| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package backoff |
| |
| import ( |
| "math" |
| "time" |
| ) |
| |
| var DefaultBackoff Backoff = &PowerBackoff{ |
| MaxDelay: 30 * time.Second, |
| InitDelay: 1 * time.Second, |
| Factor: 1.6, |
| } |
| |
| type Backoff interface { |
| Delay(retries int) time.Duration |
| } |
| |
| // delay = min(MaxDelay, InitDelay * power(Factor, retries)) |
| type PowerBackoff struct { |
| MaxDelay time.Duration |
| InitDelay time.Duration |
| Factor float64 |
| } |
| |
| func (pb *PowerBackoff) Delay(retries int) time.Duration { |
| if retries <= 0 { |
| return pb.InitDelay |
| } |
| |
| return time.Duration(math.Min(float64(pb.MaxDelay), float64(pb.InitDelay)*math.Pow(pb.Factor, float64(retries)))) |
| } |
| |
| func GetBackoff() Backoff { |
| return DefaultBackoff |
| } |