From b9957bb711c6987e361be6d8b74c70d1759a4f23 Mon Sep 17 00:00:00 2001
From: Siarhei Fedartsou <siarhei.fedartsou@gmail.com>
Date: Fri, 30 Sep 2022 15:36:19 +0200
Subject: [PATCH] Get rid of copy

---
 include/util/json_renderer.hpp | 22 +++++++--------
 include/util/string_util.hpp   |  2 +-
 src/benchmarks/json_render.cpp | 49 ----------------------------------
 3 files changed, 12 insertions(+), 61 deletions(-)

diff --git a/include/util/json_renderer.hpp b/include/util/json_renderer.hpp
index 8081eec53..b17b9bb19 100644
--- a/include/util/json_renderer.hpp
+++ b/include/util/json_renderer.hpp
@@ -35,10 +35,13 @@ template <typename Out> struct Renderer
     {
         write('"');
         auto size = SizeOfEscapedJSONString(string.value);
-        if (size == string.value.size()) {
+        if (size == string.value.size())
+        {
             // we don't need to escape anything
             write(string.value);
-        } else {
+        }
+        else
+        {
             std::string escaped;
             escaped.reserve(size);
             EscapeJSONString(string.value, escaped);
@@ -134,37 +137,34 @@ template <> void Renderer<std::vector<char>>::write(const char *str)
 }
 template <> void Renderer<std::vector<char>>::write(char ch) { out.push_back(ch); }
 
-
 template <> void Renderer<std::ostream>::write(const std::string &str) { out << str; }
 
 template <> void Renderer<std::ostream>::write(const char *str) { out << str; }
 
 template <> void Renderer<std::ostream>::write(char ch) { out << ch; }
 
-
 template <> void Renderer<std::string>::write(const std::string &str) { out += str; }
 
 template <> void Renderer<std::string>::write(const char *str) { out += str; }
 
 template <> void Renderer<std::string>::write(char ch) { out += ch; }
 
-
 inline void render(std::ostream &out, const Object &object)
 {
-    Value value = object;
-    mapbox::util::apply_visitor(Renderer(out), value);
+    Renderer renderer(out);
+    renderer(object);
 }
 
 inline void render(std::string &out, const Object &object)
 {
-    Value value = object;
-    mapbox::util::apply_visitor(Renderer(out), value);
+    Renderer renderer(out);
+    renderer(object);
 }
 
 inline void render(std::vector<char> &out, const Object &object)
 {
-    Value value = object;
-    mapbox::util::apply_visitor(Renderer(out), value);
+    Renderer renderer(out);
+    renderer(object);
 }
 
 } // namespace json
diff --git a/include/util/string_util.hpp b/include/util/string_util.hpp
index d07753b9c..477ea55e4 100644
--- a/include/util/string_util.hpp
+++ b/include/util/string_util.hpp
@@ -82,7 +82,7 @@ inline size_t SizeOfEscapedJSONString(const std::string &string)
     return size;
 }
 
-inline void EscapeJSONString(const std::string &input, std::string& output)
+inline void EscapeJSONString(const std::string &input, std::string &output)
 {
     for (const char letter : input)
     {
diff --git a/src/benchmarks/json_render.cpp b/src/benchmarks/json_render.cpp
index d76d9e54b..908d54a92 100644
--- a/src/benchmarks/json_render.cpp
+++ b/src/benchmarks/json_render.cpp
@@ -8,50 +8,6 @@
 #include <sstream>
 #include <stdexcept>
 
-// #ifdef _WIN32
-// #pragma optimize("", off)
-// template <class T> void dont_optimize_away(T &&datum) { T local = datum; }
-// #pragma optimize("", on)
-// #else
-// template <class T> void dont_optimize_away(T &&datum) { asm volatile("" : "+r"(datum)); }
-// #endif
-
-// template <std::size_t num_rounds, std::size_t num_entries, typename VectorT>
-// auto measure_random_access()
-// {
-//     std::vector<std::size_t> indices(num_entries);
-//     std::iota(indices.begin(), indices.end(), 0);
-//     std::mt19937 g(1337);
-//     std::shuffle(indices.begin(), indices.end(), g);
-
-//     VectorT vector(num_entries);
-
-//     TIMER_START(write);
-//     for (auto round : util::irange<std::size_t>(0, num_rounds))
-//     {
-//         for (auto idx : util::irange<std::size_t>(0, num_entries))
-//         {
-//             vector[indices[idx]] = idx + round;
-//         }
-//     }
-//     TIMER_STOP(write);
-
-//     TIMER_START(read);
-//     auto sum = 0;
-//     for (auto round : util::irange<std::size_t>(0, num_rounds))
-//     {
-//         sum = round;
-//         for (auto idx : util::irange<std::size_t>(0, num_entries))
-//         {
-//             sum += vector[indices[idx]];
-//         }
-//         dont_optimize_away(sum);
-//     }
-//     TIMER_STOP(read);
-
-//     return Measurement{TIMER_MSEC(write), TIMER_MSEC(read)};
-// }
-
 int main(int, char **)
 {
     using namespace osrm;
@@ -150,10 +106,5 @@ int main(int, char **)
     TIMER_STOP(vector);
     std::cout << "Vector: " << TIMER_MSEC(vector) << "ms" << std::endl;
 
-    if (std::string{out_vec.begin(), out_vec.end()} != out_str || out_str != out_ss_str) {
-        throw std::logic_error("Vector and string are not equal");
-    }
-    // (void)s;
-    // std::cerr << ss << "\n";
     return EXIT_SUCCESS;
 }