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.cassandra.tools.nodetool.stats;
  
  import java.io.PrintStream;
  import java.util.Map;
  
  import org.apache.cassandra.utils.JsonUtils;
  import org.yaml.snakeyaml.DumperOptions;
  import org.yaml.snakeyaml.Yaml;
  
  /**
   * Interface for the Stats printer, that'd output statistics
   * given the {@code StatsHolder}
   *
   * @param <T> Stats property bad type
   */
  public interface StatsPrinter<T extends StatsHolder>
  {
      default void print(T data, PrintStream out, boolean verbose)
      {
          print(data, out);
      }
  
      void print(T data, PrintStream out);
  
      static class JsonPrinter<T extends StatsHolder> implements StatsPrinter<T>
      {
          @Override
          public void print(T data, PrintStream out)
          {
              // First need to get a Map representation of stats
              final Map<String, Object> stats = data.convert2Map();
              // but then also need slight massaging to coerce NaN values into nulls
              for (Object statEntry : stats.values())
                  if (statEntry instanceof Map<?,?>)
                      for (Map.Entry<String, Object> entry : ((Map<String, Object>) statEntry).entrySet())
                          if (entry.getValue() instanceof Double && !Double.isFinite((Double) entry.getValue()))
                              entry.setValue(null);
  
              // and then we can serialize
              out.println(JsonUtils.writeAsPrettyJsonString(stats));
          }
      }
  
      static class YamlPrinter<T extends StatsHolder> implements StatsPrinter<T>
      {
          @Override
          public void print(T data, PrintStream out)
          {
              DumperOptions options = new DumperOptions();
              options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
  
              Yaml yaml = new Yaml(options);
              out.println(yaml.dump(data.convert2Map()));
          }
      }
  }
  