beagled/Lucene.Net/Search/HitCollector.cs

   1 /*
   2  * Copyright 2004 The Apache Software Foundation
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 using System;
  18
  19 namespace Lucene.Net.Search
  20 {
  21
  22         /// <summary>Lower-level search API.
  23         /// <br>HitCollectors are primarily meant to be used to implement queries,
  24         /// sorting and filtering.
  25         /// </summary>
  26         /// <seealso cref="Searcher.Search(Query,HitCollector)">
  27         /// </seealso>
  28         /// <version>  $Id: HitCollector.cs,v 1.4 2006/10/02 17:09:04 joeshaw Exp $
  29         /// </version>
  30         public abstract class HitCollector
  31         {
  32                 /// <summary>Called once for every non-zero scoring document, with the document number
  33                 /// and its score.
  34                 ///
  35                 /// <P>If, for example, an application wished to collect all of the hits for a
  36                 /// query in a BitSet, then it might:<pre>
  37                 /// Searcher searcher = new IndexSearcher(indexReader);
  38                 /// final BitSet bits = new BitSet(indexReader.maxDoc());
  39                 /// searcher.search(query, new HitCollector() {
  40                 /// public void collect(int doc, float score) {
  41                 /// bits.set(doc);
  42                 /// }
  43                 /// });
  44                 /// </pre>
  45                 ///
  46                 /// <p>Note: This is called in an inner search loop.  For good search
  47                 /// performance, implementations of this method should not call
  48                 /// {@link Searcher#Doc(int)} or
  49                 /// {@link Lucene.Net.index.IndexReader#Document(int)} on every
  50                 /// document number encountered.  Doing so can slow searches by an order
  51                 /// of magnitude or more.
  52                 /// <p>Note: The <code>score</code> passed to this method is a raw score.
  53                 /// In other words, the score will not necessarily be a float whose value is
  54                 /// between 0 and 1.
  55                 /// </summary>
  56                 public abstract void  Collect(int doc, float score);
  57         }
  58 }