Avoid repeated lookups in mapOrphanTransactions and mapOrphanTransactionsByPrev

Rebased-From: 89d91f6
Rebased-By: Wladimir J. van der Laan <laanwj@gmail.com>

src/main.cpp

@@ -318,16 +318,17 @@ bool AddOrphanTx(const CTransaction& tx)
 
 void static EraseOrphanTx(uint256 hash)
 {
-    if (!mapOrphanTransactions.count(hash))
+    map<uint256, CTransaction>::iterator it = mapOrphanTransactions.find(hash);
+    if (it == mapOrphanTransactions.end())
         return;
-    const CTransaction& tx = mapOrphanTransactions[hash];
-    BOOST_FOREACH(const CTxIn& txin, tx.vin)
+    BOOST_FOREACH(const CTxIn& txin, it->second.vin)
     {
-        mapOrphanTransactionsByPrev[txin.prevout.hash].erase(hash);
-        if (mapOrphanTransactionsByPrev[txin.prevout.hash].empty())
-            mapOrphanTransactionsByPrev.erase(txin.prevout.hash);
+        map<uint256, set<uint256> >::iterator itPrev = mapOrphanTransactionsByPrev.find(txin.prevout.hash);
+        itPrev->second.erase(hash);
+        if (itPrev->second.empty())
+            mapOrphanTransactionsByPrev.erase(itPrev);
     }
-    mapOrphanTransactions.erase(hash);
+    mapOrphanTransactions.erase(it);
 }
 
 unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
@@ -3585,9 +3586,11 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
             // Recursively process any orphan transactions that depended on this one
             for (unsigned int i = 0; i < vWorkQueue.size(); i++)
             {
-                uint256 hashPrev = vWorkQueue[i];
-                for (set<uint256>::iterator mi = mapOrphanTransactionsByPrev[hashPrev].begin();
-                     mi != mapOrphanTransactionsByPrev[hashPrev].end();
+                map<uint256, set<uint256> >::iterator itByPrev = mapOrphanTransactionsByPrev.find(vWorkQueue[i]);
+                if (itByPrev == mapOrphanTransactionsByPrev.end())
+                    continue;
+                for (set<uint256>::iterator mi = itByPrev->second.begin();
+                     mi != itByPrev->second.end();
                      ++mi)
                 {
                     const uint256& orphanHash = *mi;