Switch CTransaction storage in mempool to std::shared_ptr

src/txmempool.h

@@ -7,6 +7,7 @@
 #define BITCOIN_TXMEMPOOL_H
 
 #include <list>
+#include <memory>
 #include <set>
 
 #include "amount.h"
@@ -75,20 +76,20 @@ class CTxMemPool;
 class CTxMemPoolEntry
 {
 private:
-    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
-    size_t nUsageSize; //! ... and total memory usage
-    int64_t nTime; //! Local time when entering the mempool
-    double entryPriority; //! Priority when entering the mempool
-    unsigned int entryHeight; //! Chain height when entering the mempool
-    bool hadNoDependencies; //! Not dependent on any other txs when it entered the mempool
-    CAmount inChainInputValue; //! Sum of all txin values that are already in blockchain
-    bool spendsCoinbase; //! keep track of transactions that spend a coinbase
-    unsigned int sigOpCount; //! Legacy sig ops plus P2SH sig op count
-    int64_t feeDelta; //! Used for determining the priority of the transaction for mining in a block
-    LockPoints lockPoints; //! Track the height and time at which tx was final
+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
+    size_t nUsageSize;         //!< ... and total memory usage
+    int64_t nTime;             //!< Local time when entering the mempool
+    double entryPriority;      //!< Priority when entering the mempool
+    unsigned int entryHeight;  //!< Chain height when entering the mempool
+    bool hadNoDependencies;    //!< Not dependent on any other txs when it entered the mempool
+    CAmount inChainInputValue; //!< Sum of all txin values that are already in blockchain
+    bool spendsCoinbase;       //!< keep track of transactions that spend a coinbase
+    unsigned int sigOpCount;   //!< Legacy sig ops plus P2SH sig op count
+    int64_t feeDelta;          //!< Used for determining the priority of the transaction for mining in a block
+    LockPoints lockPoints;     //!< Track the height and time at which tx was final
 
     // Information about descendants of this transaction that are in the
     // mempool; if we remove this transaction we must remove all of these
@@ -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.
@@ -309,6 +311,21 @@ 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.
@@ -469,6 +486,8 @@ 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;
@@ -597,8 +616,9 @@ 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