ruaft/raft/src/utils/rpcs.rs

use std::future::Future;
use std::time::Duration;

pub async fn retry_rpc<'a, Func, Fut, T>(
    max_retry: usize,
    deadline: Duration,
    mut task_gen: Func,
) -> std::io::Result<T>
where
    Fut: Future<Output = std::io::Result<T>> + Send + 'a,
    Func: FnMut(usize) -> Fut,
{
    for i in 0..max_retry {
        if i != 0 {
            tokio::time::sleep(Duration::from_millis((1 << i) * 10)).await;
        }
        // Not timed-out.
        #[allow(clippy::collapsible_match)]
        if let Ok(reply) = tokio::time::timeout(deadline, task_gen(i)).await {
            // And no error
            if let Ok(reply) = reply {
                return Ok(reply);
            }
        }
    }
    Err(std::io::Error::new(
        std::io::ErrorKind::TimedOut,
        format!("Timed out after {} retries", max_retry),
    ))
}

pub const RPC_DEADLINE: Duration = Duration::from_secs(2);