From c6cb6f7d4c4bbfe96256c66b3aef4e7e3ff6285f Mon Sep 17 00:00:00 2001
From: Alex Morcos <morcos@chaincode.com>
Date: Wed, 13 Apr 2016 16:02:46 -0400
Subject: [PATCH] Avoid unnecessary database access for unknown transactions

---
 src/main.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main.cpp b/src/main.cpp
index 9b164c799..f5baf3559 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -4344,10 +4344,12 @@ bool static AlreadyHave(const CInv& inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
                 recentRejects->reset();
             }
 
+            // Use pcoinsTip->HaveCoinsInCache as a quick approximation to exclude
+            // requesting or processing some txs which have already been included in a block
             return recentRejects->contains(inv.hash) ||
                    mempool.exists(inv.hash) ||
                    mapOrphanTransactions.count(inv.hash) ||
-                   pcoinsTip->HaveCoins(inv.hash);
+                   pcoinsTip->HaveCoinsInCache(inv.hash);
         }
     case MSG_BLOCK:
         return mapBlockIndex.count(inv.hash);