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 org.apache.bookkeeper.stats;
  
  import java.io.IOException;
  import java.io.Writer;
  import org.apache.commons.configuration2.Configuration;
  import org.apache.commons.lang3.StringUtils;
  
  /**
   * Provider to provide stats logger for different scopes.
   */
  public interface StatsProvider {
      /**
       * Initialize the stats provider by loading the given configuration <i>conf</i>.
       *
       * @param conf
       *          Configuration to configure the stats provider.
       */
      void start(Configuration conf);
  
      /**
       * Close the stats provider.
       */
      void stop();
  
      /**
       *
       * @param writer
       * @throws IOException
       */
      default void writeAllMetrics(Writer writer) throws IOException {
          throw new UnsupportedOperationException("writeAllMetrics is not implemented yet");
      }
  
      /**
       * Return the stats logger to a given <i>scope</i>.
       * @param scope
       *          Scope for the given stats
       * @return stats logger for the given <i>scope</i>
       */
      StatsLogger getStatsLogger(String scope);
  
      /**
       * Return the fully qualified stats name comprised of given <tt>statsComponents</tt>.
       *
       * @param statsComponents stats components to comprise the fully qualified stats name
       * @return the fully qualified stats name
       */
      default String getStatsName(String...statsComponents) {
          return StringUtils.join(statsComponents, '/');
      }
  }
  