org.apache.lucene.queries.function.valuesource.JoinDocFreqValueSource Maven / Gradle / Ivy
/*
* 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 java.io.IOException;
import java.util.Map;
import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.MultiTerms;
import org.apache.lucene.index.ReaderUtil;
import org.apache.lucene.index.SortedDocValues;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.docvalues.IntDocValues;
import org.apache.lucene.util.BytesRef;
/**
* Use a field value and find the Document Frequency within another field.
*
* @since solr 4.0
*/
public class JoinDocFreqValueSource extends FieldCacheSource {
public static final String NAME = "joindf";
protected final String qfield;
public JoinDocFreqValueSource(String field, String qfield) {
super(field);
this.qfield = qfield;
}
@Override
public String description() {
return NAME + "(" + field + ":(" + qfield + "))";
}
@Override
public FunctionValues getValues(Map context, LeafReaderContext readerContext)
throws IOException {
final SortedDocValues terms = DocValues.getSorted(readerContext.reader(), field);
final IndexReader top = ReaderUtil.getTopLevelContext(readerContext).reader();
Terms t = MultiTerms.getTerms(top, qfield);
final TermsEnum termsEnum = t == null ? TermsEnum.EMPTY : t.iterator();
return new IntDocValues(this) {
int lastDocID = -1;
@Override
public int intVal(int doc) throws IOException {
if (doc < lastDocID) {
throw new IllegalArgumentException(
"docs were sent out-of-order: lastDocID=" + lastDocID + " vs docID=" + doc);
}
lastDocID = doc;
int curDocID = terms.docID();
if (doc > curDocID) {
curDocID = terms.advance(doc);
}
if (doc == curDocID) {
BytesRef term = terms.lookupOrd(terms.ordValue());
if (termsEnum.seekExact(term)) {
return termsEnum.docFreq();
}
}
return 0;
}
};
}
@Override
public boolean equals(Object o) {
if (o.getClass() != JoinDocFreqValueSource.class) return false;
JoinDocFreqValueSource other = (JoinDocFreqValueSource) o;
if (!qfield.equals(other.qfield)) return false;
return super.equals(other);
}
@Override
public int hashCode() {
return qfield.hashCode() + super.hashCode();
}
}