beached/json_performance

Performance profiling of JSON libraries

json_performance

Performance profiling of JSON libraries

Latest results (October, 13, 2022):

1,000,000 read and write passes on a single core (MacBook Pro M1)

Library	Runtime (s)	Ratio
Glaze	2.79	1.0
daw_json_link	3.45	1.24
nlohmann json	18.51	6.63

Test object:

{
   "fixed_object": {
      "int_array": [0, 1, 2, 3, 4, 5, 6],
      "float_array": [0.1, 0.2, 0.3, 0.4, 0.5, 0.6],
      "double_array": [3288398.238, 233e22, 289e-1, 0.928759872, 0.22222848, 0.1, 0.2, 0.3, 0.4]
   },
   "fixed_name_object": {
      "name0": "James",
      "name1": "Abraham",
      "name2": "Susan",
      "name3": "Frank",
      "name4": "Alicia"
   },
   "another_object": {
      "string": "here is some text",
      "another_string": "Hello World",
      "boolean": false,
      "nested_object": {
         "v3s": [[0.12345, 0.23456, 0.001345],
                  [0.3894675, 97.39827, 297.92387],
                  [18.18, 87.289, 2988.298]],
         "id": "298728949872"
      }
   },
   "string_array": ["Cat", "Dog", "Elephant", "Tiger"],
   "string": "Hello world",
   "number": 3.14,
   "boolean": true,
   "another_bool": false
}

Registration Comparison

Even with Glaze being the fastest, it is also the cleanest for registration and automatic type deduction. Glaze doesn't require an additional to_json definition.

Glaze

template <>
struct glz::meta<obj_t> {
   using T = obj_t;
   static constexpr auto value = object(
      "fixed_object", &T::fixed_object,
      "fixed_name_object", &T::fixed_name_object,
      "another_object", &T::another_object,
      "string_array", &T::string_array,
      "string", &T::string,
      "number", &T::number,
      "boolean", &T::boolean,
      "another_bool", &T::another_bool
   );
};

daw_json_link

template<>
struct daw::json::json_data_contract<obj_t> {
  using type = json_member_list<
   json_class<"fixed_object", fixed_object_t>,
   json_class<"fixed_name_object", fixed_name_object_t>,
   json_class<"another_object", another_object_t>,
   json_array<"string_array", std::string>,
   json_string<"string", std::string>,
   json_number<"number", double>,
   json_bool<"boolean", bool>,
   json_bool<"another_bool", bool>>;
   
   static constexpr auto to_json_data(const obj_t& v ) {
         return std::forward_as_tuple(v.fixed_object,
                                      v.fixed_name_object,
                                      v.another_object,
                                      v.string_array,
                                      v.string,
                                      v.number,
                                      v.boolean,
                                      v.another_bool);
   }
};

Nlohmann JSON

void to_json(json& j, const obj_t& v) {
   j = json{{"fixed_object", v.fixed_object},
            {"fixed_name_object", v.fixed_name_object},
            {"another_object", v.another_object},
            {"string_array", v.string_array},
            {"string", v.string},
            {"number", v.number},
            {"boolean", v.boolean},
            {"another_bool", v.another_bool}};
}

void from_json(const json& j, obj_t& v) {
   j.at("fixed_object").get_to(v.fixed_object);
   j.at("fixed_name_object").get_to(v.fixed_name_object);
   j.at("another_object").get_to(v.another_object);
   j.at("string_array").get_to(v.string_array);
   j.at("string").get_to(v.string);
   j.at("number").get_to(v.number);
   j.at("boolean").get_to(v.boolean);
   j.at("another_bool").get_to(v.another_bool);
}