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.AtomicReaderContext;
import org.apache.lucene.util.Bits;
/**
* Constrains search results to only match those which also match a provided
* query.
*
* <p> This could be used, for example, with a {@link NumericRangeQuery} on a suitably
* formatted date field to implement date filtering. One could re-use a single
* CachingWrapperFilter(QueryWrapperFilter) that matches, e.g., only documents modified
* within the last week. This would only need to be reconstructed once per day.
*/
public class QueryWrapperFilter extends Filter {
private final Query query;
/** Constructs a filter which only matches documents matching
* <code>query</code>.
*/
public QueryWrapperFilter(Query query) {
if (query == null)
throw new NullPointerException("Query may not be null");
this.query = query;
}
/** returns the inner Query */
public final Query getQuery() {
return query;
}
@Override
public DocIdSet getDocIdSet(final AtomicReaderContext context, final Bits acceptDocs) throws IOException {
// get a private context that is used to rewrite, createWeight and score eventually
final AtomicReaderContext privateContext = context.reader().getContext();
final Weight weight = new IndexSearcher(privateContext).createNormalizedWeight(query);
return new DocIdSet() {
@Override
public DocIdSetIterator iterator() throws IOException {
return weight.scorer(privateContext, true, false, acceptDocs);
}
@Override
public boolean isCacheable() { return false; }
};
}
@Override
public String toString() {
return "QueryWrapperFilter(" + query + ")";
}
@Override
public boolean equals(Object o) {
if (!(o instanceof QueryWrapperFilter))
return false;
return this.query.equals(((QueryWrapperFilter)o).query);
}
@Override
public int hashCode() {
return query.hashCode() ^ 0x923F64B9;
}
}