/*
* 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.queries.function.valuesource;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.docvalues.FloatDocValues;
import org.apache.lucene.search.IndexSearcher;
import java.io.IOException;
import java.util.Map;
/**
* <code>LinearFloatFunction</code> implements a linear function over
* another {@link ValueSource}.
* <br>
* Normally Used as an argument to a {@link org.apache.lucene.queries.function.FunctionQuery}
*
*
*/
public class LinearFloatFunction extends ValueSource {
protected final ValueSource source;
protected final float slope;
protected final float intercept;
public LinearFloatFunction(ValueSource source, float slope, float intercept) {
this.source = source;
this.slope = slope;
this.intercept = intercept;
}
@Override
public String description() {
return slope + "*float(" + source.description() + ")+" + intercept;
}
@Override
public FunctionValues getValues(Map context, AtomicReaderContext readerContext) throws IOException {
final FunctionValues vals = source.getValues(context, readerContext);
return new FloatDocValues(this) {
@Override
public float floatVal(int doc) {
return vals.floatVal(doc) * slope + intercept;
}
@Override
public String toString(int doc) {
return slope + "*float(" + vals.toString(doc) + ")+" + intercept;
}
};
}
@Override
public void createWeight(Map context, IndexSearcher searcher) throws IOException {
source.createWeight(context, searcher);
}
@Override
public int hashCode() {
int h = Float.floatToIntBits(slope);
h = (h >>> 2) | (h << 30);
h += Float.floatToIntBits(intercept);
h ^= (h << 14) | (h >>> 19);
return h + source.hashCode();
}
@Override
public boolean equals(Object o) {
if (LinearFloatFunction.class != o.getClass()) return false;
LinearFloatFunction other = (LinearFloatFunction)o;
return this.slope == other.slope
&& this.intercept == other.intercept
&& this.source.equals(other.source);
}
}