| /* |
| * 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 org.apache.pulsar.client.impl; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import org.apache.pulsar.client.api.RedeliveryBackoff; |
| |
| /** |
| * MultiplierRedeliveryBackoff. |
| */ |
| public class MultiplierRedeliveryBackoff implements RedeliveryBackoff { |
| |
| private final long minDelayMs; |
| private final long maxDelayMs; |
| private final double multiplier; |
| private final int maxMultiplierPow; |
| |
| private MultiplierRedeliveryBackoff(long minDelayMs, long maxDelayMs, double multiplier) { |
| this.minDelayMs = minDelayMs; |
| this.maxDelayMs = maxDelayMs; |
| this.multiplier = multiplier; |
| maxMultiplierPow = (int) (Math.log((double) maxDelayMs / minDelayMs) / Math.log(multiplier)) + 1; |
| } |
| |
| public static MultiplierRedeliveryBackoff.MultiplierRedeliveryBackoffBuilder builder() { |
| return new MultiplierRedeliveryBackoff.MultiplierRedeliveryBackoffBuilder(); |
| } |
| |
| @Override |
| public long next(int redeliveryCount) { |
| if (redeliveryCount <= 0 || minDelayMs <= 0) { |
| return this.minDelayMs; |
| } |
| if (redeliveryCount > maxMultiplierPow) { |
| return this.maxDelayMs; |
| } |
| return Math.min((long) (minDelayMs * Math.pow(multiplier, redeliveryCount)), this.maxDelayMs); |
| } |
| |
| /** |
| * Builder of MultiplierRedeliveryBackoff. |
| */ |
| public static class MultiplierRedeliveryBackoffBuilder { |
| private long minDelayMs = 1000 * 10; |
| private long maxDelayMs = 1000 * 60 * 10; |
| private double multiplier = 2.0; |
| |
| public MultiplierRedeliveryBackoffBuilder minDelayMs(long minDelayMs) { |
| this.minDelayMs = minDelayMs; |
| return this; |
| } |
| |
| public MultiplierRedeliveryBackoffBuilder maxDelayMs(long maxDelayMs) { |
| this.maxDelayMs = maxDelayMs; |
| return this; |
| } |
| |
| public MultiplierRedeliveryBackoffBuilder multiplier(double multiplier) { |
| this.multiplier = multiplier; |
| return this; |
| } |
| |
| public MultiplierRedeliveryBackoff build() { |
| checkArgument(minDelayMs >= 0, "min delay time must be >= 0"); |
| checkArgument(maxDelayMs >= minDelayMs, "maxDelayMs must be >= minDelayMs"); |
| checkArgument(multiplier > 1, "multiplier must be > 1"); |
| return new MultiplierRedeliveryBackoff(minDelayMs, maxDelayMs, multiplier); |
| } |
| } |
| } |