hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/hadoop-yarn-server-timelineservice-hbase-common/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/Column.java

/**
 * 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.server.timelineservice.storage.common;

import org.apache.hadoop.yarn.server.timelineservice.storage.flow.Attribute;

/**
 * A Column represents the way to store a fully qualified column in a specific
 * table.
 */
public interface Column<T extends BaseTable<T>> {
  /**
   * Returns column family name(as bytes) associated with this column.
   * @return a byte array encoding column family for this column qualifier.
   */
  byte[] getColumnFamilyBytes();

  /**
   * Get byte representation for this column qualifier.
   * @return a byte array representing column qualifier.
   */
  byte[] getColumnQualifierBytes();

  /**
   * Returns value converter implementation associated with this column.
   * @return a {@link ValueConverter} implementation.
   */
  ValueConverter getValueConverter();

  /**
   * Return attributed combined with aggregations, if any.
   * @return an array of Attributes
   */
  Attribute[] getCombinedAttrsWithAggr(Attribute... attributes);

  /**
   * Return true if the cell timestamp needs to be supplemented.
   * @return true if the cell timestamp needs to be supplemented
   */
  boolean supplementCellTimestamp();
}