| /* |
| * Copyright 2017 HugeGraph Authors |
| * |
| * 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 com.baidu.hugegraph.concurrent; |
| |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| public class LockManager { |
| |
| private static final LockManager INSTANCE = new LockManager(); |
| |
| public static LockManager instance() { |
| return INSTANCE; |
| } |
| |
| private Map<String, LockGroup> lockGroupMap; |
| |
| private LockManager() { |
| this.lockGroupMap = new ConcurrentHashMap<>(); |
| } |
| |
| public boolean exists(String group) { |
| return this.lockGroupMap.containsKey(group); |
| } |
| |
| public LockGroup create(String group) { |
| if (exists(group)) { |
| throw new RuntimeException(String.format( |
| "LockGroup '%s' already exists", group)); |
| } |
| LockGroup lockGroup = new LockGroup(group); |
| LockGroup previous = this.lockGroupMap.putIfAbsent(group, lockGroup); |
| if (previous != null) { |
| return previous; |
| } |
| return lockGroup; |
| } |
| |
| public LockGroup get(String group) { |
| LockGroup lockGroup = this.lockGroupMap.get(group); |
| if (lockGroup == null) { |
| throw new RuntimeException(String.format( |
| "LockGroup '%s' does not exists", group)); |
| } |
| return lockGroup; |
| } |
| |
| public void destroy(String group) { |
| if (this.exists(group)) { |
| this.lockGroupMap.remove(group); |
| } else { |
| throw new RuntimeException(String.format( |
| "LockGroup '%s' does not exists", group)); |
| } |
| } |
| } |