/*
* Hibernate Search, full-text search for your domain model
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.search.spatial.impl;
import java.io.IOException;
import org.apache.lucene.index.AtomicReader;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.FieldCache;
import org.apache.lucene.search.FieldCache.Doubles;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.FilteredDocIdSet;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.QueryWrapperFilter;
import org.apache.lucene.util.Bits;
import org.hibernate.search.spatial.Coordinates;
/**
* Lucene Filter for filtering documents which have been indexed with Hibernate Search spatial Field bridge
* Use double lat,long field in the index from a Coordinates field declaration
*
* @author Nicolas Helleringer <nicolas.helleringer@novacodex.net>
* @see org.hibernate.search.spatial.SpatialFieldBridgeByHash
* @see org.hibernate.search.spatial.SpatialFieldBridgeByRange
* @see org.hibernate.search.spatial.Coordinates
*/
public final class DistanceFilter extends Filter {
private Filter previousFilter;
private Point center;
private double radius;
private String coordinatesField;
private String latitudeField;
private String longitudeField;
/**
* Construct a Distance Filter to match document distant at most of radius from center Point
*
* @param previousFilter previous Filter in the chain. As Distance is costly by retrieving the lat and long field
* it is better to use it last
* @param centerCoordinates center of the search perimeter
* @param radius radius of the search perimeter
* @param coordinatesField name of the field implementing Coordinates
* @see org.hibernate.search.spatial.Coordinates
*/
public DistanceFilter(Filter previousFilter, Coordinates centerCoordinates, double radius, String coordinatesField) {
if ( previousFilter != null ) {
this.previousFilter = previousFilter;
}
else {
this.previousFilter = new QueryWrapperFilter( new MatchAllDocsQuery() );
}
this.center = Point.fromCoordinates( centerCoordinates );
this.radius = radius;
this.coordinatesField = coordinatesField;
}
/**
* Construct a Distance Filter to match document distant at most of radius from center Point
*
* @param previousFilter previous Filter in the chain. As Distance is costly by retrieving the lat and long field
* it is better to use it last
* @param centerCoordinates center of the search perimeter
* @param radius radius of the search perimeter
* @param latitudeField name of the field hosting latitude
* @param longitudeField name of the field hosting longitude
* @see org.hibernate.search.spatial.Coordinates
*/
public DistanceFilter(Filter previousFilter, Coordinates centerCoordinates, double radius, String latitudeField, String longitudeField) {
if ( previousFilter != null ) {
this.previousFilter = previousFilter;
}
else {
this.previousFilter = new QueryWrapperFilter( new MatchAllDocsQuery() );
}
this.center = Point.fromCoordinates( centerCoordinates );
this.radius = radius;
this.coordinatesField = null;
this.latitudeField = latitudeField;
this.longitudeField = longitudeField;
}
/**
* Returns Doc Ids by retrieving their lat,long and checking if within distance(radius) of the center of the search
*
* @param reader reader to the index
*/
@Override
public DocIdSet getDocIdSet(AtomicReaderContext context, Bits acceptDocs) throws IOException {
final AtomicReader atomicReader = context.reader();
final Doubles latitudeValues = FieldCache.DEFAULT.getDoubles( atomicReader, getLatitudeField(), false );
final Doubles longitudeValues = FieldCache.DEFAULT.getDoubles( atomicReader, getLongitudeField(), false );
DocIdSet docs = previousFilter.getDocIdSet( context, acceptDocs );
if ( ( docs == null ) || ( docs.iterator() == null ) ) {
return null;
}
return new FilteredDocIdSet( docs ) {
@Override
protected boolean match(int documentIndex) {
if ( center.getDistanceTo( latitudeValues.get( documentIndex ), longitudeValues.get( documentIndex ) ) <= radius ) {
return true;
}
else {
return false;
}
}
};
}
private String getLatitudeField() {
if ( latitudeField != null ) {
return latitudeField;
}
else {
return SpatialHelper.formatLatitude( coordinatesField );
}
}
private String getLongitudeField() {
if ( longitudeField != null ) {
return longitudeField;
}
else {
return SpatialHelper.formatLongitude( coordinatesField );
}
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append( "DistanceFilter" );
sb.append( "{previousFilter=" ).append( previousFilter );
sb.append( ", center=" ).append( center );
sb.append( ", radius=" ).append( radius );
if ( coordinatesField != null ) {
sb.append( ", coordinatesField='" ).append( coordinatesField ).append( '\'' );
}
else {
sb.append( ", latitudeField=" ).append( latitudeField );
sb.append( ", longitudeField=" ).append( longitudeField ).append( '\'' );
}
sb.append( '}' );
return sb.toString();
}
}