From 95d9cb8357d8950b89d3d7bc98cb7a0bd03a1247 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ezgi=20=C3=87i=C3=A7ek?= <ezgi@fb.com>
Date: Fri, 11 Feb 2022 09:14:30 -0800
Subject: [PATCH] Avoid unnecessary copy of sample_slice map (#9551)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9551

Reviewed By: riversand963

Differential Revision: D34169574

Pulled By: ezgicicek

fbshipit-source-id: 2e88db59b65bda269917a9b0bed17181a4afd281
---
 db/db_impl/db_impl.cc | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/db/db_impl/db_impl.cc b/db/db_impl/db_impl.cc
index ec0275cc3..03fa01da5 100644
--- a/db/db_impl/db_impl.cc
+++ b/db/db_impl/db_impl.cc
@@ -784,8 +784,7 @@ size_t DBImpl::EstimateInMemoryStatsHistorySize() const {
   size_t size_per_slice =
       sizeof(uint64_t) + sizeof(std::map<std::string, uint64_t>);
   // non-empty map, stats_history_.begin() guaranteed to exist
-  std::map<std::string, uint64_t> sample_slice(stats_history_.begin()->second);
-  for (const auto& pairs : sample_slice) {
+  for (const auto& pairs : stats_history_.begin()->second) {
     size_per_slice +=
         pairs.first.capacity() + sizeof(pairs.first) + sizeof(pairs.second);
   }