//! Retry logic with exponential backoff
use std::future::Future;
use std::time::Duration;
use backoff::ExponentialBackoff;
use backoff::backoff::Backoff;
use tokio::time::sleep;
use tracing::debug;
use crate::Error;
use crate::config::RetryConfig;
/// Retry policy configuration
#[derive(Clone)]
pub struct RetryPolicy {
/// Whether retries are enabled
pub enabled: bool,
/// Maximum attempts
pub max_attempts: u32,
/// Initial backoff
pub initial_backoff: Duration,
/// Maximum backoff
pub max_backoff: Duration,
/// Backoff multiplier
pub multiplier: f64,
}
impl RetryPolicy {
/// Create from config
#[must_use]
pub fn new(config: &RetryConfig) -> Self {
Self {
enabled: config.enabled,
max_attempts: config.max_attempts,
initial_backoff: config.initial_backoff,
max_backoff: config.max_backoff,
multiplier: config.multiplier,
}
}
/// Create an exponential backoff instance
#[must_use]
pub fn create_backoff(&self) -> ExponentialBackoff {
ExponentialBackoff {
current_interval: self.initial_backoff,
initial_interval: self.initial_backoff,
max_interval: self.max_backoff,
multiplier: self.multiplier,
max_elapsed_time: None,
..Default::default()
}
}
}
/// Execute a future with retry logic
pub async fn with_retry<F, Fut, T>(policy: &RetryPolicy, name: &str, mut f: F) -> Result<T, Error>
where
F: FnMut() -> Fut,
Fut: Future<Output = Result<T, Error>>,
{
if !policy.enabled {
return f().await;
}
let mut backoff = policy.create_backoff();
let mut attempts = 0u32;
loop {
attempts += 1;
match f().await {
Ok(result) => return Ok(result),
Err(e) => {
// Don't retry certain errors
if !is_retryable(&e) {
return Err(e);
}
if attempts >= policy.max_attempts {
debug!(
operation = name,
attempts = attempts,
"Max retry attempts reached"
);
return Err(e);
}
if let Some(duration) = backoff.next_backoff() {
debug!(
operation = name,
attempt = attempts,
delay_ms = duration.as_millis(),
error = %e,
"Retrying after backoff"
);
sleep(duration).await;
} else {
return Err(e);
}
}
}
}
}
/// Check if an error is retryable
fn is_retryable(error: &Error) -> bool {
matches!(
error,
Error::Transport(_) | Error::BackendTimeout(_) | Error::Http(_) | Error::Io(_)
)
}
