| package org.apache.lucene.search; |
| /** |
| * Copyright 2007 The Apache Software Foundation |
| * |
| * Licensed 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 org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.search.spans.SpanQuery; |
| import org.apache.lucene.search.spans.Spans; |
| import org.apache.lucene.util.FixedBitSet; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Constrains search results to only match those which also match a provided |
| * query. Also provides position information about where each document matches |
| * at the cost of extra space compared with the QueryWrapperFilter. |
| * There is an added cost to this above what is stored in a {@link QueryWrapperFilter}. Namely, |
| * the position information for each matching document is stored. |
| * <p/> |
| * This filter does not cache. See the {@link org.apache.lucene.search.CachingSpanFilter} for a wrapper that |
| * caches. |
| */ |
| public class SpanQueryFilter extends SpanFilter { |
| protected SpanQuery query; |
| |
| protected SpanQueryFilter() |
| { |
| |
| } |
| |
| /** Constructs a filter which only matches documents matching |
| * <code>query</code>. |
| * @param query The {@link org.apache.lucene.search.spans.SpanQuery} to use as the basis for the Filter. |
| */ |
| public SpanQueryFilter(SpanQuery query) { |
| this.query = query; |
| } |
| |
| @Override |
| public DocIdSet getDocIdSet(IndexReader reader) throws IOException { |
| SpanFilterResult result = bitSpans(reader); |
| return result.getDocIdSet(); |
| } |
| |
| @Override |
| public SpanFilterResult bitSpans(IndexReader reader) throws IOException { |
| |
| final FixedBitSet bits = new FixedBitSet(reader.maxDoc()); |
| Spans spans = query.getSpans(reader); |
| List<SpanFilterResult.PositionInfo> tmp = new ArrayList<SpanFilterResult.PositionInfo>(20); |
| int currentDoc = -1; |
| SpanFilterResult.PositionInfo currentInfo = null; |
| while (spans.next()) |
| { |
| int doc = spans.doc(); |
| bits.set(doc); |
| if (currentDoc != doc) |
| { |
| currentInfo = new SpanFilterResult.PositionInfo(doc); |
| tmp.add(currentInfo); |
| currentDoc = doc; |
| } |
| currentInfo.addPosition(spans.start(), spans.end()); |
| } |
| return new SpanFilterResult(bits, tmp); |
| } |
| |
| |
| public SpanQuery getQuery() { |
| return query; |
| } |
| |
| @Override |
| public String toString() { |
| return "SpanQueryFilter(" + query + ")"; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| return o instanceof SpanQueryFilter && this.query.equals(((SpanQueryFilter) o).query); |
| } |
| |
| @Override |
| public int hashCode() { |
| return query.hashCode() ^ 0x923F64B9; |
| } |
| } |