/*
* 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.lucene.util;
import java.util.Comparator;
/** Specialized {@link BytesRef} comparator that
* {@link FixedLengthBytesRefArray#iterator(Comparator)} has optimizations
* for.
* @lucene.internal */
public abstract class BytesRefComparator implements Comparator<BytesRef> {
final int comparedBytesCount;
/** Sole constructor.
* @param comparedBytesCount the maximum number of bytes to compare. */
protected BytesRefComparator(int comparedBytesCount) {
this.comparedBytesCount = comparedBytesCount;
}
/** Return the unsigned byte to use for comparison at index {@code i}, or
* {@code -1} if all bytes that are useful for comparisons are exhausted.
* This may only be called with a value of {@code i} between {@code 0}
* included and {@code comparedBytesCount} excluded. */
protected abstract int byteAt(BytesRef ref, int i);
@Override
public int compare(BytesRef o1, BytesRef o2) {
for (int i = 0; i < comparedBytesCount; ++i) {
final int b1 = byteAt(o1, i);
final int b2 = byteAt(o2, i);
if (b1 != b2) {
return b1 - b2;
} else if (b1 == -1) {
break;
}
}
return 0;
}
}