| // 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 pulsar |
| |
| import ( |
| "math" |
| "time" |
| ) |
| |
| // NackBackoffPolicy is a interface for custom message negativeAcked policy, users can specify a NackBackoffPolicy |
| // for a consumer. |
| // |
| // > Notice: the consumer crashes will trigger the redelivery of the unacked message, this case will not respect the |
| // > NackBackoffPolicy, which means the message might get redelivered earlier than the delay time |
| // > from the backoff. |
| type NackBackoffPolicy interface { |
| // Next param redeliveryCount indicates the number of times the message was redelivered. |
| // We can get the redeliveryCount from the CommandMessage. |
| Next(redeliveryCount uint32) time.Duration |
| } |
| |
| // defaultNackBackoffPolicy is default impl for NackBackoffPolicy. |
| type defaultNackBackoffPolicy struct{} |
| |
| func (nbp *defaultNackBackoffPolicy) Next(redeliveryCount uint32) time.Duration { |
| minNackTime := 1 * time.Second // 1sec |
| maxNackTime := 10 * time.Minute // 10min |
| |
| if redeliveryCount < 0 { |
| return minNackTime |
| } |
| |
| return time.Duration(math.Min(math.Abs(float64(minNackTime<<redeliveryCount)), float64(maxNackTime))) |
| } |