diff --git a/src/txmempool.h b/src/txmempool.h index 7657beecc..d7868f843 100644 --- a/src/txmempool.h +++ b/src/txmempool.h @@ -1,924 +1,918 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2016 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_TXMEMPOOL_H #define BITCOIN_TXMEMPOOL_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include class CBlockIndex; class Config; inline double AllowFreeThreshold() { return (144 * COIN) / (250 * SATOSHI); } inline bool AllowFree(double dPriority) { // Large (in bytes) low-priority (new, small-coin) transactions need a fee. return dPriority > AllowFreeThreshold(); } /** * Fake height value used in Coins to signify they are only in the memory * pool(since 0.8) */ static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF; struct LockPoints { // Will be set to the blockchain height and median time past values that // would be necessary to satisfy all relative locktime constraints (BIP68) // of this tx given our view of block chain history int height; int64_t time; // As long as the current chain descends from the highest height block // containing one of the inputs used in the calculation, then the cached // values are still valid even after a reorg. CBlockIndex *maxInputBlock; LockPoints() : height(0), time(0), maxInputBlock(nullptr) {} }; class CTxMemPool; /** \class CTxMemPoolEntry * * CTxMemPoolEntry stores data about the corresponding transaction, as well as * data about all in-mempool transactions that depend on the transaction * ("descendant" transactions). * * When a new entry is added to the mempool, we update the descendant state * (nCountWithDescendants, nSizeWithDescendants, and nModFeesWithDescendants) * for all ancestors of the newly added transaction. */ class CTxMemPoolEntry { private: CTransactionRef tx; //!< Cached to avoid expensive parent-transaction lookups Amount nFee; //!< ... and avoid recomputing tx size size_t nTxSize; //!< ... and modified size for priority size_t nModSize; //!< ... and total memory usage size_t nUsageSize; //!< Local time when entering the mempool int64_t nTime; //!< Priority when entering the mempool double entryPriority; //!< Chain height when entering the mempool unsigned int entryHeight; //!< Sum of all txin values that are already in blockchain Amount inChainInputValue; //!< keep track of transactions that spend a coinbase bool spendsCoinbase; //!< Total sigop plus P2SH sigops count int64_t sigOpCount; //!< Used for determining the priority of the transaction for mining in a //! block Amount feeDelta; //!< Track the height and time at which tx was final LockPoints lockPoints; // Information about descendants of this transaction that are in the // mempool; if we remove this transaction we must remove all of these // descendants as well. //!< number of descendant transactions uint64_t nCountWithDescendants; //!< ... and size uint64_t nSizeWithDescendants; //!< ... and total fees (all including us) Amount nModFeesWithDescendants; // Analogous statistics for ancestor transactions uint64_t nCountWithAncestors; uint64_t nSizeWithAncestors; Amount nModFeesWithAncestors; int64_t nSigOpCountWithAncestors; public: CTxMemPoolEntry(const CTransactionRef &_tx, const Amount _nFee, int64_t _nTime, double _entryPriority, unsigned int _entryHeight, Amount _inChainInputValue, bool spendsCoinbase, int64_t nSigOpsCost, LockPoints lp); const CTransaction &GetTx() const { return *this->tx; } CTransactionRef GetSharedTx() const { return this->tx; } /** * Fast calculation of lower bound of current priority as update from entry * priority. Only inputs that were originally in-chain will age. */ double GetPriority(unsigned int currentHeight) const; const Amount GetFee() const { return nFee; } size_t GetTxSize() const { return nTxSize; } int64_t GetTime() const { return nTime; } unsigned int GetHeight() const { return entryHeight; } int64_t GetSigOpCount() const { return sigOpCount; } Amount GetModifiedFee() const { return nFee + feeDelta; } size_t DynamicMemoryUsage() const { return nUsageSize; } const LockPoints &GetLockPoints() const { return lockPoints; } // Adjusts the descendant state. void UpdateDescendantState(int64_t modifySize, Amount modifyFee, int64_t modifyCount); // Adjusts the ancestor state void UpdateAncestorState(int64_t modifySize, Amount modifyFee, int64_t modifyCount, int modifySigOps); // Updates the fee delta used for mining priority score, and the // modified fees with descendants. void UpdateFeeDelta(Amount feeDelta); // Update the LockPoints after a reorg void UpdateLockPoints(const LockPoints &lp); uint64_t GetCountWithDescendants() const { return nCountWithDescendants; } uint64_t GetSizeWithDescendants() const { return nSizeWithDescendants; } Amount GetModFeesWithDescendants() const { return nModFeesWithDescendants; } bool GetSpendsCoinbase() const { return spendsCoinbase; } uint64_t GetCountWithAncestors() const { return nCountWithAncestors; } uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; } Amount GetModFeesWithAncestors() const { return nModFeesWithAncestors; } int64_t GetSigOpCountWithAncestors() const { return nSigOpCountWithAncestors; } //!< Index in mempool's vTxHashes mutable size_t vTxHashesIdx; }; // Helpers for modifying CTxMemPool::mapTx, which is a boost multi_index. struct update_descendant_state { update_descendant_state(int64_t _modifySize, Amount _modifyFee, int64_t _modifyCount) : modifySize(_modifySize), modifyFee(_modifyFee), modifyCount(_modifyCount) {} void operator()(CTxMemPoolEntry &e) { e.UpdateDescendantState(modifySize, modifyFee, modifyCount); } private: int64_t modifySize; Amount modifyFee; int64_t modifyCount; }; struct update_ancestor_state { update_ancestor_state(int64_t _modifySize, Amount _modifyFee, int64_t _modifyCount, int64_t _modifySigOpsCost) : modifySize(_modifySize), modifyFee(_modifyFee), modifyCount(_modifyCount), modifySigOpsCost(_modifySigOpsCost) {} void operator()(CTxMemPoolEntry &e) { e.UpdateAncestorState(modifySize, modifyFee, modifyCount, modifySigOpsCost); } private: int64_t modifySize; Amount modifyFee; int64_t modifyCount; int64_t modifySigOpsCost; }; struct update_fee_delta { explicit update_fee_delta(Amount _feeDelta) : feeDelta(_feeDelta) {} void operator()(CTxMemPoolEntry &e) { e.UpdateFeeDelta(feeDelta); } private: Amount feeDelta; }; struct update_lock_points { explicit update_lock_points(const LockPoints &_lp) : lp(_lp) {} void operator()(CTxMemPoolEntry &e) { e.UpdateLockPoints(lp); } private: const LockPoints &lp; }; // extracts a transaction hash from CTxMempoolEntry or CTransactionRef struct mempoolentry_txid { typedef uint256 result_type; result_type operator()(const CTxMemPoolEntry &entry) const { return entry.GetTx().GetId(); } result_type operator()(const CTransactionRef &tx) const { return tx->GetId(); } }; /** \class CompareTxMemPoolEntryByDescendantScore * * Sort an entry by max(score/size of entry's tx, score/size with all * descendants). */ class CompareTxMemPoolEntryByDescendantScore { public: bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const { bool fUseADescendants = UseDescendantScore(a); bool fUseBDescendants = UseDescendantScore(b); double aModFee = (fUseADescendants ? a.GetModFeesWithDescendants() : a.GetModifiedFee()) / SATOSHI; double aSize = fUseADescendants ? a.GetSizeWithDescendants() : a.GetTxSize(); double bModFee = (fUseBDescendants ? b.GetModFeesWithDescendants() : b.GetModifiedFee()) / SATOSHI; double bSize = fUseBDescendants ? b.GetSizeWithDescendants() : b.GetTxSize(); // Avoid division by rewriting (a/b > c/d) as (a*d > c*b). double f1 = aModFee * bSize; double f2 = aSize * bModFee; if (f1 == f2) { return a.GetTime() >= b.GetTime(); } return f1 < f2; } // Calculate which score to use for an entry (avoiding division). bool UseDescendantScore(const CTxMemPoolEntry &a) const { double f1 = a.GetSizeWithDescendants() * (a.GetModifiedFee() / SATOSHI); double f2 = a.GetTxSize() * (a.GetModFeesWithDescendants() / SATOSHI); return f2 > f1; } }; /** \class CompareTxMemPoolEntryByScore * * Sort by score of entry ((fee+delta)/size) in descending order */ class CompareTxMemPoolEntryByScore { public: bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const { double f1 = b.GetTxSize() * (a.GetModifiedFee() / SATOSHI); double f2 = a.GetTxSize() * (b.GetModifiedFee() / SATOSHI); if (f1 == f2) { return b.GetTx().GetId() < a.GetTx().GetId(); } return f1 > f2; } }; class CompareTxMemPoolEntryByEntryTime { public: bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const { return a.GetTime() < b.GetTime(); } }; class CompareTxMemPoolEntryByAncestorFee { public: bool operator()(const CTxMemPoolEntry &a, const CTxMemPoolEntry &b) const { double aFees = a.GetModFeesWithAncestors() / SATOSHI; double aSize = a.GetSizeWithAncestors(); double bFees = b.GetModFeesWithAncestors() / SATOSHI; double bSize = b.GetSizeWithAncestors(); // Avoid division by rewriting (a/b > c/d) as (a*d > c*b). double f1 = aFees * bSize; double f2 = aSize * bFees; if (f1 == f2) { return a.GetTx().GetId() < b.GetTx().GetId(); } return f1 > f2; } }; // Multi_index tag names struct descendant_score {}; struct entry_time {}; struct ancestor_score {}; /** * Information about a mempool transaction. */ struct TxMempoolInfo { /** The transaction itself */ CTransactionRef tx; /** Time the transaction entered the mempool. */ int64_t nTime; /** Feerate of the transaction. */ CFeeRate feeRate; /** The fee delta. */ Amount nFeeDelta; }; /** * Reason why a transaction was removed from the mempool, this is passed to the * notification signal. */ enum class MemPoolRemovalReason { //! Manually removed or unknown reason UNKNOWN = 0, //! Expired from mempool EXPIRY, //! Removed in size limiting SIZELIMIT, //! Removed for reorganization REORG, //! Removed for block BLOCK, //! Removed for conflict with in-block transaction CONFLICT, //! Removed for replacement REPLACED }; class SaltedTxidHasher { private: /** Salt */ const uint64_t k0, k1; public: SaltedTxidHasher(); size_t operator()(const uint256 &txid) const { return SipHashUint256(k0, k1, txid); } }; typedef std::pair TXModifier; /** * CTxMemPool stores valid-according-to-the-current-best-chain transactions that * may be included in the next block. * * Transactions are added when they are seen on the network (or created by the * local node), but not all transactions seen are added to the pool. For * example, the following new transactions will not be added to the mempool: * - a transaction which doesn't meet the minimum fee requirements. * - a new transaction that double-spends an input of a transaction already in * the pool where the new transaction does not meet the Replace-By-Fee * requirements as defined in BIP 125. * - a non-standard transaction. * * CTxMemPool::mapTx, and CTxMemPoolEntry bookkeeping: * * mapTx is a boost::multi_index that sorts the mempool on 4 criteria: * - transaction hash * - feerate [we use max(feerate of tx, feerate of tx with all descendants)] * - time in mempool * * Note: the term "descendant" refers to in-mempool transactions that depend on * this one, while "ancestor" refers to in-mempool transactions that a given * transaction depends on. * * In order for the feerate sort to remain correct, we must update transactions * in the mempool when new descendants arrive. To facilitate this, we track the * set of in-mempool direct parents and direct children in mapLinks. Within each * CTxMemPoolEntry, we track the size and fees of all descendants. * * Usually when a new transaction is added to the mempool, it has no in-mempool * children (because any such children would be an orphan). So in * addUnchecked(), we: * - update a new entry's setMemPoolParents to include all in-mempool parents * - update the new entry's direct parents to include the new tx as a child * - update all ancestors of the transaction to include the new tx's size/fee * * When a transaction is removed from the mempool, we must: * - update all in-mempool parents to not track the tx in setMemPoolChildren * - update all ancestors to not include the tx's size/fees in descendant state * - update all in-mempool children to not include it as a parent * * These happen in UpdateForRemoveFromMempool(). (Note that when removing a * transaction along with its descendants, we must calculate that set of * transactions to be removed before doing the removal, or else the mempool can * be in an inconsistent state where it's impossible to walk the ancestors of a * transaction.) * * In the event of a reorg, the assumption that a newly added tx has no * in-mempool children is false. In particular, the mempool is in an * inconsistent state while new transactions are being added, because there may * be descendant transactions of a tx coming from a disconnected block that are * unreachable from just looking at transactions in the mempool (the linking * transactions may also be in the disconnected block, waiting to be added). * Because of this, there's not much benefit in trying to search for in-mempool * children in addUnchecked(). Instead, in the special case of transactions * being added from a disconnected block, we require the caller to clean up the * state, to account for in-mempool, out-of-block descendants for all the * in-block transactions by calling UpdateTransactionsFromBlock(). Note that * until this is called, the mempool state is not consistent, and in particular * mapLinks may not be correct (and therefore functions like * CalculateMemPoolAncestors() and CalculateDescendants() that rely on them to * walk the mempool are not generally safe to use). * * Computational limits: * * Updating all in-mempool ancestors of a newly added transaction can be slow, * if no bound exists on how many in-mempool ancestors there may be. * CalculateMemPoolAncestors() takes configurable limits that are designed to * prevent these calculations from being too CPU intensive. */ class CTxMemPool { private: //!< Value n means that n times in 2^32 we check. uint32_t nCheckFrequency GUARDED_BY(cs); //!< Used by getblocktemplate to trigger CreateNewBlock() invocation unsigned int nTransactionsUpdated; //!< sum of all mempool tx's virtual sizes. uint64_t totalTxSize; //!< sum of dynamic memory usage of all the map elements (NOT the maps //! themselves) uint64_t cachedInnerUsage; mutable int64_t lastRollingFeeUpdate; mutable bool blockSinceLastRollingFeeBump; //!< minimum fee to get into the pool, decreases exponentially mutable double rollingMinimumFeeRate; void trackPackageRemoved(const CFeeRate &rate) EXCLUSIVE_LOCKS_REQUIRED(cs); public: // public only for testing static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12; typedef boost::multi_index_container< CTxMemPoolEntry, boost::multi_index::indexed_by< // sorted by txid boost::multi_index::hashed_unique< mempoolentry_txid, SaltedTxidHasher>, // sorted by fee rate boost::multi_index::ordered_non_unique< boost::multi_index::tag, boost::multi_index::identity, CompareTxMemPoolEntryByDescendantScore>, // sorted by entry time boost::multi_index::ordered_non_unique< boost::multi_index::tag, boost::multi_index::identity, CompareTxMemPoolEntryByEntryTime>, // sorted by fee rate with ancestors boost::multi_index::ordered_non_unique< boost::multi_index::tag, boost::multi_index::identity, CompareTxMemPoolEntryByAncestorFee>>> indexed_transaction_set; mutable CCriticalSection cs; indexed_transaction_set mapTx GUARDED_BY(cs); typedef indexed_transaction_set::nth_index<0>::type::iterator txiter; //!< All tx hashes/entries in mapTx, in random order std::vector> vTxHashes; struct CompareIteratorByHash { bool operator()(const txiter &a, const txiter &b) const { return a->GetTx().GetId() < b->GetTx().GetId(); } }; typedef std::set setEntries; const setEntries &GetMemPoolParents(txiter entry) const EXCLUSIVE_LOCKS_REQUIRED(cs); const setEntries &GetMemPoolChildren(txiter entry) const EXCLUSIVE_LOCKS_REQUIRED(cs); uint64_t CalculateDescendantMaximum(txiter entry) const EXCLUSIVE_LOCKS_REQUIRED(cs); private: typedef std::map cacheMap; struct TxLinks { setEntries parents; setEntries children; }; typedef std::map txlinksMap; txlinksMap mapLinks; void UpdateParent(txiter entry, txiter parent, bool add); void UpdateChild(txiter entry, txiter child, bool add); std::vector GetSortedDepthAndScore() const EXCLUSIVE_LOCKS_REQUIRED(cs); public: indirectmap mapNextTx GUARDED_BY(cs); std::map mapDeltas; /** * Create a new CTxMemPool. */ CTxMemPool(); ~CTxMemPool(); /** * If sanity-checking is turned on, check makes sure the pool is consistent * (does not contain two transactions that spend the same inputs, all inputs * are in the mapNextTx array). If sanity-checking is turned off, check does * nothing. */ void check(const CCoinsViewCache *pcoins) const; void setSanityCheck(double dFrequency = 1.0) { LOCK(cs); nCheckFrequency = static_cast(dFrequency * 4294967295.0); } // addUnchecked must updated state for all ancestors of a given transaction, // to track size/count of descendant transactions. First version of // addUnchecked can be used to have it call CalculateMemPoolAncestors(), and // then invoke the second version. // Note that addUnchecked is ONLY called from ATMP outside of tests // and any other callers may break wallet's in-mempool tracking (due to // lack of CValidationInterface::TransactionAddedToMempool callbacks). bool addUnchecked(const uint256 &hash, const CTxMemPoolEntry &entry); bool addUnchecked(const uint256 &hash, const CTxMemPoolEntry &entry, setEntries &setAncestors); void removeRecursive( const CTransaction &tx, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN); void removeForReorg(const Config &config, const CCoinsViewCache *pcoins, unsigned int nMemPoolHeight, int flags); void removeConflicts(const CTransaction &tx); void removeForBlock(const std::vector &vtx, unsigned int nBlockHeight); void clear(); // lock free void _clear() EXCLUSIVE_LOCKS_REQUIRED(cs); bool CompareDepthAndScore(const uint256 &hasha, const uint256 &hashb); void queryHashes(std::vector &vtxid); bool isSpent(const COutPoint &outpoint); unsigned int GetTransactionsUpdated() const; void AddTransactionsUpdated(unsigned int n); /** * Check that none of this transactions inputs are in the mempool, and thus * the tx is not dependent on other mempool transactions to be included in a * block. */ bool HasNoInputsOf(const CTransaction &tx) const; /** Affect CreateNewBlock prioritisation of transactions */ void PrioritiseTransaction(const uint256 &hash, double dPriorityDelta, const Amount nFeeDelta); void ApplyDeltas(const uint256 hash, double &dPriorityDelta, Amount &nFeeDelta) const; void ClearPrioritisation(const uint256 hash); public: /** * Remove a set of transactions from the mempool. If a transaction is in * this set, then all in-mempool descendants must also be in the set, unless * this transaction is being removed for being in a block. Set * updateDescendants to true when removing a tx that was in a block, so that * any in-mempool descendants have their ancestor state updated. */ void RemoveStaged(setEntries &stage, bool updateDescendants, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN) EXCLUSIVE_LOCKS_REQUIRED(cs); /** * When adding transactions from a disconnected block back to the mempool, * new mempool entries may have children in the mempool (which is generally * not the case when otherwise adding transactions). * UpdateTransactionsFromBlock() will find child transactions and update the * descendant state for each transaction in txidsToUpdate (excluding any * child transactions present in txidsToUpdate, which are already accounted * for). * Note: txidsToUpdate should be the set of transactions from the * disconnected block that have been accepted back into the mempool. */ void UpdateTransactionsFromBlock(const std::vector &txidsToUpdate); /** * Try to calculate all in-mempool ancestors of entry. * (these are all calculated including the tx itself) * limitAncestorCount = max number of ancestors * limitAncestorSize = max size of ancestors * limitDescendantCount = max number of descendants any ancestor can have * limitDescendantSize = max size of descendants any ancestor can have * errString = populated with error reason if any limits are hit * fSearchForParents = whether to search a tx's vin for in-mempool parents, * or look up parents from mapLinks. Must be true for entries not in the * mempool */ bool 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; /** * Populate setDescendants with all in-mempool descendants of hash. * Assumes that setDescendants includes all in-mempool descendants of * anything already in it. */ void CalculateDescendants(txiter it, setEntries &setDescendants) const EXCLUSIVE_LOCKS_REQUIRED(cs); /** * The minimum fee to get into the mempool, which may itself not be enough * for larger-sized transactions. The incrementalRelayFee policy variable is * used to bound the time it takes the fee rate to go back down all the way * to 0. When the feerate would otherwise be half of this, it is set to 0 * instead. */ CFeeRate GetMinFee(size_t sizelimit) const; /** * Remove transactions from the mempool until its dynamic size is <= * sizelimit. pvNoSpendsRemaining, if set, will be populated with the list * of outpoints which are not in mempool which no longer have any spends in * this mempool. */ void TrimToSize(size_t sizelimit, std::vector *pvNoSpendsRemaining = nullptr); /** * Expire all transaction (and their dependencies) in the mempool older than * time. Return the number of removed transactions. */ int Expire(int64_t time); /** * Reduce the size of the mempool by expiring and then trimming the mempool. */ void LimitSize(size_t limit, unsigned long age); /** * Calculate the ancestor and descendant count for the given transaction. * The counts include the transaction itself. */ void GetTransactionAncestry(const uint256 &txid, size_t &ancestors, size_t &descendants) const; unsigned long size() { LOCK(cs); return mapTx.size(); } uint64_t GetTotalTxSize() const { LOCK(cs); return totalTxSize; } bool exists(uint256 hash) const { LOCK(cs); return mapTx.count(hash) != 0; } - bool exists(const COutPoint &outpoint) const { - LOCK(cs); - auto it = mapTx.find(outpoint.GetTxId()); - return it != mapTx.end() && outpoint.GetN() < it->GetTx().vout.size(); - } - CTransactionRef get(const uint256 &hash) const; TxMempoolInfo info(const uint256 &hash) const; std::vector infoAll() const; CFeeRate estimateFee() const; size_t DynamicMemoryUsage() const; boost::signals2::signal NotifyEntryAdded; boost::signals2::signal NotifyEntryRemoved; private: /** * UpdateForDescendants is used by UpdateTransactionsFromBlock to update the * descendants for a single transaction that has been added to the mempool * but may have child transactions in the mempool, eg during a chain reorg. * setExclude is the set of descendant transactions in the mempool that must * not be accounted for (because any descendants in setExclude were added to * the mempool after the transaction being updated and hence their state is * already reflected in the parent state). * * cachedDescendants will be updated with the descendants of the transaction * being updated, so that future invocations don't need to walk the same * transaction again, if encountered in another transaction chain. */ void UpdateForDescendants(txiter updateIt, cacheMap &cachedDescendants, const std::set &setExclude) EXCLUSIVE_LOCKS_REQUIRED(cs); /** * Update ancestors of hash to add/remove it as a descendant transaction. */ void UpdateAncestorsOf(bool add, txiter hash, setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs); /** Set ancestor state for an entry */ void UpdateEntryForAncestors(txiter it, const setEntries &setAncestors) EXCLUSIVE_LOCKS_REQUIRED(cs); /** * For each transaction being removed, update ancestors and any direct * children. If updateDescendants is true, then also update in-mempool * descendants' ancestor state. */ void UpdateForRemoveFromMempool(const setEntries &entriesToRemove, bool updateDescendants) EXCLUSIVE_LOCKS_REQUIRED(cs); /** Sever link between specified transaction and direct children. */ void UpdateChildrenForRemoval(txiter entry) EXCLUSIVE_LOCKS_REQUIRED(cs); /** * Before calling removeUnchecked for a given transaction, * UpdateForRemoveFromMempool must be called on the entire (dependent) set * of transactions being removed at the same time. We use each * CTxMemPoolEntry's setMemPoolParents in order to walk ancestors of a given * transaction that is removed, so we can't remove intermediate transactions * in a chain before we've updated all the state for the removal. */ void removeUnchecked(txiter entry, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN) EXCLUSIVE_LOCKS_REQUIRED(cs); }; /** * CCoinsView that brings transactions from a memorypool into view. * It does not check for spendings by memory pool transactions. * Instead, it provides access to all Coins which are either unspent in the * base CCoinsView, or are outputs from any mempool transaction! * This allows transaction replacement to work as expected, as you want to * have all inputs "available" to check signatures, and any cycles in the * dependency graph are checked directly in AcceptToMemoryPool. * It also allows you to sign a double-spend directly in signrawtransaction, * as long as the conflicting transaction is not yet confirmed. */ class CCoinsViewMemPool : public CCoinsViewBacked { protected: const CTxMemPool &mempool; public: CCoinsViewMemPool(CCoinsView *baseIn, const CTxMemPool &mempoolIn); bool GetCoin(const COutPoint &outpoint, Coin &coin) const override; }; // We want to sort transactions by coin age priority typedef std::pair TxCoinAgePriority; struct TxCoinAgePriorityCompare { bool operator()(const TxCoinAgePriority &a, const TxCoinAgePriority &b) { if (a.first == b.first) { // Reverse order to make sort less than return CompareTxMemPoolEntryByScore()(*(b.second), *(a.second)); } return a.first < b.first; } }; /** * DisconnectedBlockTransactions * * During the reorg, it's desirable to re-add previously confirmed transactions * to the mempool, so that anything not re-confirmed in the new chain is * available to be mined. However, it's more efficient to wait until the reorg * is complete and process all still-unconfirmed transactions at that time, * since we expect most confirmed transactions to (typically) still be * confirmed in the new chain, and re-accepting to the memory pool is expensive * (and therefore better to not do in the middle of reorg-processing). * Instead, store the disconnected transactions (in order!) as we go, remove any * that are included in blocks in the new chain, and then process the remaining * still-unconfirmed transactions at the end. * * It also enables efficient reprocessing of current mempool entries, useful * when (de)activating forks that result in in-mempool transactions becoming * invalid */ // multi_index tag names struct txid_index {}; struct insertion_order {}; class DisconnectedBlockTransactions { private: typedef boost::multi_index_container< CTransactionRef, boost::multi_index::indexed_by< // sorted by txid boost::multi_index::hashed_unique< boost::multi_index::tag, mempoolentry_txid, SaltedTxidHasher>, // sorted by order in the blockchain boost::multi_index::sequenced< boost::multi_index::tag>>> indexed_disconnected_transactions; indexed_disconnected_transactions queuedTx; uint64_t cachedInnerUsage = 0; void addTransaction(const CTransactionRef &tx) { queuedTx.insert(tx); cachedInnerUsage += RecursiveDynamicUsage(tx); } public: // It's almost certainly a logic bug if we don't clear out queuedTx before // destruction, as we add to it while disconnecting blocks, and then we // need to re-process remaining transactions to ensure mempool consistency. // For now, assert() that we've emptied out this object on destruction. // This assert() can always be removed if the reorg-processing code were // to be refactored such that this assumption is no longer true (for // instance if there was some other way we cleaned up the mempool after a // reorg, besides draining this object). ~DisconnectedBlockTransactions() { assert(queuedTx.empty()); } // Estimate the overhead of queuedTx to be 6 pointers + an allocation, as // no exact formula for boost::multi_index_contained is implemented. size_t DynamicMemoryUsage() const { return memusage::MallocUsage(sizeof(CTransactionRef) + 6 * sizeof(void *)) * queuedTx.size() + cachedInnerUsage; } const indexed_disconnected_transactions &GetQueuedTx() const { return queuedTx; } // Import mempool entries in topological order into queuedTx and clear the // mempool. Caller should call updateMempoolForReorg to reprocess these // transactions void importMempool(CTxMemPool &pool); // Add entries for a block while reconstructing the topological ordering so // they can be added back to the mempool simply. void addForBlock(const std::vector &vtx); // Remove entries based on txid_index, and update memory usage. void removeForBlock(const std::vector &vtx) { // Short-circuit in the common case of a block being added to the tip if (queuedTx.empty()) { return; } for (auto const &tx : vtx) { auto it = queuedTx.find(tx->GetId()); if (it != queuedTx.end()) { cachedInnerUsage -= RecursiveDynamicUsage(*it); queuedTx.erase(it); } } } // Remove an entry by insertion_order index, and update memory usage. void removeEntry(indexed_disconnected_transactions::index< insertion_order>::type::iterator entry) { cachedInnerUsage -= RecursiveDynamicUsage(*entry); queuedTx.get().erase(entry); } bool isEmpty() const { return queuedTx.empty(); } void clear() { cachedInnerUsage = 0; queuedTx.clear(); } /** * Make mempool consistent after a reorg, by re-adding or recursively * erasing disconnected block transactions from the mempool, and also * removing any other transactions from the mempool that are no longer valid * given the new tip/height. * * Note: we assume that disconnectpool only contains transactions that are * NOT confirmed in the current chain nor already in the mempool (otherwise, * in-mempool descendants of such transactions would be removed). * * Passing fAddToMempool=false will skip trying to add the transactions * back, and instead just erase from the mempool as needed. */ void updateMempoolForReorg(const Config &config, bool fAddToMempool); }; #endif // BITCOIN_TXMEMPOOL_H