go.temporal.io/server@v1.23.0/common/backoff/jitter.go (about) 1 // The MIT License 2 // 3 // Copyright (c) 2020 Temporal Technologies Inc. All rights reserved. 4 // 5 // Copyright (c) 2020 Uber Technologies, Inc. 6 // 7 // Permission is hereby granted, free of charge, to any person obtaining a copy 8 // of this software and associated documentation files (the "Software"), to deal 9 // in the Software without restriction, including without limitation the rights 10 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 // copies of the Software, and to permit persons to whom the Software is 12 // furnished to do so, subject to the following conditions: 13 // 14 // The above copyright notice and this permission notice shall be included in 15 // all copies or substantial portions of the Software. 16 // 17 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 20 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 // THE SOFTWARE. 24 25 package backoff 26 27 import ( 28 "math/rand" 29 ) 30 31 const fullCoefficient float64 = 1 32 33 // FullJitter return random number from 0 to input, inclusive, exclusive 34 func FullJitter[T ~int64 | ~int | ~int32 | ~float64 | ~float32](input T) T { 35 return Jitter(input, fullCoefficient) / 2 36 } 37 38 // Jitter return random number from (1-coefficient)*input to (1+coefficient)*input, inclusive, exclusive 39 func Jitter[T ~int64 | ~int | ~int32 | ~float64 | ~float32](input T, coefficient float64) T { 40 validateCoefficient(coefficient) 41 42 if coefficient == 0 { 43 return input 44 } 45 46 base := float64(input) * (1 - coefficient) 47 addon := rand.Float64() * 2 * (float64(input) - base) 48 return T(base + addon) 49 } 50 51 func validateCoefficient(coefficient float64) { 52 if coefficient < 0 || coefficient > 1 { 53 panic("coefficient cannot be < 0 or > 1") 54 } 55 }