package org.apache.lucene.search;
/*
* 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 java.io.IOException;
import java.util.Comparator;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.SortedSetDocValues;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.util.Bits;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.OpenBitSet;
/**
* Rewrites MultiTermQueries into a filter, using DocTermOrds for term enumeration.
* <p>
* This can be used to perform these queries against an unindexed docvalues field.
* @lucene.experimental
*/
public final class DocTermOrdsRewriteMethod extends MultiTermQuery.RewriteMethod {
@Override
public Query rewrite(IndexReader reader, MultiTermQuery query) {
Query result = new ConstantScoreQuery(new MultiTermQueryDocTermOrdsWrapperFilter(query));
result.setBoost(query.getBoost());
return result;
}
static class MultiTermQueryDocTermOrdsWrapperFilter extends Filter {
protected final MultiTermQuery query;
/**
* Wrap a {@link MultiTermQuery} as a Filter.
*/
protected MultiTermQueryDocTermOrdsWrapperFilter(MultiTermQuery query) {
this.query = query;
}
@Override
public String toString() {
// query.toString should be ok for the filter, too, if the query boost is 1.0f
return query.toString();
}
@Override
public final boolean equals(final Object o) {
if (o==this) return true;
if (o==null) return false;
if (this.getClass().equals(o.getClass())) {
return this.query.equals( ((MultiTermQueryDocTermOrdsWrapperFilter)o).query );
}
return false;
}
@Override
public final int hashCode() {
return query.hashCode();
}
/** Returns the field name for this query */
public final String getField() { return query.getField(); }
/**
* Returns a DocIdSet with documents that should be permitted in search
* results.
*/
@Override
public DocIdSet getDocIdSet(AtomicReaderContext context, final Bits acceptDocs) throws IOException {
final SortedSetDocValues docTermOrds = FieldCache.DEFAULT.getDocTermOrds(context.reader(), query.field);
// Cannot use FixedBitSet because we require long index (ord):
final OpenBitSet termSet = new OpenBitSet(docTermOrds.getValueCount());
TermsEnum termsEnum = query.getTermsEnum(new Terms() {
@Override
public Comparator<BytesRef> getComparator() {
return BytesRef.getUTF8SortedAsUnicodeComparator();
}
@Override
public TermsEnum iterator(TermsEnum reuse) {
return docTermOrds.termsEnum();
}
@Override
public long getSumTotalTermFreq() {
return -1;
}
@Override
public long getSumDocFreq() {
return -1;
}
@Override
public int getDocCount() {
return -1;
}
@Override
public long size() {
return -1;
}
@Override
public boolean hasOffsets() {
return false;
}
@Override
public boolean hasPositions() {
return false;
}
@Override
public boolean hasPayloads() {
return false;
}
});
assert termsEnum != null;
if (termsEnum.next() != null) {
// fill into a OpenBitSet
do {
termSet.set(termsEnum.ord());
} while (termsEnum.next() != null);
} else {
return DocIdSet.EMPTY_DOCIDSET;
}
return new FieldCacheDocIdSet(context.reader().maxDoc(), acceptDocs) {
@Override
protected final boolean matchDoc(int doc) throws ArrayIndexOutOfBoundsException {
docTermOrds.setDocument(doc);
long ord;
// TODO: we could track max bit set and early terminate (since they come in sorted order)
while ((ord = docTermOrds.nextOrd()) != SortedSetDocValues.NO_MORE_ORDS) {
if (termSet.get(ord)) {
return true;
}
}
return false;
}
};
}
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
return true;
}
@Override
public int hashCode() {
return 877;
}
}