org.apache.solr.search.function.ReverseOrdFieldSource Maven / Gradle / Ivy
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/*
* 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.solr.search.function;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.LeafReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.MultiReader;
import org.apache.lucene.index.ReaderUtil;
import org.apache.lucene.index.SortedDocValues;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.queries.function.docvalues.IntDocValues;
import org.apache.lucene.search.SortedSetSelector;
import org.apache.solr.common.SolrException;
import org.apache.solr.index.SlowCompositeReaderWrapper;
import org.apache.solr.schema.SchemaField;
import org.apache.solr.search.NumericHidingLeafReader;
import org.apache.solr.search.SolrIndexSearcher;
/**
* Obtains the ordinal of the field value from {@link
* org.apache.lucene.index.LeafReader#getSortedDocValues} and reverses the order.
* The native lucene index order is used to assign an ordinal value for each field value.
* Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1.
*
* Example of reverse ordinal (rord):
* If there were only three field values: "apple","banana","pear"
* then rord("apple")=3, rord("banana")=2, ord("pear")=1
*
* WARNING: ord() depends on the position in an index and can thus change when other documents
* are inserted or deleted, or if a MultiSearcher is used.
* WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use since they must use a
* FieldCache entry at the top level reader, while sorting and function queries now use entries at
* the segment level. Hence sorting or using a different function query, in addition to ord()/rord()
* will double memory use.
*/
public class ReverseOrdFieldSource extends ValueSource {
public final String field;
public ReverseOrdFieldSource(String field) {
this.field = field;
}
@Override
public String description() {
return "rord(" + field + ')';
}
@Override
public FunctionValues getValues(Map context, LeafReaderContext readerContext)
throws IOException {
final int off = readerContext.docBase;
final LeafReader r;
Object o = context.get("searcher");
if (o instanceof SolrIndexSearcher) {
@SuppressWarnings("resource")
final SolrIndexSearcher is = (SolrIndexSearcher) o;
SchemaField sf = is.getSchema().getFieldOrNull(field);
if (sf != null && sf.getType().isPointField()) {
throw new SolrException(
SolrException.ErrorCode.BAD_REQUEST,
"rord() is not supported over Points based field " + field);
}
if (sf != null
&& sf.hasDocValues() == false
&& sf.multiValued() == false
&& sf.getType().getNumberType() != null) {
// it's a single-valued numeric field: we must hide the numeric
List leaves = is.getIndexReader().leaves();
LeafReader hidingLeaves[] = new LeafReader[leaves.size()];
int upto = 0;
for (LeafReaderContext raw : leaves) {
hidingLeaves[upto++] = NumericHidingLeafReader.wrap(raw.reader(), field);
}
r = SlowCompositeReaderWrapper.wrap(new MultiReader(hidingLeaves));
} else {
// reuse ordinalmap
r = ((SolrIndexSearcher) o).getSlowAtomicReader();
}
} else {
IndexReader topReader = ReaderUtil.getTopLevelContext(readerContext).reader();
r = SlowCompositeReaderWrapper.wrap(topReader);
}
// if it's e.g. tokenized/multivalued, emulate old behavior of single-valued fc
final SortedDocValues sindex =
SortedSetSelector.wrap(DocValues.getSortedSet(r, field), SortedSetSelector.Type.MIN);
final int end = sindex.getValueCount();
return new IntDocValues(this) {
@Override
public int intVal(int doc) throws IOException {
if (doc + off > sindex.docID()) {
sindex.advance(doc + off);
}
if (doc + off == sindex.docID()) {
return (end - sindex.ordValue() - 1);
} else {
return end;
}
}
};
}
@Override
public boolean equals(Object o) {
if (!(o instanceof ReverseOrdFieldSource)) return false;
ReverseOrdFieldSource other = (ReverseOrdFieldSource) o;
return this.field.equals(other.field);
}
private static final int hcode = ReverseOrdFieldSource.class.hashCode();
@Override
public int hashCode() {
return hcode + field.hashCode();
}
}