Switch CTransaction storage in mempool to std::shared_ptr

src/main.cpp

@@ -4519,10 +4519,11 @@ void static ProcessGetData(CNode* pfrom, const Consensus::Params& consensusParam
                     }
                 }
                 if (!push && inv.type == MSG_TX) {
-                    int64_t txtime;
+                    auto txinfo = mempool.info(inv.hash);
                     // To protect privacy, do not answer getdata using the mempool when
                     // that TX couldn't have been INVed in reply to a MEMPOOL request.
-                    if (mempool.lookup(inv.hash, tx, txtime) && txtime <= pfrom->timeLastMempoolReq) {
+                    if (txinfo.tx && txinfo.nTime <= pfrom->timeLastMempoolReq) {
+                        tx = *txinfo.tx;
                         push = true;
                     }
                 }
@@ -5900,8 +5901,7 @@ bool SendMessages(CNode* pto)
 
             // Respond to BIP35 mempool requests
             if (fSendTrickle && pto->fSendMempool) {
-                std::vector<uint256> vtxid;
-                mempool.queryHashes(vtxid);
+                auto vtxinfo = mempool.infoAll();
                 pto->fSendMempool = false;
                 CAmount filterrate = 0;
                 {
@@ -5911,20 +5911,16 @@ bool SendMessages(CNode* pto)
 
                 LOCK(pto->cs_filter);
 
-                BOOST_FOREACH(const uint256& hash, vtxid) {
+                for (const auto& txinfo : vtxinfo) {
+                    const uint256& hash = txinfo.tx->GetHash();
                     CInv inv(MSG_TX, hash);
                     pto->setInventoryTxToSend.erase(hash);
                     if (filterrate) {
-                        CFeeRate feeRate;
-                        mempool.lookupFeeRate(hash, feeRate);
-                        if (feeRate.GetFeePerK() < filterrate)
+                        if (txinfo.feeRate.GetFeePerK() < filterrate)
                             continue;
                     }
                     if (pto->pfilter) {
-                        CTransaction tx;
-                        bool fInMemPool = mempool.lookup(hash, tx);
-                        if (!fInMemPool) continue; // another thread removed since queryHashes, maybe...
-                        if (!pto->pfilter->IsRelevantAndUpdate(tx)) continue;
+                        if (!pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) continue;
                     }
                     pto->filterInventoryKnown.insert(hash);
                     vInv.push_back(inv);
@@ -5970,16 +5966,14 @@ bool SendMessages(CNode* pto)
                         continue;
                     }
                     // Not in the mempool anymore? don't bother sending it.
-                    CFeeRate feeRate;
-                    if (!mempool.lookupFeeRate(hash, feeRate)) {
+                    auto txinfo = mempool.info(hash);
+                    if (!txinfo.tx) {
                         continue;
                     }
-                    if (filterrate && feeRate.GetFeePerK() < filterrate) {
+                    if (filterrate && txinfo.feeRate.GetFeePerK() < filterrate) {
                         continue;
                     }
-                    CTransaction tx;
-                    if (!mempool.lookup(hash, tx)) continue;
-                    if (pto->pfilter && !pto->pfilter->IsRelevantAndUpdate(tx)) continue;
+                    if (pto->pfilter && !pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) continue;
                     // Send
                     vInv.push_back(CInv(MSG_TX, hash));
                     nRelayedTransactions++;
@@ -5992,7 +5986,7 @@ bool SendMessages(CNode* pto)
                             vRelayExpiration.pop_front();
                         }
 
-                        auto ret = mapRelay.insert(std::make_pair(hash, tx));
+                        auto ret = mapRelay.insert(std::make_pair(hash, *txinfo.tx));
                         if (ret.second) {
                             vRelayExpiration.push_back(std::make_pair(GetTime() + 15 * 60, hash));
                         }

src/txmempool.cpp

@@ -23,18 +23,18 @@ CTxMemPoolEntry::CTxMemPoolEntry(const CTransaction& _tx, const CAmount& _nFee,
                                  int64_t _nTime, double _entryPriority, unsigned int _entryHeight,
                                  bool poolHasNoInputsOf, CAmount _inChainInputValue,
                                  bool _spendsCoinbase, unsigned int _sigOps, LockPoints lp):
-    tx(_tx), nFee(_nFee), nTime(_nTime), entryPriority(_entryPriority), entryHeight(_entryHeight),
+    tx(std::make_shared<CTransaction>(_tx)), nFee(_nFee), nTime(_nTime), entryPriority(_entryPriority), entryHeight(_entryHeight),
     hadNoDependencies(poolHasNoInputsOf), inChainInputValue(_inChainInputValue),
     spendsCoinbase(_spendsCoinbase), sigOpCount(_sigOps), lockPoints(lp)
 {
-    nTxSize = ::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION);
-    nModSize = tx.CalculateModifiedSize(nTxSize);
-    nUsageSize = RecursiveDynamicUsage(tx);
+    nTxSize = ::GetSerializeSize(_tx, SER_NETWORK, PROTOCOL_VERSION);
+    nModSize = _tx.CalculateModifiedSize(nTxSize);
+    nUsageSize = RecursiveDynamicUsage(*tx) + memusage::DynamicUsage(tx);
 
     nCountWithDescendants = 1;
     nSizeWithDescendants = nTxSize;
     nModFeesWithDescendants = nFee;
-    CAmount nValueIn = tx.GetValueOut()+nFee;
+    CAmount nValueIn = _tx.GetValueOut()+nFee;
     assert(inChainInputValue <= nValueIn);
 
     feeDelta = 0;
@@ -768,50 +768,86 @@ bool CTxMemPool::CompareDepthAndScore(const uint256& hasha, const uint256& hashb
 namespace {
 class DepthAndScoreComparator
 {
-    CTxMemPool *mp;
 public:
-    DepthAndScoreComparator(CTxMemPool *mempool) : mp(mempool) {}
-    bool operator()(const uint256& a, const uint256& b) { return mp->CompareDepthAndScore(a, b); }
+    bool operator()(const CTxMemPool::indexed_transaction_set::const_iterator& a, const CTxMemPool::indexed_transaction_set::const_iterator& b)
+    {
+        uint64_t counta = a->GetCountWithAncestors();
+        uint64_t countb = b->GetCountWithAncestors();
+        if (counta == countb) {
+            return CompareTxMemPoolEntryByScore()(*a, *b);
+        }
+        return counta < countb;
+    }
 };
 }
 
-void CTxMemPool::queryHashes(vector<uint256>& vtxid)
+std::vector<CTxMemPool::indexed_transaction_set::const_iterator> CTxMemPool::GetSortedDepthAndScore() const
 {
-    vtxid.clear();
+    std::vector<indexed_transaction_set::const_iterator> iters;
+    AssertLockHeld(cs);
+
+    iters.reserve(mapTx.size());
 
+    for (indexed_transaction_set::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi) {
+        iters.push_back(mi);
+    }
+    std::sort(iters.begin(), iters.end(), DepthAndScoreComparator());
+    return iters;
+}
+
+void CTxMemPool::queryHashes(vector<uint256>& vtxid)
+{
     LOCK(cs);
+    auto iters = GetSortedDepthAndScore();
+
+    vtxid.clear();
     vtxid.reserve(mapTx.size());
-    for (indexed_transaction_set::iterator mi = mapTx.begin(); mi != mapTx.end(); ++mi)
-        vtxid.push_back(mi->GetTx().GetHash());
 
-    std::sort(vtxid.begin(), vtxid.end(), DepthAndScoreComparator(this));
+    for (auto it : iters) {
+        vtxid.push_back(it->GetTx().GetHash());
+    }
 }
 
+std::vector<TxMempoolInfo> CTxMemPool::infoAll() const
+{
+    LOCK(cs);
+    auto iters = GetSortedDepthAndScore();
+
+    std::vector<TxMempoolInfo> ret;
+    ret.reserve(mapTx.size());
+    for (auto it : iters) {
+        ret.push_back(TxMempoolInfo{it->GetSharedTx(), it->GetTime(), CFeeRate(it->GetFee(), it->GetTxSize())});
+    }
+
+    return ret;
+}
 
-bool CTxMemPool::lookup(uint256 hash, CTransaction& result, int64_t& time) const
+std::shared_ptr<const CTransaction> CTxMemPool::get(const uint256& hash) const
 {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(hash);
-    if (i == mapTx.end()) return false;
-    result = i->GetTx();
-    time = i->GetTime();
-    return true;
+    if (i == mapTx.end())
+        return nullptr;
+    return i->GetSharedTx();
 }
 
 bool CTxMemPool::lookup(uint256 hash, CTransaction& result) const
 {
-    int64_t time;
-    return CTxMemPool::lookup(hash, result, time);
+    auto tx = get(hash);
+    if (tx) {
+        result = *tx;
+        return true;
+    }
+    return false;
 }
 
-bool CTxMemPool::lookupFeeRate(const uint256& hash, CFeeRate& feeRate) const
+TxMempoolInfo CTxMemPool::info(const uint256& hash) const
 {
     LOCK(cs);
     indexed_transaction_set::const_iterator i = mapTx.find(hash);
     if (i == mapTx.end())
-        return false;
-    feeRate = CFeeRate(i->GetFee(), i->GetTxSize());
-    return true;
+        return TxMempoolInfo();
+    return TxMempoolInfo{i->GetSharedTx(), i->GetTime(), CFeeRate(i->GetFee(), i->GetTxSize())};
 }
 
 CFeeRate CTxMemPool::estimateFee(int nBlocks) const

src/txmempool.h

@@ -7,6 +7,7 @@
 #define BITCOIN_TXMEMPOOL_H
 
 #include <list>
+#include <memory>
 #include <set>
 
 #include "amount.h"
@@ -75,7 +76,7 @@ class CTxMemPool;
 class CTxMemPoolEntry
 {
 private:
-    CTransaction tx;
+    std::shared_ptr<const CTransaction> tx;
     CAmount nFee;              //!< Cached to avoid expensive parent-transaction lookups
     size_t nTxSize;            //!< ... and avoid recomputing tx size
     size_t nModSize;           //!< ... and modified size for priority
@@ -112,7 +113,8 @@ public:
                     unsigned int nSigOps, LockPoints lp);
     CTxMemPoolEntry(const CTxMemPoolEntry& other);
 
-    const CTransaction& GetTx() const { return this->tx; }
+    const CTransaction& GetTx() const { return *this->tx; }
+    std::shared_ptr<const CTransaction> 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.
@@ -307,6 +309,21 @@ struct ancestor_score {};
 
 class CBlockPolicyEstimator;
 
+/**
+ * Information about a mempool transaction.
+ */
+struct TxMempoolInfo
+{
+    /** The transaction itself */
+    std::shared_ptr<const CTransaction> tx;
+
+    /** Time the transaction entered the mempool. */
+    int64_t nTime;
+
+    /** Feerate of the transaction. */
+    CFeeRate feeRate;
+};
+
 /**
  * CTxMemPool stores valid-according-to-the-current-best-chain
  * transactions that may be included in the next block.
@@ -464,6 +481,8 @@ private:
     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, const CTransaction*> mapNextTx;
     std::map<uint256, std::pair<double, CAmount> > mapDeltas;
@@ -589,8 +608,9 @@ public:
     }
 
     bool lookup(uint256 hash, CTransaction& result) const;
-    bool lookup(uint256 hash, CTransaction& result, int64_t& time) const;
-    bool lookupFeeRate(const uint256& hash, CFeeRate& feeRate) const;
+    std::shared_ptr<const CTransaction> get(const uint256& hash) const;
+    TxMempoolInfo info(const uint256& hash) const;
+    std::vector<TxMempoolInfo> infoAll() const;
 
     /** Estimate fee rate needed to get into the next nBlocks
      *  If no answer can be given at nBlocks, return an estimate