      }
1025      m_pool->Apply(this);
1026      m_to_add.clear();
1027      m_to_remove.clear();
1028      m_entry_vec.clear();
1029      m_ancestors.clear();
1030  }
1031  
1032  void CTxMemPool::ChangeSet::ProcessDependencies()
1033  {
1034      LOCK(m_pool->cs);
1035      Assume(!m_dependencies_processed); // should only call this once.
1036      for (const auto& entryptr : m_entry_vec) {
1037          for (const auto &txin : entryptr->GetSharedTx()->vin) {
1038              std::optional<txiter> piter = m_pool->GetIter(txin.prevout.hash);
1039              if (!piter) {
1040                  auto it = m_to_add.find(txin.prevout.hash);
1041                  if (it != m_to_add.end()) {
1042                      piter = std::make_optional(it);
1043                  }
1044              }
1045              if (piter) {
1046                  m_pool->m_txgraph->AddDependency(/*parent=*/**piter, /*child=*/*entryptr);
1047              }
1048          }
1049      }
1050      m_dependencies_processed = true;
1051      return;
1052   }
1053  
1054  bool CTxMemPool::ChangeSet::CheckMemPoolPolicyLimits()
1055  {
1056      LOCK(m_pool->cs);
1057      if (!m_dependencies_processed) {
1058          ProcessDependencies();
1059      }
1060  
1061      return !m_pool->m_txgraph->IsOversized(TxGraph::Level::TOP);
1062  }
1063  
1064  std::vector<FeePerWeight> CTxMemPool::GetFeerateDiagram() const
1065  {
1066      FeePerWeight zero{};
1067      std::vector<FeePerWeight> ret;
1068  
1069      ret.emplace_back(zero);
1070  
1071      StartBlockBuilding();
1072  
1073      std::vector<CTxMemPoolEntry::CTxMemPoolEntryRef> dummy;
1074  
1075      FeePerWeight last_selection = GetBlockBuilderChunk(dummy);
1076      while (last_selection != FeePerWeight{}) {
1077          last_selection += ret.back();
1078          ret.emplace_back(last_selection);
1079          IncludeBuilderChunk();
1080          last_selection = GetBlockBuilderChunk(dummy);
1081      }
1082      StopBlockBuilding();
1083      return ret;
1084  }