From 201f8eea1af7d2dc957257dd33c87938ba00ee93 Mon Sep 17 00:00:00 2001
From: Alexander Block <ablock84@gmail.com>
Date: Tue, 7 Apr 2020 06:47:16 +0200
Subject: [PATCH] Optimize vInv.reserve in SendMessages

1. Don't call it while holding cs_invetory
2. Also take setInventoryTxToSend.size() into account
---
 src/net_processing.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index bcf4521ea3..4e0d7322cb 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3812,8 +3812,12 @@ bool PeerLogicValidation::SendMessages(CNode* pto, std::atomic<bool>& interruptM
         //
         std::vector<CInv> vInv;
         {
+            size_t reserve = std::min<size_t>(pto->setInventoryTxToSend.size(), INVENTORY_BROADCAST_MAX_PER_1MB_BLOCK * MaxBlockSize(true) / 1000000);
+            reserve = std::max<size_t>(reserve, pto->vInventoryBlockToSend.size());
+            reserve = std::min<size_t>(reserve, MAX_INV_SZ);
+            vInv.reserve(reserve);
+
             LOCK(pto->cs_inventory);
-            vInv.reserve(std::max<size_t>(pto->vInventoryBlockToSend.size(), INVENTORY_BROADCAST_MAX_PER_1MB_BLOCK * MaxBlockSize(true) / 1000000));
 
             // Add blocks
             for (const uint256& hash : pto->vInventoryBlockToSend) {