feat: Replace serde_json with sonic_rs for poem crate

[Mr-Leshiy]

Refactored poem crate, replaced at some places usage of serde_json with the more faster json serde crate sonic_rs.

I've locally benchmarked a simple poem service like this

use poem::{handler, listener::TcpListener, post, web::Json, Route, Server};

#[handler]
fn echo(val: Json<serde_json::Value>) -> Json<serde_json::Value> {
    val
}

#[tokio::main]
async fn main() -> Result<(), std::io::Error> {
    let app = Route::new().at("/echo", post(echo));
    Server::new(TcpListener::bind("0.0.0.0:3000"))
      .run(app)
      .await
}

With the help of locust I've got a 20% decrease of response time, with the following benchmark.

from locust import FastHttpUser, task
import json

# Opening JSON file
f = open('large-file.json')
data = json.load(f)


class HelloWorldUser(FastHttpUser):
    @task
    def hello_world(self):
        self.client.post(
            "/echo",
            json=data
        )

large-file.json

Issue

#813

[attila-lin]

How about be a feature?

Someone may not care about the performance.

[Mr-Leshiy]

@attila-lin updated it with adding a new feature flag sonic-rs.
Should I also put some notes in somewhere in docs about this new feature ?

[Mr-Leshiy]

@attila-lin
So sorry for the delay, forgot about this PR.
I've updated corresponded README.md files and rust docs.

[attila-lin]

I'd like to merge this. Any suggestions? @sunli829

[sunli829]

does sonic-rs only work with nightly Rust?

[Mr-Leshiy]

@sunli829 no, it works on stable one