package org.apache.lucene.spatial.prefix;
/*
* 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.
*/
import com.spatial4j.core.shape.Shape;
import org.apache.lucene.queries.TermsFilter;
import org.apache.lucene.search.Filter;
import org.apache.lucene.spatial.prefix.tree.Cell;
import org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree;
import org.apache.lucene.spatial.query.SpatialArgs;
import org.apache.lucene.spatial.query.SpatialOperation;
import org.apache.lucene.spatial.query.UnsupportedSpatialOperation;
import org.apache.lucene.util.BytesRef;
import java.util.List;
/**
* A basic implementation of {@link PrefixTreeStrategy} using a large {@link
* TermsFilter} of all the cells from {@link SpatialPrefixTree#getCells(com.spatial4j.core.shape.Shape,
* int, boolean, boolean)}. It only supports the search of indexed Point shapes.
* <p/>
* The precision of query shapes (distErrPct) is an important factor in using
* this Strategy. If the precision is too precise then it will result in many
* terms which will amount to a slower query.
*
* @lucene.experimental
*/
public class TermQueryPrefixTreeStrategy extends PrefixTreeStrategy {
public TermQueryPrefixTreeStrategy(SpatialPrefixTree grid, String fieldName) {
super(grid, fieldName,
false);//do not simplify indexed cells
}
@Override
public Filter makeFilter(SpatialArgs args) {
final SpatialOperation op = args.getOperation();
if (op != SpatialOperation.Intersects)
throw new UnsupportedSpatialOperation(op);
Shape shape = args.getShape();
int detailLevel = grid.getLevelForDistance(args.resolveDistErr(ctx, distErrPct));
List<Cell> cells = grid.getCells(shape, detailLevel,
false,//no parents
true);//simplify
BytesRef[] terms = new BytesRef[cells.size()];
int i = 0;
for (Cell cell : cells) {
terms[i++] = new BytesRef(cell.getTokenString());
}
return new TermsFilter(getFieldName(), terms);
}
}