Make CTxMemPool::remove more effecient by avoiding recursion

Author: TheBlueMatt

src/txmempool.cpp

@@ -427,26 +427,32 @@ bool CTxMemPool::addUnchecked(const uint256& hash, const CTxMemPoolEntry &entry)
 }
 
 
-void CTxMemPool::remove(const CTransaction &tx, std::list<CTransaction>& removed, bool fRecursive)
+void CTxMemPool::remove(const CTransaction &origTx, std::list<CTransaction>& removed, bool fRecursive)
 {
     // Remove transaction from memory pool
     {
         LOCK(cs);
-        uint256 hash = tx.GetHash();
-        if (fRecursive) {
-            for (unsigned int i = 0; i < tx.vout.size(); i++) {
-                std::map<COutPoint, CInPoint>::iterator it = mapNextTx.find(COutPoint(hash, i));
-                if (it == mapNextTx.end())
-                    continue;
-                remove(*it->second.ptx, removed, true);
-            }
-        }
-        if (mapTx.count(hash))
+        std::deque<uint256> txToRemove;
+        txToRemove.push_back(origTx.GetHash());
+        while (!txToRemove.empty())
         {
-            removed.push_front(tx);
+            uint256 hash = txToRemove.front();
+            txToRemove.pop_front();
+            if (!mapTx.count(hash))
+                continue;
+            const CTransaction& tx = mapTx[hash].GetTx();
+            if (fRecursive) {
+                for (unsigned int i = 0; i < tx.vout.size(); i++) {
+                    std::map<COutPoint, CInPoint>::iterator it = mapNextTx.find(COutPoint(hash, i));
+                    if (it == mapNextTx.end())
+                        continue;
+                    txToRemove.push_back(it->second.ptx->GetHash());
+                }
+            }
             BOOST_FOREACH(const CTxIn& txin, tx.vin)
                 mapNextTx.erase(txin.prevout);
 
+            removed.push_back(tx);
             totalTxSize -= mapTx[hash].GetTxSize();
             mapTx.erase(hash);
             nTransactionsUpdated++;