Sonic-Cpp

---

A fast JSON serializing & deserializing library, accelerated by SIMD.

Requirement

• c++11 or above
• x86 platform with AVX2 instruction
• GCC or LLVM compiler (not support MSVC compiler now)
• Linux OS

Features

• Complete APIs for JSON value manipulation
• Fast on JSON serializing and parsing
• Support parse ondemand

Benchmarks

• use CMake

  cmake -S . -B build -DBUILD_BENCH=ON
  cmake --build build --target bench -j
  ./build/benchmark/bench

• use bazel

  bazel run :benchmark --compilation_mode=opt

Performance by sonic benchmark

• Run

# build by bazel
python3 ./scripts/tools/draw-decode-encode.py

• Result

Parsing Performance

Serializing performance

Performance by third-party benchmark

Below data is test by https://github.com/miloyip/nativejson-benchmark:

Parsing Performance

Serializing Performance

API Document

Make sure Doxygen 1.8.13 or higher version has been installed. Then following:

mdkir api-doc && cd api-doc
doxygen ../Doxyfile

Design

Sonic-cpp parses JSON into a compact document tree. The document structure is as follows:

There are many optimizations in parsing as follows:

• using SIMD to accelerate skipping white space.
• using SIMD to find escaped chars when parsing strings.
• using the STOA float pointing algorithm.

Sonic-cpp serializes a document to JSON. When serializing JSON strings, we should check the escaped characters first. So, we use SIMD instructions(AVX2/SSE) to find the escaped char for a long JSON string.

Sonic-cpp also supports ParseOnDemand if the user knows the target key at compile time. ParseOndemand also used SIMD and bit manipulation to skip the unwanted values fastly.

Usage

Include

Sonic-Cpp is a header-only library, you only need to include the directory of Sonic-Cpp header files, such as adding -I/path/to/sonic/include/ to your compiler.

Parsing and Serializing

#include "sonic/sonic.h"

#include <string>
#include <iostream>

int main()
{
  std::string json = R"(
    {
      "a": 1,
      "b": 2
    }
  )";

  sonic_json::Document doc;
  doc.Parse(json);

  sonic_json::WriteBuffer wb;
  doc.Serialize(wb);
  std::cout << wb.ToString() << std::endl;
}
// g++ -I./include/ -march=haswell --std=c++11 -O3 example/parse_and_serialize.cpp -o example/parse_and_serialize

Checking parse result

#include "sonic/sonic.h"

#include <string>
#include <iostream>

int main()
{
  std::string json = R"(
    {
      "a": 1,
      "b": 2
    }
  )";

  sonic_json::Document doc;
  doc.Parse(json);
  if (doc.HasParseError()) {
    std::cout << "Parse failed!\n";
  } else {
    std::cout << "Parse successful!\n";
  }
  return 0;
}
// g++ -I./include/ -march=haswell --std=c++11 -O3 example/check_parse_result.cpp -o example/check_parse_result

Getting and Setting

#include "sonic/sonic.h"

#include <string>
#include <iostream>

using member_itr_type = typename sonic_json::Document::MemberIterator;

void print_member(member_itr_type m) {
  const sonic_json::Node& key = m->name;
  sonic_json::Node& value = m->value;
  if (key.IsString()) {
    std::cout << "Key is: "
              << key.GetString()
              << std::endl;
  } else {
    std::cout << "Incorrect key type!\n";
    return;
  }
  if (value.IsInt64()) {
    std::cout << "Value is " << value.GetInt64() << std::endl;
  }

  return;
}

void set_new_value(member_itr_type m) {
  sonic_json::Node& value = m->value;
  value.SetInt64(2);
  return;
}

int main()
{
  std::string json = R"(
    {
      "a": 1,
      "b": 2
    }
  )";

  sonic_json::Document doc;
  doc.Parse(json);

  if (doc.HasParseError()) {
    std::cout << "Parse failed!\n";
    return -1;
  }

  // Find member by key
  if (!doc.IsObject()) { // Check JSON value type.
    std::cout << "Incorrect doc type!\n";
    return -1;
  }
  auto m = doc.FindMember("a");
  if (m != doc.MemberEnd()) {
    std::cout << "Before Setting new value:\n";
    print_member(m);
    std::cout << "After Setting value:\n";
    set_new_value(m);
    print_member(m);
  } else {
    std::cout << "Find key doesn't exist!\n";
  }
  return 0;
}
// g++ -I./include/ -march=haswell --std=c++11 -O3 example/get_and_set.cpp -o example/get_and_set

The following Is*, Get* and Set* methods are supported:

• IsNull(), SetNull()
• IsBool(), GetBool(), SetBool(bool)
• IsString(), GetString(), GetStringView(), SetString(const char*, size_t)
• IsNumber()
• IsArray(), SetArray()
• IsObject(), SetObject()
• IsTrue(), IsFalse()
• IsDouble(), GetDouble(), SetDouble(double)
• IsInt64(), GetInt64(), SetInt64(int64_t)
• IsUint64(), GetUint64(), SetUint64_t(uint64_t)

---

More usage.

RoadMap

• Support RawNumber for JSON parsing.
• Support JSON Path.
• Support JSON Merge Patch.
• Support JSON Pointer.
• Support more platforms, e.g. ARM.
• Support struct bind.
• Support validating UTF-8.

Contributing

Please read CONTRIBUTING.md for information on contributing to sonic-cpp.