/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.script.expression;
import java.io.IOException;
import java.util.Map;
import java.util.Objects;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.docvalues.DoubleDocValues;
import org.elasticsearch.index.fielddata.AtomicNumericFieldData;
import org.elasticsearch.index.fielddata.IndexFieldData;
import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
/**
* A ValueSource to create FunctionValues to get the count of the number of values in a field for a document.
*/
final class CountMethodValueSource extends ValueSource {
IndexFieldData<?> fieldData;
CountMethodValueSource(IndexFieldData<?> fieldData) {
Objects.requireNonNull(fieldData);
this.fieldData = fieldData;
}
@Override
@SuppressWarnings("rawtypes") // ValueSource uses a rawtype
public FunctionValues getValues(Map context, LeafReaderContext leaf) throws IOException {
AtomicNumericFieldData leafData = (AtomicNumericFieldData) fieldData.load(leaf);
final SortedNumericDoubleValues values = leafData.getDoubleValues();
return new DoubleDocValues(this) {
@Override
public double doubleVal(int doc) throws IOException {
if (values.advanceExact(doc)) {
return values.docValueCount();
} else {
return 0;
}
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
FieldDataValueSource that = (FieldDataValueSource) o;
return fieldData.equals(that.fieldData);
}
@Override
public int hashCode() {
return 31 * getClass().hashCode() + fieldData.hashCode();
}
@Override
public String description() {
return "count: field(" + fieldData.getFieldName() + ")";
}
}