/**
 * 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.hadoop.yarn.util.timeline;

import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.map.AnnotationIntrospector;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
import org.codehaus.jackson.xc.JaxbAnnotationIntrospector;

/**
 * The helper class for the timeline module.
 * 
 */
@Public
@Evolving
public class TimelineUtils {

  private static ObjectMapper mapper;

  static {
    mapper = new ObjectMapper();
    AnnotationIntrospector introspector = new JaxbAnnotationIntrospector();
    mapper.setAnnotationIntrospector(introspector);
    mapper.getSerializationConfig()
        .setSerializationInclusion(Inclusion.NON_NULL);
  }

  /**
   * Serialize a POJO object into a JSON string not in a pretty format
   * 
   * @param o
   *          an object to serialize
   * @return a JSON string
   * @throws IOException
   * @throws JsonMappingException
   * @throws JsonGenerationException
   */
  public static String dumpTimelineRecordtoJSON(Object o)
      throws JsonGenerationException, JsonMappingException, IOException {
    return dumpTimelineRecordtoJSON(o, false);
  }

  /**
   * Serialize a POJO object into a JSON string
   * 
   * @param o
   *          an object to serialize
   * @param pretty
   *          whether in a pretty format or not
   * @return a JSON string
   * @throws IOException
   * @throws JsonMappingException
   * @throws JsonGenerationException
   */
  public static String dumpTimelineRecordtoJSON(Object o, boolean pretty)
      throws JsonGenerationException, JsonMappingException, IOException {
    if (pretty) {
      return mapper.defaultPrettyPrintingWriter().writeValueAsString(o);
    } else {
      return mapper.writeValueAsString(o);
    }
  }

}