Pros of simdjson

• Extremely fast JSON parsing, leveraging SIMD instructions
• Language-agnostic C++ implementation with bindings for multiple languages
• Designed for handling large JSON files efficiently

Cons of simdjson

• Focused solely on JSON parsing, lacking serialization capabilities
• May have a steeper learning curve for integration compared to OJ
• Limited to JSON-specific operations

Code Comparison

simdjson:

#include "simdjson.h"
using namespace simdjson;
ondemand::parser parser;
auto json = padded_string::load("large.json");
ondemand::document doc = parser.iterate(json);

OJ:

require 'oj'
json = File.read('large.json')
parsed = Oj.load(json)

Key Differences

• simdjson is primarily a C++ library with a focus on high-performance JSON parsing
• OJ is a Ruby-specific gem that offers both parsing and serialization
• simdjson excels at handling large JSON files with minimal memory usage
• OJ provides a more comprehensive JSON toolkit for Ruby developers
• simdjson's performance benefits are most noticeable with larger JSON payloads
• OJ offers easier integration and a wider range of features for Ruby projects

Pros of rapidjson

• Supports both SAX and DOM parsing styles, offering more flexibility
• Generally faster performance, especially for parsing large JSON documents
• More extensive documentation and examples available

Cons of rapidjson

• Larger codebase and more complex API, potentially steeper learning curve
• C++ only, while oj supports both C and Ruby

Code Comparison

oj (Ruby):

require 'oj'
json = Oj.dump({ foo: 'bar' })
parsed = Oj.load(json)

rapidjson (C++):

#include "rapidjson/document.h"
#include "rapidjson/writer.h"
#include "rapidjson/stringbuffer.h"

rapidjson::Document d;
d.SetObject();
d.AddMember("foo", "bar", d.GetAllocator());

rapidjson::StringBuffer buffer;
rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
d.Accept(writer);

std::string json = buffer.GetString();

Summary

rapidjson offers more features and better performance for C++ projects, while oj provides a simpler API and Ruby support. The choice between them depends on the specific project requirements, language preferences, and performance needs.

Pros of json

• Header-only library, easy to integrate into C++ projects
• Extensive documentation and examples
• Wide range of JSON manipulation features, including JSON Pointer and JSON Patch

Cons of json

• Slower parsing and serialization compared to oj
• Higher memory usage, especially for large JSON documents
• Steeper learning curve for advanced features

Code Comparison

json:

#include <nlohmann/json.hpp>
using json = nlohmann::json;

json j = {
  {"name", "John"},
  {"age", 30},
  {"city", "New York"}
};
std::string s = j.dump();

oj:

#include "oj.h"

const char *json = "{\"name\":\"John\",\"age\":30,\"city\":\"New York\"}";
Val val = oj_parse(json, strlen(json));
char *s = oj_write_val(val, OJ_INDENT);

json offers a more C++-centric approach with modern language features, while oj provides a C-based interface with a focus on performance. json's syntax is more intuitive for C++ developers, but oj's simplicity can be advantageous in certain scenarios. The choice between the two depends on specific project requirements, performance needs, and developer preferences.

Pros of nativejson-benchmark

• Comprehensive benchmarking of multiple JSON libraries across different languages
• Provides detailed performance metrics and comparisons
• Useful for developers choosing a JSON library based on performance needs

Cons of nativejson-benchmark

• Not a JSON library itself, only a benchmarking tool
• May not reflect real-world performance in specific use cases
• Requires more setup and configuration to run benchmarks

Code Comparison

nativejson-benchmark (C++):

void ParseDouble(Benchmark& b) {
    char buffer[32];
    double d = 1.2345678;
    int length = sprintf(buffer, "%g", d);
    b.Run([&]() {
        return std::stod(buffer);
    });
}

oj (Ruby):

def parse_double(str)
  Oj.load(str)
end

str = '1.2345678'
parse_double(str)

Summary

nativejson-benchmark is a comprehensive benchmarking tool for JSON libraries, while oj is a high-performance JSON parser for Ruby. nativejson-benchmark offers broader language support and detailed metrics, but oj provides a ready-to-use JSON parsing solution for Ruby developers. The choice between them depends on whether you need benchmarking capabilities or a specific JSON library for Ruby.