content: /**
   * Copyright The Apache Software Foundation
   *
   * 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.wasp.fserver.metrics;
  
  import com.alibaba.wasp.fserver.MetricsEntityGroupAggregateSourceImpl;
  import com.alibaba.wasp.fserver.MetricsEntityGroupSourceImpl;
  import com.alibaba.wasp.fserver.MetricsFServerSourceImpl;
  
  /**
   * Factory to create MetricsFServerSource when given a MetricsFServerWrapper
   */
  public class MetricsFServerSourceFactory {
    private static enum FactoryStorage {
      INSTANCE;
      private MetricsFServerSource serverSource;
      private MetricsEntityGroupAggregateSourceImpl aggImpl;
    }
  
    private static synchronized MetricsEntityGroupAggregateSourceImpl getAggregate() {
      if (FactoryStorage.INSTANCE.aggImpl == null) {
        FactoryStorage.INSTANCE.aggImpl = new MetricsEntityGroupAggregateSourceImpl();
      }
      return FactoryStorage.INSTANCE.aggImpl;
    }
  
  
    public static  synchronized MetricsFServerSource createServer(MetricsFServerWrapper fserverWrapper) {
      if (FactoryStorage.INSTANCE.serverSource == null) {
        FactoryStorage.INSTANCE.serverSource = new MetricsFServerSourceImpl(fserverWrapper);
      }
      return FactoryStorage.INSTANCE.serverSource;
    }
  
    public static MetricsEntityGroupSource createEntityGroup(MetricsEntityGroupWrapper wrapper) {
      return new MetricsEntityGroupSourceImpl(wrapper, getAggregate());
    }
  }
  