| package org.apache.lucene.search; |
| |
| /* ==================================================================== |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, |
| * if any, must include the following acknowledgment: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowledgment may appear in the software itself, |
| * if and wherever such third-party acknowledgments normally appear. |
| * |
| * 4. The names "Apache" and "Apache Software Foundation" and |
| * "Apache Lucene" must not be used to endorse or promote products |
| * derived from this software without prior written permission. For |
| * written permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache", |
| * "Apache Lucene", nor may "Apache" appear in their name, without |
| * prior written permission of the Apache Software Foundation. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import java.io.IOException; |
| import java.util.BitSet; |
| |
| import org.apache.lucene.store.Directory; |
| import org.apache.lucene.document.Document; |
| import org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.index.Term; |
| import org.apache.lucene.util.PriorityQueue; |
| |
| /** Implements search over a single IndexReader. */ |
| public final class IndexSearcher extends Searcher { |
| IndexReader reader; |
| |
| /** Creates a searcher searching the index in the named directory. */ |
| public IndexSearcher(String path) throws IOException { |
| this(IndexReader.open(path)); |
| } |
| |
| /** Creates a searcher searching the index in the provided directory. */ |
| public IndexSearcher(Directory directory) throws IOException { |
| this(IndexReader.open(directory)); |
| } |
| |
| /** Creates a searcher searching the provided index. */ |
| public IndexSearcher(IndexReader r) { |
| reader = r; |
| } |
| |
| /** Frees resources associated with this Searcher. */ |
| public final void close() throws IOException { |
| reader.close(); |
| } |
| |
| final int docFreq(Term term) throws IOException { |
| return reader.docFreq(term); |
| } |
| |
| /** For use by {@link HitCollector} implementations. */ |
| public final Document doc(int i) throws IOException { |
| return reader.document(i); |
| } |
| |
| final int maxDoc() throws IOException { |
| return reader.maxDoc(); |
| } |
| |
| final TopDocs search(Query query, Filter filter, final int nDocs) |
| throws IOException { |
| Scorer scorer = Query.scorer(query, this, reader); |
| if (scorer == null) |
| return new TopDocs(0, new ScoreDoc[0]); |
| |
| final BitSet bits = filter != null ? filter.bits(reader) : null; |
| final HitQueue hq = new HitQueue(nDocs); |
| final int[] totalHits = new int[1]; |
| scorer.score(new HitCollector() { |
| private float minScore = 0.0f; |
| public final void collect(int doc, float score) { |
| if (score > 0.0f && // ignore zeroed buckets |
| (bits==null || bits.get(doc))) { // skip docs not in bits |
| totalHits[0]++; |
| if (score >= minScore) { |
| hq.put(new ScoreDoc(doc, score)); // update hit queue |
| if (hq.size() > nDocs) { // if hit queue overfull |
| hq.pop(); // remove lowest in hit queue |
| minScore = ((ScoreDoc)hq.top()).score; // reset minScore |
| } |
| } |
| } |
| } |
| }, reader.maxDoc()); |
| |
| ScoreDoc[] scoreDocs = new ScoreDoc[hq.size()]; |
| for (int i = hq.size()-1; i >= 0; i--) // put docs in array |
| scoreDocs[i] = (ScoreDoc)hq.pop(); |
| |
| return new TopDocs(totalHits[0], scoreDocs); |
| } |
| |
| /** Lower-level search API. |
| * |
| * <p>{@link HitCollector#collect(int,float)} is called for every non-zero |
| * scoring document. |
| * |
| * <p>Applications should only use this if they need <it>all</it> of the |
| * matching documents. The high-level search API ({@link |
| * Searcher#search(Query)}) is usually more efficient, as it skips |
| * non-high-scoring hits. |
| * |
| * @param query to match documents |
| * @param filter if non-null, a bitset used to eliminate some documents |
| * @param results to receive hits |
| */ |
| public final void search(Query query, Filter filter, |
| final HitCollector results) throws IOException { |
| HitCollector collector = results; |
| if (filter != null) { |
| final BitSet bits = filter.bits(reader); |
| collector = new HitCollector() { |
| public final void collect(int doc, float score) { |
| if (bits.get(doc)) { // skip docs not in bits |
| results.collect(doc, score); |
| } |
| } |
| }; |
| } |
| |
| Scorer scorer = Query.scorer(query, this, reader); |
| if (scorer == null) |
| return; |
| scorer.score(collector, reader.maxDoc()); |
| } |
| |
| } |