/**
* 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.hbase.types;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.util.Order;
import org.apache.hadoop.hbase.util.PositionedByteRange;
/**
* The {@code Union} family of {@link DataType}s encode one of a fixed
* set of {@code Object}s. They provide convenience methods which handle
* type casting on your behalf.
*/
@SuppressWarnings("unchecked")
@InterfaceAudience.Public
public abstract class Union2<A, B> implements DataType<Object> {
protected final DataType<A> typeA;
protected final DataType<B> typeB;
/**
* Create an instance of {@code Union2} over the set of specified
* types.
*/
public Union2(DataType<A> typeA, DataType<B> typeB) {
this.typeA = typeA;
this.typeB = typeB;
}
@Override
public boolean isOrderPreserving() {
return typeA.isOrderPreserving() && typeB.isOrderPreserving();
}
@Override
public Order getOrder() { return null; }
@Override
public boolean isNullable() {
return typeA.isNullable() && typeB.isNullable();
}
@Override
public boolean isSkippable() {
return typeA.isSkippable() && typeB.isSkippable();
}
@Override
public Class<Object> encodedClass() {
throw new UnsupportedOperationException(
"Union types do not expose a definitive encoded class.");
}
/**
* Read an instance of the first type parameter from buffer {@code src}.
*/
public A decodeA(PositionedByteRange src) {
return (A) decode(src);
}
/**
* Read an instance of the second type parameter from buffer {@code src}.
*/
public B decodeB(PositionedByteRange src) {
return (B) decode(src);
}
}