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>intmain()
{
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>intmain()
{
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";
}
return0;
}
// 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;
voidprint_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;
}
voidset_new_value(member_itr_type m) {
sonic_json::Node& value = m->value;
value.SetInt64(2);
return;
}
intmain()
{
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 keyif (!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";
}
return0;
}
// 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.