| /* |
| * 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.spatial.prefix.tree; |
| |
| import java.text.ParseException; |
| import java.util.Map; |
| |
| import org.apache.lucene.util.Version; |
| import org.locationtech.spatial4j.context.SpatialContext; |
| import org.locationtech.spatial4j.distance.DistanceUtils; |
| |
| /** |
| * Abstract Factory for creating {@link SpatialPrefixTree} instances with useful |
| * defaults and passed on configurations defined in a Map. |
| * |
| * @lucene.experimental |
| */ |
| public abstract class SpatialPrefixTreeFactory { |
| |
| private static final double DEFAULT_GEO_MAX_DETAIL_KM = 0.001;//1m |
| public static final String PREFIX_TREE = "prefixTree"; |
| public static final String MAX_LEVELS = "maxLevels"; |
| public static final String MAX_DIST_ERR = "maxDistErr"; |
| public static final String VERSION = "version"; |
| |
| protected Map<String, String> args; |
| protected SpatialContext ctx; |
| protected Integer maxLevels; |
| private Version version; |
| |
| /** |
| * The factory is looked up via "prefixTree" in args, expecting "geohash" or "quad". |
| * If it's neither of these, then "geohash" is chosen for a geo context, otherwise "quad" is chosen. |
| * The "version" arg, if present, is parsed with {@link Version} and the prefix tree might be sensitive to it. |
| */ |
| public static SpatialPrefixTree makeSPT(Map<String,String> args, ClassLoader classLoader, SpatialContext ctx) { |
| //TODO refactor to use Java SPI like how Lucene already does for codecs/postingsFormats, etc |
| SpatialPrefixTreeFactory instance; |
| String cname = args.get(PREFIX_TREE); |
| if (cname == null) |
| cname = ctx.isGeo() ? "geohash" : "quad"; |
| if ("geohash".equalsIgnoreCase(cname)) |
| instance = new GeohashPrefixTree.Factory(); |
| else if ("quad".equalsIgnoreCase(cname)) |
| instance = new QuadPrefixTree.Factory(); |
| else if ("packedQuad".equalsIgnoreCase(cname)) |
| instance = new PackedQuadPrefixTree.Factory(); |
| else if ("s2".equalsIgnoreCase(cname)) |
| instance = new S2PrefixTree.Factory(); |
| else { |
| try { |
| Class<?> c = classLoader.loadClass(cname); |
| instance = (SpatialPrefixTreeFactory) c.newInstance(); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| instance.init(args, ctx); |
| return instance.newSPT(); |
| } |
| |
| protected void init(Map<String, String> args, SpatialContext ctx) { |
| this.args = args; |
| this.ctx = ctx; |
| initVersion(); |
| initMaxLevels(); |
| } |
| |
| protected void initVersion() { |
| String versionStr = args.get(VERSION); |
| try { |
| setVersion(versionStr == null ? Version.LATEST : Version.parseLeniently(versionStr)); |
| } catch (ParseException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| protected void initMaxLevels() { |
| String mlStr = args.get(MAX_LEVELS); |
| if (mlStr != null) { |
| maxLevels = Integer.valueOf(mlStr); |
| return; |
| } |
| |
| double degrees; |
| String maxDetailDistStr = args.get(MAX_DIST_ERR); |
| if (maxDetailDistStr == null) { |
| if (!ctx.isGeo()) { |
| return;//let default to max |
| } |
| degrees = DistanceUtils.dist2Degrees(DEFAULT_GEO_MAX_DETAIL_KM, DistanceUtils.EARTH_MEAN_RADIUS_KM); |
| } else { |
| degrees = Double.parseDouble(maxDetailDistStr); |
| } |
| maxLevels = getLevelForDistance(degrees); |
| } |
| |
| /** |
| * Set the version of Lucene this tree should mimic the behavior for for analysis. |
| */ |
| public void setVersion(Version v) { |
| version = v; |
| } |
| |
| /** |
| * Return the version of Lucene this tree will mimic the behavior of for analysis. |
| */ |
| public Version getVersion() { |
| return version; |
| } |
| |
| /** Calls {@link SpatialPrefixTree#getLevelForDistance(double)}. */ |
| protected abstract int getLevelForDistance(double degrees); |
| |
| protected abstract SpatialPrefixTree newSPT(); |
| |
| } |