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diff --git a/vendor/github.com/jpillora/backoff/README.md b/vendor/github.com/jpillora/backoff/README.md new file mode 100644 index 00000000..81e77cd7 --- /dev/null +++ b/vendor/github.com/jpillora/backoff/README.md @@ -0,0 +1,119 @@ +# Backoff + +A simple exponential backoff counter in Go (Golang) + +[](https://godoc.org/github.com/jpillora/backoff) [](https://circleci.com/gh/jpillora/backoff) + +### Install + +``` +$ go get -v github.com/jpillora/backoff +``` + +### Usage + +Backoff is a `time.Duration` counter. It starts at `Min`. After every call to `Duration()` it is multiplied by `Factor`. It is capped at `Max`. It returns to `Min` on every call to `Reset()`. `Jitter` adds randomness ([see below](#example-using-jitter)). Used in conjunction with the `time` package. + +--- + +#### Simple example + +``` go + +b := &backoff.Backoff{ + //These are the defaults + Min: 100 * time.Millisecond, + Max: 10 * time.Second, + Factor: 2, + Jitter: false, +} + +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) + +fmt.Printf("Reset!\n") +b.Reset() + +fmt.Printf("%s\n", b.Duration()) +``` + +``` +100ms +200ms +400ms +Reset! +100ms +``` + +--- + +#### Example using `net` package + +``` go +b := &backoff.Backoff{ + Max: 5 * time.Minute, +} + +for { + conn, err := net.Dial("tcp", "example.com:5309") + if err != nil { + d := b.Duration() + fmt.Printf("%s, reconnecting in %s", err, d) + time.Sleep(d) + continue + } + //connected + b.Reset() + conn.Write([]byte("hello world!")) + // ... Read ... Write ... etc + conn.Close() + //disconnected +} + +``` + +--- + +#### Example using `Jitter` + +Enabling `Jitter` adds some randomization to the backoff durations. [See Amazon's writeup of performance gains using jitter](http://www.awsarchitectureblog.com/2015/03/backoff.html). Seeding is not necessary but doing so gives repeatable results. + +```go +import "math/rand" + +b := &backoff.Backoff{ + Jitter: true, +} + +rand.Seed(42) + +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) + +fmt.Printf("Reset!\n") +b.Reset() + +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) +fmt.Printf("%s\n", b.Duration()) +``` + +``` +100ms +106.600049ms +281.228155ms +Reset! +100ms +104.381845ms +214.957989ms +``` + +#### Documentation + +https://godoc.org/github.com/jpillora/backoff + +#### Credits + +Forked from some JavaScript written by [@tj](https://github.com/tj)
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