1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
//! backon intends to provide an opposite backoff implementation of the popular [backoff](https://docs.rs/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.
//! - [`FibonacciBackoff`]: backoff with fibonacci delay, also provides jitter supports.
//!
//! Internally, `tokio::time::sleep()` will be used to sleep between retries, therefore
//! it will respect [pausing/auto-advancing](https://docs.rs/tokio/latest/tokio/time/fn.pause.html)
//! tokio's Runtime semantics, if enabled.
//!
//! # Examples
//!
//! Retry with default settings.
//!
//! ```no_run
//! 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(flavor = "current_thread")]
//! async fn main() -> Result<()> {
//!     let content = fetch.retry(&ExponentialBuilder::default()).await?;
//!
//!     println!("fetch succeeded: {}", content);
//!     Ok(())
//! }
//! ```
//!
//! Retry with specify retryable error.
//!
//! ```no_run
//! 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(flavor = "current_thread")]
//! async fn main() -> Result<()> {
//!     let content = fetch
//!         .retry(&ExponentialBuilder::default())
//!         .when(|e| e.to_string() == "retryable")
//!         .await?;
//!
//!     println!("fetch succeeded: {}", content);
//!     Ok(())
//! }
//! ```
//!
//! Retry functions with args.
//!
//! ```no_run
//! use anyhow::Result;
//! use backon::ExponentialBuilder;
//! use backon::Retryable;
//!
//! async fn fetch(url: &str) -> Result<String> {
//!     Ok(reqwest::get(url).await?.text().await?)
//! }
//!
//! #[tokio::main(flavor = "current_thread")]
//! async fn main() -> Result<()> {
//!     let content = (|| async { fetch("https://www.rust-lang.org").await })
//!         .retry(&ExponentialBuilder::default())
//!         .when(|e| e.to_string() == "retryable")
//!         .await?;
//!
//!     println!("fetch succeeded: {}", content);
//!     Ok(())
//! }
//! ```
//!
//! Retry functions with receiver `&self`.
//!
//! ```no_run
//! use anyhow::Result;
//! use backon::ExponentialBuilder;
//! use backon::Retryable;
//!
//! struct Test;
//!
//! impl Test {
//!     async fn fetch(&self, url: &str) -> Result<String> {
//!         Ok(reqwest::get(url).await?.text().await?)
//!     }
//! }
//!
//! #[tokio::main(flavor = "current_thread")]
//! async fn main() -> Result<()> {
//!     let test = Test;
//!     let content = (|| async { test.fetch("https://www.rust-lang.org").await })
//!         .retry(&ExponentialBuilder::default())
//!         .when(|e| e.to_string() == "retryable")
//!         .await?;
//!
//!     println!("fetch succeeded: {}", content);
//!     Ok(())
//! }
//! ```
//!
//! Retry functions with receiver `&mut self`.
//!
//! ```no_run
//! use anyhow::Result;
//! use backon::ExponentialBuilder;
//! use backon::RetryableWithContext;
//!
//! struct Test;
//!
//! impl Test {
//!     async fn fetch(&mut self, url: &str) -> Result<String> {
//!         Ok(reqwest::get(url).await?.text().await?)
//!     }
//! }
//!
//! #[tokio::main(flavor = "current_thread")]
//! async fn main() -> Result<()> {
//!     let test = Test;
//!
//!     let (_, result) = (|mut v: Test| async {
//!         let res = v.fetch("https://www.rust-lang.org").await;
//!         // Return input context back.
//!         (v, res)
//!     })
//!     .retry(&ExponentialBuilder::default())
//!     // Passing context in.
//!     .context(test)
//!     .when(|e| e.to_string() == "retryable")
//!     .await;
//!
//!     println!("fetch succeeded: {}", result.unwrap());
//!     Ok(())
//! }
//! ```

#![deny(missing_docs)]
#![deny(unused_qualifications)]

mod backoff;
pub use backoff::Backoff;
pub use backoff::BackoffBuilder;

mod constant;
pub use constant::ConstantBackoff;
pub use constant::ConstantBuilder;

mod exponential;
pub use exponential::ExponentialBackoff;
pub use exponential::ExponentialBuilder;

mod fibonacci;
pub use fibonacci::FibonacciBackoff;
pub use fibonacci::FibonacciBuilder;

mod retry;
pub use retry::Retry;
pub use retry::Retryable;

mod retry_with_context;
pub use retry_with_context::RetryableWithContext;

mod blocking_retry;
pub use blocking_retry::BlockingRetry;
pub use blocking_retry::BlockingRetryable;

mod blocking_retry_with_context;
pub use blocking_retry_with_context::BlockingRetryableWithContext;