Dependencies

libevent

# Ubunto
sudo apt install libevent-dev

# macOS
brew install libevent

http-parser-with-libevent

A mini C++ http server backed by I/O event libraries: libevent and http-parser

It is a fun project, creating a http server from scratch.

http server

you can quick start creating a http server by the below source code.

#include "http.hpp"
using namespace std::placeholders;
using namespace http;
int main(int argc, char * args[])
{
    if (argc != 3)
    {
        std::cerr << "\nUsage: " << args[0] << " address port\n" << "Example: \n" << args[0] << " 0.0.0.0 12345" << std::endl;
        return -1;
    }

    std::string addr(args[1]);
    uint16_t port = static_cast<uint16_t>(std::atoi(args[2]));

    http::start_server(port, [](response & res) { res.body() = "hello world\n"; });
}

compilation and run

The program has been tested under the Linux 5.15.153.1-microsoft-standard-WSL2

$ mkdir build && cd build && cmake ..
$ make        # complation
$ ./http_srv 0.0.0.0 12345 # run server

Performance

There are several criterias for measuring the performance of a http server. The performance is measured on environment:

• CPU: 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
• OS: microsoft-standard-WSL2 Ubuntu 22.04

The ab tool is used to measure the performance. It is also understood that the evaluation result may vary on the environment (OS and hardware).

Request per second

This criteria is to measure the responsive of a http server. It is tested by 50 concurrency active connection and 100,000 request in total.

$ ab -k -c 50 -n 100000 127.0.0.1:12345/route_01

http server	Request per second	Remark
http-parser-with-libevent	~150,000	using llhttp-parser (not internal http of libevent)
internal http libevent	~95,000	bench_http of libevent (release-2.1.12-stable)
nodejs	12,000	v12.22.9
asiohttp	11,000	3.10.6
flask	697	3.0.3

Appendix

nodejs server code test

const { createServer } = require('http');

const hostname = '127.0.0.1';
const port = 12345;

const server = createServer((req, res) => {
    res.statusCode = 200;
    res.setHeader('Content-Type', 'text/plain');
    res.end('Hello World');
});


server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});

asionhttp server code test

from aiohttp import web

async def handle(request):
    name = request.match_info.get('name', "Anonymous")
    text = "Hello, " + name
    return web.Response(text=text)

app = web.Application()
app.add_routes([web.get('/', handle),
                web.get('/{name}', handle)])

if __name__ == '__main__':
    web.run_app(app, port=12345)

flask server code test

from flask import Flask
app = Flask(__name__)
@app.route("/")
def hello_world():
    return "Hello, World"

if __name__ == "__main__":
    app.run(port=12345)