beagled/Lucene.Net/Index/TermDocs.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.Index
  20 {
  21
  22         /// <summary>TermDocs provides an interface for enumerating &lt;document, frequency&gt;
  23         /// pairs for a term.  <p> The document portion names each document containing
  24         /// the term.  Documents are indicated by number.  The frequency portion gives
  25         /// the number of times the term occurred in each document.  <p> The pairs are
  26         /// ordered by document number.
  27         /// </summary>
  28         /// <seealso cref="IndexReader.TermDocs()">
  29         /// </seealso>
  30
  31         public interface TermDocs
  32         {
  33                 /// <summary>Sets this to the data for a term.
  34                 /// The enumeration is reset to the start of the data for this term.
  35                 /// </summary>
  36                 void  Seek(Term term);
  37
  38                 /// <summary>Sets this to the data for the current term in a {@link TermEnum}.
  39                 /// This may be optimized in some implementations.
  40                 /// </summary>
  41                 void  Seek(TermEnum termEnum);
  42
  43                 /// <summary>Returns the current document number.  <p> This is invalid until {@link
  44                 /// #Next()} is called for the first time.
  45                 /// </summary>
  46                 int Doc();
  47
  48                 /// <summary>Returns the frequency of the term within the current document.  <p> This
  49                 /// is invalid until {@link #Next()} is called for the first time.
  50                 /// </summary>
  51                 int Freq();
  52
  53                 /// <summary>Moves to the next pair in the enumeration.  <p> Returns true iff there is
  54                 /// such a next pair in the enumeration.
  55                 /// </summary>
  56                 bool Next();
  57
  58                 /// <summary>Attempts to read multiple entries from the enumeration, up to length of
  59                 /// <i>docs</i>.  Document numbers are stored in <i>docs</i>, and term
  60                 /// frequencies are stored in <i>freqs</i>.  The <i>freqs</i> array must be as
  61                 /// long as the <i>docs</i> array.
  62                 ///
  63                 /// <p>Returns the number of entries read.  Zero is only returned when the
  64                 /// stream has been exhausted.
  65                 /// </summary>
  66                 int Read(int[] docs, int[] freqs);
  67
  68                 /// <summary>Skips entries to the first beyond the current whose document number is
  69                 /// greater than or equal to <i>target</i>. <p>Returns true iff there is such
  70                 /// an entry.  <p>Behaves as if written: <pre>
  71                 /// boolean skipTo(int target) {
  72                 /// do {
  73                 /// if (!next())
  74                 /// return false;
  75                 /// } while (target > doc());
  76                 /// return true;
  77                 /// }
  78                 /// </pre>
  79                 /// Some implementations are considerably more efficient than that.
  80                 /// </summary>
  81                 bool SkipTo(int target);
  82
  83                 /// <summary>Frees associated resources. </summary>
  84                 void  Close();
  85         }
  86 }