From 23123a0166bd33ce56d1cbea778bdfacf746e7d7 Mon Sep 17 00:00:00 2001
From: Ben Maurer <bmaurer@fb.com>
Date: Mon, 25 Nov 2013 11:28:40 -0800
Subject: [PATCH] Avoid copy in folly::toJson
Summary: Adding const avoids a copy constuctor.
Test Plan:
Unit tests, new benchmark:
toJson 1.83us 546.15K
toJson 1.54us 649.98K
Reviewed By: tudorb@fb.com
FB internal diff: D1071781
---
folly/json.cpp | 2 +-
folly/test/JsonTest.cpp | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/folly/json.cpp b/folly/json.cpp
index 7711a203..5fe44a59 100644
--- a/folly/json.cpp
+++ b/folly/json.cpp
@@ -149,7 +149,7 @@ struct Printer {
}
private:
- void printKV(const std::pair<dynamic, dynamic>& p) const {
+ void printKV(const std::pair<const dynamic, dynamic>& p) const {
if (!opts_.allow_non_string_keys && !p.first.isString()) {
throw std::runtime_error("folly::toJson: JSON object key was not a "
"string");
diff --git a/folly/test/JsonTest.cpp b/folly/test/JsonTest.cpp
index 6ab97686..cfa84f4c 100644
--- a/folly/test/JsonTest.cpp
+++ b/folly/test/JsonTest.cpp
@@ -419,6 +419,16 @@ BENCHMARK(parseBigString, iters) {
}
}
+BENCHMARK(toJson, iters) {
+ dynamic something = parseJson(
+ "{\"old_value\":40,\"changed\":true,\"opened\":false,\"foo\":[1,2,3,4,5,6]}"
+ );
+
+ for (int i = 0; i < iters; i++) {
+ toJson(something);
+ }
+}
+
int main(int argc, char** argv) {
testing::InitGoogleTest(&argc, argv);
google::ParseCommandLineFlags(&argc, &argv, true);
--
2.34.1