| /* |
| * 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.codecs.lucene86; |
| |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.codecs.PointsFormat; |
| import org.apache.lucene.codecs.PointsReader; |
| import org.apache.lucene.codecs.PointsWriter; |
| import org.apache.lucene.index.SegmentReadState; |
| import org.apache.lucene.index.SegmentWriteState; |
| |
| /** |
| * Lucene 8.6 point format, which encodes dimensional values in a block KD-tree structure |
| * for fast 1D range and N dimensional shape intersection filtering. |
| * See <a href="https://www.cs.duke.edu/~pankaj/publications/papers/bkd-sstd.pdf">this paper</a> for details. |
| * |
| * <p>Data is stored across three files |
| * <ul> |
| * <li>A .kdm file that records metadata about the fields, such as numbers of |
| * dimensions or numbers of bytes per dimension. |
| * <li>A .kdi file that stores inner nodes of the tree. |
| * <li>A .kdm file that stores leaf nodes, where most of the data lives. |
| * </ul> |
| * |
| * @lucene.experimental |
| */ |
| public final class Lucene86PointsFormat extends PointsFormat { |
| |
| static final String DATA_CODEC_NAME = "Lucene86PointsFormatData"; |
| static final String INDEX_CODEC_NAME = "Lucene86PointsFormatIndex"; |
| static final String META_CODEC_NAME = "Lucene86PointsFormatMeta"; |
| |
| /** |
| * Filename extension for the leaf blocks |
| */ |
| public static final String DATA_EXTENSION = "kdd"; |
| |
| /** |
| * Filename extension for the index per field |
| */ |
| public static final String INDEX_EXTENSION = "kdi"; |
| |
| /** |
| * Filename extension for the meta per field |
| */ |
| public static final String META_EXTENSION = "kdm"; |
| |
| static final int VERSION_START = 0; |
| static final int VERSION_CURRENT = VERSION_START; |
| |
| /** Sole constructor */ |
| public Lucene86PointsFormat() { |
| } |
| |
| @Override |
| public PointsWriter fieldsWriter(SegmentWriteState state) throws IOException { |
| return new Lucene86PointsWriter(state); |
| } |
| |
| @Override |
| public PointsReader fieldsReader(SegmentReadState state) throws IOException { |
| return new Lucene86PointsReader(state); |
| } |
| } |