Structure Packing Optimizations in C{,Mutable}Transaction #8330

 432 | @@ -433,15 +433,14 @@ class CTransaction
 433 |  
 434 |      void UpdateHash() const;
 435 |  };
 436 | -

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 109 | +    // Space that is typically used as padding. Commented out so that it doesn't cause extra memory use on different architectures.
 110 | +    // char PADDING_FREE_SPACE[2];
 111 | +
 112 | +    // Bool flags
 113 | +    struct CTxMemPoolEntryFlags {
 114 | +        int UNUSED_BITS : 6;

---

  88 | @@ -94,7 +89,17 @@ class CTxMemPoolEntry
  89 |      uint64_t nSizeWithAncestors;
  90 |      CAmount nModFeesWithAncestors;
  91 |      int64_t nSigOpCostWithAncestors;
  92 | +    size_t nTxWeight;          //!< ... and avoid recomputing tx weight (also used for GetTxSize())
  93 | +    size_t nModSize;           //!< ... and modified size for priority

---

  96 | +    mutable size_t vTxHashesIdx; //!< Index in mempool's vTxHashes
  97 | +private:
  98 | +    unsigned int entryHeight;  //!< Chain height when entering the mempool
  99 |  
 100 | +    // Bool flags
 101 | +    bool hadNoDependencies;    //!< Not dependent on any other txs when it entered the mempool

---

  75 | @@ -76,9 +76,12 @@ uint256 CTransaction::GetWitnessHash() const
  76 |  }
  77 |  
  78 |  /* For backward compatibility, the hash is initialized to 0. TODO: remove the need for this default constructor entirely. */
  79 | -CTransaction::CTransaction() : nVersion(CTransaction::CURRENT_VERSION), vin(), vout(), nLockTime(0), hash() {}
  80 | -CTransaction::CTransaction(const CMutableTransaction &tx) : nVersion(tx.nVersion), vin(tx.vin), vout(tx.vout), nLockTime(tx.nLockTime), hash(ComputeHash()) {}

---

 105 |      // Bool flags
 106 | -    bool hadNoDependencies;    //!< Not dependent on any other txs when it entered the mempool
 107 | -    bool spendsCoinbase;       //!< keep track of transactions that spend a coinbase
 108 | +    struct CTxMemPoolEntryFlags {
 109 | +        //int UNUSED_BITS : 7;
 110 | +        bool spendsCoinbase : 1;       //!< keep track of transactions that spend a coinbase

---

  19 | @@ -20,9 +20,10 @@
  20 |  
  21 |  CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef& _tx, const CAmount& _nFee,
  22 |                                   int64_t _nTime, unsigned int _entryHeight,
  23 | -                                 bool _spendsCoinbase, int64_t _sigOpsCost, LockPoints lp):
  24 | -    tx(_tx), nFee(_nFee), nTime(_nTime), entryHeight(_entryHeight),
  25 | -    spendsCoinbase(_spendsCoinbase), sigOpCost(_sigOpsCost), lockPoints(lp)
  26 | +                                 bool _spendsCoinbase, int64_t _sigOpsCost, LockPoints lp): 
  27 | +lockPoints(lp), tx(_tx), nFee(_nFee)

---

 105 | +    // Bool flags
 106 | +    struct CTxMemPoolEntryFlags {
 107 | +        //int UNUSED_BITS : 7;
 108 | +        bool spendsCoinbase : 1;       //!< keep track of transactions that spend a coinbase
 109 | +    };
 110 | +    CTxMemPoolEntryFlags flags;

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