package org.apache.solr.search.function.distance;
/**
* 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 org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.spatial.DistanceUtils;
import org.apache.solr.common.SolrException;
import org.apache.solr.search.function.MultiValueSource;
import org.apache.solr.search.function.DocValues;
import org.apache.solr.search.function.ValueSource;
import java.io.IOException;
import java.util.Map;
/**
* Calculate the Haversine formula (distance) between any two points on a sphere
* Takes in four value sources: (latA, lonA); (latB, lonB).
* <p/>
* Assumes the value sources are in radians unless
* <p/>
* See http://en.wikipedia.org/wiki/Great-circle_distance and
* http://en.wikipedia.org/wiki/Haversine_formula for the actual formula and
* also http://www.movable-type.co.uk/scripts/latlong.html
*/
public class HaversineFunction extends ValueSource {
private MultiValueSource p1;
private MultiValueSource p2;
private boolean convertToRadians = false;
private double radius;
public HaversineFunction(MultiValueSource p1, MultiValueSource p2, double radius) {
this(p1, p2, radius, false);
}
public HaversineFunction(MultiValueSource p1, MultiValueSource p2, double radius, boolean convertToRads){
this.p1 = p1;
this.p2 = p2;
if (p1.dimension() != 2 || p2.dimension() != 2) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Illegal dimension for value sources");
}
this.radius = radius;
this.convertToRadians = convertToRads;
}
protected String name() {
return "hsin";
}
/**
* @param doc The doc to score
* @param p1DV
* @param p2DV
* @return The haversine distance formula
*/
protected double distance(int doc, DocValues p1DV, DocValues p2DV) {
double[] p1D = new double[2];
double[] p2D = new double[2];
p1DV.doubleVal(doc, p1D);
p2DV.doubleVal(doc, p2D);
double x1;
double y1;
double x2;
double y2;
if (convertToRadians) {
x1 = p1D[0] * DistanceUtils.DEGREES_TO_RADIANS;
y1 = p1D[1] * DistanceUtils.DEGREES_TO_RADIANS;
x2 = p2D[0] * DistanceUtils.DEGREES_TO_RADIANS;
y2 = p2D[1] * DistanceUtils.DEGREES_TO_RADIANS;
} else {
x1 = p1D[0];
y1 = p1D[1];
x2 = p2D[0];
y2 = p2D[1];
}
return DistanceUtils.haversine(x1, y1, x2, y2, radius);
}
@Override
public DocValues getValues(Map context, IndexReader reader) throws IOException {
final DocValues vals1 = p1.getValues(context, reader);
final DocValues vals2 = p2.getValues(context, reader);
return new DocValues() {
@Override
public float floatVal(int doc) {
return (float) doubleVal(doc);
}
@Override
public int intVal(int doc) {
return (int) doubleVal(doc);
}
@Override
public long longVal(int doc) {
return (long) doubleVal(doc);
}
@Override
public double doubleVal(int doc) {
return distance(doc, vals1, vals2);
}
@Override
public String strVal(int doc) {
return Double.toString(doubleVal(doc));
}
@Override
public String toString(int doc) {
StringBuilder sb = new StringBuilder();
sb.append(name()).append('(');
sb.append(vals1.toString(doc)).append(',').append(vals2.toString(doc));
sb.append(')');
return sb.toString();
}
};
}
@Override
public void createWeight(Map context, Searcher searcher) throws IOException {
p1.createWeight(context, searcher);
p2.createWeight(context, searcher);
}
@Override
public boolean equals(Object o) {
if (this.getClass() != o.getClass()) return false;
HaversineFunction other = (HaversineFunction) o;
return this.name().equals(other.name())
&& p1.equals(other.p1) &&
p2.equals(other.p2) && radius == other.radius;
}
@Override
public int hashCode() {
int result;
long temp;
result = p1.hashCode();
result = 31 * result + p2.hashCode();
result = 31 * result + name().hashCode();
temp = Double.doubleToRawLongBits(radius);
result = 31 * result + (int) (temp ^ (temp >>> 32));
return result;
}
@Override
public String description() {
StringBuilder sb = new StringBuilder();
sb.append(name()).append('(');
sb.append(p1).append(',').append(p2);
sb.append(')');
return sb.toString();
}
}