package org.apache.lucene.spatial.util;
/*
* 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.context.SpatialContext;
import com.spatial4j.core.distance.DistanceCalculator;
import com.spatial4j.core.shape.Point;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
* An implementation of the Lucene ValueSource that returns the spatial distance
* between an input point and a document's points in
* {@link ShapeFieldCacheProvider}. The shortest distance is returned if a
* document has more than one point.
*
* @lucene.internal
*/
public class ShapeFieldCacheDistanceValueSource extends ValueSource {
private final SpatialContext ctx;
private final Point from;
private final ShapeFieldCacheProvider<Point> provider;
private final double multiplier;
public ShapeFieldCacheDistanceValueSource(SpatialContext ctx,
ShapeFieldCacheProvider<Point> provider, Point from, double multiplier) {
this.ctx = ctx;
this.from = from;
this.provider = provider;
this.multiplier = multiplier;
}
@Override
public String description() {
return getClass().getSimpleName()+"("+provider+", "+from+")";
}
@Override
public FunctionValues getValues(Map context, final AtomicReaderContext readerContext) throws IOException {
return new FunctionValues() {
private final ShapeFieldCache<Point> cache =
provider.getCache(readerContext.reader());
private final Point from = ShapeFieldCacheDistanceValueSource.this.from;
private final DistanceCalculator calculator = ctx.getDistCalc();
private final double nullValue = (ctx.isGeo() ? 180 * multiplier : Double.MAX_VALUE);
@Override
public float floatVal(int doc) {
return (float) doubleVal(doc);
}
@Override
public double doubleVal(int doc) {
List<Point> vals = cache.getShapes( doc );
if( vals != null ) {
double v = calculator.distance(from, vals.get(0));
for( int i=1; i<vals.size(); i++ ) {
v = Math.min(v, calculator.distance(from, vals.get(i)));
}
return v * multiplier;
}
return nullValue;
}
@Override
public String toString(int doc) {
return description() + "=" + floatVal(doc);
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ShapeFieldCacheDistanceValueSource that = (ShapeFieldCacheDistanceValueSource) o;
if (!ctx.equals(that.ctx)) return false;
if (!from.equals(that.from)) return false;
if (!provider.equals(that.provider)) return false;
if (multiplier != that.multiplier) return false;
return true;
}
@Override
public int hashCode() {
return from.hashCode();
}
}