use futures::{executor::LocalPool, task::LocalSpawnExt, Future};
use std::io::Write;
use r2r::{example_interfaces::srv::AddTwoInts, QosProfile};
async fn requester_task(
node_available: impl Future<Output = r2r::Result<()>>, c: r2r::Client<AddTwoInts::Service>,
) -> Result<(), Box<dyn std::error::Error>> {
let mut x: i64 = 0;
println!("waiting for service...");
node_available.await?;
println!("service available.");
loop {
let req = AddTwoInts::Request { a: 10 * x, b: x };
print!("{} + {} = ", req.a, req.b);
std::io::stdout().flush()?;
let resp = c.request(&req)?.await?;
println!("{}", resp.sum);
x += 1;
if x == 10 {
break;
}
}
Ok(())
}
fn main() -> Result<(), Box<dyn std::error::Error>> {
let ctx = r2r::Context::create()?;
let mut node = r2r::Node::create(ctx, "testnode", "")?;
let client =
node.create_client::<AddTwoInts::Service>("/add_two_ints", QosProfile::default())?;
let service_available = r2r::Node::is_available(&client)?;
let mut pool = LocalPool::new();
let spawner = pool.spawner();
spawner.spawn_local(async move {
match requester_task(service_available, client).await {
Ok(()) => println!("done."),
Err(e) => println!("error: {}", e),
}
})?;
loop {
node.spin_once(std::time::Duration::from_millis(100));
pool.run_until_stalled();
}
}