From 03a472ea080e98b26d50efd1548bb47a90ca556e Mon Sep 17 00:00:00 2001
From: Marcin Kowalczyk <qrczak@google.com>
Date: Mon, 26 Feb 2024 09:36:14 -0800
Subject: [PATCH] Optimize `Reflection::ScratchSpace::CopyFromCord()`.

If the Cord is already flat, return a pointer to its data instead of copying
them to a string.

PiperOrigin-RevId: 610434454
---
 src/google/protobuf/message.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/google/protobuf/message.h b/src/google/protobuf/message.h
index aa46aa9b79..6c9872ab3b 100644
--- a/src/google/protobuf/message.h
+++ b/src/google/protobuf/message.h
@@ -101,6 +101,7 @@
 #include "absl/memory/memory.h"
 #include "absl/strings/cord.h"
 #include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
 #include "google/protobuf/arena.h"
 #include "google/protobuf/descriptor.h"
 #include "google/protobuf/generated_message_reflection.h"
@@ -601,6 +602,9 @@ class PROTOBUF_EXPORT Reflection final {
     friend class Reflection;
 
     absl::string_view CopyFromCord(const absl::Cord& cord) {
+      if (absl::optional<absl::string_view> flat = cord.TryFlat()) {
+        return *flat;
+      }
       if (!buffer_) {
         buffer_ = absl::make_unique<std::string>();
       }