content: /**
   * 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.alibaba.jstorm.metric;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import backtype.storm.utils.NimbusClientWrapper;
  
  /**
   * @author Cody (weiyue.wy@alibaba-inc.com)
   * @since 2.1.2
   */
  public class MetricsRegister {
      private final Logger LOG = LoggerFactory.getLogger(getClass());
  
      private Map conf;
      private String topologyId;
      private NimbusClientWrapper client = null;
      private final Object lock = new Object();
  
      public MetricsRegister(Map conf, String topologyId) {
          this.conf = conf;
          this.topologyId = topologyId;
      }
  
      public Map<String, Long> registerMetrics(Set<String> names) {
          if (!JStormMetrics.enabled) {
              return new HashMap<>();
          }
          try {
              synchronized (lock){
                  if (client == null) {
                      client = new NimbusClientWrapper();
                      client.init(conf);
                  }
              }
              return client.getClient().registerMetrics(topologyId, names);
          } catch (Exception e) {
              LOG.error("Failed to gen metric ids", e);
              if (client != null) {
                  client.cleanup();
                  client = null;
              }
          }
  
          return new HashMap<>();
      }
  
  }
  