001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.types;
019
020import org.apache.hadoop.hbase.util.Order;
021import org.apache.hadoop.hbase.util.PositionedByteRange;
022import org.apache.yetus.audience.InterfaceAudience;
023
024/**
025 * The {@code Union} family of {@link DataType}s encode one of a fixed
026 * collection of Objects. They provide convenience methods which handle type
027 * casting on your behalf.
028 * @see Union2
029 */
030@SuppressWarnings("unchecked")
031@InterfaceAudience.Public
032public abstract class Union3<A, B, C> extends Union2<A, B> {
033
034  protected final DataType<C> typeC;
035
036  /**
037   * Create an instance of {@code Union3} over the set of specified
038   * types.
039   */
040  public Union3(DataType<A> typeA, DataType<B> typeB, DataType<C> typeC) {
041    super(typeA, typeB);
042    this.typeC = typeC;
043  }
044
045  @Override
046  public boolean isOrderPreserving() {
047    return super.isOrderPreserving() && typeC.isOrderPreserving();
048  }
049
050  @Override
051  public Order getOrder() {
052    return null;
053  }
054
055  @Override
056  public boolean isNullable() {
057    return super.isNullable() && typeC.isNullable();
058  }
059
060  @Override
061  public boolean isSkippable() {
062    return super.isSkippable() && typeC.isSkippable();
063  }
064
065  /**
066   * Read an instance of the third type parameter from buffer {@code src}.
067   */
068  public C decodeC(PositionedByteRange src) {
069    return (C) decode(src);
070  }
071}