| 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.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 the FieldCache for term enumeration. |
| * <p> |
| * WARNING: This is only appropriate for single-valued unanalyzed fields. Additionally, for |
| * most queries this method is actually SLOWER than using the default CONSTANT_SCORE_AUTO |
| * in MultiTermQuery. This method is only faster than other methods for certain queries, |
| * such as ones that enumerate many terms. |
| * |
| * @lucene.experimental |
| */ |
| public final class FieldCacheRewriteMethod extends MultiTermQuery.RewriteMethod { |
| |
| @Override |
| public Query rewrite(IndexReader reader, MultiTermQuery query) { |
| Query result = new ConstantScoreQuery(new MultiTermQueryFieldCacheWrapperFilter(query)); |
| result.setBoost(query.getBoost()); |
| return result; |
| } |
| |
| static class MultiTermQueryFieldCacheWrapperFilter extends Filter { |
| |
| protected final MultiTermQuery query; |
| |
| /** |
| * Wrap a {@link MultiTermQuery} as a Filter. |
| */ |
| protected MultiTermQueryFieldCacheWrapperFilter(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( ((MultiTermQueryFieldCacheWrapperFilter)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 FieldCache.DocTermsIndex fcsi = FieldCache.DEFAULT.getTermsIndex(context.reader(), query.field); |
| // Cannot use FixedBitSet because we require long index (ord): |
| final OpenBitSet termSet = new OpenBitSet(fcsi.numOrd()); |
| TermsEnum termsEnum = query.getTermsEnum(new Terms() { |
| |
| @Override |
| public Comparator<BytesRef> getComparator() throws IOException { |
| return BytesRef.getUTF8SortedAsUnicodeComparator(); |
| } |
| |
| @Override |
| public TermsEnum iterator(TermsEnum reuse) throws IOException { |
| return fcsi.getTermsEnum(); |
| } |
| |
| @Override |
| public long getSumTotalTermFreq() { |
| return -1; |
| } |
| |
| @Override |
| public long getSumDocFreq() throws IOException { |
| return -1; |
| } |
| |
| @Override |
| public int getDocCount() throws IOException { |
| return -1; |
| } |
| |
| @Override |
| public long size() throws IOException { |
| return -1; |
| } |
| }); |
| |
| assert termsEnum != null; |
| if (termsEnum.next() != null) { |
| // fill into a OpenBitSet |
| do { |
| long ord = termsEnum.ord(); |
| if (ord > 0) { |
| termSet.set(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 { |
| return termSet.get(fcsi.getOrd(doc)); |
| } |
| }; |
| } |
| } |
| } |