mirror of
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99 lines
2.1 KiB
Markdown
99 lines
2.1 KiB
Markdown
# retry
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[](https://travis-ci.org/Rican7/retry)
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[](https://godoc.org/github.com/Rican7/retry)
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[](http://goreportcard.com/report/Rican7/retry)
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[](https://github.com/Rican7/retry/releases)
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A simple, stateless, functional mechanism to perform actions repetitively until successful.
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## Project Status
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This project is currently in "pre-release". While the code is heavily tested, the API may change.
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Vendor (commit or lock) this dependency if you plan on using it.
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## Install
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`go get github.com/Rican7/retry`
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## Examples
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### Basic
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```go
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Retry(func(attempt uint) error {
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return nil // Do something that may or may not cause an error
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})
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```
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### File Open
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```go
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const logFilePath = "/var/log/myapp.log"
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var logFile *os.File
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err := Retry(func(attempt uint) error {
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var err error
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logFile, err = os.Open(logFilePath)
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return err
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})
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if nil != err {
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log.Fatalf("Unable to open file %q with error %q", logFilePath, err)
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}
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```
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### HTTP request with strategies and backoff
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```go
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var response *http.Response
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action := func(attempt uint) error {
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var err error
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response, err = http.Get("https://api.github.com/repos/Rican7/retry")
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if nil == err && nil != response && response.StatusCode > 200 {
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err = fmt.Errorf("failed to fetch (attempt #%d) with status code: %d", attempt, response.StatusCode)
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}
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return err
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}
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err := Retry(
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action,
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strategy.Limit(5),
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strategy.Backoff(backoff.Fibonacci(10*time.Millisecond)),
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)
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if nil != err {
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log.Fatalf("Failed to fetch repository with error %q", err)
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}
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```
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### Retry with backoff jitter
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```go
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action := func(attempt uint) error {
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return errors.New("something happened")
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}
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seed := time.Now().UnixNano()
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random := rand.New(rand.NewSource(seed))
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Retry(
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action,
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strategy.Limit(5),
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strategy.BackoffWithJitter(
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backoff.BinaryExponential(10*time.Millisecond),
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jitter.Deviation(random, 0.5),
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),
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)
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```
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