Merge bitcoin/bitcoin#26048: mempool clean up: replace update_* structs with lambdas

1b348d2 [mempool] replace update_descendant_state with lambda (glozow)

Pull request description:

  These were introduced in commit bitcoin/bitcoin@5add7a7, when the codebase was pre-C++11. We can use lambdas now.

ACKs for top commit:
  MarcoFalke:
    review ACK 1b348d2 👮
  w0xlt:
    ACK bitcoin/bitcoin@1b348d2

Tree-SHA512: b664425b395e39ecf1cfc1e731200378261cf58c3985075fdc6027731a5caf995de72ea25be99b4c0dbec2e3ee6cf940e7c577638844619c66c8494ead5da459

Author: MacroFake

src/txmempool.cpp

@@ -24,38 +24,6 @@
 #include <cmath>
 #include <optional>
 
-// 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, int64_t _modifySigOpsCost) :
-        modifySize(_modifySize), modifyFee(_modifyFee), modifyCount(_modifyCount), modifySigOpsCost(_modifySigOpsCost)
-    {}
-
-    void operator() (CTxMemPoolEntry &e)
-        { e.UpdateAncestorState(modifySize, modifyFee, modifyCount, modifySigOpsCost); }
-
-    private:
-        int64_t modifySize;
-        CAmount modifyFee;
-        int64_t modifyCount;
-        int64_t modifySigOpsCost;
-};
-
 bool TestLockPointValidity(CChain& active_chain, const LockPoints& lp)
 {
     AssertLockHeld(cs_main);
@@ -146,7 +114,9 @@ void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendan
             modifyCount++;
             cachedDescendants[updateIt].insert(mapTx.iterator_to(descendant));
             // Update ancestor state for each descendant
-            mapTx.modify(mapTx.iterator_to(descendant), update_ancestor_state(updateIt->GetTxSize(), updateIt->GetModifiedFee(), 1, updateIt->GetSigOpCost()));
+            mapTx.modify(mapTx.iterator_to(descendant), [=](CTxMemPoolEntry& e) {
+              e.UpdateAncestorState(updateIt->GetTxSize(), updateIt->GetModifiedFee(), 1, updateIt->GetSigOpCost());
+            });
             // Don't directly remove the transaction here -- doing so would
             // invalidate iterators in cachedDescendants. Mark it for removal
             // by inserting into descendants_to_remove.
@@ -155,7 +125,7 @@ void CTxMemPool::UpdateForDescendants(txiter updateIt, cacheMap& cachedDescendan
             }
         }
     }
-    mapTx.modify(updateIt, update_descendant_state(modifySize, modifyFee, modifyCount));
+    mapTx.modify(updateIt, [=](CTxMemPoolEntry& e) { e.UpdateDescendantState(modifySize, modifyFee, modifyCount); });
 }
 
 void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256>& vHashesToUpdate)
@@ -347,7 +317,7 @@ void CTxMemPool::UpdateAncestorsOf(bool add, txiter it, setEntries &setAncestors
     const int64_t updateSize = updateCount * it->GetTxSize();
     const CAmount updateFee = updateCount * it->GetModifiedFee();
     for (txiter ancestorIt : setAncestors) {
-        mapTx.modify(ancestorIt, update_descendant_state(updateSize, updateFee, updateCount));
+        mapTx.modify(ancestorIt, [=](CTxMemPoolEntry& e) { e.UpdateDescendantState(updateSize, updateFee, updateCount); });
     }
 }
 
@@ -362,7 +332,7 @@ void CTxMemPool::UpdateEntryForAncestors(txiter it, const setEntries &setAncesto
         updateFee += ancestorIt->GetModifiedFee();
         updateSigOpsCost += ancestorIt->GetSigOpCost();
     }
-    mapTx.modify(it, update_ancestor_state(updateSize, updateFee, updateCount, updateSigOpsCost));
+    mapTx.modify(it, [=](CTxMemPoolEntry& e){ e.UpdateAncestorState(updateSize, updateFee, updateCount, updateSigOpsCost); });
 }
 
 void CTxMemPool::UpdateChildrenForRemoval(txiter it)
@@ -393,7 +363,7 @@ void CTxMemPool::UpdateForRemoveFromMempool(const setEntries &entriesToRemove, b
             CAmount modifyFee = -removeIt->GetModifiedFee();
             int modifySigOps = -removeIt->GetSigOpCost();
             for (txiter dit : setDescendants) {
-                mapTx.modify(dit, update_ancestor_state(modifySize, modifyFee, -1, modifySigOps));
+                mapTx.modify(dit, [=](CTxMemPoolEntry& e){ e.UpdateAncestorState(modifySize, modifyFee, -1, modifySigOps); });
             }
         }
     }
@@ -942,14 +912,14 @@ void CTxMemPool::PrioritiseTransaction(const uint256& hash, const CAmount& nFeeD
             std::string dummy;
             CalculateMemPoolAncestors(*it, setAncestors, nNoLimit, nNoLimit, nNoLimit, nNoLimit, dummy, false);
             for (txiter ancestorIt : setAncestors) {
-                mapTx.modify(ancestorIt, update_descendant_state(0, nFeeDelta, 0));
+                mapTx.modify(ancestorIt, [=](CTxMemPoolEntry& e){ e.UpdateDescendantState(0, nFeeDelta, 0);});
             }
             // Now update all descendants' modified fees with ancestors
             setEntries setDescendants;
             CalculateDescendants(it, setDescendants);
             setDescendants.erase(it);
             for (txiter descendantIt : setDescendants) {
-                mapTx.modify(descendantIt, update_ancestor_state(0, nFeeDelta, 0, 0));
+                mapTx.modify(descendantIt, [=](CTxMemPoolEntry& e){ e.UpdateAncestorState(0, nFeeDelta, 0, 0); });
             }
             ++nTransactionsUpdated;
         }