| /* |
| * 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; |
| } |
| |
| } |