/**
* 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.geohash;
import java.io.IOException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.FieldCache;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.FilteredDocIdSet;
import org.apache.lucene.spatial.tier.DistanceFilter;
import org.apache.lucene.spatial.tier.DistanceUtils;
/** <p><font color="red"><b>NOTE:</b> This API is still in
* flux and might change in incompatible ways in the next
* release.</font>
*/
public class GeoHashDistanceFilter extends DistanceFilter {
/**
*
*/
private static final long serialVersionUID = 1L;
private double lat;
private double lng;
private String geoHashField;
/**
* Provide a distance filter based from a center point with a radius
* in miles
* @param startingFilter
* @param lat
* @param lng
* @param miles
*/
public GeoHashDistanceFilter(Filter startingFilter, double lat, double lng, double miles, String geoHashField) {
super(startingFilter, miles);
this.lat = lat;
this.lng = lng;
this.geoHashField = geoHashField;
}
@Override
public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
final String[] geoHashValues = FieldCache.DEFAULT.getStrings(reader, geoHashField);
final int docBase = nextDocBase;
nextDocBase += reader.maxDoc();
return new FilteredDocIdSet(startingFilter.getDocIdSet(reader)) {
public boolean match(int doc) {
String geoHash = geoHashValues[doc];
double[] coords = GeoHashUtils.decode(geoHash);
double x = coords[0];
double y = coords[1];
// round off lat / longs if necessary
// x = DistanceHandler.getPrecision(x, precise);
// y = DistanceHandler.getPrecision(y, precise);
Double cachedDistance = distanceLookupCache.get(geoHash);
double d;
if (cachedDistance != null) {
d = cachedDistance.doubleValue();
} else {
d = DistanceUtils.getInstance().getDistanceMi(lat, lng, x, y);
distanceLookupCache.put(geoHash, d);
}
if (d < distance){
distances.put(doc+docBase, d);
return true;
} else {
return false;
}
}
};
}
/** Returns true if <code>o</code> is equal to this. */
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (!(o instanceof GeoHashDistanceFilter)) return false;
GeoHashDistanceFilter other = (GeoHashDistanceFilter) o;
if (!this.startingFilter.equals(other.startingFilter) ||
this.distance != other.distance ||
this.lat != other.lat ||
this.lng != other.lng ||
!this.geoHashField.equals(other.geoHashField) ) {
return false;
}
return true;
}
/** Returns a hash code value for this object.*/
@Override
public int hashCode() {
int h = new Double(distance).hashCode();
h ^= startingFilter.hashCode();
h ^= new Double(lat).hashCode();
h ^= new Double(lng).hashCode();
h ^= geoHashField.hashCode();
return h;
}
}