| // 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.cloudstack.agent.lb.algorithm; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.cloudstack.agent.lb.IndirectAgentLBAlgorithm; |
| |
| public class IndirectAgentLBRoundRobinAlgorithm implements IndirectAgentLBAlgorithm { |
| |
| private int findRRPivotIndex(final List<String> msList, final List<Long> orderedHostList, final Long hostId) { |
| return orderedHostList.indexOf(hostId) % msList.size(); |
| } |
| |
| @Override |
| public List<String> sort(final List<String> msList, final List<Long> orderedHostList, final Long hostId) { |
| if (msList.size() < 2) { |
| return msList; |
| } |
| |
| final List<Long> hostList = new ArrayList<>(orderedHostList); |
| Long searchId = hostId; |
| if (hostId == null) { |
| searchId = -1L; |
| hostList.add(searchId); |
| } |
| |
| final int pivotIndex = findRRPivotIndex(msList, hostList, searchId); |
| final List<String> roundRobin = new ArrayList<>(msList.subList(pivotIndex, msList.size())); |
| roundRobin.addAll(msList.subList(0, pivotIndex)); |
| |
| return roundRobin; |
| } |
| |
| @Override |
| public String getName() { |
| return "roundrobin"; |
| } |
| |
| @Override |
| public boolean compare(final List<String> msList, final List<String> receivedMsList) { |
| return msList != null && receivedMsList != null && msList.equals(receivedMsList); |
| } |
| } |