package org.apache.lucene.queries.function.valuesource;
/*
* 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.AtomicReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.util.BytesRef;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
/**
* {@link ValueSource} implementation which only returns the values from the provided
* ValueSources which are available for a particular docId. Consequently, when combined
* with a {@link ConstValueSource}, this function serves as a way to return a default
* value when the values for a field are unavailable.
*/
public class DefFunction extends MultiFunction {
public DefFunction(List<ValueSource> sources) {
super(sources);
}
@Override
protected String name() {
return "def";
}
@Override
public FunctionValues getValues(Map fcontext, AtomicReaderContext readerContext) throws IOException {
return new Values(valsArr(sources, fcontext, readerContext)) {
final int upto = valsArr.length - 1;
private FunctionValues get(int doc) {
for (int i=0; i<upto; i++) {
FunctionValues vals = valsArr[i];
if (vals.exists(doc)) {
return vals;
}
}
return valsArr[upto];
}
@Override
public byte byteVal(int doc) {
return get(doc).byteVal(doc);
}
@Override
public short shortVal(int doc) {
return get(doc).shortVal(doc);
}
@Override
public float floatVal(int doc) {
return get(doc).floatVal(doc);
}
@Override
public int intVal(int doc) {
return get(doc).intVal(doc);
}
@Override
public long longVal(int doc) {
return get(doc).longVal(doc);
}
@Override
public double doubleVal(int doc) {
return get(doc).doubleVal(doc);
}
@Override
public String strVal(int doc) {
return get(doc).strVal(doc);
}
@Override
public boolean boolVal(int doc) {
return get(doc).boolVal(doc);
}
@Override
public boolean bytesVal(int doc, BytesRef target) {
return get(doc).bytesVal(doc, target);
}
@Override
public Object objectVal(int doc) {
return get(doc).objectVal(doc);
}
@Override
public boolean exists(int doc) {
// return true if any source is exists?
for (FunctionValues vals : valsArr) {
if (vals.exists(doc)) {
return true;
}
}
return false;
}
@Override
public ValueFiller getValueFiller() {
// TODO: need ValueSource.type() to determine correct type
return super.getValueFiller();
}
};
}
}