txmempool.h

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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin developers
// Copyright (c) 2016-2021 The PIVX Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
#ifndef PIVX_TXMEMPOOL_H
#define PIVX_TXMEMPOOL_H
 
#include <list>
#include <memory>
#include <set>
 
#include "amount.h"
#include "coins.h"
#include "crypto/siphash.h"
#include "indirectmap.h"
#include "policy/feerate.h"
#include "primitives/transaction.h"
#include "sync.h"
#include "random.h"
#include "netaddress.h"
 
#include "boost/multi_index_container.hpp"
#include "boost/multi_index/ordered_index.hpp"
#include "boost/multi_index/hashed_index.hpp"
#include <boost/multi_index/sequenced_index.hpp>
 
class CAutoFile;
class CBLSPublicKey;
 
 
static const uint32_t MEMPOOL_HEIGHT = 0x7FFFFFFF;
 
class CTxMemPool;
 
class CTxMemPoolEntry
{
private:
    CTransactionRef tx;
    CAmount nFee;         
    size_t nTxSize;       
    size_t nUsageSize;    
    CFeeRate feeRate;     
    bool hasZerocoins{false}; 
    bool m_isShielded{false}; 
    int64_t nTime;        
    unsigned int entryHeight; 
    bool spendsCoinbaseOrCoinstake; 
    unsigned int sigOpCount; 
    int64_t feeDelta; 
 
    // 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.  if nCountWithDescendants is 0, treat this entry as
    // dirty, and nSizeWithDescendants and nModFeesWithDescendants will not be
    // correct.
    uint64_t nCountWithDescendants; 
    uint64_t nSizeWithDescendants;  
    CAmount nModFeesWithDescendants;  
 
    // Analogous statistics for ancestor transactions
    uint64_t nCountWithAncestors;
    uint64_t nSizeWithAncestors;
    CAmount nModFeesWithAncestors;
    unsigned int nSigOpCountWithAncestors;
 
public:
    CTxMemPoolEntry(const CTransactionRef& _tx, const CAmount& _nFee,
            int64_t _nTime, unsigned int _entryHeight,
            bool _spendsCoinbaseOrCoinstake, unsigned int nSigOps);
 
    const CTransaction& GetTx() const { return *this->tx; }
    std::shared_ptr<const CTransaction> GetSharedTx() const { return this->tx; }
    const CAmount& GetFee() const { return nFee; }
    size_t GetTxSize() const { return nTxSize; }
    int64_t GetTime() const { return nTime; }
    unsigned int GetHeight() const { return entryHeight; }
    bool HasZerocoins() const { return hasZerocoins; }
    bool IsShielded() const { return m_isShielded; }
    unsigned int GetSigOpCount() const { return sigOpCount; }
    int64_t GetModifiedFee() const { return nFee + feeDelta; }
    size_t DynamicMemoryUsage() const { return nUsageSize; }
 
    // Adjusts the descendant state, if this entry is not dirty.
    void UpdateDescendantState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount);
    // Adjusts the ancestor state
    void UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int modifySigOps);
    // Updates the fee delta used for mining priority score, and the
    // modified fees with descendants.
    void UpdateFeeDelta(int64_t feeDelta);
 
    uint64_t GetCountWithDescendants() const { return nCountWithDescendants; }
    uint64_t GetSizeWithDescendants() const { return nSizeWithDescendants; }
    CAmount GetModFeesWithDescendants() const { return nModFeesWithDescendants; }
 
    bool GetSpendsCoinbaseOrCoinstake() const { return spendsCoinbaseOrCoinstake; }
 
    uint64_t GetCountWithAncestors() const { return nCountWithAncestors; }
    uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
    CAmount GetModFeesWithAncestors() const { return nModFeesWithAncestors; }
    unsigned int GetSigOpCountWithAncestors() const { return nSigOpCountWithAncestors; }
};
 
// Helpers for modifying CTxMemPool::mapTx, which is a boost multi_index.
struct update_descendant_state
{
    update_descendant_state(int64_t _modifySize, CAmount _modifyFee, int64_t _modifyCount) :
        modifySize(_modifySize), modifyFee(_modifyFee), modifyCount(_modifyCount)
    {}
 
    void operator() (CTxMemPoolEntry &e)
        { e.UpdateDescendantState(modifySize, modifyFee, modifyCount); }
 
    private:
        int64_t modifySize;
        CAmount modifyFee;
        int64_t modifyCount;
};
 
struct update_ancestor_state
{
    update_ancestor_state(int64_t _modifySize, CAmount _modifyFee, int64_t _modifyCount, int _modifySigOps) :
            modifySize(_modifySize), modifyFee(_modifyFee), modifyCount(_modifyCount), modifySigOps(_modifySigOps)
    {}
 
    void operator() (CTxMemPoolEntry &e)
    { e.UpdateAncestorState(modifySize, modifyFee, modifyCount, modifySigOps); }
 
private:
    int64_t modifySize;
    CAmount modifyFee;
    int64_t modifyCount;
    int modifySigOps;
};
 
struct update_fee_delta
{
    explicit update_fee_delta(int64_t _feeDelta) : feeDelta(_feeDelta) { }
 
    void operator() (CTxMemPoolEntry &e) { e.UpdateFeeDelta(feeDelta); }
 
private:
    int64_t feeDelta;
};
 
// 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().GetHash();
    }
 
    result_type operator() (const CTransactionRef& tx) const
    {
        return tx->GetHash();
    }
};
 
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();
        double aSize = fUseADescendants ? a.GetSizeWithDescendants() : a.GetTxSize();
 
        double bModFee = fUseBDescendants ? b.GetModFeesWithDescendants() : b.GetModifiedFee();
        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 = (double)a.GetModifiedFee() * a.GetSizeWithDescendants();
        double f2 = (double)a.GetModFeesWithDescendants() * a.GetTxSize();
        return f2 > f1;
    }
};
 
class CompareTxMemPoolEntryByScore
{
public:
    bool operator()(const CTxMemPoolEntry& a, const CTxMemPoolEntry& b) const
    {
        double f1 = (double)a.GetModifiedFee() * b.GetTxSize();
        double f2 = (double)b.GetModifiedFee() * a.GetTxSize();
        if (f1 == f2) {
            return b.GetTx().GetHash() < a.GetTx().GetHash();
        }
        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();
        double aSize = a.GetSizeWithAncestors();
 
        double bFees = b.GetModFeesWithAncestors();
        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().GetHash() < b.GetTx().GetHash();
        }
 
        return f1 > f2;
    }
};
 
// Multi_index tag names
struct descendant_score {};
struct entry_time {};
struct mining_score {};
struct ancestor_score {};
 
class CBlockPolicyEstimator;
 
struct TxMempoolInfo
{
    CTransactionRef tx;
 
    int64_t nTime;
 
    CFeeRate feeRate;
 
    int64_t nFeeDelta;
};
 
enum class MemPoolRemovalReason {
    UNKNOWN = 0, 
    EXPIRY,      
    SIZELIMIT,   
    REORG,       
    BLOCK,       
    CONFLICT,    
    REPLACED     
};
 
class CTxMemPool
{
private:
    uint32_t nCheckFrequency; 
    unsigned int nTransactionsUpdated;
    CBlockPolicyEstimator* minerPolicyEstimator;
 
    CFeeRate minRelayFee; 
    uint64_t totalTxSize; 
    uint64_t cachedInnerUsage; 
 
    CFeeRate minReasonableRelayFee;
 
    mutable int64_t lastRollingFeeUpdate;
    mutable bool blockSinceLastRollingFeeBump;
    mutable double rollingMinimumFeeRate; 
 
    void trackPackageRemoved(const CFeeRate& rate);
 
    // Shielded txes
    std::map<uint256, CTransactionRef> mapSaplingNullifiers;
    void checkNullifiers() const;
 
    bool m_is_loaded GUARDED_BY(cs){false};
 
public:
 
    static const int ROLLING_FEE_HALFLIFE = 60 * 60 * 12; // public only for testing
 
    typedef boost::multi_index_container<
        CTxMemPoolEntry,
        boost::multi_index::indexed_by<
            // sorted by txid
            boost::multi_index::hashed_unique<mempoolentry_txid, SaltedIdHasher>,
            // sorted by fee rate
            boost::multi_index::ordered_non_unique<
                boost::multi_index::tag<descendant_score>,
                boost::multi_index::identity<CTxMemPoolEntry>,
                CompareTxMemPoolEntryByDescendantScore
            >,
            // sorted by entry time
            boost::multi_index::ordered_non_unique<
                boost::multi_index::tag<entry_time>,
                boost::multi_index::identity<CTxMemPoolEntry>,
                CompareTxMemPoolEntryByEntryTime
            >,
            // sorted by score (for mining prioritization)
            boost::multi_index::ordered_unique<
                boost::multi_index::tag<mining_score>,
                boost::multi_index::identity<CTxMemPoolEntry>,
                CompareTxMemPoolEntryByScore
            >,
            // sorted by fee rate with ancestors
            boost::multi_index::ordered_non_unique<
                boost::multi_index::tag<ancestor_score>,
                boost::multi_index::identity<CTxMemPoolEntry>,
                CompareTxMemPoolEntryByAncestorFee
            >
        >
    > indexed_transaction_set;
 
    mutable RecursiveMutex cs;
    indexed_transaction_set mapTx;
 
    typedef indexed_transaction_set::nth_index<0>::type::iterator txiter;
 
    struct CompareIteratorByHash {
        bool operator()(const txiter &a, const txiter &b) const {
            return a->GetTx().GetHash() < b->GetTx().GetHash();
        }
    };
    typedef std::set<txiter, CompareIteratorByHash> setEntries;
 
    const setEntries & GetMemPoolParents(txiter entry) const;
    const setEntries & GetMemPoolChildren(txiter entry) const;
 
private:
    typedef std::map<txiter, setEntries, CompareIteratorByHash> cacheMap;
 
    struct TxLinks {
        setEntries parents;
        setEntries children;
    };
 
    typedef std::map<txiter, TxLinks, CompareIteratorByHash> txlinksMap;
    txlinksMap mapLinks;
 
    std::multimap<uint256, uint256> mapProTxRefs; // proTxHash -> transaction (all TXs that refer to an existing proTx)
    std::map<CService, uint256> mapProTxAddresses;
    std::map<CKeyID, uint256> mapProTxPubKeyIDs;
    std::map<uint256, uint256> mapProTxBlsPubKeyHashes;
    std::map<COutPoint, uint256> mapProTxCollaterals;
 
    void UpdateParent(txiter entry, txiter parent, bool add);
    void UpdateChild(txiter entry, txiter child, bool add);
 
    std::vector<indexed_transaction_set::const_iterator> GetSortedDepthAndScore() const;
 
public:
    indirectmap<COutPoint, CTransactionRef> mapNextTx;
    std::map<uint256, CAmount> mapDeltas;
 
    explicit CTxMemPool(const CFeeRate& _minReasonableRelayFee);
    ~CTxMemPool();
 
    void check(const CCoinsViewCache *pcoins) const;
    void setSanityCheck(double dFrequency = 1.0) { nCheckFrequency = 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 validFeeEstimate = true);
    bool addUnchecked(const uint256& hash, const CTxMemPoolEntry &entry, setEntries &setAncestors, bool validFeeEstimate = true);
 
    void removeRecursive(const CTransaction& tx, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN);
    void removeForReorg(const CCoinsViewCache* pcoins, unsigned int nMemPoolHeight, int flags);
    void removeWithAnchor(const uint256& invalidRoot);
    void removeConflicts(const CTransaction& tx);
    void removeForBlock(const std::vector<CTransactionRef>& vtx, unsigned int nBlockHeight);
 
    void clear();
    void _clear();  // lock-free
    bool CompareDepthAndScore(const uint256& hasha, const uint256& hashb);
    void queryHashes(std::vector<uint256>& vtxid);
    void getTransactions(std::set<uint256>& setTxid);
    bool isSpent(const COutPoint& outpoint);
    unsigned int GetTransactionsUpdated() const;
    void AddTransactionsUpdated(unsigned int n);
    bool HasNoInputsOf(const CTransaction& tx) const;
 
    void PrioritiseTransaction(const uint256& hash, const CAmount& nFeeDelta);
    void ApplyDelta(const uint256& hash, CAmount& nFeeDelta) const;
    void ClearPrioritisation(const uint256 hash);
 
    bool nullifierExists(const uint256& nullifier) const;
 
    void RemoveStaged(setEntries &stage, bool updateDescendants, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN);
 
    void UpdateTransactionsFromBlock(const std::vector<uint256> &hashesToUpdate);
 
    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;
 
    void CalculateDescendants(txiter it, setEntries &setDescendants);
 
    CFeeRate GetMinFee(size_t sizelimit) const;
 
    void TrimToSize(size_t sizelimit, std::vector<COutPoint>* pvNoSpendsRemaining = nullptr);
 
    int Expire(int64_t time);
 
    bool TransactionWithinChainLimit(const uint256& txid, size_t chainLimit) const;
 
    bool IsLoaded() const;
 
    void SetIsLoaded(bool loaded);
 
    unsigned long size() const
    {
        LOCK(cs);
        return mapTx.size();
    }
    uint64_t GetTotalTxSize()
    {
        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.hash);
        return (it != mapTx.end() && outpoint.n < it->GetTx().vout.size());
    }
 
    CTransactionRef get(const uint256& hash) const;
    TxMempoolInfo info(const uint256& hash) const;
    std::vector<TxMempoolInfo> infoAll() const;
 
    bool existsProviderTxConflict(const CTransaction &tx) const;
    void removeProTxReferences(const uint256& proTxHash, MemPoolRemovalReason reason);
 
    CFeeRate estimateSmartFee(int nBlocks, int *answerFoundAtBlocks = nullptr) const;
 
    CFeeRate estimateFee(int nBlocks) const;
 
    bool WriteFeeEstimates(CAutoFile& fileout) const;
    bool ReadFeeEstimates(CAutoFile& filein);
 
    size_t DynamicMemoryUsage() const;
 
private:
    void UpdateForDescendants(txiter updateIt,
            cacheMap &cachedDescendants,
            const std::set<uint256> &setExclude);
    void UpdateAncestorsOf(bool add, txiter hash, setEntries &setAncestors);
    void UpdateEntryForAncestors(txiter it, const setEntries &setAncestors);
    void UpdateForRemoveFromMempool(const setEntries &entriesToRemove, bool updateDescendants);
    void UpdateChildrenForRemoval(txiter entry);
 
    void removeUnchecked(txiter entry, MemPoolRemovalReason reason = MemPoolRemovalReason::UNKNOWN);
 
    void addUncheckedSpecialTx(const CTransaction& tx);
    void removeUncheckedSpecialTx(const CTransaction& tx);
    void removeProTxPubKeyConflicts(const CTransaction &tx, const CKeyID &keyId);
    void removeProTxPubKeyConflicts(const CTransaction& tx, const CBLSPublicKey& pubKey);
    void removeProTxCollateralConflicts(const CTransaction &tx, const COutPoint &collateralOutpoint);
    void removeProTxSpentCollateralConflicts(const CTransaction &tx);
    void removeProTxConflicts(const CTransaction &tx);
 
};
 
class CCoinsViewMemPool : public CCoinsViewBacked
{
protected:
    CTxMemPool& mempool;
 
public:
    CCoinsViewMemPool(CCoinsView* baseIn, CTxMemPool& mempoolIn);
    bool GetCoin(const COutPoint& outpoint, Coin& coin) const;
    bool HaveCoin(const COutPoint& outpoint) const;
    bool GetNullifier(const uint256& nullifier) const;
};
 
// multi_index tag names
struct txid_index {};
struct insertion_order {};
 
struct DisconnectedBlockTransactions {
    typedef boost::multi_index_container<
        CTransactionRef,
        boost::multi_index::indexed_by<
            // sorted by txid
            boost::multi_index::hashed_unique<
                boost::multi_index::tag<txid_index>,
                mempoolentry_txid,
                SaltedIdHasher
            >,
            // sorted by order in the blockchain
            boost::multi_index::sequenced<
                boost::multi_index::tag<insertion_order>
            >
        >
    > indexed_disconnected_transactions;
 
    // 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()); }
 
    indexed_disconnected_transactions queuedTx;
    uint64_t cachedInnerUsage = 0;
 
    // 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;
    }
 
    void addTransaction(const CTransactionRef& tx)
    {
        queuedTx.insert(tx);
        cachedInnerUsage += memusage::RecursiveDynamicUsage(tx);
    }
 
    // Remove entries based on txid_index, and update memory usage.
    void removeForBlock(const std::vector<CTransactionRef>& 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->GetHash());
            if (it != queuedTx.end()) {
                cachedInnerUsage -= memusage::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 -= memusage::RecursiveDynamicUsage(*entry);
        queuedTx.get<insertion_order>().erase(entry);
    }
 
    void clear()
    {
        cachedInnerUsage = 0;
        queuedTx.clear();
    }
};
 
#endif // PIVX_TXMEMPOOL_H