beagled/Lucene.Net/Search/FieldCache.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 using System;
  17 using IndexReader = Lucene.Net.Index.IndexReader;
  18 namespace Lucene.Net.Search
  19 {
  20
  21         /// <summary> Expert: Maintains caches of term values.
  22         ///
  23         /// <p>Created: May 19, 2004 11:13:14 AM
  24         ///
  25         /// </summary>
  26         /// <author>   Tim Jones (Nacimiento Software)
  27         /// </author>
  28         /// <since>   lucene 1.4
  29         /// </since>
  30         /// <version>  $Id: FieldCache.cs,v 1.1 2005/01/17 19:54:30 joeshaw Exp $
  31         /// </version>
  32         /// <summary>Expert: Stores term text values and document ordering data. </summary>
  33         public class StringIndex
  34         {
  35
  36                 /// <summary>All the term values, in natural order. </summary>
  37                 public System.String[] lookup;
  38
  39                 /// <summary>For each document, an index into the lookup array. </summary>
  40                 public int[] order;
  41
  42                 /// <summary>Creates one of these objects </summary>
  43                 public StringIndex(int[] values, System.String[] lookup)
  44                 {
  45                         this.order = values;
  46                         this.lookup = lookup;
  47                 }
  48         }
  49         public struct FieldCache_Fields
  50     {
  51                 /// <summary>Indicator for StringIndex values in the cache. </summary>
  52                 // NOTE: the value assigned to this constant must not be
  53                 // the same as any of those in SortField!!
  54                 public readonly static int STRING_INDEX = - 1;
  55                 /// <summary>Expert: The cache used internally by sorting and range query classes. </summary>
  56                 public readonly static FieldCache DEFAULT;
  57                 static FieldCache_Fields()
  58                 {
  59                         DEFAULT = new FieldCacheImpl();
  60                 }
  61         }
  62         public interface FieldCache
  63         {
  64
  65
  66                 /// <summary>Checks the internal cache for an appropriate entry, and if none is
  67                 /// found, reads the terms in <code>Field</code> as integers and returns an array
  68                 /// of size <code>reader.maxDoc()</code> of the value each document
  69                 /// has in the given Field.
  70                 /// </summary>
  71                 /// <param name="reader"> Used to get Field values.
  72                 /// </param>
  73                 /// <param name="Field">  Which Field contains the integers.
  74                 /// </param>
  75                 /// <returns> The values in the given Field for each document.
  76                 /// </returns>
  77                 /// <throws>  IOException  If any error occurs. </throws>
  78                 int[] GetInts(IndexReader reader, System.String field);
  79
  80                 /// <summary>Checks the internal cache for an appropriate entry, and if
  81                 /// none is found, reads the terms in <code>Field</code> as floats and returns an array
  82                 /// of size <code>reader.maxDoc()</code> of the value each document
  83                 /// has in the given Field.
  84                 /// </summary>
  85                 /// <param name="reader"> Used to get Field values.
  86                 /// </param>
  87                 /// <param name="Field">  Which Field contains the floats.
  88                 /// </param>
  89                 /// <returns> The values in the given Field for each document.
  90                 /// </returns>
  91                 /// <throws>  IOException  If any error occurs. </throws>
  92                 float[] GetFloats(IndexReader reader, System.String field);
  93
  94                 /// <summary>Checks the internal cache for an appropriate entry, and if none
  95                 /// is found, reads the term values in <code>Field</code> and returns an array
  96                 /// of size <code>reader.maxDoc()</code> containing the value each document
  97                 /// has in the given Field.
  98                 /// </summary>
  99                 /// <param name="reader"> Used to get Field values.
 100                 /// </param>
 101                 /// <param name="Field">  Which Field contains the strings.
 102                 /// </param>
 103                 /// <returns> The values in the given Field for each document.
 104                 /// </returns>
 105                 /// <throws>  IOException  If any error occurs. </throws>
 106                 System.String[] GetStrings(IndexReader reader, System.String field);
 107
 108                 /// <summary>Checks the internal cache for an appropriate entry, and if none
 109                 /// is found reads the term values in <code>Field</code> and returns
 110                 /// an array of them in natural order, along with an array telling
 111                 /// which element in the term array each document uses.
 112                 /// </summary>
 113                 /// <param name="reader"> Used to get Field values.
 114                 /// </param>
 115                 /// <param name="Field">  Which Field contains the strings.
 116                 /// </param>
 117                 /// <returns> Array of terms and index into the array for each document.
 118                 /// </returns>
 119                 /// <throws>  IOException  If any error occurs. </throws>
 120                 StringIndex GetStringIndex(IndexReader reader, System.String field);
 121
 122                 /// <summary>Checks the internal cache for an appropriate entry, and if
 123                 /// none is found reads <code>Field</code> to see if it contains integers, floats
 124                 /// or strings, and then calls one of the other methods in this class to get the
 125                 /// values.  For string values, a StringIndex is returned.  After
 126                 /// calling this method, there is an entry in the cache for both
 127                 /// type <code>AUTO</code> and the actual found type.
 128                 /// </summary>
 129                 /// <param name="reader"> Used to get Field values.
 130                 /// </param>
 131                 /// <param name="Field">  Which Field contains the values.
 132                 /// </param>
 133                 /// <returns> int[], float[] or StringIndex.
 134                 /// </returns>
 135                 /// <throws>  IOException  If any error occurs. </throws>
 136                 System.Object GetAuto(IndexReader reader, System.String field);
 137
 138                 /// <summary>Checks the internal cache for an appropriate entry, and if none
 139                 /// is found reads the terms out of <code>Field</code> and calls the given SortComparator
 140                 /// to get the sort values.  A hit in the cache will happen if <code>reader</code>,
 141                 /// <code>Field</code>, and <code>comparator</code> are the same (using <code>equals()</code>)
 142                 /// as a previous call to this method.
 143                 /// </summary>
 144                 /// <param name="reader"> Used to get Field values.
 145                 /// </param>
 146                 /// <param name="Field">  Which Field contains the values.
 147                 /// </param>
 148                 /// <param name="comparator">Used to convert terms into something to sort by.
 149                 /// </param>
 150                 /// <returns> Array of sort objects, one for each document.
 151                 /// </returns>
 152                 /// <throws>  IOException  If any error occurs. </throws>
 153                 System.IComparable[] GetCustom(IndexReader reader, System.String field, SortComparator comparator);
 154         }
 155 }