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ASF GitHub Bot commented on LUCENE-8126: ---------------------------------------- Github user iverase commented on a diff in the pull request: https://github.com/apache/lucene-solr/pull/302#discussion_r160868387 --- Diff: lucene/spatial-extras/src/java/org/apache/lucene/spatial/prefix/tree/S2PrefixTreeCell.java --- @@ -0,0 +1,285 @@ +/* + * 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.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +import com.google.common.geometry.S2CellId; +import org.apache.lucene.util.BytesRef; +import org.locationtech.spatial4j.shape.Shape; +import org.locationtech.spatial4j.shape.SpatialRelation; + +/** + * This class represents a S2 pixel in the RPT. + * + * @lucene.internal + */ +class S2PrefixTreeCell implements Cell { + + //Faces of S2 Geometry + private static S2CellId[] FACES = new S2CellId[6]; + static { + FACES[0] = S2CellId.fromFacePosLevel(0, 0, 0); + FACES[1] = S2CellId.fromFacePosLevel(1, 0, 0); + FACES[2] = S2CellId.fromFacePosLevel(2, 0, 0); + FACES[3] = S2CellId.fromFacePosLevel(3, 0, 0); + FACES[4] = S2CellId.fromFacePosLevel(4, 0, 0); + FACES[5] = S2CellId.fromFacePosLevel(5, 0, 0); + } + + /*Special character to define a cell leaf*/ + private static final byte LEAF = '+'; + + /*Tokens are used to serialize cells*/ + private static final byte[] TOKENS; + /*Map containing mapping between tokens and integer values*/ + private static final Map<Byte,Integer> PIXELS; + static { + TOKENS = new byte[]{'0', '1', '2', '3', '4', '5'}; + PIXELS = new HashMap<>(6); + PIXELS.put(TOKENS[0], 0); + PIXELS.put(TOKENS[1], 1); + PIXELS.put(TOKENS[2], 2); + PIXELS.put(TOKENS[3], 3); + PIXELS.put(TOKENS[4], 4); + PIXELS.put(TOKENS[5], 5); + } + + S2CellId cellId; + int level; //cache level + S2PrefixTree tree; + + SpatialRelation shapeRel= null; + boolean isLeaf; + Shape shape = null; + + S2PrefixTreeCell(S2PrefixTree tree, S2CellId cellId){ + this.cellId= cellId; + this.tree = tree; + setLevel(); + if (getLevel() == tree.getMaxLevels()) { + setLeaf(); + } + } + + void readCell(S2PrefixTree tree, BytesRef ref){ + isLeaf = false; + shape = null; + shapeRel = null; + this.tree = tree; + cellId = getS2CellIdFromBytesRef(ref); + setLevel(); + if (isLeaf(ref) || getLevel() == tree.getMaxLevels()){ + setLeaf(); + } + } + + @Override + public SpatialRelation getShapeRel() { + return shapeRel; + } + + @Override + public void setShapeRel(SpatialRelation rel) { + shapeRel = rel; + } + + @Override + public boolean isLeaf() { + return isLeaf; + } + + @Override + public void setLeaf() { + isLeaf = true; + } + + @Override + public BytesRef getTokenBytesWithLeaf(BytesRef result) { + result = getTokenBytesNoLeaf(result); + //max levels do not have leaf + if (isLeaf() && !(getLevel() == tree.getMaxLevels())){ + //Add leaf byte + result.bytes[result.offset + result.length] = LEAF; + result.length++; + } + return result; + } + + @Override + public BytesRef getTokenBytesNoLeaf(BytesRef result) { + if (result == null){ + result = new BytesRef(); + } + getBytesRefFromS2CellId(cellId, result); + return result; + } + + @Override + public int getLevel() { + return this.level; + } + + /** + * Cache level of cell. + */ + private void setLevel() { --- End diff -- The method cellId.level() is probably efficient but because it can be called several times I think we are saving some ticks on the clock by caching it. > Spatial prefix tree based on S2 geometry > ---------------------------------------- > > Key: LUCENE-8126 > URL: https://issues.apache.org/jira/browse/LUCENE-8126 > Project: Lucene - Core > Issue Type: New Feature > Components: modules/spatial-extras > Reporter: Ignacio Vera > > Hi [~dsmiley], > I have been working on a prefix tree based on goggle S2 geometry > (https://s2geometry.io/) to be used mainly with Geo3d shapes with very > promising results, in particular for complex shapes (e.g polygons). Using > this pixelization scheme reduces the size of the index, improves the > performance of the queries and reduces the loading time for non-point shapes. > If you are ok with this contribution and before providing any code I would > like to understand what is the correct/prefered approach: > 1) Add new depency to the S2 library > (https://mvnrepository.com/artifact/io.sgr/s2-geometry-library-java). It has > Apache 2.0 license so it should be ok. > 2) Create a utility class with all methods necessary to navigate the S2 tree > and create shapes from S2 cells (basically port what we need from the library > into Lucene). > What do you think? -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org