/*
* Licensed to Elastic Search and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Elastic Search 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.elasticsearch.index.search.geo;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.Filter;
import org.elasticsearch.common.lucene.docset.GetDocSet;
import org.elasticsearch.index.cache.field.data.FieldDataCache;
import org.elasticsearch.index.mapper.geo.GeoPointFieldData;
import org.elasticsearch.index.mapper.geo.GeoPointFieldDataType;
import java.io.IOException;
/**
* @author kimchy (shay.banon)
*/
public class GeoPolygonFilter extends Filter {
private final Point[] points;
private final String fieldName;
private final FieldDataCache fieldDataCache;
public GeoPolygonFilter(Point[] points, String fieldName, FieldDataCache fieldDataCache) {
this.points = points;
this.fieldName = fieldName;
this.fieldDataCache = fieldDataCache;
}
public Point[] points() {
return points;
}
public String fieldName() {
return this.fieldName;
}
@Override public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
final GeoPointFieldData fieldData = (GeoPointFieldData) fieldDataCache.cache(GeoPointFieldDataType.TYPE, reader, fieldName);
return new GetDocSet(reader.maxDoc()) {
@Override public boolean isCacheable() {
// not cacheable for several reasons:
// 1. It is only relevant when _cache is set to true, and then, we really want to create in mem bitset
// 2. Its already fast without in mem bitset, since it works with field data
return false;
}
@Override public boolean get(int doc) throws IOException {
if (!fieldData.hasValue(doc)) {
return false;
}
if (fieldData.multiValued()) {
double[] lats = fieldData.latValues(doc);
double[] lons = fieldData.lonValues(doc);
for (int i = 0; i < lats.length; i++) {
if (pointInPolygon(points, lats[i], lons[i])) {
return true;
}
}
} else {
double lat = fieldData.latValue(doc);
double lon = fieldData.lonValue(doc);
return pointInPolygon(points, lat, lon);
}
return false;
}
};
}
private static boolean pointInPolygon(Point[] points, double lat, double lon) {
int i;
int j = points.length - 1;
boolean inPoly = false;
for (i = 0; i < points.length; i++) {
if (points[i].lon < lon && points[j].lon >= lon
|| points[j].lon < lon && points[i].lon >= lon) {
if (points[i].lat + (lon - points[i].lon) /
(points[j].lon - points[i].lon) * (points[j].lat - points[i].lat) < lat) {
inPoly = !inPoly;
}
}
j = i;
}
return inPoly;
}
public static class Point {
public double lat;
public double lon;
public Point() {
}
public Point(double lat, double lon) {
this.lat = lat;
this.lon = lon;
}
}
}