mcs/tools/monkeydoc/Lucene.Net/Lucene.Net/Search/ReqExclScorer.cs

   1 /*
   2  * Licensed to the Apache Software Foundation (ASF) under one or more
   3  * contributor license agreements.  See the NOTICE file distributed with
   4  * this work for additional information regarding copyright ownership.
   5  * The ASF licenses this file to You under the Apache License, Version 2.0
   6  * (the "License"); you may not use this file except in compliance with
   7  * the License.  You may obtain a copy of the License at
   8  *
   9  * http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 using System;
  19
  20 namespace Mono.Lucene.Net.Search
  21 {
  22
  23
  24         /// <summary>A Scorer for queries with a required subscorer
  25         /// and an excluding (prohibited) sub DocIdSetIterator.
  26         /// <br/>
  27         /// This <code>Scorer</code> implements {@link Scorer#SkipTo(int)},
  28         /// and it uses the skipTo() on the given scorers.
  29         /// </summary>
  30         class ReqExclScorer:Scorer
  31         {
  32                 private Scorer reqScorer;
  33                 private DocIdSetIterator exclDisi;
  34                 private int doc = - 1;
  35
  36                 /// <summary>Construct a <code>ReqExclScorer</code>.</summary>
  37                 /// <param name="reqScorer">The scorer that must match, except where
  38                 /// </param>
  39                 /// <param name="exclDisi">indicates exclusion.
  40                 /// </param>
  41                 public ReqExclScorer(Scorer reqScorer, DocIdSetIterator exclDisi):base(null)
  42                 { // No similarity used.
  43                         this.reqScorer = reqScorer;
  44                         this.exclDisi = exclDisi;
  45                 }
  46
  47                 /// <deprecated> use {@link #NextDoc()} instead.
  48                 /// </deprecated>
  49         [Obsolete("use NextDoc() instead. ")]
  50                 public override bool Next()
  51                 {
  52                         return NextDoc() != NO_MORE_DOCS;
  53                 }
  54
  55                 public override int NextDoc()
  56                 {
  57                         if (reqScorer == null)
  58                         {
  59                                 return doc;
  60                         }
  61                         doc = reqScorer.NextDoc();
  62                         if (doc == NO_MORE_DOCS)
  63                         {
  64                                 reqScorer = null; // exhausted, nothing left
  65                                 return doc;
  66                         }
  67                         if (exclDisi == null)
  68                         {
  69                                 return doc;
  70                         }
  71                         return doc = ToNonExcluded();
  72                 }
  73
  74                 /// <summary>Advance to non excluded doc.
  75                 /// <br/>On entry:
  76                 /// <ul>
  77                 /// <li>reqScorer != null, </li>
  78                 /// <li>exclScorer != null, </li>
  79                 /// <li>reqScorer was advanced once via next() or skipTo()
  80         /// and reqScorer.doc() may still be excluded.</li>
  81                 /// </ul>
  82                 /// Advances reqScorer a non excluded required doc, if any.
  83                 /// </summary>
  84                 /// <returns> true iff there is a non excluded required doc.
  85                 /// </returns>
  86                 private int ToNonExcluded()
  87                 {
  88                         int exclDoc = exclDisi.DocID();
  89                         int reqDoc = reqScorer.DocID(); // may be excluded
  90                         do
  91                         {
  92                                 if (reqDoc < exclDoc)
  93                                 {
  94                                         return reqDoc; // reqScorer advanced to before exclScorer, ie. not excluded
  95                                 }
  96                                 else if (reqDoc > exclDoc)
  97                                 {
  98                                         exclDoc = exclDisi.Advance(reqDoc);
  99                                         if (exclDoc == NO_MORE_DOCS)
 100                                         {
 101                                                 exclDisi = null; // exhausted, no more exclusions
 102                                                 return reqDoc;
 103                                         }
 104                                         if (exclDoc > reqDoc)
 105                                         {
 106                                                 return reqDoc; // not excluded
 107                                         }
 108                                 }
 109                         }
 110                         while ((reqDoc = reqScorer.NextDoc()) != NO_MORE_DOCS);
 111                         reqScorer = null; // exhausted, nothing left
 112                         return NO_MORE_DOCS;
 113                 }
 114
 115                 /// <deprecated> use {@link #DocID()} instead.
 116                 /// </deprecated>
 117         [Obsolete("use DocID() instead.")]
 118                 public override int Doc()
 119                 {
 120                         return reqScorer.Doc(); // reqScorer may be null when next() or skipTo() already return false
 121                 }
 122
 123                 public override int DocID()
 124                 {
 125                         return doc;
 126                 }
 127
 128                 /// <summary>Returns the score of the current document matching the query.
 129                 /// Initially invalid, until {@link #Next()} is called the first time.
 130                 /// </summary>
 131                 /// <returns> The score of the required scorer.
 132                 /// </returns>
 133                 public override float Score()
 134                 {
 135                         return reqScorer.Score(); // reqScorer may be null when next() or skipTo() already return false
 136                 }
 137
 138                 /// <deprecated> use {@link #Advance(int)} instead.
 139                 /// </deprecated>
 140         [Obsolete("use Advance(int) instead.")]
 141                 public override bool SkipTo(int target)
 142                 {
 143                         return Advance(target) != NO_MORE_DOCS;
 144                 }
 145
 146                 public override int Advance(int target)
 147                 {
 148                         if (reqScorer == null)
 149                         {
 150                                 return doc = NO_MORE_DOCS;
 151                         }
 152                         if (exclDisi == null)
 153                         {
 154                                 return doc = reqScorer.Advance(target);
 155                         }
 156                         if (reqScorer.Advance(target) == NO_MORE_DOCS)
 157                         {
 158                                 reqScorer = null;
 159                                 return doc = NO_MORE_DOCS;
 160                         }
 161                         return doc = ToNonExcluded();
 162                 }
 163
 164                 public override Explanation Explain(int doc)
 165                 {
 166                         Explanation res = new Explanation();
 167                         if (exclDisi.Advance(doc) == doc)
 168                         {
 169                                 res.SetDescription("excluded");
 170                         }
 171                         else
 172                         {
 173                                 res.SetDescription("not excluded");
 174                                 res.AddDetail(reqScorer.Explain(doc));
 175                         }
 176                         return res;
 177                 }
 178         }
 179 }