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}