| 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.Vector; |
| |
| import org.apache.lucene.document.Document; |
| import org.apache.lucene.index.Term; |
| import org.apache.lucene.util.PriorityQueue; |
| |
| /** Implements search over a set of Searcher's. */ |
| public final class MultiSearcher extends Searcher { |
| private Searcher[] searchers; |
| private int[] starts; |
| private int maxDoc = 0; |
| |
| /** Creates a searcher which searches <i>searchers</i>. */ |
| public MultiSearcher(Searcher[] searchers) throws IOException { |
| this.searchers = searchers; |
| |
| starts = new int[searchers.length + 1]; // build starts array |
| for (int i = 0; i < searchers.length; i++) { |
| starts[i] = maxDoc; |
| maxDoc += searchers[i].maxDoc(); // compute maxDocs |
| } |
| starts[searchers.length] = maxDoc; |
| } |
| |
| /** Frees resources associated with this Searcher. */ |
| public final void close() throws IOException { |
| for (int i = 0; i < searchers.length; i++) |
| searchers[i].close(); |
| } |
| |
| final int docFreq(Term term) throws IOException { |
| int docFreq = 0; |
| for (int i = 0; i < searchers.length; i++) |
| docFreq += searchers[i].docFreq(term); |
| return docFreq; |
| } |
| |
| /** For use by {@link HitCollector} implementations. */ |
| public final Document doc(int n) throws IOException { |
| int i = searcherIndex(n); // find searcher index |
| return searchers[i].doc(n - starts[i]); // dispatch to searcher |
| } |
| |
| /** For use by {@link HitCollector} implementations to identify the |
| * index of the sub-searcher that a particular hit came from. */ |
| public final int searcherIndex(int n) { // find searcher for doc n: |
| // replace w/ call to Arrays.binarySearch in Java 1.2 |
| int lo = 0; // search starts array |
| int hi = searchers.length - 1; // for first element less |
| // than n, return its index |
| while (hi >= lo) { |
| int mid = (lo + hi) >> 1; |
| int midValue = starts[mid]; |
| if (n < midValue) |
| hi = mid - 1; |
| else if (n > midValue) |
| lo = mid + 1; |
| else |
| return mid; |
| } |
| return hi; |
| } |
| |
| final int maxDoc() throws IOException { |
| return maxDoc; |
| } |
| |
| final TopDocs search(Query query, Filter filter, int nDocs) |
| throws IOException { |
| HitQueue hq = new HitQueue(nDocs); |
| float minScore = 0.0f; |
| int totalHits = 0; |
| |
| for (int i = 0; i < searchers.length; i++) { // search each searcher |
| TopDocs docs = searchers[i].search(query, filter, nDocs); |
| totalHits += docs.totalHits; // update totalHits |
| ScoreDoc[] scoreDocs = docs.scoreDocs; |
| for (int j = 0; j < scoreDocs.length; j++) { // merge scoreDocs into hq |
| ScoreDoc scoreDoc = scoreDocs[j]; |
| if (scoreDoc.score >= minScore) { |
| scoreDoc.doc += starts[i]; // convert doc |
| hq.put(scoreDoc); // 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 |
| } |
| } else |
| break; // no more scores > minScore |
| } |
| } |
| |
| 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, 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 { |
| for (int i = 0; i < searchers.length; i++) { |
| |
| final int start = starts[i]; |
| |
| searchers[i].search(query, filter, new HitCollector() { |
| public void collect(int doc, float score) { |
| results.collect(doc + start, score); |
| } |
| }); |
| |
| } |
| } |
| } |