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 set of {@code Object}s. They 026 * provide convenience methods which handle type casting on your behalf. 027 */ 028@SuppressWarnings("unchecked") 029@InterfaceAudience.Public 030public abstract class Union2<A, B> implements DataType<Object> { 031 032 protected final DataType<A> typeA; 033 protected final DataType<B> typeB; 034 035 /** 036 * Create an instance of {@code Union2} over the set of specified types. 037 */ 038 public Union2(DataType<A> typeA, DataType<B> typeB) { 039 this.typeA = typeA; 040 this.typeB = typeB; 041 } 042 043 @Override 044 public boolean isOrderPreserving() { 045 return typeA.isOrderPreserving() && typeB.isOrderPreserving(); 046 } 047 048 @Override 049 public Order getOrder() { 050 return null; 051 } 052 053 @Override 054 public boolean isNullable() { 055 return typeA.isNullable() && typeB.isNullable(); 056 } 057 058 @Override 059 public boolean isSkippable() { 060 return typeA.isSkippable() && typeB.isSkippable(); 061 } 062 063 @Override 064 public Class<Object> encodedClass() { 065 throw new UnsupportedOperationException( 066 "Union types do not expose a definitive encoded class."); 067 } 068 069 /** 070 * Read an instance of the first type parameter from buffer {@code src}. 071 */ 072 public A decodeA(PositionedByteRange src) { 073 return (A) decode(src); 074 } 075 076 /** 077 * Read an instance of the second type parameter from buffer {@code src}. 078 */ 079 public B decodeB(PositionedByteRange src) { 080 return (B) decode(src); 081 } 082}