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 */
029@SuppressWarnings("unchecked")
030@InterfaceAudience.Public
031public abstract class Union4<A, B, C, D> extends Union3<A, B, C> {
032
033  protected final DataType<D> typeD;
034
035  /**
036   * Create an instance of {@code Union4} over the set of specified
037   * types.
038   */
039  public Union4(DataType<A> typeA, DataType<B> typeB, DataType<C> typeC, DataType<D> typeD) {
040    super(typeA, typeB, typeC);
041    this.typeD = typeD;
042  }
043
044  @Override
045  public boolean isOrderPreserving() {
046    return super.isOrderPreserving() && typeD.isOrderPreserving();
047  }
048
049  @Override
050  public Order getOrder() {
051    return null;
052  }
053
054  @Override
055  public boolean isNullable() {
056    return super.isNullable() && typeD.isNullable();
057  }
058
059  @Override
060  public boolean isSkippable() {
061    return super.isSkippable() && typeD.isSkippable();
062  }
063
064  /**
065   * Read an instance of the fourth type parameter from buffer {@code src}.
066   */
067  public D decodeD(PositionedByteRange src) {
068    return (D) decode(src);
069  }
070}