......
#[derive(Clone, Default)]
struct HelloSvc;

impl hello_pb::HelloService for HelloSvc {
    async fn hello(
        &self,
        req: Request<hello_pb::HelloRequest>,
    ) -> Result<Response<hello_pb::HelloReply>, Status> {
        let name: &str = req.get_ref().name.as_ref();
        let preview: String = name.chars().take(10).collect();
        println!(
            "Received Hello request: name length={}, preview='{}'",
            name.chars().count(),
            preview
        );
        let ok = is_valid_name(name);
        Ok(Response::new(hello_pb::HelloReply { ok }))
    }
}

fn is_valid_name(name: &str) -> bool {
    !name.trim().is_empty()
}

#[volo::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
    let addr: SocketAddr = "[::]:50051".parse()?;
    let addr = Address::from(addr);

    Server::new()
        .http2_adaptive_window(true)
        .http2_init_connection_window_size(1024u32 * 1024)
        .http2_init_stream_window_size(1024u32 * 1024)
        .http2_max_frame_size(1024u32 * 1024)
        .http2_max_send_buf_size(1024usize * 1024)
        
        .add_service(ServiceBuilder::new(hello_pb::HelloServiceServer::new(HelloSvc)).build())
        .run(addr)
        .await?;

    Ok(())
}