Crate backon

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Expand description

backon intends to provide an opposite backoff implementation of the popular backoff.

Newer: developed by Rust edition 2021 and latest stable.
Cleaner: Iterator based abstraction, easy to use, customization friendly.
Easier: Trait based implementations, works like a native function provided by closures.

Backoff

Any types that implements Iterator<Item = Duration> can be used as backoff.

backon also provides backoff implementations with reasonable defaults:

ConstantBackoff: backoff with constant delay and limited times.
ExponentialBackoff: backoff with exponential delay, also provides jitter supports.

Examples

Retry with default settings.

use anyhow::Result;
use backon::ExponentialBuilder;
use backon::Retryable;

async fn fetch() -> Result<String> {
    Ok(reqwest::get("https://www.rust-lang.org")
        .await?
        .text()
        .await?)
}

#[tokio::main]
async fn main() -> Result<()> {
    let content = fetch.retry(&ExponentialBuilder::default()).await?;

    println!("fetch succeeded: {}", content);
    Ok(())
}

Retry with specify retryable error.

use anyhow::Result;
use backon::ExponentialBuilder;
use backon::Retryable;

async fn fetch() -> Result<String> {
    Ok(reqwest::get("https://www.rust-lang.org")
        .await?
        .text()
        .await?)
}

#[tokio::main]
async fn main() -> Result<()> {
    let content = fetch
        .retry(&ExponentialBuilder::default())
        .when(|e| e.to_string() == "retryable")
        .await?;

    println!("fetch succeeded: {}", content);
    Ok(())
}