rpc Demo with rust

Sure, I can help you with that! Rust has a built-in library for handling RPC (remote procedure call) communication called `tonic`. You can use this library to create both server and client components for your RPC interface. Here's a basic example of how to create a simple RPC demo:

1. Define your service interface using Protocol Buffers (protobuf) IDL.

// example.proto

syntax = "proto3";

package example;

service Greeter {
    rpc SayHello(HelloRequest) returns (HelloResponse);
}

message HelloRequest {
    string name = 1;
}

message HelloResponse {
    string message = 1;
}

2. Use `tonic-build` to generate Rust code from your protobuf IDL.

$ cargo install protobuf-codegen
$ cargo install tonic-build
$ tonic-build example.proto

3. Implement your service using Rust.

// server.rs

use example::{greeter_server::Greeter, HelloRequest, HelloResponse};
use tonic::{transport::Server, Request, Response, Status};

#[derive(Default)]
pub struct GreeterService {}

#[tonic::async_trait]
impl Greeter for GreeterService {
    async fn say_hello(&self, request: Request<HelloRequest>) -> Result<Response<HelloResponse>, Status> {
        let name = &request.get_ref().name;
        let message = format!("Hello, {}!", name);
        let response = HelloResponse { message };
        Ok(Response::new(response))
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let addr = "127.0.0.1:50051".parse()?;
    let greeter_service = GreeterService::default();
    println!("Listening on: {}", addr);
    Server::builder()
        .add_service(GreeterServer::new(greeter_service))
        .serve(addr)
        .await?;
    Ok(())
}

4. Create a client for your service.

// client.rs

use example::{greeter_client::GreeterClient, HelloRequest};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let addr = "http://127.0.0.1:50051";
    let mut client = GreeterClient::connect(addr).await?;
    let request = HelloRequest { name: "World".to_string() };
    let response = client.say_hello(request).await?;
    println!("Got response: {:?}", response);
    Ok(())
}

5. Build and run both the server and client.

$ cargo build && ./target/debug/server
$ cargo build && ./target/debug/client

You should see output from the server saying it's listening on `127.0.0.1:50051` and output from the client saying it got a response with the message `"Hello, World!"`.