Wala shell

Advanced PHP File Manager

Server IP: 127.0.0.1 | PHP Version: 8.3.30 | Domains Hosted: 54

Name	Size	Last Modified	Actions
📁 ..	-	2025-05-25 12:27
📄 LICENSE The MIT License (MIT) Copyright (c) 2017 Jaime Pillora Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.	1.05 KB	2025-05-25 12:27
📄 README.md # Backoff A simple exponential backoff counter in Go (Golang) [![GoDoc](https://godoc.org/github.com/jpillora/backoff?status.svg)](https://godoc.org/github.com/jpillora/backoff) [![Circle CI](https://circleci.com/gh/jpillora/backoff.svg?style=shield)](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](https://github.com/segmentio/backo) written by [@tj](https://github.com/tj)	2.27 KB	2025-05-25 12:27
📄 backoff.go // Package backoff provides an exponential-backoff implementation. package backoff import ( "math" "math/rand" "sync/atomic" "time" ) // Backoff is a time.Duration counter, starting at Min. After every call to // the Duration method the current timing is multiplied by Factor, but it // never exceeds Max. // // Backoff is not generally concurrent-safe, but the ForAttempt method can // be used concurrently. type Backoff struct { attempt uint64 // Factor is the multiplying factor for each increment step Factor float64 // Jitter eases contention by randomizing backoff steps Jitter bool // Min and Max are the minimum and maximum values of the counter Min, Max time.Duration } // Duration returns the duration for the current attempt before incrementing // the attempt counter. See ForAttempt. func (b Backoff) Duration() time.Duration { d := b.ForAttempt(float64(atomic.AddUint64(&b.attempt, 1) - 1)) return d } const maxInt64 = float64(math.MaxInt64 - 512) // ForAttempt returns the duration for a specific attempt. This is useful if // you have a large number of independent Backoffs, but don't want use // unnecessary memory storing the Backoff parameters per Backoff. The first // attempt should be 0. // // ForAttempt is concurrent-safe. func (b Backoff) ForAttempt(attempt float64) time.Duration { // Zero-values are nonsensical, so we use // them to apply defaults min := b.Min if min <= 0 { min = 100 * time.Millisecond } max := b.Max if max <= 0 { max = 10 * time.Second } if min >= max { // short-circuit return max } factor := b.Factor if factor <= 0 { factor = 2 } //calculate this duration minf := float64(min) durf := minf * math.Pow(factor, attempt) if b.Jitter { durf = rand.Float64()(durf-minf) + minf } //ensure float64 wont overflow int64 if durf > maxInt64 { return max } dur := time.Duration(durf) //keep within bounds if dur < min { return min } if dur > max { return max } return dur } // Reset restarts the current attempt counter at zero. func (b Backoff) Reset() { atomic.StoreUint64(&b.attempt, 0) } // Attempt returns the current attempt counter value. func (b Backoff) Attempt() float64 { return float64(atomic.LoadUint64(&b.attempt)) } // Copy returns a backoff with equals constraints as the original func (b Backoff) Copy() *Backoff { return &Backoff{ Factor: b.Factor, Jitter: b.Jitter, Min: b.Min, Max: b.Max, } }	2.38 KB	2025-05-25 12:27
📄 backoff_test.go package backoff import ( "reflect" "sync" "testing" "time" ) func Test1(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, } equals(t, b.Duration(), 100time.Millisecond) equals(t, b.Duration(), 200time.Millisecond) equals(t, b.Duration(), 400time.Millisecond) b.Reset() equals(t, b.Duration(), 100time.Millisecond) } func TestForAttempt(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, } equals(t, b.ForAttempt(0), 100time.Millisecond) equals(t, b.ForAttempt(1), 200time.Millisecond) equals(t, b.ForAttempt(2), 400time.Millisecond) b.Reset() equals(t, b.ForAttempt(0), 100time.Millisecond) } func Test2(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 1.5, } equals(t, b.Duration(), 100time.Millisecond) equals(t, b.Duration(), 150time.Millisecond) equals(t, b.Duration(), 225time.Millisecond) b.Reset() equals(t, b.Duration(), 100time.Millisecond) } func Test3(t testing.T) { b := &Backoff{ Min: 100 time.Nanosecond, Max: 10 * time.Second, Factor: 1.75, } equals(t, b.Duration(), 100time.Nanosecond) equals(t, b.Duration(), 175time.Nanosecond) equals(t, b.Duration(), 306time.Nanosecond) b.Reset() equals(t, b.Duration(), 100time.Nanosecond) } func Test4(t testing.T) { b := &Backoff{ Min: 500 time.Second, Max: 100 * time.Second, Factor: 1, } equals(t, b.Duration(), b.Max) } func TestGetAttempt(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, } equals(t, b.Attempt(), float64(0)) equals(t, b.Duration(), 100time.Millisecond) equals(t, b.Attempt(), float64(1)) equals(t, b.Duration(), 200time.Millisecond) equals(t, b.Attempt(), float64(2)) equals(t, b.Duration(), 400time.Millisecond) equals(t, b.Attempt(), float64(3)) b.Reset() equals(t, b.Attempt(), float64(0)) equals(t, b.Duration(), 100time.Millisecond) equals(t, b.Attempt(), float64(1)) } func TestJitter(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, Jitter: true, } equals(t, b.Duration(), 100time.Millisecond) between(t, b.Duration(), 100time.Millisecond, 200time.Millisecond) between(t, b.Duration(), 100time.Millisecond, 400time.Millisecond) b.Reset() equals(t, b.Duration(), 100time.Millisecond) } func TestCopy(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, } b2 := b.Copy() equals(t, b, b2) } func TestConcurrent(t testing.T) { b := &Backoff{ Min: 100 time.Millisecond, Max: 10 * time.Second, Factor: 2, } wg := &sync.WaitGroup{} test := func() { time.Sleep(b.Duration()) wg.Done() } wg.Add(2) go test() go test() wg.Wait() } func between(t testing.T, actual, low, high time.Duration) { t.Helper() if actual < low { t.Fatalf("Got %s, Expecting >= %s", actual, low) } if actual > high { t.Fatalf("Got %s, Expecting <= %s", actual, high) } } func equals(t testing.T, v1, v2 interface{}) { t.Helper() if !reflect.DeepEqual(v1, v2) { t.Fatalf("Got %v, Expecting %v", v1, v2) } }	3.2 KB	2025-05-25 12:27
📄 go.mod module github.com/jpillora/backoff go 1.13	44 B	2025-05-25 12:27

Terminal