beagled/Lucene.Net/Index/SegmentTermPositions.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 using IndexInput = Lucene.Net.Store.IndexInput;
  19
  20 namespace Lucene.Net.Index
  21 {
  22
  23         sealed class SegmentTermPositions : SegmentTermDocs, TermPositions
  24         {
  25                 private IndexInput proxStream;
  26                 private int proxCount;
  27                 private int position;
  28
  29                 internal SegmentTermPositions(SegmentReader p) : base(p)
  30                 {
  31                         this.proxStream = (IndexInput) parent.proxStream.Clone();
  32                 }
  33
  34                 internal override void  Seek(TermInfo ti)
  35                 {
  36                         base.Seek(ti);
  37                         if (ti != null)
  38                                 proxStream.Seek(ti.proxPointer);
  39                         proxCount = 0;
  40                 }
  41
  42                 public override void  Close()
  43                 {
  44                         base.Close();
  45                         proxStream.Close();
  46                 }
  47
  48                 public int NextPosition()
  49                 {
  50                         proxCount--;
  51                         return position += proxStream.ReadVInt();
  52                 }
  53
  54                 protected internal override void  SkippingDoc()
  55                 {
  56                         for (int f = freq; f > 0; f--)
  57                         // skip all positions
  58                                 proxStream.ReadVInt();
  59                 }
  60
  61                 public override bool Next()
  62                 {
  63                         for (int f = proxCount; f > 0; f--)
  64                         // skip unread positions
  65                                 proxStream.ReadVInt();
  66
  67                         if (base.Next())
  68                         {
  69                                 // run super
  70                                 proxCount = freq; // note frequency
  71                                 position = 0; // reset position
  72                                 return true;
  73                         }
  74                         return false;
  75                 }
  76
  77                 public override int Read(int[] docs, int[] freqs)
  78                 {
  79                         throw new System.NotSupportedException("TermPositions does not support processing multiple documents in one call. Use TermDocs instead.");
  80                 }
  81
  82
  83                 /// <summary>Called by super.skipTo(). </summary>
  84                 protected internal override void  SkipProx(long proxPointer)
  85                 {
  86                         proxStream.Seek(proxPointer);
  87                         proxCount = 0;
  88                 }
  89         }
  90 }