again ♻️

wasm-compatible retry interfaces for fallible Rustlang std library Futures

A goal of any operation should be a successful outcome. This crate gives operations a better chance at achieving that.

📦 install

In your Cargo.toml file, add the following under the [dependencies] heading

again = "0.1"

🤸usage

For very simple cases you can use the module level retry function to retry a potentially fallible operation.

use std::error::Error;#[tokio::main]asyncfnmain() -> Result<(),Box<dynError>>{
pretty_env_logger::init();
again::retry(|| reqwest::get("https://api.you.com")).await?;Ok(())}

You may not want to retry every kind of error. For preciseness you can be more explicit in which kinds of errors should be retried with the module level retry_if function.

use std::error::Error;#[tokio::main]asyncfnmain() -> Result<(),Box<dynError>>{
pretty_env_logger::init();
again::retry_if(
|| reqwest::get("https://api.you.com")
reqwest::Error::is_status
).await?;Ok(())}

You can also customize retry behavior to suit your applications needs with a configurable and reusable RetryPolicy.

use std::error::Error;use std::time::Duration;use again::RetryPolicy;#[tokio::main]asyncfnmain() -> Result<(),Box<dynError>>{
pretty_env_logger::init();let policy = RetryPolicy::exponential(Duration::from_millis(200)).with_max_retries(10).with_jitter(true);
policy.retry(|| reqwest::get("https://api.you.com")).await?;Ok(())}

See the docs for more examples.

Doug Tangren (softprops) 2020