RecordConsumer.java

package org.apache.hadoop.hive.mastiffFlexibleEncoding.parquet;

/*
 * adapted  from Parquet*
 */

/**
 *
 * Abstraction for writing records
 * It decouples the striping algorithm from the actual record model
 * example:
 * <pre>
 * startMessage()
 *  startField("A", 0)
 *   addValue(1)
 *   addValue(2)
 *  endField("A", 0)
 *  startField("B", 1)
 *   startGroup()
 *    startField("C", 0)
 *     addValue(3)
 *    endField("C", 0)
 *   endGroup()
 *  endField("B", 1)
 * endMessage()
 * </pre>
 *
 * would produce the following message:
 * <pre>
 * {
 *   A: [1, 2]
 *   B: {
 *     C: 3
 *   }
 * }
 * </pre>
 * @author Julien Le Dem
 *
 */
abstract public class RecordConsumer {

  /**
   * start a new record
   */
  abstract public void startMessage();

  /**
   * end of a record
   */
   public abstract void endMessage();

  /**
   * start of a field in a group or message
   * if the field is repeated the field is started only once and all values added in between start and end
   * @param field name of the field
   * @param index of the field in the group or message
   */
  abstract public void startField(String field, int index);

  /**
   * end of a field in a group or message
   * @param field name of the field
   * @param index of the field in the group or message
   */
  abstract public void endField(String field, int index);

  /**
   * start of a group in a field
   */
  abstract public void startGroup();

  /**
   * end of a group in a field
   */
  abstract public void endGroup();

  /**
   * add an int value in the current field
   * @param value
   */
  abstract public void addInteger(int value);

  /**
   * add a long value in the current field
   * @param value
   */
  abstract public void addLong(long value);

  /**
   * add a boolean value in the current field
   * @param value
   */
  abstract public void addBoolean(boolean value);

  /**
   * add a binary value in the current field
   * @param value
   */
  abstract public void addBinary(Binary value);

  /**
   * add a float value in the current field
   * @param value
   */
  abstract public void addFloat(float value);

  /**
   * add a double value in the current field
   * @param value
   */
  abstract public void addDouble(double value);

}