Merge bitcoin/bitcoin#24625: Replace struct update_fee_delta with lambda

fa84a49526 Use CAmount for fee delta and modified fee (MarcoFalke)
fa8857c3f7 Replace struct update_fee_delta with lambda (MarcoFalke)

Pull request description:

  The same was done for another struct in e177fcab38.

  Also, change type of feeDelta from int64_t to CAmount.

ACKs for top commit:
  hebasto:
    re-ACK fa84a49526
  promag:
    Code review ACK fa84a49526.

Tree-SHA512: 2b9ee449d348b0f685793a35c6dd3c57ed97fdf707a89495a0518bb332f407303b48723e667351e96f2b698e0a2ade27095517a3accd926d4ec85e58d6fd441f

src/node/miner.h

@@ -45,7 +45,7 @@ struct CTxMemPoolModifiedEntry {
         nSigOpCostWithAncestors = entry->GetSigOpCostWithAncestors();
     }
 
-    int64_t GetModifiedFee() const { return iter->GetModifiedFee(); }
+    CAmount GetModifiedFee() const { return iter->GetModifiedFee(); }
     uint64_t GetSizeWithAncestors() const { return nSizeWithAncestors; }
     CAmount GetModFeesWithAncestors() const { return nModFeesWithAncestors; }
     size_t GetTxSize() const { return iter->GetTxSize(); }

src/txmempool.cpp

@@ -54,16 +54,6 @@ struct update_ancestor_state
         int64_t modifySigOpsCost;
 };
 
-struct update_fee_delta
-{
-    explicit update_fee_delta(int64_t _feeDelta) : feeDelta(_feeDelta) { }
-
-    void operator() (CTxMemPoolEntry &e) { e.UpdateFeeDelta(feeDelta); }
-
-private:
-    int64_t feeDelta;
-};
-
 bool TestLockPointValidity(CChain& active_chain, const LockPoints& lp)
 {
     AssertLockHeld(cs_main);
@@ -99,7 +89,7 @@ CTxMemPoolEntry::CTxMemPoolEntry(const CTransactionRef& tx, CAmount fee,
       nModFeesWithAncestors{nFee},
       nSigOpCostWithAncestors{sigOpCost} {}
 
-void CTxMemPoolEntry::UpdateFeeDelta(int64_t newFeeDelta)
+void CTxMemPoolEntry::UpdateFeeDelta(CAmount newFeeDelta)
 {
     nModFeesWithDescendants += newFeeDelta - feeDelta;
     nModFeesWithAncestors += newFeeDelta - feeDelta;
@@ -496,7 +486,7 @@ void CTxMemPool::addUnchecked(const CTxMemPoolEntry &entry, setEntries &setAnces
     CAmount delta{0};
     ApplyDelta(entry.GetTx().GetHash(), delta);
     if (delta) {
-            mapTx.modify(newit, update_fee_delta(delta));
+        mapTx.modify(newit, [&delta](CTxMemPoolEntry& e) { e.UpdateFeeDelta(delta); });
     }
 
     // Update cachedInnerUsage to include contained transaction's usage.
@@ -931,7 +921,7 @@ void CTxMemPool::PrioritiseTransaction(const uint256& hash, const CAmount& nFeeD
         delta += nFeeDelta;
         txiter it = mapTx.find(hash);
         if (it != mapTx.end()) {
-            mapTx.modify(it, update_fee_delta(delta));
+            mapTx.modify(it, [&delta](CTxMemPoolEntry& e) { e.UpdateFeeDelta(delta); });
             // Now update all ancestors' modified fees with descendants
             setEntries setAncestors;
             uint64_t nNoLimit = std::numeric_limits<uint64_t>::max();

src/txmempool.h

@@ -101,7 +101,7 @@ private:
     const unsigned int entryHeight; //!< Chain height when entering the mempool
     const bool spendsCoinbase;      //!< keep track of transactions that spend a coinbase
     const int64_t sigOpCost;        //!< Total sigop cost
-    int64_t feeDelta{0};            //!< Used for determining the priority of the transaction for mining in a block
+    CAmount feeDelta{0};            //!< 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
@@ -131,7 +131,7 @@ public:
     std::chrono::seconds GetTime() const { return std::chrono::seconds{nTime}; }
     unsigned int GetHeight() const { return entryHeight; }
     int64_t GetSigOpCost() const { return sigOpCost; }
-    int64_t GetModifiedFee() const { return nFee + feeDelta; }
+    CAmount GetModifiedFee() const { return nFee + feeDelta; }
     size_t DynamicMemoryUsage() const { return nUsageSize; }
     const LockPoints& GetLockPoints() const { return lockPoints; }
 
@@ -140,8 +140,8 @@ public:
     // Adjusts the ancestor state
     void UpdateAncestorState(int64_t modifySize, CAmount modifyFee, int64_t modifyCount, int64_t modifySigOps);
     // Updates the fee delta used for mining priority score, and the
-    // modified fees with descendants.
-    void UpdateFeeDelta(int64_t feeDelta);
+    // modified fees with descendants/ancestors.
+    void UpdateFeeDelta(CAmount newFeeDelta);
     // Update the LockPoints after a reorg
     void UpdateLockPoints(const LockPoints& lp);