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
```toml
again = "0.1"
```
## 🤸usage
For very simple cases you can use the module level `retry` function
to retry a potentially fallible operation.
```rust
use std::error::Error;
#[tokio::main]
async fn main() -> Result<(), Box> {
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.
```rust
use std::error::Error;
#[tokio::main]
async fn main() -> Result<(), Box> {
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`.
```rust
use std::error::Error;
use std::time::Duration;
use again::RetryPolicy;
#[tokio::main]
async fn main() -> Result<(), Box> {
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](http://docs.rs/again) for more examples.
Doug Tangren (softprops) 2020
