src/txmempool.cpp

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 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 "consensus/consensus.h"
   9 #include "consensus/tx_verify.h"
  10 #include "consensus/validation.h"
  11 #include "validation.h"
  12 #include "policy/policy.h"
  13 #include "policy/fees.h"
  14 #include "streams.h"
  15 #include "timedata.h"
  16 #include "util.h"
  17 #include "utilmoneystr.h"
  18 #include "utiltime.h"
  19
  20 CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef& _tx, const CAmount& _nFee,
  21                                  int64_t _nTime, unsigned int _entryHeight,
  22                                  bool _spendsCoinbase, int64_t _sigOpsCost, LockPoints lp):
  23     tx(_tx), nFee(_nFee), nTime(_nTime), entryHeight(_entryHeight),
  24     spendsCoinbase(_spendsCoinbase), sigOpCost(_sigOpsCost), lockPoints(lp)
  25 {
  26     nTxWeight = GetTransactionWeight(*tx);
  27     nUsageSize = RecursiveDynamicUsage(tx);
  28
  29     nCountWithDescendants = 1;
  30     nSizeWithDescendants = GetTxSize();
  31     nModFeesWithDescendants = nFee;
  32
  33     feeDelta = 0;
  34
  35     nCountWithAncestors = 1;
  36     nSizeWithAncestors = GetTxSize();
  37     nModFeesWithAncestors = nFee;
  38     nSigOpCostWithAncestors = sigOpCost;
  39 }
  40
  41 CTxMemPoolEntry::CTxMemPoolEntry(const CTxMemPoolEntry& other)
  42 {
  43     *this = other;
  44 }
  45
  46 void CTxMemPoolEntry::UpdateFeeDelta(int64_t newFeeDelta)
  47 {
  48     nModFeesWithDescendants += newFeeDelta - feeDelta;
  49     nModFeesWithAncestors += newFeeDelta - feeDelta;
  50     feeDelta = newFeeDelta;
  51 }
  52
  53 void CTxMemPoolEntry::UpdateLockPoints(const LockPoints& lp)
  54 {
  55     lockPoints = lp;
  56 }
  57
  58 size_t CTxMemPoolEntry::GetTxSize() const
  59 {
  60     return GetVirtualTransactionSize(nTxWeight, sigOpCost);
  61 }
  62
  63 // Update the given tx for any in-mempool descendants.
  64 // Assumes that setMemPoolChildren is correct for the given tx and all
  65 // descendants.
  66 void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap &cachedDescendants, const std::set<uint256> &setExclude)
  67 {
  68     setEntries stageEntries, setAllDescendants;
  69     stageEntries = GetMemPoolChildren(updateIt);
  70
  71     while (!stageEntries.empty()) {
  72         const txiter cit = *stageEntries.begin();
  73         setAllDescendants.insert(cit);
  74         stageEntries.erase(cit);
  75         const setEntries &setChildren = GetMemPoolChildren(cit);
  76         BOOST_FOREACH(const txiter childEntry, setChildren) {
  77             cacheMap::iterator cacheIt = cachedDescendants.find(childEntry);
  78             if (cacheIt != cachedDescendants.end()) {
  79                 // We've already calculated this one, just add the entries for this set
  80                 // but don't traverse again.
  81                 BOOST_FOREACH(const txiter cacheEntry, cacheIt->second) {
  82                     setAllDescendants.insert(cacheEntry);
  83                 }
  84             } else if (!setAllDescendants.count(childEntry)) {
  85                 // Schedule for later processing
  86                 stageEntries.insert(childEntry);
  87             }
  88         }
  89     }
  90     // setAllDescendants now contains all in-mempool descendants of updateIt.
  91     // Update and add to cached descendant map
  92     int64_t modifySize = 0;
  93     CAmount modifyFee = 0;
  94     int64_t modifyCount = 0;
  95     BOOST_FOREACH(txiter cit, setAllDescendants) {
  96         if (!setExclude.count(cit->GetTx().GetHash())) {
  97             modifySize += cit->GetTxSize();
  98             modifyFee += cit->GetModifiedFee();
  99             modifyCount++;
 100             cachedDescendants[updateIt].insert(cit);
 101             // Update ancestor state for each descendant
 102             mapTx.modify(cit, update_ancestor_state(updateIt->GetTxSize(), updateIt->GetModifiedFee(), 1, updateIt->GetSigOpCost()));
 103         }
 104     }
 105     mapTx.modify(updateIt, update_descendant_state(modifySize, modifyFee, modifyCount));
 106 }
 107
 108 // vHashesToUpdate is the set of transaction hashes from a disconnected block
 109 // which has been re-added to the mempool.
 110 // for each entry, look for descendants that are outside vHashesToUpdate, and
 111 // add fee/size information for such descendants to the parent.
 112 // for each such descendant, also update the ancestor state to include the parent.
 113 void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256> &vHashesToUpdate)
 114 {
 115     LOCK(cs);
 116     // For each entry in vHashesToUpdate, store the set of in-mempool, but not
 117     // in-vHashesToUpdate transactions, so that we don't have to recalculate
 118     // descendants when we come across a previously seen entry.
 119     cacheMap mapMemPoolDescendantsToUpdate;
 120
 121     // Use a set for lookups into vHashesToUpdate (these entries are already
 122     // accounted for in the state of their ancestors)
 123     std::set<uint256> setAlreadyIncluded(vHashesToUpdate.begin(), vHashesToUpdate.end());
 124
 125     // Iterate in reverse, so that whenever we are looking at at a transaction
 126     // we are sure that all in-mempool descendants have already been processed.
 127     // This maximizes the benefit of the descendant cache and guarantees that
 128     // setMemPoolChildren will be updated, an assumption made in
 129     // UpdateForDescendants.
 130     BOOST_REVERSE_FOREACH(const uint256 &hash, vHashesToUpdate) {
 131         // we cache the in-mempool children to avoid duplicate updates
 132         setEntries setChildren;
 133         // calculate children from mapNextTx
 134         txiter it = mapTx.find(hash);
 135         if (it == mapTx.end()) {
 136             continue;
 137         }
 138         auto iter = mapNextTx.lower_bound(COutPoint(hash, 0));
 139         // First calculate the children, and update setMemPoolChildren to
 140         // include them, and update their setMemPoolParents to include this tx.
 141         for (; iter != mapNextTx.end() && iter->first->hash == hash; ++iter) {
 142             const uint256 &childHash = iter->second->GetHash();
 143             txiter childIter = mapTx.find(childHash);
 144             assert(childIter != mapTx.end());
 145             // We can skip updating entries we've encountered before or that
 146             // are in the block (which are already accounted for).
 147             if (setChildren.insert(childIter).second && !setAlreadyIncluded.count(childHash)) {
 148                 UpdateChild(it, childIter, true);
 149                 UpdateParent(childIter, it, true);
 150             }
 151         }
 152         UpdateForDescendants(it, mapMemPoolDescendantsToUpdate, setAlreadyIncluded);
 153     }
 154 }
 155
 156 bool CTxMemPool::CalculateMemPoolAncestors(const CTxMemPoolEntry &entry, setEntries &setAncestors, uint64_t limitAncestorCount, uint64_t limitAncestorSize, uint64_t limitDescendantCount, uint64_t limitDescendantSize, std::string &errString, bool fSearchForParents /* = true */) const
 157 {
 158     LOCK(cs);
 159
 160     setEntries parentHashes;
 161     const CTransaction &tx = entry.GetTx();
 162
 163     if (fSearchForParents) {
 164         // Get parents of this transaction that are in the mempool
 165         // GetMemPoolParents() is only valid for entries in the mempool, so we
 166         // iterate mapTx to find parents.
 167         for (unsigned int i = 0; i < tx.vin.size(); i++) {
 168             txiter piter = mapTx.find(tx.vin[i].prevout.hash);
 169             if (piter != mapTx.end()) {
 170                 parentHashes.insert(piter);
 171                 if (parentHashes.size() + 1 > limitAncestorCount) {
 172                     errString = strprintf("too many unconfirmed parents [limit: %u]", limitAncestorCount);
 173                     return false;
 174                 }
 175             }
 176         }
 177     } else {
 178         // If we're not searching for parents, we require this to be an
 179         // entry in the mempool already.
 180         txiter it = mapTx.iterator_to(entry);
 181         parentHashes = GetMemPoolParents(it);
 182     }
 183
 184     size_t totalSizeWithAncestors = entry.GetTxSize();
 185
 186     while (!parentHashes.empty()) {
 187         txiter stageit = *parentHashes.begin();
 188
 189         setAncestors.insert(stageit);
 190         parentHashes.erase(stageit);
 191         totalSizeWithAncestors += stageit->GetTxSize();
 192
 193         if (stageit->GetSizeWithDescendants() + entry.GetTxSize() > limitDescendantSize) {
 194             errString = strprintf("exceeds descendant size limit for tx %s [limit: %u]", stageit->GetTx().GetHash().ToString(), limitDescendantSize);
 195             return false;
 196         } else if (stageit->GetCountWithDescendants() + 1 > limitDescendantCount) {
 197             errString = strprintf("too many descendants for tx %s [limit: %u]", stageit->GetTx().GetHash().ToString(), limitDescendantCount);
 198             return false;
 199         } else if (totalSizeWithAncestors > limitAncestorSize) {
 200             errString = strprintf("exceeds ancestor size limit [limit: %u]", limitAncestorSize);
 201             return false;
 202         }
 203
 204         const setEntries & setMemPoolParents = GetMemPoolParents(stageit);
 205         BOOST_FOREACH(const txiter &phash, setMemPoolParents) {
 206             // If this is a new ancestor, add it.
 207             if (setAncestors.count(phash) == 0) {
 208                 parentHashes.insert(phash);
 209             }
 210             if (parentHashes.size() + setAncestors.size() + 1 > limitAncestorCount) {
 211                 errString = strprintf("too many unconfirmed ancestors [limit: %u]", limitAncestorCount);
 212                 return false;
 213             }
 214         }
 215     }
 216
 217     return true;
 218 }
 219
 220 void CTxMemPool::UpdateAncestorsOf(bool add, txiter it, setEntries &setAncestors)
 221 {
 222     setEntries parentIters = GetMemPoolParents(it);
 223     // add or remove this tx as a child of each parent
 224     BOOST_FOREACH(txiter piter, parentIters) {
 225         UpdateChild(piter, it, add);
 226     }
 227     const int64_t updateCount = (add ? 1 : -1);
 228     const int64_t updateSize = updateCount * it->GetTxSize();
 229     const CAmount updateFee = updateCount * it->GetModifiedFee();
 230     BOOST_FOREACH(txiter ancestorIt, setAncestors) {
 231         mapTx.modify(ancestorIt, update_descendant_state(updateSize, updateFee, updateCount));
 232     }
 233 }
 234
 235 void CTxMemPool::UpdateEntryForAncestors(txiter it, const setEntries &setAncestors)
 236 {
 237     int64_t updateCount = setAncestors.size();
 238     int64_t updateSize = 0;
 239     CAmount updateFee = 0;
 240     int64_t updateSigOpsCost = 0;
 241     BOOST_FOREACH(txiter ancestorIt, setAncestors) {
 242         updateSize += ancestorIt->GetTxSize();
 243         updateFee += ancestorIt->GetModifiedFee();
 244         updateSigOpsCost += ancestorIt->GetSigOpCost();
 245     }
 246     mapTx.modify(it, update_ancestor_state(updateSize, updateFee, updateCount, updateSigOpsCost));
 247 }
 248
 249 void CTxMemPool::UpdateChildrenForRemoval(txiter it)
 250 {
 251     const setEntries &setMemPoolChildren = GetMemPoolChildren(it);
 252     BOOST_FOREACH(txiter updateIt, setMemPoolChildren) {
 253         UpdateParent(updateIt, it, false);
 254     }
 255 }
 256
 257 void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove, bool updateDescendants)
 258 {
 259     // For each entry, walk back all ancestors and decrement size associated with this
 260     // transaction
 261     const uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
 262     if (updateDescendants) {
 263         // updateDescendants should be true whenever we're not recursively
 264         // removing a tx and all its descendants, eg when a transaction is
 265         // confirmed in a block.
 266         // Here we only update statistics and not data in mapLinks (which
 267         // we need to preserve until we're finished with all operations that
 268         // need to traverse the mempool).
 269         BOOST_FOREACH(txiter removeIt, entriesToRemove) {
 270             setEntries setDescendants;
 271             CalculateDescendants(removeIt, setDescendants);
 272             setDescendants.erase(removeIt); // don't update state for self
 273             int64_t modifySize = -((int64_t)removeIt->GetTxSize());
 274             CAmount modifyFee = -removeIt->GetModifiedFee();
 275             int modifySigOps = -removeIt->GetSigOpCost();
 276             BOOST_FOREACH(txiter dit, setDescendants) {
 277                 mapTx.modify(dit, update_ancestor_state(modifySize, modifyFee, -1, modifySigOps));
 278             }
 279         }
 280     }
 281     BOOST_FOREACH(txiter removeIt, entriesToRemove) {
 282         setEntries setAncestors;
 283         const CTxMemPoolEntry &entry = *removeIt;
 284         std::string dummy;
 285         // Since this is a tx that is already in the mempool, we can call CMPA
 286         // with fSearchForParents = false.  If the mempool is in a consistent
 287         // state, then using true or false should both be correct, though false
 288         // should be a bit faster.
 289         // However, if we happen to be in the middle of processing a reorg, then
 290         // the mempool can be in an inconsistent state.  In this case, the set
 291         // of ancestors reachable via mapLinks will be the same as the set of
 292         // ancestors whose packages include this transaction, because when we
 293         // add a new transaction to the mempool in addUnchecked(), we assume it
 294         // has no children, and in the case of a reorg where that assumption is
 295         // false, the in-mempool children aren't linked to the in-block tx's
 296         // until UpdateTransactionsFromBlock() is called.
 297         // So if we're being called during a reorg, ie before
 298         // UpdateTransactionsFromBlock() has been called, then mapLinks[] will
 299         // differ from the set of mempool parents we'd calculate by searching,
 300         // and it's important that we use the mapLinks[] notion of ancestor
 301         // transactions as the set of things to update for removal.
 302         CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false);
 303         // Note that UpdateAncestorsOf severs the child links that point to
 304         // removeIt in the entries for the parents of removeIt.
 305         UpdateAncestorsOf(false, removeIt, setAncestors);
 306     }
 307     // After updating all the ancestor sizes, we can now sever the link between each
 308     // transaction being removed and any mempool children (ie, update setMemPoolParents
 309     // for each direct child of a transaction being removed).
 310     BOOST_FOREACH(txiter removeIt, entriesToRemove) {
 311         UpdateChildrenForRemoval(removeIt);
 312     }
 313 }
 314
 315 void CTxMemPoolEntry::UpdateDescendantState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount)
 316 {
 317     nSizeWithDescendants += modifySize;
 318     assert(int64_t(nSizeWithDescendants) > 0);
 319     nModFeesWithDescendants += modifyFee;
 320     nCountWithDescendants += modifyCount;
 321     assert(int64_t(nCountWithDescendants) > 0);
 322 }
 323
 324 void CTxMemPoolEntry::UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int modifySigOps)
 325 {
 326     nSizeWithAncestors += modifySize;
 327     assert(int64_t(nSizeWithAncestors) > 0);
 328     nModFeesWithAncestors += modifyFee;
 329     nCountWithAncestors += modifyCount;
 330     assert(int64_t(nCountWithAncestors) > 0);
 331     nSigOpCostWithAncestors += modifySigOps;
 332     assert(int(nSigOpCostWithAncestors) >= 0);
 333 }
 334
 335 CTxMemPool::CTxMemPool(CBlockPolicyEstimator* estimator) :
 336     nTransactionsUpdated(0), minerPolicyEstimator(estimator)
 337 {
 338     _clear(); //lock free clear
 339
 340     // Sanity checks off by default for performance, because otherwise
 341     // accepting transactions becomes O(N^2) where N is the number
 342     // of transactions in the pool
 343     nCheckFrequency = 0;
 344 }
 345
 346 bool CTxMemPool::isSpent(const COutPoint& outpoint)
 347 {
 348     LOCK(cs);
 349     return mapNextTx.count(outpoint);
 350 }
 351
 352 unsigned int CTxMemPool::GetTransactionsUpdated() const
 353 {
 354     LOCK(cs);
 355     return nTransactionsUpdated;
 356 }
 357
 358 void CTxMemPool::AddTransactionsUpdated(unsigned int n)
 359 {
 360     LOCK(cs);
 361     nTransactionsUpdated += n;
 362 }
 363
 364 bool CTxMemPool::addUnchecked(const uint256& hash, const CTxMemPoolEntry &entry, setEntries &setAncestors, bool validFeeEstimate)
 365 {
 366     NotifyEntryAdded(entry.GetSharedTx());
 367     // Add to memory pool without checking anything.
 368     // Used by AcceptToMemoryPool(), which DOES do
 369     // all the appropriate checks.
 370     LOCK(cs);
 371     indexed_transaction_set::iterator newit = mapTx.insert(entry).first;
 372     mapLinks.insert(make_pair(newit, TxLinks()));
 373
 374     // Update transaction for any feeDelta created by PrioritiseTransaction
 375     // TODO: refactor so that the fee delta is calculated before inserting
 376     // into mapTx.
 377     std::map<uint256, CAmount>::const_iterator pos = mapDeltas.find(hash);
 378     if (pos != mapDeltas.end()) {
 379         const CAmount &delta = pos->second;
 380         if (delta) {
 381             mapTx.modify(newit, update_fee_delta(delta));
 382         }
 383     }
 384
 385     // Update cachedInnerUsage to include contained transaction's usage.
 386     // (When we update the entry for in-mempool parents, memory usage will be
 387     // further updated.)
 388     cachedInnerUsage += entry.DynamicMemoryUsage();
 389
 390     const CTransaction& tx = newit->GetTx();
 391     std::set<uint256> setParentTransactions;
 392     for (unsigned int i = 0; i < tx.vin.size(); i++) {
 393         mapNextTx.insert(std::make_pair(&tx.vin[i].prevout, &tx));
 394         setParentTransactions.insert(tx.vin[i].prevout.hash);
 395     }
 396     // Don't bother worrying about child transactions of this one.
 397     // Normal case of a new transaction arriving is that there can't be any
 398     // children, because such children would be orphans.
 399     // An exception to that is if a transaction enters that used to be in a block.
 400     // In that case, our disconnect block logic will call UpdateTransactionsFromBlock
 401     // to clean up the mess we're leaving here.
 402
 403     // Update ancestors with information about this tx
 404     BOOST_FOREACH (const uint256 &phash, setParentTransactions) {
 405         txiter pit = mapTx.find(phash);
 406         if (pit != mapTx.end()) {
 407             UpdateParent(newit, pit, true);
 408         }
 409     }
 410     UpdateAncestorsOf(true, newit, setAncestors);
 411     UpdateEntryForAncestors(newit, setAncestors);
 412
 413     nTransactionsUpdated++;
 414     totalTxSize += entry.GetTxSize();
 415     if (minerPolicyEstimator) {minerPolicyEstimator->processTransaction(entry, validFeeEstimate);}
 416
 417     vTxHashes.emplace_back(tx.GetWitnessHash(), newit);
 418     newit->vTxHashesIdx = vTxHashes.size() - 1;
 419
 420     return true;
 421 }
 422
 423 void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason)
 424 {
 425     NotifyEntryRemoved(it->GetSharedTx(), reason);
 426     const uint256 hash = it->GetTx().GetHash();
 427     BOOST_FOREACH(const CTxIn& txin, it->GetTx().vin)
 428         mapNextTx.erase(txin.prevout);
 429
 430     if (vTxHashes.size() > 1) {
 431         vTxHashes[it->vTxHashesIdx] = std::move(vTxHashes.back());
 432         vTxHashes[it->vTxHashesIdx].second->vTxHashesIdx = it->vTxHashesIdx;
 433         vTxHashes.pop_back();
 434         if (vTxHashes.size() * 2 < vTxHashes.capacity())
 435             vTxHashes.shrink_to_fit();
 436     } else
 437         vTxHashes.clear();
 438
 439     totalTxSize -= it->GetTxSize();
 440     cachedInnerUsage -= it->DynamicMemoryUsage();
 441     cachedInnerUsage -= memusage::DynamicUsage(mapLinks[it].parents) + memusage::DynamicUsage(mapLinks[it].children);
 442     mapLinks.erase(it);
 443     mapTx.erase(it);
 444     nTransactionsUpdated++;
 445     if (minerPolicyEstimator) {minerPolicyEstimator->removeTx(hash, false);}
 446 }
 447
 448 // Calculates descendants of entry that are not already in setDescendants, and adds to
 449 // setDescendants. Assumes entryit is already a tx in the mempool and setMemPoolChildren
 450 // is correct for tx and all descendants.
 451 // Also assumes that if an entry is in setDescendants already, then all
 452 // in-mempool descendants of it are already in setDescendants as well, so that we
 453 // can save time by not iterating over those entries.
 454 void CTxMemPool::CalculateDescendants(txiter entryit, setEntries &setDescendants)
 455 {
 456     setEntries stage;
 457     if (setDescendants.count(entryit) == 0) {
 458         stage.insert(entryit);
 459     }
 460     // Traverse down the children of entry, only adding children that are not
 461     // accounted for in setDescendants already (because those children have either
 462     // already been walked, or will be walked in this iteration).
 463     while (!stage.empty()) {
 464         txiter it = *stage.begin();
 465         setDescendants.insert(it);
 466         stage.erase(it);
 467
 468         const setEntries &setChildren = GetMemPoolChildren(it);
 469         BOOST_FOREACH(const txiter &childiter, setChildren) {
 470             if (!setDescendants.count(childiter)) {
 471                 stage.insert(childiter);
 472             }
 473         }
 474     }
 475 }
 476
 477 void CTxMemPool::removeRecursive(const CTransaction &origTx, MemPoolRemovalReason reason)
 478 {
 479     // Remove transaction from memory pool
 480     {
 481         LOCK(cs);
 482         setEntries txToRemove;
 483         txiter origit = mapTx.find(origTx.GetHash());
 484         if (origit != mapTx.end()) {
 485             txToRemove.insert(origit);
 486         } else {
 487             // When recursively removing but origTx isn't in the mempool
 488             // be sure to remove any children that are in the pool. This can
 489             // happen during chain re-orgs if origTx isn't re-accepted into
 490             // the mempool for any reason.
 491             for (unsigned int i = 0; i < origTx.vout.size(); i++) {
 492                 auto it = mapNextTx.find(COutPoint(origTx.GetHash(), i));
 493                 if (it == mapNextTx.end())
 494                     continue;
 495                 txiter nextit = mapTx.find(it->second->GetHash());
 496                 assert(nextit != mapTx.end());
 497                 txToRemove.insert(nextit);
 498             }
 499         }
 500         setEntries setAllRemoves;
 501         BOOST_FOREACH(txiter it, txToRemove) {
 502             CalculateDescendants(it, setAllRemoves);
 503         }
 504
 505         RemoveStaged(setAllRemoves, false, reason);
 506     }
 507 }
 508
 509 void CTxMemPool::removeForReorg(const CCoinsViewCache *pcoins, unsigned int nMemPoolHeight, int flags)
 510 {
 511     // Remove transactions spending a coinbase which are now immature and no-longer-final transactions
 512     LOCK(cs);
 513     setEntries txToRemove;
 514     for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) {
 515         const CTransaction& tx = it->GetTx();
 516         LockPoints lp = it->GetLockPoints();
 517         bool validLP =  TestLockPointValidity(&lp);
 518         if (!CheckFinalTx(tx, flags) || !CheckSequenceLocks(tx, flags, &lp, validLP)) {
 519             // Note if CheckSequenceLocks fails the LockPoints may still be invalid
 520             // So it's critical that we remove the tx and not depend on the LockPoints.
 521             txToRemove.insert(it);
 522         } else if (it->GetSpendsCoinbase()) {
 523             BOOST_FOREACH(const CTxIn& txin, tx.vin) {
 524                 indexed_transaction_set::const_iterator it2 = mapTx.find(txin.prevout.hash);
 525                 if (it2 != mapTx.end())
 526                     continue;
 527                 const Coin &coin = pcoins->AccessCoin(txin.prevout);
 528                 if (nCheckFrequency != 0) assert(!coin.IsSpent());
 529                 if (coin.IsSpent() || (coin.IsCoinBase() && ((signed long)nMemPoolHeight) - coin.nHeight < COINBASE_MATURITY)) {
 530                     txToRemove.insert(it);
 531                     break;
 532                 }
 533             }
 534         }
 535         if (!validLP) {
 536             mapTx.modify(it, update_lock_points(lp));
 537         }
 538     }
 539     setEntries setAllRemoves;
 540     for (txiter it : txToRemove) {
 541         CalculateDescendants(it, setAllRemoves);
 542     }
 543     RemoveStaged(setAllRemoves, false, MemPoolRemovalReason::REORG);
 544 }
 545
 546 void CTxMemPool::removeConflicts(const CTransaction &tx)
 547 {
 548     // Remove transactions which depend on inputs of tx, recursively
 549     LOCK(cs);
 550     BOOST_FOREACH(const CTxIn &txin, tx.vin) {
 551         auto it = mapNextTx.find(txin.prevout);
 552         if (it != mapNextTx.end()) {
 553             const CTransaction &txConflict = *it->second;
 554             if (txConflict != tx)
 555             {
 556                 ClearPrioritisation(txConflict.GetHash());
 557                 removeRecursive(txConflict, MemPoolRemovalReason::CONFLICT);
 558             }
 559         }
 560     }
 561 }
 562
 563 /**
 564  * Called when a block is connected. Removes from mempool and updates the miner fee estimator.
 565  */
 566 void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight)
 567 {
 568     LOCK(cs);
 569     std::vector<const CTxMemPoolEntry*> entries;
 570     for (const auto& tx : vtx)
 571     {
 572         uint256 hash = tx->GetHash();
 573
 574         indexed_transaction_set::iterator i = mapTx.find(hash);
 575         if (i != mapTx.end())
 576             entries.push_back(&*i);
 577     }
 578     // Before the txs in the new block have been removed from the mempool, update policy estimates
 579     if (minerPolicyEstimator) {minerPolicyEstimator->processBlock(nBlockHeight, entries);}
 580     for (const auto& tx : vtx)
 581     {
 582         txiter it = mapTx.find(tx->GetHash());
 583         if (it != mapTx.end()) {
 584             setEntries stage;
 585             stage.insert(it);
 586             RemoveStaged(stage, true, MemPoolRemovalReason::BLOCK);
 587         }
 588         removeConflicts(*tx);
 589         ClearPrioritisation(tx->GetHash());
 590     }
 591     lastRollingFeeUpdate = GetTime();
 592     blockSinceLastRollingFeeBump = true;
 593 }
 594
 595 void CTxMemPool::_clear()
 596 {
 597     mapLinks.clear();
 598     mapTx.clear();
 599     mapNextTx.clear();
 600     totalTxSize = 0;
 601     cachedInnerUsage = 0;
 602     lastRollingFeeUpdate = GetTime();
 603     blockSinceLastRollingFeeBump = false;
 604     rollingMinimumFeeRate = 0;
 605     ++nTransactionsUpdated;
 606 }
 607
 608 void CTxMemPool::clear()
 609 {
 610     LOCK(cs);
 611     _clear();
 612 }
 613
 614 void CTxMemPool::check(const CCoinsViewCache *pcoins) const
 615 {
 616     if (nCheckFrequency == 0)
 617         return;
 618
 619     if (GetRand(std::numeric_limits<uint32_t>::max()) >= nCheckFrequency)
 620         return;
 621
 622     LogPrint(BCLog::MEMPOOL, "Checking mempool with %u transactions and %u inputs\n", (unsigned int)mapTx.size(), (unsigned int)mapNextTx.size());
 623
 624     uint64_t checkTotal = 0;
 625     uint64_t innerUsage = 0;
 626
 627     CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache*>(pcoins));
 628     const int64_t nSpendHeight = GetSpendHeight(mempoolDuplicate);
 629
 630     LOCK(cs);
 631     std::list<const CTxMemPoolEntry*> waitingOnDependants;
 632     for (indexed_transaction_set::const_iterator it = mapTx.begin(); it != mapTx.end(); it++) {
 633         unsigned int i = 0;
 634         checkTotal += it->GetTxSize();
 635         innerUsage += it->DynamicMemoryUsage();
 636         const CTransaction& tx = it->GetTx();
 637         txlinksMap::const_iterator linksiter = mapLinks.find(it);
 638         assert(linksiter != mapLinks.end());
 639         const TxLinks &links = linksiter->second;
 640         innerUsage += memusage::DynamicUsage(links.parents) + memusage::DynamicUsage(links.children);
 641         bool fDependsWait = false;
 642         setEntries setParentCheck;
 643         int64_t parentSizes = 0;
 644         int64_t parentSigOpCost = 0;
 645         BOOST_FOREACH(const CTxIn &txin, tx.vin) {
 646             // Check that every mempool transaction's inputs refer to available coins, or other mempool tx's.
 647             indexed_transaction_set::const_iterator it2 = mapTx.find(txin.prevout.hash);
 648             if (it2 != mapTx.end()) {
 649                 const CTransaction& tx2 = it2->GetTx();
 650                 assert(tx2.vout.size() > txin.prevout.n && !tx2.vout[txin.prevout.n].IsNull());
 651                 fDependsWait = true;
 652                 if (setParentCheck.insert(it2).second) {
 653                     parentSizes += it2->GetTxSize();
 654                     parentSigOpCost += it2->GetSigOpCost();
 655                 }
 656             } else {
 657                 assert(pcoins->HaveCoin(txin.prevout));
 658             }
 659             // Check whether its inputs are marked in mapNextTx.
 660             auto it3 = mapNextTx.find(txin.prevout);
 661             assert(it3 != mapNextTx.end());
 662             assert(it3->first == &txin.prevout);
 663             assert(it3->second == &tx);
 664             i++;
 665         }
 666         assert(setParentCheck == GetMemPoolParents(it));
 667         // Verify ancestor state is correct.
 668         setEntries setAncestors;
 669         uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
 670         std::string dummy;
 671         CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy);
 672         uint64_t nCountCheck = setAncestors.size() + 1;
 673         uint64_t nSizeCheck = it->GetTxSize();
 674         CAmount nFeesCheck = it->GetModifiedFee();
 675         int64_t nSigOpCheck = it->GetSigOpCost();
 676
 677         BOOST_FOREACH(txiter ancestorIt, setAncestors) {
 678             nSizeCheck += ancestorIt->GetTxSize();
 679             nFeesCheck += ancestorIt->GetModifiedFee();
 680             nSigOpCheck += ancestorIt->GetSigOpCost();
 681         }
 682
 683         assert(it->GetCountWithAncestors() == nCountCheck);
 684         assert(it->GetSizeWithAncestors() == nSizeCheck);
 685         assert(it->GetSigOpCostWithAncestors() == nSigOpCheck);
 686         assert(it->GetModFeesWithAncestors() == nFeesCheck);
 687
 688         // Check children against mapNextTx
 689         CTxMemPool::setEntries setChildrenCheck;
 690         auto iter = mapNextTx.lower_bound(COutPoint(it->GetTx().GetHash(), 0));
 691         int64_t childSizes = 0;
 692         for (; iter != mapNextTx.end() && iter->first->hash == it->GetTx().GetHash(); ++iter) {
 693             txiter childit = mapTx.find(iter->second->GetHash());
 694             assert(childit != mapTx.end()); // mapNextTx points to in-mempool transactions
 695             if (setChildrenCheck.insert(childit).second) {
 696                 childSizes += childit->GetTxSize();
 697             }
 698         }
 699         assert(setChildrenCheck == GetMemPoolChildren(it));
 700         // Also check to make sure size is greater than sum with immediate children.
 701         // just a sanity check, not definitive that this calc is correct...
 702         assert(it->GetSizeWithDescendants() >= childSizes + it->GetTxSize());
 703
 704         if (fDependsWait)
 705             waitingOnDependants.push_back(&(*it));
 706         else {
 707             CValidationState state;
 708             bool fCheckResult = tx.IsCoinBase() ||
 709                 Consensus::CheckTxInputs(tx, state, mempoolDuplicate, nSpendHeight);
 710             assert(fCheckResult);
 711             UpdateCoins(tx, mempoolDuplicate, 1000000);
 712         }
 713     }
 714     unsigned int stepsSinceLastRemove = 0;
 715     while (!waitingOnDependants.empty()) {
 716         const CTxMemPoolEntry* entry = waitingOnDependants.front();
 717         waitingOnDependants.pop_front();
 718         CValidationState state;
 719         if (!mempoolDuplicate.HaveInputs(entry->GetTx())) {
 720             waitingOnDependants.push_back(entry);
 721             stepsSinceLastRemove++;
 722             assert(stepsSinceLastRemove < waitingOnDependants.size());
 723         } else {
 724             bool fCheckResult = entry->GetTx().IsCoinBase() ||
 725                 Consensus::CheckTxInputs(entry->GetTx(), state, mempoolDuplicate, nSpendHeight);
 726             assert(fCheckResult);
 727             UpdateCoins(entry->GetTx(), mempoolDuplicate, 1000000);
 728             stepsSinceLastRemove = 0;
 729         }
 730     }
 731     for (auto it = mapNextTx.cbegin(); it != mapNextTx.cend(); it++) {
 732         uint256 hash = it->second->GetHash();
 733         indexed_transaction_set::const_iterator it2 = mapTx.find(hash);
 734         const CTransaction& tx = it2->GetTx();
 735         assert(it2 != mapTx.end());
 736         assert(&tx == it->second);
 737     }
 738
 739     assert(totalTxSize == checkTotal);
 740     assert(innerUsage == cachedInnerUsage);
 741 }
 742
 743 bool CTxMemPool::CompareDepthAndScore(const uint256& hasha, const uint256& hashb)
 744 {
 745     LOCK(cs);
 746     indexed_transaction_set::const_iterator i = mapTx.find(hasha);
 747     if (i == mapTx.end()) return false;
 748     indexed_transaction_set::const_iterator j = mapTx.find(hashb);
 749     if (j == mapTx.end()) return true;
 750     uint64_t counta = i->GetCountWithAncestors();
 751     uint64_t countb = j->GetCountWithAncestors();
 752     if (counta == countb) {
 753         return CompareTxMemPoolEntryByScore()(*i, *j);
 754     }
 755     return counta < countb;
 756 }
 757
 758 namespace {
 759 class DepthAndScoreComparator
 760 {
 761 public:
 762     bool operator()(const CTxMemPool::indexed_transaction_set::const_iterator& a, const CTxMemPool::indexed_transaction_set::const_iterator& b)
 763     {
 764         uint64_t counta = a->GetCountWithAncestors();
 765         uint64_t countb = b->GetCountWithAncestors();
 766         if (counta == countb) {
 767             return CompareTxMemPoolEntryByScore()(*a, *b);
 768         }
 769         return counta < countb;
 770     }
 771 };
 772 }
 773
 774 std::vector<CTxMemPool::indexed_transaction_set::const_iterator> CTxMemPool::GetSortedDepthAndScore() const
 775 {
 776     std::vector<indexed_transaction_set::const_iterator> iters;
 777     AssertLockHeld(cs);
 778
 779     iters.reserve(mapTx.size());
 780
 781     for (indexed_transaction_set::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi) {
 782         iters.push_back(mi);
 783     }
 784     std::sort(iters.begin(), iters.end(), DepthAndScoreComparator());
 785     return iters;
 786 }
 787
 788 void CTxMemPool::queryHashes(std::vector<uint256>& vtxid)
 789 {
 790     LOCK(cs);
 791     auto iters = GetSortedDepthAndScore();
 792
 793     vtxid.clear();
 794     vtxid.reserve(mapTx.size());
 795
 796     for (auto it : iters) {
 797         vtxid.push_back(it->GetTx().GetHash());
 798     }
 799 }
 800
 801 static TxMempoolInfo GetInfo(CTxMemPool::indexed_transaction_set::const_iterator it) {
 802     return TxMempoolInfo{it->GetSharedTx(), it->GetTime(), CFeeRate(it->GetFee(), it->GetTxSize()), it->GetModifiedFee() - it->GetFee()};
 803 }
 804
 805 std::vector<TxMempoolInfo> CTxMemPool::infoAll() const
 806 {
 807     LOCK(cs);
 808     auto iters = GetSortedDepthAndScore();
 809
 810     std::vector<TxMempoolInfo> ret;
 811     ret.reserve(mapTx.size());
 812     for (auto it : iters) {
 813         ret.push_back(GetInfo(it));
 814     }
 815
 816     return ret;
 817 }
 818
 819 CTransactionRef CTxMemPool::get(const uint256& hash) const
 820 {
 821     LOCK(cs);
 822     indexed_transaction_set::const_iterator i = mapTx.find(hash);
 823     if (i == mapTx.end())
 824         return nullptr;
 825     return i->GetSharedTx();
 826 }
 827
 828 TxMempoolInfo CTxMemPool::info(const uint256& hash) const
 829 {
 830     LOCK(cs);
 831     indexed_transaction_set::const_iterator i = mapTx.find(hash);
 832     if (i == mapTx.end())
 833         return TxMempoolInfo();
 834     return GetInfo(i);
 835 }
 836
 837 void CTxMemPool::PrioritiseTransaction(const uint256& hash, const CAmount& nFeeDelta)
 838 {
 839     {
 840         LOCK(cs);
 841         CAmount &delta = mapDeltas[hash];
 842         delta += nFeeDelta;
 843         txiter it = mapTx.find(hash);
 844         if (it != mapTx.end()) {
 845             mapTx.modify(it, update_fee_delta(delta));
 846             // Now update all ancestors' modified fees with descendants
 847             setEntries setAncestors;
 848             uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
 849             std::string dummy;
 850             CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false);
 851             BOOST_FOREACH(txiter ancestorIt, setAncestors) {
 852                 mapTx.modify(ancestorIt, update_descendant_state(0, nFeeDelta, 0));
 853             }
 854             // Now update all descendants' modified fees with ancestors
 855             setEntries setDescendants;
 856             CalculateDescendants(it, setDescendants);
 857             setDescendants.erase(it);
 858             BOOST_FOREACH(txiter descendantIt, setDescendants) {
 859                 mapTx.modify(descendantIt, update_ancestor_state(0, nFeeDelta, 0, 0));
 860             }
 861             ++nTransactionsUpdated;
 862         }
 863     }
 864     LogPrintf("PrioritiseTransaction: %s feerate += %s\n", hash.ToString(), FormatMoney(nFeeDelta));
 865 }
 866
 867 void CTxMemPool::ApplyDelta(const uint256 hash, CAmount &nFeeDelta) const
 868 {
 869     LOCK(cs);
 870     std::map<uint256, CAmount>::const_iterator pos = mapDeltas.find(hash);
 871     if (pos == mapDeltas.end())
 872         return;
 873     const CAmount &delta = pos->second;
 874     nFeeDelta += delta;
 875 }
 876
 877 void CTxMemPool::ClearPrioritisation(const uint256 hash)
 878 {
 879     LOCK(cs);
 880     mapDeltas.erase(hash);
 881 }
 882
 883 bool CTxMemPool::HasNoInputsOf(const CTransaction &tx) const
 884 {
 885     for (unsigned int i = 0; i < tx.vin.size(); i++)
 886         if (exists(tx.vin[i].prevout.hash))
 887             return false;
 888     return true;
 889 }
 890
 891 CCoinsViewMemPool::CCoinsViewMemPool(CCoinsView* baseIn, const CTxMemPool& mempoolIn) : CCoinsViewBacked(baseIn), mempool(mempoolIn) { }
 892
 893 bool CCoinsViewMemPool::GetCoin(const COutPoint &outpoint, Coin &coin) const {
 894     // If an entry in the mempool exists, always return that one, as it's guaranteed to never
 895     // conflict with the underlying cache, and it cannot have pruned entries (as it contains full)
 896     // transactions. First checking the underlying cache risks returning a pruned entry instead.
 897     CTransactionRef ptx = mempool.get(outpoint.hash);
 898     if (ptx) {
 899         if (outpoint.n < ptx->vout.size()) {
 900             coin = Coin(ptx->vout[outpoint.n], MEMPOOL_HEIGHT, false);
 901             return true;
 902         } else {
 903             return false;
 904         }
 905     }
 906     return (base->GetCoin(outpoint, coin) && !coin.IsSpent());
 907 }
 908
 909 bool CCoinsViewMemPool::HaveCoin(const COutPoint &outpoint) const {
 910     return mempool.exists(outpoint) || base->HaveCoin(outpoint);
 911 }
 912
 913 size_t CTxMemPool::DynamicMemoryUsage() const {
 914     LOCK(cs);
 915     // Estimate the overhead of mapTx to be 15 pointers + an allocation, as no exact formula for boost::multi_index_contained is implemented.
 916     return memusage::MallocUsage(sizeof(CTxMemPoolEntry) + 15 * sizeof(void*)) * mapTx.size() + memusage::DynamicUsage(mapNextTx) + memusage::DynamicUsage(mapDeltas) + memusage::DynamicUsage(mapLinks) + memusage::DynamicUsage(vTxHashes) + cachedInnerUsage;
 917 }
 918
 919 void CTxMemPool::RemoveStaged(setEntries &stage, bool updateDescendants, MemPoolRemovalReason reason) {
 920     AssertLockHeld(cs);
 921     UpdateForRemoveFromMempool(stage, updateDescendants);
 922     BOOST_FOREACH(const txiter& it, stage) {
 923         removeUnchecked(it, reason);
 924     }
 925 }
 926
 927 int CTxMemPool::Expire(int64_t time) {
 928     LOCK(cs);
 929     indexed_transaction_set::index<entry_time>::type::iterator it = mapTx.get<entry_time>().begin();
 930     setEntries toremove;
 931     while (it != mapTx.get<entry_time>().end() && it->GetTime() < time) {
 932         toremove.insert(mapTx.project<0>(it));
 933         it++;
 934     }
 935     setEntries stage;
 936     BOOST_FOREACH(txiter removeit, toremove) {
 937         CalculateDescendants(removeit, stage);
 938     }
 939     RemoveStaged(stage, false, MemPoolRemovalReason::EXPIRY);
 940     return stage.size();
 941 }
 942
 943 bool CTxMemPool::addUnchecked(const uint256&hash, const CTxMemPoolEntry &entry, bool validFeeEstimate)
 944 {
 945     LOCK(cs);
 946     setEntries setAncestors;
 947     uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();
 948     std::string dummy;
 949     CalculateMemPoolAncestors(entry, setAncestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy);
 950     return addUnchecked(hash, entry, setAncestors, validFeeEstimate);
 951 }
 952
 953 void CTxMemPool::UpdateChild(txiter entry, txiter child, bool add)
 954 {
 955     setEntries s;
 956     if (add && mapLinks[entry].children.insert(child).second) {
 957         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
 958     } else if (!add && mapLinks[entry].children.erase(child)) {
 959         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
 960     }
 961 }
 962
 963 void CTxMemPool::UpdateParent(txiter entry, txiter parent, bool add)
 964 {
 965     setEntries s;
 966     if (add && mapLinks[entry].parents.insert(parent).second) {
 967         cachedInnerUsage += memusage::IncrementalDynamicUsage(s);
 968     } else if (!add && mapLinks[entry].parents.erase(parent)) {
 969         cachedInnerUsage -= memusage::IncrementalDynamicUsage(s);
 970     }
 971 }
 972
 973 const CTxMemPool::setEntries & CTxMemPool::GetMemPoolParents(txiter entry) const
 974 {
 975     assert (entry != mapTx.end());
 976     txlinksMap::const_iterator it = mapLinks.find(entry);
 977     assert(it != mapLinks.end());
 978     return it->second.parents;
 979 }
 980
 981 const CTxMemPool::setEntries & CTxMemPool::GetMemPoolChildren(txiter entry) const
 982 {
 983     assert (entry != mapTx.end());
 984     txlinksMap::const_iterator it = mapLinks.find(entry);
 985     assert(it != mapLinks.end());
 986     return it->second.children;
 987 }
 988
 989 CFeeRate CTxMemPool::GetMinFee(size_t sizelimit) const {
 990     LOCK(cs);
 991     if (!blockSinceLastRollingFeeBump || rollingMinimumFeeRate == 0)
 992         return CFeeRate(rollingMinimumFeeRate);
 993
 994     int64_t time = GetTime();
 995     if (time > lastRollingFeeUpdate + 10) {
 996         double halflife = ROLLING_FEE_HALFLIFE;
 997         if (DynamicMemoryUsage() < sizelimit / 4)
 998             halflife /= 4;
 999         else if (DynamicMemoryUsage() < sizelimit / 2)
1000             halflife /= 2;
1001
1002         rollingMinimumFeeRate = rollingMinimumFeeRate / pow(2.0, (time - lastRollingFeeUpdate) / halflife);
1003         lastRollingFeeUpdate = time;
1004
1005         if (rollingMinimumFeeRate < (double)incrementalRelayFee.GetFeePerK() / 2) {
1006             rollingMinimumFeeRate = 0;
1007             return CFeeRate(0);
1008         }
1009     }
1010     return std::max(CFeeRate(rollingMinimumFeeRate), incrementalRelayFee);
1011 }
1012
1013 void CTxMemPool::trackPackageRemoved(const CFeeRate& rate) {
1014     AssertLockHeld(cs);
1015     if (rate.GetFeePerK() > rollingMinimumFeeRate) {
1016         rollingMinimumFeeRate = rate.GetFeePerK();
1017         blockSinceLastRollingFeeBump = false;
1018     }
1019 }
1020
1021 void CTxMemPool::TrimToSize(size_t sizelimit, std::vector<COutPoint>* pvNoSpendsRemaining) {
1022     LOCK(cs);
1023
1024     unsigned nTxnRemoved = 0;
1025     CFeeRate maxFeeRateRemoved(0);
1026     while (!mapTx.empty() && DynamicMemoryUsage() > sizelimit) {
1027         indexed_transaction_set::index<descendant_score>::type::iterator it = mapTx.get<descendant_score>().begin();
1028
1029         // We set the new mempool min fee to the feerate of the removed set, plus the
1030         // "minimum reasonable fee rate" (ie some value under which we consider txn
1031         // to have 0 fee). This way, we don't allow txn to enter mempool with feerate
1032         // equal to txn which were removed with no block in between.
1033         CFeeRate removed(it->GetModFeesWithDescendants(), it->GetSizeWithDescendants());
1034         removed += incrementalRelayFee;
1035         trackPackageRemoved(removed);
1036         maxFeeRateRemoved = std::max(maxFeeRateRemoved, removed);
1037
1038         setEntries stage;
1039         CalculateDescendants(mapTx.project<0>(it), stage);
1040         nTxnRemoved += stage.size();
1041
1042         std::vector<CTransaction> txn;
1043         if (pvNoSpendsRemaining) {
1044             txn.reserve(stage.size());
1045             BOOST_FOREACH(txiter iter, stage)
1046                 txn.push_back(iter->GetTx());
1047         }
1048         RemoveStaged(stage, false, MemPoolRemovalReason::SIZELIMIT);
1049         if (pvNoSpendsRemaining) {
1050             BOOST_FOREACH(const CTransaction& tx, txn) {
1051                 BOOST_FOREACH(const CTxIn& txin, tx.vin) {
1052                     if (exists(txin.prevout.hash)) continue;
1053                     if (!mapNextTx.count(txin.prevout)) {
1054                         pvNoSpendsRemaining->push_back(txin.prevout);
1055                     }
1056                 }
1057             }
1058         }
1059     }
1060
1061     if (maxFeeRateRemoved > CFeeRate(0)) {
1062         LogPrint(BCLog::MEMPOOL, "Removed %u txn, rolling minimum fee bumped to %s\n", nTxnRemoved, maxFeeRateRemoved.ToString());
1063     }
1064 }
1065
1066 bool CTxMemPool::TransactionWithinChainLimit(const uint256& txid, size_t chainLimit) const {
1067     LOCK(cs);
1068     auto it = mapTx.find(txid);
1069     return it == mapTx.end() || (it->GetCountWithAncestors() < chainLimit &&
1070        it->GetCountWithDescendants() < chainLimit);
1071 }
1072
1073 SaltedTxidHasher::SaltedTxidHasher() : k0(GetRand(std::numeric_limits<uint64_t>::max())), k1(GetRand(std::numeric_limits<uint64_t>::max())) {}