/**
*
* 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 org.apache.hadoop.hbase.util.Bytes;
import com.google.protobuf.InvalidProtocolBufferException;
/**
* This comparator is for use with SingleColumnValueFilter, for filtering based on
* the value of a given column. Use it to test if a given substring appears
* in a cell value in the column. The comparison is case insensitive.
* <p>
* Only EQUAL or NOT_EQUAL tests are valid with this comparator.
* <p>
* For example:
* <p>
* <pre>
* SingleColumnValueFilter scvf =
* new SingleColumnValueFilter("col", CompareOp.EQUAL,
* new SubstringComparator("substr"));
* </pre>
*/
@InterfaceAudience.Public
@InterfaceStability.Stable
public class SubstringComparator extends ByteArrayComparable {
private String substr;
/**
* Constructor
* @param substr the substring
*/
public SubstringComparator(String substr) {
super(Bytes.toBytes(substr.toLowerCase()));
this.substr = substr.toLowerCase();
}
@Override
public byte[] getValue() {
return Bytes.toBytes(substr);
}
@Override
public int compareTo(byte[] value, int offset, int length) {
return Bytes.toString(value, offset, length).toLowerCase().contains(substr) ? 0
: 1;
}
/**
* @return The comparator serialized using pb
*/
public byte [] toByteArray() {
ComparatorProtos.SubstringComparator.Builder builder =
ComparatorProtos.SubstringComparator.newBuilder();
builder.setSubstr(this.substr);
return builder.build().toByteArray();
}
/**
* @param pbBytes A pb serialized {@link SubstringComparator} instance
* @return An instance of {@link SubstringComparator} made from <code>bytes</code>
* @throws DeserializationException
* @see #toByteArray
*/
public static SubstringComparator parseFrom(final byte [] pbBytes)
throws DeserializationException {
ComparatorProtos.SubstringComparator proto;
try {
proto = ComparatorProtos.SubstringComparator.parseFrom(pbBytes);
} catch (InvalidProtocolBufferException e) {
throw new DeserializationException(e);
}
return new SubstringComparator(proto.getSubstr());
}
/**
* @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 SubstringComparator)) return false;
SubstringComparator comparator = (SubstringComparator)other;
return super.areSerializedFieldsEqual(comparator)
&& this.substr.equals(comparator.substr);
}
}