| /** |
| * 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.curator.framework.recipes.locks; |
| |
| import org.apache.curator.framework.CuratorFramework; |
| import org.apache.zookeeper.CreateMode; |
| import org.apache.zookeeper.KeeperException; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import java.util.List; |
| |
| public class StandardLockInternalsDriver implements LockInternalsDriver |
| { |
| static private final Logger log = LoggerFactory.getLogger(StandardLockInternalsDriver.class); |
| |
| @Override |
| public PredicateResults getsTheLock(CuratorFramework client, List<String> children, String sequenceNodeName, int maxLeases) throws Exception |
| { |
| int ourIndex = children.indexOf(sequenceNodeName); |
| validateOurIndex(sequenceNodeName, ourIndex); |
| |
| boolean getsTheLock = ourIndex < maxLeases; |
| String pathToWatch = getsTheLock ? null : children.get(ourIndex - maxLeases); |
| |
| return new PredicateResults(pathToWatch, getsTheLock); |
| } |
| |
| @Override |
| public String createsTheLock(CuratorFramework client, String path, byte[] lockNodeBytes) throws Exception |
| { |
| String ourPath; |
| if ( lockNodeBytes != null ) |
| { |
| ourPath = client.create().creatingParentContainersIfNeeded().withProtection().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(path, lockNodeBytes); |
| } |
| else |
| { |
| ourPath = client.create().creatingParentContainersIfNeeded().withProtection().withMode(CreateMode.EPHEMERAL_SEQUENTIAL).forPath(path); |
| } |
| return ourPath; |
| } |
| |
| |
| @Override |
| public String fixForSorting(String str, String lockName) |
| { |
| return standardFixForSorting(str, lockName); |
| } |
| |
| public static String standardFixForSorting(String str, String lockName) |
| { |
| int index = str.lastIndexOf(lockName); |
| if ( index >= 0 ) |
| { |
| index += lockName.length(); |
| return index <= str.length() ? str.substring(index) : ""; |
| } |
| return str; |
| } |
| |
| static void validateOurIndex(String sequenceNodeName, int ourIndex) throws KeeperException |
| { |
| if ( ourIndex < 0 ) |
| { |
| throw new KeeperException.NoNodeException("Sequential path not found: " + sequenceNodeName); |
| } |
| } |
| } |