From 218e2ea91210fd6fa9149dcac16ec172226b09fb Mon Sep 17 00:00:00 2001
From: Peter Todd <pete@petertodd.org>
Date: Wed, 21 Aug 2013 12:30:32 -0400
Subject: [PATCH] Don't waste work on slow peers until they catch up

---
 src/main.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index a90af4898e..06fea7446e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -3068,6 +3068,12 @@ void static ProcessGetData(CNode* pfrom)
         if (pfrom->nSendSize >= SendBufferSize())
             break;
 
+        // Don't waste work on slow peers until they catch up on the blocks we
+        // give them. 80 bytes is just the size of a block header - obviously
+        // the minimum we might return.
+        if (pfrom->nBlocksRequested * 80 > pfrom->nSendBytes)
+            break;
+
         const CInv &inv = *it;
         {
             boost::this_thread::interruption_point();