| 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 org.apache.lucene.index.DocsEnum; |
| import org.apache.lucene.index.Fields; |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.Terms; |
| import org.apache.lucene.index.TermsEnum; |
| import org.apache.lucene.util.BitDocIdSet; |
| import org.apache.lucene.util.Bits; |
| |
| /** |
| * A wrapper for {@link MultiTermQuery}, that exposes its |
| * functionality as a {@link Filter}. |
| * <P> |
| * <code>MultiTermQueryWrapperFilter</code> is not designed to |
| * be used by itself. Normally you subclass it to provide a Filter |
| * counterpart for a {@link MultiTermQuery} subclass. |
| * <P> |
| * For example, {@link TermRangeFilter} and {@link PrefixFilter} extend |
| * <code>MultiTermQueryWrapperFilter</code>. |
| * This class also provides the functionality behind |
| * {@link MultiTermQuery#CONSTANT_SCORE_FILTER_REWRITE}; |
| * this is why it is not abstract. |
| */ |
| public class MultiTermQueryWrapperFilter<Q extends MultiTermQuery> extends Filter { |
| |
| protected final Q query; |
| |
| /** |
| * Wrap a {@link MultiTermQuery} as a Filter. |
| */ |
| protected MultiTermQueryWrapperFilter(Q 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 |
| @SuppressWarnings({"unchecked","rawtypes"}) |
| 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( ((MultiTermQueryWrapperFilter)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(LeafReaderContext context, Bits acceptDocs) throws IOException { |
| final Terms terms = context.reader().terms(query.field); |
| if (terms == null) { |
| // field does not exist |
| return null; |
| } |
| |
| final TermsEnum termsEnum = query.getTermsEnum(terms); |
| assert termsEnum != null; |
| |
| BitDocIdSet.Builder builder = new BitDocIdSet.Builder(context.reader().maxDoc()); |
| DocsEnum docs = null; |
| while (termsEnum.next() != null) { |
| docs = termsEnum.docs(acceptDocs, docs, DocsEnum.FLAG_NONE); |
| builder.or(docs); |
| } |
| return builder.build(); |
| } |
| } |