Merge #8498: Near-Bugfix: Optimization: Minimize the number of times it is checked that no money...

4e955c5 Near-Bugfix: Reestablish consensus check removed in 8d7849b (Jorge Timón)
3e8c916 Introduce CheckInputsAndUpdateCoins static wrapper in txmempool.cpp (Jorge Timón)
832e074 Optimization: Minimize the number of times it is checked that no money is created (Jorge Timón)
3f0ee3e Proper indentation for CheckTxInputs and other minor fixes (Jorge Timón)

Pull request description:

  ...is created by individual transactions to 2 places (but call only once in each):

  - ConnectBlock ( before calculated fees per txs twice )
  - AcceptToMemoryPoolWorker ( before called CheckTxInputs 4 times and calculated
     fees per tx one extra time )

  Also call tx.GetValueOut() only once per call of CheckTxInputs (instead of 2)

  For more motivation:

  ~~https://github.com/bitcoin/bitcoin/blob/master/src/main.cpp#L1493~~
  https://github.com/jtimon/bitcoin/compare/0.13-consensus-inputs...jtimon:0.13-consensus-inputs-comments

  EDIT: partially replaces #6445

  Near-Bugfix as pointed out in https://github.com/bitcoin/bitcoin/pull/8498#discussion_r124346132

Tree-SHA512: c71188e7c7c2425c9170ed7b803896755a92fd22f43b136eedaa6e554106696f0b10271d0ef0d0127c1eaafbc31d12eb19143df4f1b6882feecedf6ef05ea346

1 files changed, 12 insertions, 10 deletions

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 776d3f36ca..b0306811cb 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -607,6 +607,15 @@ void CTxMemPool::clear()
     _clear();
 }
 
+static void CheckInputsAndUpdateCoins(const CTransaction& tx, CCoinsViewCache& mempoolDuplicate, const int64_t spendheight)
+{
+    CValidationState state;
+    CAmount txfee = 0;
+    bool fCheckResult = tx.IsCoinBase() || Consensus::CheckTxInputs(tx, state, mempoolDuplicate, spendheight, txfee);
+    assert(fCheckResult);
+    UpdateCoins(tx, mempoolDuplicate, 1000000);
+}
+
 void CTxMemPool::check(const CCoinsViewCache *pcoins) const
 {
     if (nCheckFrequency == 0)
@@ -621,7 +630,7 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
     uint64_t innerUsage = 0;
 
     CCoinsViewCache mempoolDuplicate(const_cast<CCoinsViewCache*>(pcoins));
-    const int64_t nSpendHeight = GetSpendHeight(mempoolDuplicate);
+    const int64_t spendheight = GetSpendHeight(mempoolDuplicate);
 
     LOCK(cs);
     std::list<const CTxMemPoolEntry*> waitingOnDependants;
@@ -700,11 +709,7 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
         if (fDependsWait)
             waitingOnDependants.push_back(&(*it));
         else {
-            CValidationState state;
-            bool fCheckResult = tx.IsCoinBase() ||
-                Consensus::CheckTxInputs(tx, state, mempoolDuplicate, nSpendHeight);
-            assert(fCheckResult);
-            UpdateCoins(tx, mempoolDuplicate, 1000000);
+            CheckInputsAndUpdateCoins(tx, mempoolDuplicate, spendheight);
         }
     }
     unsigned int stepsSinceLastRemove = 0;
@@ -717,10 +722,7 @@ void CTxMemPool::check(const CCoinsViewCache *pcoins) const
             stepsSinceLastRemove++;
             assert(stepsSinceLastRemove < waitingOnDependants.size());
         } else {
-            bool fCheckResult = entry->GetTx().IsCoinBase() ||
-                Consensus::CheckTxInputs(entry->GetTx(), state, mempoolDuplicate, nSpendHeight);
-            assert(fCheckResult);
-            UpdateCoins(entry->GetTx(), mempoolDuplicate, 1000000);
+            CheckInputsAndUpdateCoins(entry->GetTx(), mempoolDuplicate, spendheight);
             stepsSinceLastRemove = 0;
         }
     }