/*
*
* 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.filter;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.hbase.DeserializationException;
import org.apache.hadoop.hbase.protobuf.generated.ComparatorProtos;
import com.google.protobuf.InvalidProtocolBufferException;
/**
* A binary comparator which lexicographically compares against the specified
* byte array using {@link org.apache.hadoop.hbase.util.Bytes#compareTo(byte[], byte[])}.
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class NullComparator extends ByteArrayComparable {
public NullComparator() {
super(new byte[0]);
}
@Override
public int compareTo(byte[] value) {
return value != null ? 1 : 0;
}
@Override
public boolean equals(Object obj) {
return obj == null;
}
@Override
public int compareTo(byte[] value, int offset, int length) {
throw new UnsupportedOperationException();
}
/**
* @return The comparator serialized using pb
*/
public byte [] toByteArray() {
ComparatorProtos.NullComparator.Builder builder =
ComparatorProtos.NullComparator.newBuilder();
return builder.build().toByteArray();
}
/**
* @param pbBytes A pb serialized {@link NullComparator} instance
* @return An instance of {@link NullComparator} made from <code>bytes</code>
* @throws DeserializationException
* @see #toByteArray
*/
public static NullComparator parseFrom(final byte [] pbBytes)
throws DeserializationException {
ComparatorProtos.NullComparator proto;
try {
proto = ComparatorProtos.NullComparator.parseFrom(pbBytes);
} catch (InvalidProtocolBufferException e) {
throw new DeserializationException(e);
}
return new NullComparator();
}
/**
* @param other
* @return true if and only if the fields of the comparator that are serialized
* are equal to the corresponding fields in other. Used for testing.
*/
boolean areSerializedFieldsEqual(ByteArrayComparable other) {
if (other == this) return true;
if (!(other instanceof NullComparator)) return false;
return super.areSerializedFieldsEqual(other);
}
}